Saturday, August 31, 2019

Engineering Materials for Product Design and Fabrication



INTRODUCTION 


Engineering materials used to manufacture of articles or products, dictates which manufacturing process or processes are to be used to provide it the desired shape. Sometimes, it is possible to use more than one manufacturing processes, then the best possible process must be utilized in manufacture of product. It is therefore important to know what materials are available in the universe with it usual cost. What are the common characteristics of engineering materials such as physical, chemical, mechanical, thermal, optical, electrical, and mechanical? How they can be processed economically to get the desired product. The basic knowledge of engineering materials and their properties is of great significance for a design, manufacturing and industrial engineers. The elements of tools, machines and equipments should be made of such a material which has properties suitable for the conditions of operation. In addition to this, a product designer, tool designer and design engineer should always be familiar with various kinds of  engineering materials, their properties and applications to meet the functional requirements of the design product. Product industrial engineers also need to have this knowledge. They must understand all the effects which the manufacturing processes and heat treatment have on the properties of the engineering materials.

CLASSIFICATION OF ENGINEERING MATERIALS 


A large numbers of engineering materials exists in the universe such as metals and non metals (leather, rubber, asbestos, plastic, ceramics, organic polymers, composites and semiconductor).  Leather is generally used for shoes, belt drives, packing, washers etc. It is highly flexible and can easily withstand against considerable wear under suitable conditions. Rubber is commonly employed as packing material, belt drive as an electric insulator. Asbestos is basically utilized for lagging round steam pipes and steam pipe and steam boilers because it is poor conductor of heat, so avoids loss of heat to the surroundings. Engineering materials may also be categorized into metals and alloys, ceramic materials, organic polymers, composites and semiconductors. The metal and alloys have tremendous applications for manufacturing the products required by the customers.


Metals and Alloys

Pure metals possess low strength and do not have the required properties. So, alloys are produced by melting or sintering two or more metals or metals and a non-metal, together. Alloys may consist of two more components. Metals and alloys are further classified into two major kind namely ferrous metals and non-ferrous metals.

(a) Ferrous metals are those which have the iron as their main constituent, such as pig iron, cast iron, wrought iron and steels.

( b ) Non-ferrous metals are those which have a metal other than iron as their main constituent, such as copper, aluminium, brass, bronze, tin, silver zinc, invar etc.

Ferrous metals are iron base metals which include all variety of pig iron, cast iron wrought iron and steels. The ferrous metals are those which have iron as their main constituents. The ferrous metals commonly used in engineering practice are cast iron, wrought iron, steel and alloy steels.

Main Types of Iron 


1. Pig iron
2. Cast iron

(A) White cast iron
(B) Gray cast iron
(C) Malleable cast iron
(D) Ductile cast iron
(E) Meehanite cast iron
(F) Alloy cast iron

3. Wrought iron
4. Steel

(A) Plain carbon steels
1. Dead Carbon steels
2. Low Carbon steels
3. Medium Carbon steels
4. High Carbon steels

(B) Alloy steels
1. High speed steel
2. Stainless steel



Grey Cast Iron: Applications
The grey iron castings are mainly used for machine tool bodies, automotive cylinder
blocks, pipes and pipe fittings and agricultural implements. The other applications involved
are

(i) Machine tool structures such as bed, frames, column etc.
(ii) Household appliances etc.
(iii) Gas or water pipes for under ground purposes.
(iv) Man holes covers.
(v) Piston rings.
(vi) Rolling mill and general machinery parts.
(vii) Cylinder blocks and heads for I.C. engines.
(viii) Frames of electric motor.
(ix) Ingot mould
(x) General machinery parts.
(xi) Sanitary wares.
(xii) Tunnel segment.

White Cast Iron: Applications
(i) For producing malleable iron castings.
(ii) For manufacturing those component or parts which require a hard, and abrasion resistant surface such as rim of car.
(iii) Railway brake blocks.

Malleable cast iron
Malleable cast iron are generally used to form automobile parts, agriculture
implementation, hinges, door keys, spanners mountings of all sorts, seat wheels, cranks,
levers thin, waned components of sewing machines and textiles machine parts.


Wrought Iron: Applications
It is used for making chains, crane hooks, railway couplings, and water and steam pipes. It has application in the form of plates, sheets, bars, structural works, forging blooms and billets, rivets, and a wide range of tubular products including pipe, tubing and casing, electrical conduit, cold drawn tubing, nipples and welding fittings, bridge railings, blast plates, drainage lines and troughs, sewer outfall lines, weir plates, sludge tanks and lines, condenser tubes, unfired heat exchangers, acid and alkali process lines, skimmer bars, diesel exhaust and air brake piping, gas collection hoods, coal equipment, cooling tower and spray pond piping.


Aluminium: Applications
It is mainly used in aircraft and automobile parts where saving of weight is an advantage.
The high resistance to corrosion and its non-toxicity make it a useful metal for cooking
utensils under ordinary conditions. Aluminium metal of high purity has got high reflecting
power in the form of sheets and is, therefore, widely used for reflectors, mirrors and telescopes.
It is used in making furniture, doors and window components, rail road, trolley cars, automobile
bodies and pistons, electrical cables, rivets, kitchen utensils and collapsible tubes for pastes.
Aluminium foil is used as silver paper for food packing etc. In a finely divided flake form,
aluminium is employed as a pigment in paint. It is a cheap and very important non ferrous
metal used for making cooking utensils.

Copper: Applications
Copper is mainly used in making electric cables and wires for electric machinery, motor
winding, electric conducting appliances, and electroplating etc. It can be easily forged, casted,
rolled and drawn into wires. Copper in the form of tubes is used widely in heat transfer work
mechanical engineering field. It is used for household utensils. It is also used in production
of boilers, condensers, roofing etc. It is used for making useful alloys with tin, zinc, nickel
and aluminium. It is used to form alloys like brass, bronze and gun metal. Alloys of copper
are made by alloying it with zinc, tin, and lead and these find wide range of applications.
Brass, which is an alloy of copper and zinc, finds applications in utensils, household fittings,
decorative objects, etc. Bronze is an alloy of copper and tin and possesses very good corrosion
resistance. It is used in making valves and bearings. Brass and bronze can be machined at
high speeds to fine surface finish.


Red Brass: Applications
Red brass is mainly utilized for making, heat exchanger tubes, condenser, radiator cores,
plumbing pipes, sockets, hardware, etc.

Muntz metal: Applications
It is utilized for making for making tubes, automotive radiator cores, hardware fasteners, rivets, springs, plumber accessories and in tube manufacture.

Admiralty Brass: Applications
Admiralty brass is utilized for making condenser tubes in marine and other installations. It is used for making plates used for ship building. It is utilized also for making bolts, nuts, washers, condenser plant and ship fittings parts, etc.

Updated on 2 September 2019, 23 August 2019

Friday, August 30, 2019

Metal Cutting: Theory and Practice - Stephenson and Agapiou - Book Information and Chapter Summaries



https://books.google.co.in/books?id=PvK72Ymaj10C

3rd Edition
https://books.google.co.in/books?id=77n1CwAAQBAJ

1. Introduction

2. Metal Cutting Operations

1. Introduction
2. Turning,
3. Boring,
4. Drilling,
    Deep Hole Drilling
    Microdrilling
5. Reaming,
6. Milling
7. Planing and Shaping
8. Broaching
9. Tapping and Threading
10. Grinding and Related Abrasive Processes
     Lapping, Honing
11. Roller Burnishing
12. Deburring

3. Machine Tools

1. Introduction
2. Production Machine Tools
3. CNC Machine Tools and Cellular Manufacturing Systems
4. Machine Tools Structures
5. Slides and Guideways
6. Axis Drives
7. Spindles
8. Coolant systems
9. Tool Changing Systems




Updated on 31 August 2019, 26 August 2019, 4 April 2015

Tuesday, August 27, 2019

Timber - Carpentry Material

Timber

Timber is obtained from trees by cutting the main body of tree in the suitable sizes after the full growth of tree. The timber structure is consisting of annual rings, heartwood, sapwood, pith, cambium layer, bast, medullary rays and bark. Commercial timbers are commonly classified into hardwoods and softwoods. Hardwoods comprises of oak and beech that have a broad leaf. Whereas softwoods include pine and spruce which have narrow needle like leaf.

Conversion means sawing of timber logs into different commercial sizes. A notable feature in conversion is to provide an adequate allowance for shrinkage that takes place during
seasoning of sawn or converted wood. The shrinkage of wood usually varies between 3.2 mm
to 6.4 mm, according to the type of wood and its time of cutting.

Seasoning of wood is the reduction of the moisture or sap content of it to the point where, under normal conditions of use, no further drying out will take place. The main objective of seasoning is to reduce the unwanted amount of moisture from the timber

Good timber is free from knots, insects attack, excessive moisture, discoloration, twisted fibers,
cup and ring shake, sound, bright and free from any discoloration. It is solid with annual rings
but not hallow in the center. Timber should be well seasoned for easily workable specific use.
It should possess straight fibers and high fire resistance. It should not split when nails are
driven in it. It should not clog with the saw teeth during the sawing operation. Timber should
be highly suitable for polishing and painting.

The factors influencing the selection of timber involve the quality of timber in terms of its durability, workability, weight, hardness, cohesiveness, elasticity, type of texture, type of grains, resistance to fire, resistance to various stresses, ability to retain shape, suitability for polishing and painting.

Monday, August 26, 2019

Metal Forming - Hot Working - Cold Working





Metal forming is also known as mechanical working of metals. Metal forming operations are employed  either to produce a new shape or to improve the properties of the metal. Metal forming is  an intentional and permanent deformation of metals plastically beyond the elastic range of the material. The main objectives of metal forming processes are to provide the desired shape and size, under the action of externally applied forces in metals. The process improves required mechanical properties in the metal and reduces any internal voids or cavities present and thus make the metal dense.

The plastic deformation of a metal takes place when applied forces reaches the yield point.

Plasticity, ductility and malleability are the properties of a material, which retains the deformation produced under applied forces permanently and hence these metal properties are important for metal working processes.

Mechanical working/forming processes which are done above recrystallisation temperature of the metal are know as hot working processes.  If the hot working is completed just above the recrystallisation temperature then the resultant grain size would be fine. For any hot working process the metal should be heated to such a temperature below its solidus temperature, that after completion of the hot working its temperature will remain a little higher than and as close as possible to its rccrystalisation temperature




 HOT WORKING PROCESSES


1. Hot rolling

2. Hot forging

3 . Hot extrusion

4. Hot drawing

5. Hot spinning

6. Hot piercing or seamless tubing

7. Tube Forming and

8. Hot forming of welded pipes




Hot Rolling


Rolling is the most rapid method of forming metal into desired shapes by plastic deformation through compressive stresses using two or more than two rolls. It is one of the most widely used of all the metal working processes. The main objective of rolling is to convert larger sections such as ingots into smaller sections which can be used either directly in as rolled state or as stock for working through other processes.

The coarse structure of cast ingot is convened into a fine grained structure in rolling.  Significant improvement is accomplished in rolled parts in their various mechanical properties such as toughness, ductility, strength and shock resistance. The crystals in parts are elongated in the direction of rolling, and they start to reform after leaving the zone of stress.

The majority of steel products are being converted from the ingot form by the process of rolling. Hot rolling process is being widely used in the production of large number of useful products such as rails, sheets, structural sections, plates etc. There are different types of rolling mills.

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Two-High Rolling Mill

A two-high rolling mill  has two horizontal rolls revolving at the same speed but
in opposite direction. The rolls are supported on bearings housed in sturdy upright side
frames called stands. The space between the rolls can be adjusted by raising or lowering the
upper roll. Their direction of rotation is fixed and cannot be reversed. The reduction in the
thickness of work is achieved by feeding from one direction only. However, there is another
type of two-high rolling mill, which incorporates a drive mechanism that can reverse the
direction of rotation of the rolls. A Two- high reverse arrangement is also there.
In a two-high reversing rolling mill, there is continuous rolling of the workpiece through
back-and-forth passes between the rolls.

Three-High Rolling Mills

It consists of three parallel rolls, arranged one above the other.  The directions of rotation of the upper and lower rolls are the same but the intermediate roll rotates in a direction opposite to both of these. This type of rolling mill is used for rolling of two continuous passes in a rolling sequence without reversing the drives. This results in a higher rate of production than the two-high rolling mill.

Four-High Rolling Mill

It is essentially a two-high rolling mill, but with small sized rolls. Practically, it consists of four horizontal rolls, the two middle rolls are smaller in size than the top and bottom rolls. The smaller size rolls are known as working rolls which concentrate the total rolling pressure over the work piece. The larger diameter rolls are called back-up rolls and their main function is to prevent the deflection of the smaller rolls, which otherwise would result in thickening of rolled plates or sheets at the centre. The common products of these mills are hot or cold rolled plates and sheets.

Cluster Mill

It is a special type of four-high rolling mill in which each of the two smaller working rolls are backed up by two or more of the larger back-up rolls.  For rolling hard thin materials, it may be necessary to employ work rolls of very small diameter but of considerable length. In such cases adequate support of the working rolls can be obtained by using a cluster-mill. This type of mill is generally used for cold rolling work.


Continuous Rolling Mill

It consists of a number of non reversing two-high rolling mills arranged one after the other, so that the material can be passed through all of them in sequence. It is suitable for mass production work only, because for smaller quantities quick changes of set-up will be required and they will consume lot of time and labor.


Applications of Rolling

Rolling mills produce girders, channels, angle irons and tee-irons. Plate mill rolls slabs into plates. The materials commonly hot rolled are aluminium, copper magnesium, their alloys and many grades of steel.

Industrial Engineering and Productivity Management of Hot Rolling


Analysing quality and productivity improvement in steel rolling industry in central India
International Conference on Advances in Engineering & Technology – 2014 (ICAET-2014)
PP 06-11
http://iosrjournals.org/iosr-jmce/papers/ICAET-2014/me/volume-7/2.pdf?id=7622

The rolled product quality depends on the quality of the charge, the construction of a rolling machine, setting of the rolls, a kind and state of armament, temperature and a way of heating as well as the level of training a worker and his experience. Other significant quality parameters which need to be addressed are; Raw Material Inspection and Approval Process, Finished Product quality Approval Process, Geometrical Parameter Test, Physical Parameter Test, Chemical Test.

Productivity and Quality Improvement through Setting Parameters in
Hot Rolling Mill
International Research Journal of Engineering and Technology (IRJET)
Volume: 05 Issue: 04 | Apr-2018
https://www.irjet.net/archives/V5/i4/IRJET-V5I4239.pdf

HIGH-PERFORMANCE HOT ROLLING MILLS
Electrics and Automation
Good information on electrical drives, control of quality parameters
https://www.sms-group.com/press-media/downloads/download-detail/15493/


 Hot Piercing or Seamless tubing


Hot piercing is also known as seamless tubing or roll piercing process. . It is used for making thin-
walled round objects. Seamless tube forming is popular and economical process in comparison to machining because it saves material wasted in boring of parts.

Hot piercing includes rotary piercing to obtain formed tube by piercing a pointed mandrel through a billet in a specially designed rolling mill. The rotary piercing can be performed either on a two-high rolling mill or on a three-high rolling mill. In the former, the two rolls are set at an angle to each other. The billet under the rolls is deformed and a cavity formation is initiated at the centre due to tensile stressing. The carefully profiled shape of the mandrel assists and controls the formation of cavity. In a three-high rolling mill, the three shaped rolls are located at 1200 and their axes are inclined at a feed angle to permit forward and rotary motion of the billet. The squeezing and bulging of the billet open up a seam in its center pass makes a rather thick-walled tube which is again passed over plug and through grooved rolls in a two-high roll mill where the thickness is decreased and the length is increased. While it is still up to a temperature, it is passed on to a reeling machine which has two rolls similar to the piercing rolls, but with flat surfaces. If more accuracy and better finish are desired, the run through sizing dies or rolls. After cooling, the tubes are used in a pickling bath of dilute sulphuric acid to remove the scale.

Seamless steel pipe manufacturing process

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https://www.youtube.com/watch?v=ewA1v-s0Dp4

HOT EXTRUSION


It is the process of enclosing the heated billet or slug of metal in a closed cavity and then
pushing it to flow from only one die opening so that the metal will take the shape of the
opening. The pressure is applied either hydraulically or mechanically. Extrusion process is
identical to the squeezing of tooth paste out of the tooth paste tube. Tubes, rods, hose, casing,
brass cartridge, moulding-trims, structural shapes, aircraft parts, gear profiles, cable sheathing
etc. are some typical products of extrusion. Using extrusion process, it is possible to make
components, which have a constant cross-section over any length as can be had by the rolling
process. The intricacy in parts that can be obtained by extrusion is more than that of rolling,
because the die required being very simple and easier to make. Also extrusion is a single pass
process unlike rolling. The amount of reduction that is possible in extrusion is large. Generally
brittle materials can also be easily extruded. It is possible to produce sharp corners and re-
entrant angles. It is also possible to get shapes with internal cavities in extrusion by the use
of spider dies, which are explained later.

The extrusion setup consists of a cylinder container into which the heated billet or slug of
metal is loaded. On one end of the container, the die plate with the necessary opening is fixed. From
the other end, a plunger or ram compresses the metal billet against the container walls and the
die plate, thus forcing it to flow through the die opening, acquiring the shape of the opening. The
extruded metal is then carried by the metal handling system as it comes out of the die.

The extrusion ratio is defined as the ratio of cross- sectional area of the billet to that
of the extruded section. The typical values of the extrusion ratio are 20 to 50. Horizontal
hydraulic presses of capacities between 250 to 5500 tonnes are generally used for conventional
extrusion. The pressure requirement for extrusion is varying from material to material. The
extrusion pressure for a given material depends on the extrusion temperature, the reduction
in area and the extrusion speed.

Methods of Hot Extrusion

Hot extrusion process is classified as

1. Direct or forward hot extrusion

2. Indirect or backward hot extrusion

3. Tube extrusion




Different methods of extrusion  Each method is described as
under.

Direct or Forward Hot Extrusion

In this method, the heated metal billet is placed in to the die chamber and the pressure is applied through ram. The metal is extruded through die opening in the forward direction, i.e. the same as that of the ram. In forward extrusion, the problem of friction is prevalent because of the relative motion between the heated metal billet and the cylinder walls. To reduce such friction, lubricants are to be commonly used. At lower temperatures, a mixture of oil and graphite is generally used. The problem of lubrication gets compounded at the higher operating temperatures. Molten glass is generally used for extruding steels.

Aluminum Extrusion

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https://www.youtube.com/watch?v=iiGlq7408ME

Indirect or Backward Hot Extrusion

In indirect extrusion, the billet remains stationary while the die moves into the billet by the hollow ram (or punch), through which the backward extrusion takes place. Since, there is no friction force between the billet and the container wall, therefore, less force is required by this method. However
this process is not widely used because of the difficulty occurred in providing support for the extruded part.

Tube Extrusion

This process is an extension of direct extrusion process where additional mandrel is needed to restrict flow of metal for production of seamless tubes. Aluminium based toothpaste and medicated tubes are produced using this process.


HOT DRAWING


Drawing is pulling of metal through a die or a set of dies for achieving a reduction in a diameter. The material to be drawn is reduced in diameter. Fig.  is another method used in hot drawing or shaping of materials where the heated blank is placed over the die opening the punch forces the blank through the die opening to form a cup or shell. The multiple dies are also used to accomplish the stages in drawing process. Kitchen utensils and components of food processing industries are manufactured by this process.

EJP Chain Draw Bench Line DB 120


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________________
https://www.youtube.com/watch?v=INgJSHOgioU

HOT SPINNING


Hot spinning is a process in which pressure and plastic flow is used to shape material. Spinning is generally carried over a spinning lathe. The metal is forced to flow over a rotating shape by pressure of a blunt tool.  The amount of pressure of the blunt tool against the disc controls the generated
heat, which helps in forming processes.

Hot spinning machine for CNG cylinder

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https://www.youtube.com/watch?v=Z39GZYZ5l9U


EFFECT OF HOT WORKING ON MECHANICAL PROPERTIES OF METALS



1. Raising the metal temperature lowers the stresses required to produce deformations
and increases the possible amount of deformation before excessive work hardening
takes place.

2. In hot working processes, compositional irregularities are ironed out and non-metallic impurities are broken up into small, relatively harmless fragments, which are uniformly dispersed throughout the metal instead of being concentrated in large stress-raising metal working masses.

3. Hot working such as rolling process refines grain structure. The coarse columnar dendrites of cast metal are refined to smaller equiaxed grains with corresponding improvement in mechanical properties of the component.

4. Oxidation and scaling take place and hence surface finish of hot worked metal is not nearly as good as with cold working.

5. The temperatures at which  hot work is started and stopped  affects the properties to be introduced in the hot worked metal.

6. Too high a temperature may cause phase change and overheat the steel whereas too low temperature may result in excessive work hardening.

7. Defects in the metal such as blowholes, internal porosity and cracks get removed
or welded up during hot working.

8. During hot working, self-annealing occurs and recrystallization takes place immediately following plastic deformation. This self-annealing action prevents hardening and loss of ductility.

  HOT WORKING - MERITS

1. As the material is above the recrystallisation temperature, any amount of working
can be imparted since there is no strain hardening taking place.

2. At a high temperature, the material would have higher amount of ductility and
therefore there is no limit on the amount of hot working that can be done on a
material. Even brittle materials can be hot worked.

3. In hot working process, the grain structure of the metal is refined and thus mechanical
properties improved.

4. Porosity of the metal is considerably minimized.

5. If process is properly carried out, hot work does not affect tensile strength, hardness,
corrosion resistance, etc.

6. Since the shear stress gets reduced at higher temperatures, this process requires
much less force to achieve the necessary deformation.

7. It is possible to continuously reform the grains in metal working and if the temperature and rate of working are properly controlled, a very favorable grain size could be achieved giving rise to better mechanical properties.

8. Larger deformation can be accomplished more rapidly as the metal is in plastic state.

9. No residual stresses are introduced in the metal due to hot working.

10. Concentrated impurities, if any in the metal are disintegrated and distributed throughout the metal.

11. Mechanical properties, especially elongation, reduction of area and izod values are
improved, but fibre and directional properties are produced.

12. Hot work promotes uniformity of material by facilitating diffusion of alloy constituents and breaks up brittle films of hard constituents or impurity namely cementite in steel.

DEMERITS OF HOT WORKING

1. Due to high temperature in hot working, rapid oxidation or scale formation and surface de-carburization take place on the metal surface leading to poor surface finish and loss of metal.

2. On account of the loss of carbon from the surface of the steel piece being worked the surface layer loses its strength. This is a major disadvantage when the part is put to service.

3 . The weakening of the surface layer may give rise to a fatigue crack which may ultimately result in fatigue failure of the component.

4. Some metals cannot be hot worked because of their brittleness at high temperatures.

5. Because of the thermal expansion of metals, the dimensional accuracy in hot working is difficult to achieve.

6. The process involves excessive expenditure on account of high cost of tooling. This however is compensated by the high production rate and better quality of components.

7. Handling and maintaining of hot working setups is difficult and troublesome.


Cold working of a metal is carried out below its recrystallisation temperature. Normal room temperatures are ordinarily used for cold working of various types of steel. But temperatures up to the recrystallisation range are sometimes used in certain applications.

COLD WORKING PROCESSES


1. Rolling

2. Extrusion

3. Wire drawing

4. Forging

5. Cold spinning

6. Shot peening





Cold working processes are also similar to hot working processes except for the temperature at which work is done.


COLD-ROLLING


Cold rolling process setup is similar to hot rolling. Bars of all shapes such as rods, sheets and strips are commonly finished by rolling. Foil is made of the softer metals in this way. Cold-rolling metals impart smooth bright surface finish and in good physical and mechanical properties to cold rolled parts.. Cold rolling also improves machinability in the cold rolled part by conferring the property of brittleness, a condition, which is conducive to smooth tool, finishes with broken chips.

The preliminary step to the cold-rolling operation, the sheets of pre hot-rolled steel are immersed in an acid solution to remove the washed in water and then dried. The cleaned steel is passed through set of rolls of cold rolling process thereby producing a slight reduction in each the required thickness is obtained.

The arrangement of rolls in a rolling mill, also called rolling stand, varies depending on the application. The various possible configurations of rolls are similar to hot rolling.  Internal stresses are set up in cold rolled parts which remain in the metal unless they are removed by proper heat-treatment. This process needs more power for accomplishing the operation in comparison to hot rolling.

COLD EXTRUSION


Principle of cold extrusion is similar to that of hot extrusion.   Impact extrusion is also a cold extrusion process. It is used for making small components from ductile materials.  Impact extrusion of material is accomplished where the work blank is placed in position over the die opening the punch forces the blank through the die opening causing material to flow plastically around the punch. The outside diameter of the tube is same as diameter of the die, and the thickness is controlled by the clearance between punch and die. Collapsible medicare tubes and toothpastes etc. are produced using this impact extrusion.

WIRE DRAWING


The process of producing the wires of different diameters is accomplished by pulling a wire through a hardened die usually made up carbide. However a smaller diameter wires are drawn through a die made of diamond. The larger diameter oriented wire is first cleaned, pickled, washed and then lubricated.  It is normally done by acid pickling. After picklng, it is washed in water and coated with lime and other lubricants. To make for an easier entrance of wire into the die, the end of the stock is made pointed to facilitate the entry. A pointed or reduced diameter at the end of wire duly lubricated is pushed or introduced through the die which is water cooled also. This pointing is done by means of rotary swaging or by simple hammering. It is then gripped and pulled for attaching it to a power driven reel. The wire diameter is reduced in die because of the ductility property of the material to the smaller diameter through one set of die. For more reduction in diameter of the wire, various sets of dies can be used in line for subsequent reduction in diameter at each stage.  The reduction in each pass through the die range about 10% for steel and 40% for ductile materials such as copper.

The drawing of the wire starts with a rod or coil of hot rolled steel, which is 0.8 to 1.6 mm larger than the final size required.  The material should be sufficiently ductile since it is pulled by the tensile forces. Hence, the wire may have to be annealed properly to provide the necessary ductility. Further, the wire is to go through the conical portion and then pulled out through the exit by the gripper. To carry the lubricant input through the die, special methods such as gulling, coppering, phosphating and liming are used.  

For very thin wires, electrolytic coating of copper is used to reduce friction. The dies used for wire drawing are severely affected because of high stresses and abrasion.

The various die materials that are used are chilled cast iron, tool steels, tungsten carbide and diamond. The cast iron dies are used for small runs. For very large sizes, alloy steels are used in making the dies. The tungsten carbide dies are used most commonly for medium size wires and large productions. The tungsten carbide dies arep referred because of their long life that is 2 to 3 times that of alloy steel dies. For very fine wires, diamond dies are used. Wire drawing improves the mechanical properties because of the cold working. The material loses its ductility during the wire drawing process and when it is to be repeatedly drawn to bring it to the final size, intermediate annealing is required to restore the ductility.




Cold Drawing


Like hot drawing, it also involves the forcing of a metal through by means of a tensile force applied to the exit side of the drawing die. Most of the plastic flow is accomplished by the compressive force which arises from the reaction of metal with die. It is the operation in which the metal is made to flow plastically by applying tensile stresses to the metal. The blank of calculated diameter is placed on a die and held of it by a blank holder and bottom is pressed into the die by a punch and the walls are pulled.  

This process is generally used for making cup shaped parts from the sheet blanks, without excessive wrinkling, thinning and fracturing. It can undertake jobs of nearly any size. It is a process of managing a flat precut metal blank into a hollow vessel. Utensils of stainless steel are generally made by this process.

Efficiency of operation


The efficiency of operation depends upon blank size, reduction factor, drawing pressure, blank holding pressure, punch and die diameters, type of lubricant, die material etc.

SHOT PEENING

It is a process of increasing the hardness and fatigue strength on parts surfaces. The process comprises of throwing a blast of metal shot on to the surface of a component requiring shot peening. It is used to set up a superficial state of surface compression stress, causing the interior of the member to assume an opposite tensile stress. Blast may be thrown either by air pressure or with help of a wheel revolving at high speed. This high velocity blast of metal shot provides a sort of compression over the components surface and increases hardness and strength of the surface and also its fatigue resistance.






Sunday, August 25, 2019

Process Planning - Bibliography



Process Planning - Routing - Gideon Halevi
https://books.google.co.in/books?id=qoeddvtDl8AC&pg=PA17#v=onepage&q&f=false

Assembly Planning and Design - Gideon Halevi
https://books.google.co.in/books?id=tcHxCAAAQBAJ&pg=PA17#v=onepage&q&f=false

Conceptual Process Planning - A Definition and Functional Decomposition
Shaw C. Feng, Y. Zhang
Manufacturing Engineering Laboratory
National Institute of Standards and Technology
https://ws680.nist.gov/publication/get_pdf.cfm?pub_id=821981

MODEL-BASED INTERACTIVE LEARNING OF PROCESS PLANNING
Magnus Lundgren, Mikael Hedlind, Torsten Kjellberg
KTH – Production Engineering, Scania CV AB

Process Selection, Sequence of Operations and Shape
Complexity - Criteria for Process Improvement
https://pdfs.semanticscholar.org/b41e/1d27df883c65e1247aa1926ee7fbd08fbb63.pdf


Production Engineering -  introduction to a department that works behind the scenes, though its impact is often front and center
Toyota USA
July 10, 2018
https://www.toyotadriverseat.com/team-members/production-engineering-101.htm


Increasing efficiency of SMT

SMT is a system engineering project that involves components and their packaging and tape form, PCB, materials and accessories, design, manufacturing technology and production process, equipment and spare parts, tooling, inspection and management. Production technology, only focusing on a certain link or a certain number of links, can not achieve a good sense of good operation. In the past, some enterprises have a misunderstanding of understanding, and it is considered that the placement equipment is used well and SMT is running well. The actual situation is not so simple, all the links that make up SMT are interrelated.

The design process is not a traditional design idea. It requires technical decision makers and designers to understand and use SMT from a deep level, familiar with equipment and processes, and use and promote SMT on new products and technologies.
http://www.wisdommobi.com/wdgweb_content-63800.html

Wednesday, August 14, 2019

Patterns for Moulds - Design Considerations

A pattern is a model or the replica of the object to be casted.

Utility of a Pattern


1 Pattern prepares a mould cavity for the purpose of making a casting.
2 Pattern possesses core prints which produces seats in form of extra recess for core placement in the mould.
3 It establishes the parting line and parting surfaces in the mould.
4 Runner, gates and riser may form a part of the pattern.
5 Properly constructed patterns minimize overall cost of the casting.
https://www.metalcastingdesign.com/articles/2014/07/01/10-cost-considerations-your-castings

6 Pattern may help in establishing locating pins on the mould and therefore on the casting with a purpose to check the casting dimensions.
7 Properly made pattern having finished and smooth surface reduce casting defects.

Patterns are generally made in pattern making shop. Proper construction of pattern and its material may reduce overall cost of the castings.

Materials for Patterns


The common materials used for making patterns are wood, metal, plastic, plaster, wax or mercury. The some important pattern materials are discussed as under.

Advantages of wooden patterns
Wood is cheap, light in weight, easily available and  can be easily worked. It is easy to join and repair.

But it is susceptible to moisture,  tends to warp and  wears out quickly due to sand abrasion.


Metallic Patterns

Metallic  patterns are not much affected by moisture as wooden pattern. The wear and

tear of this pattern is very less. Metal can be shaped with good precision, surface finish and intricacy. The main disadvantages of metallic patterns are higher cost, higher weight and tendency of rusting.
It is preferred for production of castings in large quantities with same pattern. The metals commonly used for pattern making are cast iron, brass and bronzes and aluminum alloys.

Cast Iron
It is cheaper, stronger, tough, and durable and can produce a smooth surface finish. It
also possesses good resistance to sand abrasion. The drawbacks of cast iron patterns are that
they are hard, heavy, brittle and get rusted easily in presence of moisture.

But  it is heavy,  brittle and hence it can be easily broken and it  may rust.

Brasses and Bronzes
These are heavier and expensive than cast iron and hence are preferred for manufacturing
small castings. They possess good strength, machinability and resistance to corrosion and
wear. They can produce a better surface finish than cast iron. Very thin sections can be easily casted. Brass and bronze pattern is finding application in making match plate pattern

But it is costlier than cast iron and it is heavier than cast iron.

Aluminum Alloys
Aluminum alloy patterns are more popular and best among all the metallic patterns
because of their high lightness, good surface finish, low melting point and good strength.
They also possesses good resistance to corrosion and abrasion by sand and there by enhancing
longer life of pattern. These materials do not withstand against rough handling. These have
poor repair ability and are preferred for making large castings.

They can be damaged by sharp edges. . They are softer than brass and cast iron.  Their storing and transportation needs proper care.

White Metal (Alloy of Antimony, Copper and Lead)

Advantages
1. It is best material for lining and stripping plates.
2. It has low melting point around 260°C
3. It can be cast into narrow cavities.


Disadvantages
1. It is too soft.  Its storing and transportation needs proper care.  It wears away by sand or sharp edges.

Plastic
Plastics are getting more popularity now a days because the patterns made of these materials
are lighter, stronger, moisture and wear resistant, non sticky to molding sand, durable and
they are not affected by the moisture of the molding sand. Moreover they impart very smooth
surface finish on the pattern surface. These materials are somewhat fragile, less resistant to
sudden loading and their section may need metal reinforcement.

The plastics used for this purpose are thermosetting resins. Phenolic resin plastics are commonly used. These are originally in liquid form and get solidified when heated to a specified temperature. To prepare a plastic pattern, a mould in two halves is prepared in plaster of paris with the help of a
wooden pattern known as a master pattern. The phenolic resin is poured into the mould and
the mould is subjected to heat. The resin solidifies giving the plastic pattern. Recently a new
material has stepped into the field of plastic which is known as foam plastic. Foam plastic is
now being produced in several forms and the most common is the expandable polystyrene
plastic category. It is made from benzene and ethyl benzene.


 Plaster
This material belongs to gypsum family The main advantages of plaster are that it has high compressive strength and is of high expansion setting type which compensate for the shrinkage allowance of the casting metal. Plaster of paris pattern can be prepared either by directly pouring the slurry of plaster and water in moulds prepared earlier from a master pattern or by sweeping it into desired shape or form by the sweep and strickle method. It is also preferred for production of small size intricate castings and making core boxes.

Wax
Patterns made from wax are excellent for investment casting process. The materials used
are blends of several types of waxes, and other additives which act as polymerizing agents,
stabilizers, etc. The commonly used waxes are paraffin wax, shellac wax, bees-wax, cerasin
wax, and micro-crystalline wax. The properties desired in a good wax pattern include low
ash content up to 0.05 per cent, resistant to the primary coat material used for investment,
high tensile strength and hardness, and substantial weld strength. The general practice of
making wax pattern is to inject liquid or semi-liquid wax into a split die. Solid injection is
also used to avoid shrinkage and for better strength. Waxes use helps in imparting a high
degree of surface finish and dimensional accuracy castings. Wax patterns are prepared by
pouring heated wax into split moulds or a pair of dies. The dies after having been cooled
down are parted off. Now the wax pattern is taken out and used for molding. Such
patterns need not to be drawn out solid from the mould. After the mould is ready, the wax
is poured out by heating the mould and keeping it upside down. Such patterns are
generally used in the process of investment casting where accuracy is linked with intricacy
of the cast object.


SELECTION OF PATTERN MATERIAL

The following factors must be taken into consideration while selecting pattern materials.

1. Number of castings to be produced. Metal pattern are preferred when castings are required large in number.
2. Type of mould material used.
3. Kind of molding process.
4. Method of molding (hand or machine).
5. Degree of dimensional accuracy and surface finish required.
6. Minimum thickness required.
7. Shape, complexity and size of casting.
8. Cost of pattern and chances of repeat orders of the pattern


TYPES OF PATTERNS


____________

____________



The types of the pattern and the description of each are given as under.



1. One piece or solid pattern
2. Two piece or split pattern
3. Cope and drag pattern
4. Three-piece or multi- piece pattern
5. Loose piece pattern
6. Match plate pattern
7. Follow board pattern
8. Gated pattern
9. Sweep pattern
10. Skeleton pattern
11. Segmental or part pattern



PATTERN ALLOWANCES

Pattern may be made from wood or metal and its color may not be same as that of the casting. The material of the pattern is not necessarily same as that of the casting. Pattern carries an additional allowance to compensate for metal shrinkage. It carries additional allowance for machining. It carries the necessary draft to enable its easy removal from the sand mass. It carries distortions allowance also. Due to distortion allowance, the shape of casting is opposite to pattern. Pattern may carry additional projections, called core prints to produce seats or extra recess in mold for setting or adjustment or location for cores in mold cavity. It may be in pieces (more than one piece) whereas casting is in one piece. Sharp changes are not provided on the patterns. These are provided on the casting with the help of machining. Surface finish may not be same as that of casting.

CORE AND CORE BOX

Cores are compact mass of core sand that when placed in mould cavity at required location with proper alignment does not allow the molten metal to occupy space for solidification in that portion and hence help to produce hollowness in the casting. The core  has to withstand the severe action of hot metal which completely surrounds it. Cores are classified according to shape and position in the mold. There are various types of cores  are horizontal core), vertical core, balanced core, drop core  and hanging core.

Functions of cores


1. Core is used to produce hollowness in castings in form of internal cavities.
3. It may be deployed to improve mold surface.
4. It may provide external under cut features in casting.
5. It may be used to strengthen the mold.
6. It may be used to form gating system of large size mold
7. It may be inserted to achieve deep recesses in the casting




 CORE PRINTS

When a hole blind or through is needed in the casting, a core is placed in the mould cavity to produce the same. The core has to be properly located or positioned in the mould cavity on pre-formed recesses or impressions in the sand. To form these recesses or impressions for generating seat for placement of core, extra projections are added on the pattern surface at proper places. These extra projections on the pattern (used for producing recesses in the mould for placement of cores at that location) are known as core prints. Core prints may be of horizontal, vertical, balanced, wing and core types. Horizontal core print produces seats for horizontal core in the mould. Vertical core print produces seats to support a vertical core in the mould. Balanced core print produces a single seat on one side of the mould and the core remains partly in this formed seat and partly in the mould cavity, the two portions balancing each other. The hanging portion of the core may be supported on chaplets. Wing core print is used to form a seat for a wing core. Cover core print forms seat to support a cover core.



DESIGN CONSIDERATIONS IN PATTERN AND CORE MAKING

http://www.themetalcasting.com/casting-designing-framework.html



1. All Abrupt changes in section of the pattern should be avoided as far as possible.
2. Parting line should be selected carefully, so as to allow as small portion of the
pattern as far as possible in the cope area.
3. The thickness and section of the pattern should be kept as uniform as possible.
4. Sharp corners and edges should be supported by suitable fillets or otherwise rounded
of. It will facilitate easy withdrawal of pattern, smooth flow of molten metal and
ensure a sound casting. Wherever there is a sharp corner, a fillet should be provided, and the corners may be rounded up for easy withdrawal of patterns as well as easy flow of molten metal
in the mould.
5. Surfaces of the casting which are specifically required to be perfectly sound and
clean should be so designed that they will be molded in the drag because the
possible defects due to loose sand and inclusions will occur in the cope.
6. As far as possible, full cores should be used instead of cemented half cores for
reducing cost and for accuracy.  This will reduce cost and ensure greater dimensional accuracy.
7. For mass production, the use of several patterns in a mould with common riser is
to be preferred.
8. The pattern should have very good surface finish as it directly affects the corresponding
finish of the casting. As for as possible, the pattern should have a good surface finish because the surface finish of the casting depends totally on the surface finish of the pattern and the kind of facing of the mold cavity.
9. Shape and size of the casting and that of the core should be carefully considered to
decide the size and location of the core prints.
10. Proper material should always be selected for the pattern after carefully analyzing
the factors responsible for their selection.
11. The use of offset parting, instead of cores as for as possible should be encouraged
to the great extent.
12. For large scale production of small castings, the use of gated or match- plate
patterns should be preferred wherever the existing facilities permit.
14. If gates, runners and risers are required to be attached with the pattern, they should
be properly located and their sudden variation in dimensions should be avoided.
15. Proper allowances should be provided, wherever necessary.




PATTERN LAYOUT

A layout of the different parts of the pattern has to be made first. The next stage is to shape them. The layout preparation consists of measuring, marking, and setting out the dimensions on a layout board including needed allowances. The first step in laying out is to study the working drawing carefully and select a suitable board of wood that can accommodate at least two views of the same on full size scale. The next step is to decide a working face of the board and plane an adjacent edge smooth and square with the said face. Select a proper contraction scale for measuring and marking dimensions according to the material of the casting. Further the layout is prepared properly and neatly using different measuring and making tools specifying the locations of core prints and machined surfaces. Finally on completion of the layout, check carefully the dimension and other requirements by incorporating all necessary pattern allowances before starting construction of the pattern.



PATTERN CONSTRUCTION

From the layout, try to visualize the shape of the pattern and determine the number of separate pieces to be made and the process to be employed for making them. Then the main part of pattern body is first constructed using pattern making tools. The direction of wood grains is kept along the length of pattern as far as possible to ensure due strength and accuracy. Further cut and shape the other different parts of pattern providing adequate draft on them. The prepared parts are then checked by placing them over the prepared layout. Further the different parts of the pattern are assembled with the main body in proper position by gluing or by means of dowels as the case may be. Next the relative locations of all the assembled parts on the pattern are adjusted carefully. Then, the completed pattern is checked for accuracy. Next all the rough surfaces of pattern are finished and imparted with a thin coating of shellac varnish. The wax or leather fillets are then fitted wherever necessary. Wooden fillets should also be fitted before sanding and finishing. The pattern surface once again prepared for good surface and give final coat of shellac. Finally different parts or surfaces of pattern are colored with specific colors mixed in shellac or by painting as per coloring specifications.

https://www.indiamart.com/proddetail/cast-iron-casting-pattern-with-core-box-15991422588.html

Tuesday, August 13, 2019

Carpentry - Introduction


Timber - Wood


Timber is a common name imparted to wood suitable for engineering, construction and building purposes. 
Apart from wood, there are a number of other materials used in carpentry shop besides timber. The main materials are dowels, nails, screws, adhesives, paints and varnishes.


________________

________________

Tools


 A broad classification of tools used in the wood working or carpentry shop are measuring and marking tools, supporting and holding tools, cutting tools, striking tools and miscellaneous tools.

Work Bench

Every carpenter generally needs a good solid bench or table of rigid construction of hard wood on which he can perform or carry out the carpentry operations. Work bench should be equipped with a vice for holding the work and with slots and holes for keeping the common hand tools.

Carpenter Vice

Carpenter vice  is very important tool in wood working shops for holding wooden jobs. There are several varieties of vices, each possessing its own particular merit.

Saws

Saws are wood cutting tools having handle and a thin steel blade with small sharp teeth along the edge. They are utilized to cut wood to different sizes and shapes used for making the wooden joints that hold parts together. They can be further classified into three major types namely hand Saws (Rip, Cross-cut, Panel, Keyhole and, Pad saw), Snuff Saws (Tenon and Dovetail) and Frame Saws (Coping, Bow and Fret).


Rip Saw
The rip saw is  used for cutting timber along the grains. The teeth of rip saw are chisel-shaped and are set alternately to the right and left. A 24" long point saw is a good for sawing work. Depending upon whether the saw is designed to rip or cross-cut, the shape of the teeth will also vary. In the case of a ripsaw, the teeth are shaped like chisels.

Planes

A plane is a special tool with a cutting blade for smoothing and removing wood as shavings. It is just like a chisel fixed in a wooden or steel body. The modern plane has been developed from the chisel. They can also be classified as jack plane, smooth plane, jointer plane, trying plane, rabbit plane, circular plane and fore plane.


Jack Plane

Jack plane is most commonly used plane. It comprises of its body about 40 cm long, blade 5-6 cm wide and handle. It is good for rough surfaces that require a heavier chip. It is ideal for obtaining a smooth and flat surface. There are actually forty-six different parts of jack plane, the carpenter needs only acquainted with the working or regulating parts. The main working parts are the cutting blade or plane iron. The adjusting nut is operated to raise or lower the blade and the adjusting lever which regulates the blade so as to make possible an even or slanted cut. The cutting blade of the jack plane is guarded with a metal cap which is adjusted on top of the blade to within about 2.4 mm of the cutting edge. The metal cap of the jack plane eases the cutting action by curling and breaking off the
wood shavings evenly, thus preventing splitting or splintering of the wooden part.

 Chisels

A Chisel is a strong sharp edge cutting tool with a sharp bevel edge at one end. Its construction is composed of handle, tang, ferrule, shoulder, and blade. Chisels are generally made up of high carbon steel. They are used to shape and fit parts as required in joint making.



A gouge  is a curved chisel. It may be outside or inside ground. Outside ground gouges are called firmer gouges and inside ground gouges are called scribing gouges. The scribing gouges are made long and thin, they are known as paring gouges. Several varieties of chisels are available, each having special characteristics which fit it for its special use.There are two types of construction employed in the making of chisels named as tang and socket types. The tang chisel is made with a ranged or pointed end which pierces into the handle. The socket chisel reverses the process by having the handle fit into the socket collar on the blade.

Boring Tools

Boring is cutting a hole in wood with a tool called a bit. Holes of 6 mm size or larger are bored. Holes of 6 mm size or smaller are drilled. Boring is the first step in making any kind of shaped opening or making holes. The commonly used boring tools bits are discussed as under.

The center bit

The center bits are available in sizes ranging .from 4 mm to 50 mm and are useful for boring holes through thin wood. The screwed center of the improved center bit helps to draw the bit into the wood and therefore requires less pressure to obtain a cutting action.

Striking tools

Mallets and various types of hammers are generally used as striking tools in carpentry shop. A hammer delivers a sharp blow, its steel face being likely to damage the chisel handle whereas
the softer striking surface such as mallet will give better result.

Mallet

A mallet is a short handled wooden hammer with a large head. It is used to strike a chisel for heavy cutting waste wood, from joints such as mortises and halving joints and also for removing unwanted, wood on shaped work etc. Mallet is frequently also used to tap parts of a project together during the assembly process.

Hammers

Warrington, peen and claw hammers are generally used by carpenters.

Pincer

Pincers are commonly used for withdrawing nails. They are made of cast steel, the jaws being hardened. The end of one of the arms is shaped to form a claw for removing nails






Joints

All wooden objects whether doors, windows, furniture, pattern, core boxes, handicrafts, toys, cots, etc., are all assembled with joints. The various common used wood working joints are:

Groove and tongue joint
Mortise and tenon joint
Trap joint
Open or through dove-tail joint
Cross-lap joint
Briddle joint

Carpentry machines


1. Wood Working Lathe
2. Circular Saw
3. Band Saw

Carpentry Machines
ME Mechanical Team
https://me-mechanicalengineering.com/carpentry-machines/

The common types of well recognized timbers available in India are Shisham, Sal, Teak, Deodar, Mango, Mahogany, Kail, Chid, Babul, Fir wood, Walnut and Haldu,. Out of these, Deodar, Chid, Kail, Fir wood and Haldu fall in the categories of softwoods and Shisham, Sal, Teak, Kiker, Mango, Walnut fall in the categories of hardwoods. Some of the other foreign timbers commonly used in India are Ash, Burma, Hickory, Oak and Pine.


https://www.bls.gov/ooh/construction-and-extraction/carpenters.htm

https://alison.com/course/diploma-in-carpentry-studies-revised


Robot Carpenters
Feb 28, 2018
Researchers at MIT's Computer Science and Artificial Intelligence Laboratory (CSAIL) have built robots that can build custom carpentry projects with expert skill. Robot's could eventually prove as vital helpers, especially for new hands on the job.
https://www.popularmechanics.com/technology/robots/a18925053/the-robot-carpenters-are-coming/

A Manual of Carpentry and Joinery - The Woodworks Library
http://www.woodworkslibrary.com/repository/a_manual_of_carpentry_and_joinery.pdf


Monday, August 12, 2019

Computer Integrated Manufacturing


Computer Integrated Manufacturing
Prentice Hall
Author: James A. Rehg / Henry W Kraebber
Pearson
Edition 3
Total pages 592
Pub.-date March 2004



Table of Contents
I. INTRODUCTION TO CIM AND THE MANUFACTURING ENTERPRISE.

1. The Manufacturing Enterprise.
Introduction. External Challenges. Internal Challenges. World-Class Order-Winning Criteria. The Problem and a Solution. Learning CIM Concepts. Going for the Globe. Summary. Bibliography. Questions. Problems. Projects. Appendix 1-1: The Benefits of a CIM Implementation. Appendix 1-2: Technology and the Fundamentals of an Operation-Authors' Commentary.
2. Manufacturing Systems.
Manufacturing Classifications. Product Development Cycle. Enterprise Organization. Manual Production Operations. Summary. Bibliography. Questions. Projects. Case Study: Evolution and Progress-One World-Class Company's Measurement System. Appendix 2-1: CIM as a Competitive Weapon.
II. THE DESIGN ELEMENTS AND PRODUCTION ENGINEERING.

3. Product Design and Production Engineering.
Product Design and Production Engineering. Organization Model. The Design Process: A Model. Concurrent Engineering. Production Engineering. Summary. Bibliography. Questions. Projects. Case Study: Repetitive Design.
4. Design Automation: CAD and PDM.
Introduction to CAD. The Cost of Paper-Based Design Data. CAD Software. CAD: Yesterday, Today, and Tomorrow. Application of CAD to Manufacturing Systems. Selecting CAD Software for an Enterprise. Product Data Management. Summary. Bibliography. Questions. Projects. Appendix 4-1: Web Sites for CAD Vendors. Appendix 4-2: B-Splines to NURBS. Appendix 4-3: Web Sites for Computer Companies.
5. Design Automation: CAE.
Design for Manufacturing and Assembly. CAE Analysis. CAE Evaluation. Group Technology. Production Engineering Strategies. Design and Production Engineering Network. Summary. Bibliography. Questions. Problems. Projects. Appendix 5-1: Ten Guidelines for DFA. Appendix 5-2: Web Sites for CAE Vendors. Appendix 5-3: Web Sites for Rapid Prototyping Vendors.
III. CONTROLLING THE ENTERPRISE RESOURCES.

6. Introduction to Production and Operations Planning.
Operations Management. Planning for Manufacturing. MPC Model-Manufacturing Resource Planning (MRP II). Production Planning. Master Production Schedule. Inventory Management. Planning for Material and Capacity Resources. Introduction to Production Activity Control. Shop Loading. Input-Output Control. Automating the Planning and Control Functions. Summary. Bibliography. Questions. Problems. Projects. Appendix 6-1: Priority Rule System.

7. Detailed Planning and Production-Scheduling Systems.
From Reorder-Point Systems to Manufacturing Resource Planning (MRP II). Material Requirements Planning. Capacity Requirements Planning. Manufacturing Resource Planning. Features of Modern Manufacturing Planning and Control Systems. Summary. Bibliography. Questions. Problems. Projects. Appendix 7-1: Wright's Bicycle Example. Appendix 7-2: ABCD Checklist. Appendix 7-3: An ERP Example Using WinMan.

8. Enterprise Resources Planning, and Beyond.
MRP II: A Driver of Effective ERP Systems. Information Technology. The Decision to Implement an ERP System. Identifying ERP System Suppliers. Developing Technologies: Converging and Enabling. Integrating Systems to Manage Design Data. Summary. Bibliography. Questions. Projects.

9. The Revolution in Manufacturing.
Just-in-Time Manufacturing. Synchronized Production. The Emergence of Lean Production. Modern Manufacturing Systems in a Lean Environment. Summary. Bibliography. Questions. Projects. Case Study: Production System at New United Motor Manufacturing, Part 1. Case Study: Production System at New United Motor Manufacturing, Part 2.

IV. ENABLING PROCESSES AND SYSTEMS FOR MODERN MANUFACTURING.

10. Production Process Machines and Systems.
Material and Machine Processes. Flexible Manufacturing. Fixed High-Volume Automation. Summary. Bibliography. Questions. Projects. Appendix 10-1: History of Computer-Controlled Machines.
11. Production Support Machines and Systems.
Industrial Robots. Program Statements for Servo Robots. Programming a Servo Robot. Automated Material Handling. Automatic Guided Vehicles. Automated Storage and Retrieval. Summary. Bibliography. Questions. Projects. Case Study: AGV Applications at General Motors.
12. Machine and System Control.
System Overview. Cell Control. Proprietary Versus Open System Interconnect Software. Device Control. Programmable Logic Controllers. Relay Ladder Logic. PLC System and Components. PLC Types. Relay Logic Versus Ladder Logic. Computer Numerical Control. Automatic Tracking. Network Communications. Summary. Bibliography. Questions. Projects. Appendix 12-1: Turning G Codes.
13. Quality and Human Resource Issues in Manufacturing.
Quality Foundations. Total Quality Management. Quality Tools and Processes. Defect-Free Design Philosophy. The Changing Workforce. Self-Directed Work Teams. Summary. Bibliography. Questions. Projects.

http://www.engr.sjsu.edu/sobi/Tech%20180B%20Readings.htm

This article is based on  the summary made by Dr. Samuel C. Obi. I am trying to modifying and linking various articles that I already wrote on industrial engineering and manufacturing management.  Many of the issues discussed in this summary are relevant to Production Industrial Engineering a subject that I am now proposing.

Introduction to CIM Technology

Objectives:
a)     Describe the nature of computer integrated manufacturing enterprise
b)     Define computer integrated manufacturing (CIM)
c)      Develop an understanding of the basic components of CIM
d)     Develop an understanding of the goals and objectives of CIM
e)     Explore various manufacturing practices and the various issues related to the application of CIM

Rehg & Kraebber, Chapter 1: The manufacturing Enterprise

Introduction:
·           Manufacturing enterprise is a collection of interrelated activities that includes product design and documentation, material selection, planning, production, quality assurance, management, and marketing of goods
·           The fundamental goal of the enterprise is to use these activities to convert raw materials into finished goods on a profitable basis
·        


·     




Computer-integrated manufacturing defined:
CIM is the integration of the total manufacturing enterprise through the use of integrated systems and data communications coupled with new managerial philosophies that improve organizational and personal efficiency




Learning CIM concepts:
Process segments

Going for the Globe:
The CIM process: Step 1 (assessment of the enterprise in technology, human resources, and systems)
The CIM process: Step 2 (simplification or elimination of waste)
The CIM process: Step 3 (implementation with performance measures)



Rehg & Kraebber, Chapter 2: Manufacturing Systems

Manufacturing system classifications:

Project
Job shop
Repetitive
Line
Continuous



Categories of production strategies used to match customer and manufacturing lead times:
Engineer to order (ETO)
Make to order (MTO)
Assemble to order (ATO)
Make to stock (MTS)


Enterprise organization:
A successful CIM implementation requires an understanding of the functions performed by each block of an enterprise. They include:

Sales and promotion
Finance and management
Product/process definition
Manufacturing planning and control
Shop floor
Support organizations

Manual production operations:
Activity enters system as either a design or request for engineering action
Product design uses CAD to make the drawing
The product definition group lists the different parts of the drawing as BOM
The manufacturing definition group separates the BOM into those to be purchased and those to be manufactured inside
Manufacturing process planning determines the type of machines and process sequences required to process the parts
The business production planning produces the production schedule

Implementing a CIM system enhances and automates the above manual production operations


What is CIM?
C + I + M

C = Computer
It is an    
 i. Enabling tool.
It facilitates
ii. Information flow
iii. Information management

I = Integrated
                        i. Integration vs. interfacing
                        ii. Shared information
                        iii. Shared functionality

M = Manufacturing
                        i. Production control
                        ii. Production scheduling
                        iii. Process design
                        iv. Product design
                        v. Manufacturing enterprise


Different definitions for different users
                        i. Shop communications
                        ii. Recurring processes
                        iii. Non-recurring processes
                        iv. Engineering/manufacturing communication
                        v. Other users
                        vi. Improving communication through CIM




Computer Integrated  Manufacturing

A) Computer Integrated Manufacturing (CIM) systems technology refers to the technology, tool or method used to improve entirely the design and manufacturing process and increase productivity, to help people and machines to communicate. It includes CAD (Computer-Aided Design), CAM (Computer- Aided Manufacturing), CAPP (Computer-Aided Process Planning, CNC (Computer Numerical Control Machine tools), DNC (Direct Numerical Control Machine tools), FMS (Flexible Machining Systems), ASRS (Automated Storage and Retrieval Systems), AGV (Automated Guided Vehicles), use of robotics and automated conveyance, computerized scheduling and production control, and a business system integrated by a common database. (Houston Cole Library)                                                                                                                                              
B) Computer Integrated Manufacturing (CIM) is the process of automating various functions in a manufacturing company (business, engineering, and production) by integrating the work through computer networks and common databases. CIM is a critical element in the competitive strategy of global manufacturing firms because it lowers costs, improves delivery times and improves quality. (Amatrol)

Potential Benefits of CIM

Shorter time to market with new products
Increase in manufacturing productivity
Shorter customer lead times
Improved quality
Improved customer service
Shorter vendor lead times
Reduced inventory levels
Greater flexibility and responsiveness
Lower total cost
Great long - term flexibility



UNIT 2: COMPONENTS OF COMPUTER INTEGRATED MANUFACTURING

Objectives:
a)     Explore the design, nature and relationships of CIM sub-systems
b)     Develop an advanced understanding of CIM sub-systems
c)      Describe activities performed in each CIM sub-system
d)     Determine the nature of enabling technologies behind each CIM sub-system
e)     Relate the concept of CIM to a manufacturing enterprise’s model


Rehg & Kraebber: Chapter 3: Product Design and Production Engineering


Product design and production engineering:
These areas or departments are appropriate starting points for a detailed study of CIM
The two have embraced and encouraged the use of technology to reduce many tedious manual tasks
The initial creation of data starts in these areas
It is appropriate to have a common data base for all the data

Organizational Model:
Design information flow
The product area is responsible for product design and analysis, material selection, and design and production documentation
The production engineering area adds production standards for labor, process, and quality to the product data from design area.
Engineering release is responsible for product change control.

The design process: A model:
·        Although there is a five-step design process, marketing plays a role before design engineering picks up
·        Form (shape, style, and character), fit (marketing fit or order winning criteria), and function are determined  with data from marketing department


Step 1: Conceptualization (recognition of need & definition of the problem)
Divided into two: Typical and atypical
Typical design relates to repetitive design
Atypical design is for new product
Step 2: Synthesis:
Specification of material
Addition of geometric features
Inclusion of greater dimensional details to conceptualized design
Removes (filters) cost-adding features and materials
Employs DFM and DFA to ensure good design
About 70% of manufacturing cost is fixed in steps 1 and 2 activities
Step 3: Analysis:
Analysis means determining/describing the nature of the design by separating it into its parts to determine the fit between the proposed design and the original design goals
Two categories of analysis are mass properties and finite
Can be performed manually, but the computer increases analysis capability and reduces its time

Step 4: Evaluation:
Checks the design against the original specifications
Often requires construction of a prototype to test for conformance
Often employs rapid prototyping technique
Documentation:
Creating all necessary product and part views in the form of working drawings, detailed and assembly drawings
Addition of dimensions, tolerances, special manufacturing notes, and standard components
Creation of part numbers, bill of materials, and detailed part specifications
Creation of product electronic data files used by manufacturing planning and control, production engineering, marketing and quality control

Concurrent Engineering:
Implies that the design of a product and the systems to manufacture, service, and dispose it are considered from the initial design concept
The traditional systems (process and disadvantages)
The new model for product design (participation in product deign broadens)
Automating the concurrent engineering process

Production Engineering:
Has the responsibility for developing a plan for the manufacture of the new or modified product.
Its seven areas of activities include process planning, NC/CNC programming, tool/fixture engineering, work & production standards, plant engineering, analysis for manufacturability and assembly, and manufacturing cost estimation
Concurrent engineering is used to bring production engineering activities together


Production Engineering Activities


Came across this process in Mallikarjuna Rao's Book.  Page 69.

Process planning:

The procedure used to develop a detailed list of manufacturing operations required for the production of a part or product
Every part to be made has a routing sheet prepared
Routing sheets (also called process plans or operation sheets) describe the sequence of operations required to produce the finished product
The time data include setup time, unit run time, queue time etc.
The operation sheet also includes tooling, jig/fixtures needed, machines, operator skill levels and other key information needed.
In CIM environment, the operation sheet need not move with the part. The process information can be viewed on computer terminals

Production machine programming (NC, CNC and CAM)

Tool and fixture engineering:

Used to hold and position work while cutting
Request for this is made by production engineering
Tooling normally begins after the design is completed

Work and production standards:

Using direct time studies
Using motion and time measurement (MTM) or standard time data

Plant engineering (for the construction of a new facility when necessary)

Analysis for manufacturability and assembly


Design for manufacturing and assembly (DFMA)
Concept of DFX

Manufacturing cost estimation


Using manual approach
Using software packages

Rehg & Kraebber: Chapter 10: Production Process Machines and Systems


A part spends only 5% of the total time utilized for production on the machine
Only 1% is used for material removal
Load, unload and gauging take another 4% of the time
The majority of production time (95%) is divided among setup, moving, waiting, and inspection time
Production machines are producing nothing during setup, moving, waiting, load, unload and gauging times
Reducing these wasted times is the goal of world-class manufacturing

Material and machine processes:
Process operations are classified as:
Primary operations (converts raw material into basic geometry required for the finished product, e.g. casting, forming, sawing and oxyfuel and arc cutting)
Secondary operations (gives the raw material its final shape, e.g. turning, boring, milling, drilling, reaming, grinding and nontraditional machining processes)
Physical properties operations (changes physical properties but not the part geometry, e.g. heat treating)
Finishing operations, e.g. painting, plating, and etching/pickling
Flexible manufacturing. Flexibility refers to:
The number of different parts that a workstation can produce under normal production conditions
The ability to adapt easily to engineering changes in the part
The increase in the number of similar parts produced on the system
The ability to accommodate routing changes that allow a part to be produced on different types of machines
The ability to change the system setup rapidly from one type of production to another
Group technology focuses on the design of production cells to handle a family of parts with common production characteristics
Flexible manufacturing systems:
A group of NC machine tools that can randomly process a group of parts, having automatic material handling and central control to balance resource utilization dynamically so that the system can adapt automatically to changes in parts production, mixes, and levels of output.
An FMS is a collection of hardware linked together by computer software.
It includes NC and CNC machines, tooling and setup systems, part cleaning, deburring stations, material automatic storage and retrieval systems, CMM, and is linked by automatic material handling system such as robots, AGVs, and belt conveyors.
A minimum of five technology levels are present in an FMS:
Enterprise level for scheduling, programming, purchase orders and shipping documents
System level for coolant/chip, computer-controlled carts, downloading of codes, synchronization of cell operations, calibration and setup of tools, tool/material/finished goods inventory tracking
Cell level for machining cells, tool gauge and calibration station, material load and unload stations, testing and quality control cell, and part washing cell
Machine level for CNC machining centers, manual operations, AGVs, work holders and changers, quality testing machines, automatic parts washing machines, and tool interchange stations
Device level for sensors, ac and dc motors, pneumatic and hydraulic components, tools, fixtures, electrical components, connectors, wire, and fiber optics
FMC versus FMS:
An FMC is a group of related machines that perform a particular process or step in a larger manufacturing process
The production building blocks used to assemble an FMS are flexible manufacturing cells
Production machines can be a combination of manual and computer-controlled machines
Frequently, one operator runs two CNC machines, a process called two-to-one operation
Fixed high-volume automation:
Manufacturing systems capable of satisfying this type of production are called transfer machines or transfer lines
These large volume production systems are collectively called Detroit-type, fixed, or hard automation
Two types available: In-line and rotary fixed automation


OTHER MATERIALS

Changing Needs Call for New Methods
Complexity forces division of labor
Technology Growth
Availability of computers
NC programming
CAD systems
Databases
Need for data sharing
·        Data Integrity
Current Capabilities and Applications
·        Networks
·        Hardware communications
·        Embedded computers
·        Systems integration
Problems to Overcome in Implementing CIM
·        Interdepartmental support/politics
·        CIM justification
·        Intangible benefits
Additional Aspects of CIM
·        Simulation
·        Organizational awareness
·        File management systems
·        The “paperless factory”
·        Features-based design systems
·        Evolving standards (IGES, PDES, CALS)
·        Concurrent engineering




Factory of the Future

Manufacturing Today
As islands of automation
Implementing automaton and the need for standards
The role of the computer in computer-integrated manufacturing
Managing change
Planning for the Factory of the Future
o       The “as is” factory scenario
o       The “to be” factory scenario
o       JIT manufacturing
o       GT manufacturing
o       Types of manufacturing systems
o       Automated material handling
o       Scheduling system
o       Control functions
o       Machine tool requirements
o       Unattended machine operation
Evolution of Manufacturing
·        Manufacturing partnerships
o       Role of the employee
o       Customer and supplier roles

Unit 3: Computer Integrated Manufacturing Technology: (CAD & CAM)

Objectives:
a)     Apply CIM concepts in the creation of an appropriate database
b)     Develop product from CAD-CAM interface as CIM sub-systems
c)      Describe the concept of computer numerical control programming as part of CIM
d)     Describe the role of inventory control system in CIM environment
e)     Generate and edit part programs using latest CAM software
f)        Develop the concept of group technology as an aspect of CIM

REHG & KRAEBBER, CHAPTER 4: DESIGN AUTOMATION: CAD


CAD is the application of computers and graphics software to aid or enhance the product design from conceptualization to documentation.
Computer-aided drafting (CAD) automates the drawing or product documentation process.
Computer-aided design (CAD) is used to increase the productivity of the product designers.

CAD system capabilities include:
Stand-alone PC and RISC-based CAD workstations at each engineering and design drafting location
The ability to share part data and product information with every station in the system
Access to part data files from the mainframe computers on the network
Shared peripheral resources such as printers and plotters
Concurrent work on the same project from multiple workstations, one of the reasons our team project needs a web site or data base.

Basic CAD system includes:
Keyboard
Input devices
Output devices

Application of CAD to manufacturing systems:
Concept and repetitive design (product, fixtures, gauges, pallets, mold, etc.)
Drafting
New product development management (PDM) and the Internet

Rehg & Kraebber, Chapter 5: Design Automation: Computer-Aided Engineering


·        Computer-aided engineering (CAE) is the analysis of the engineering design using computer-based techniques to calculate product operational, functional, and manufacturing parameters too complex for classical methods.
·        CAE also provides productivity tools to aid production engineering area by providing software to support group technology (GT), computer-aided process planning (CAPP), and computer-aided manufacturing (CAM)


Design for manufacture and assembly (DFMA):

·        DFMA is any procedure or design process that considers the production factors from the beginning of the product design.
·        Originated from producibility engineering (DFM) and design for assembly (DFA)


Computer-aided engineering analysis:

·        Finite-element analysis (most frequently used)
·        Mass property analysis


Computer-aided engineering evaluation:

·        Prototyping
o       Rapid prototyping
§         Stereolithography
§         Solid ground curing
§         Selective laser sintering
§         Three-dimensional printing
§         Fused-deposition modeling
§         Laminated object manufacturing


Group Technology (GT):

·        GT is a manufacturing philosophy that justifies small and medium-sized batch production by capitalizing on design and/or manufacturing similarities among component parts.
·        Coding and classification:
o       Coding is a systematic process of establishing an alphanumeric value for parts based on selected part features.
o       Classification is the grouping of parts based on code values
o       Coding and classification in GT are highly interactive because the coding system must be designed to produce classified groups with the correct combination of common features.
·        In GT production cells, groups of different machines are identified based on their ability to produce families of parts.


Computer-aided process planning (CAPP):

·        Consistent and correct process planning requires both knowledge of the manufacturing processes and experience.
·        Two automation techniques are called variant and generative process planning.
·        The CAPP variant approach uses a library of manually prepared process plans in the database and a retrieval system to match components on new parts to existing process pans of similar components.
·        The CAPP generative approach utilizes a process information knowledge base that includes the decision logic used by expert human planners.


Computer-aided manufacturing (CAM):

·        CAM is the effective use of computer technology in the planning, management, and control of production for the enterprise.
·        One of the major applications of CAM is in CAD/CAM where the part geometry created with CAD in the design engineering is used with CAM software to create machine code (NC/CNC) capable of machining the part.
·        Production and process modeling
·        Production and process simulation
·        Production cost analysis


Design and production engineering network demands:

·        A common database for enterprise information flow
·        Easy, accurate and instantaneous movement of part geometry files and product data between departments
·        An enterprise network is a communications system that supports communications and the exchange of information and data among various devices connected to the network over distances from several feet to thousands of miles

Review and Other Materials

Manufacturing Product Planning
·        Market Research and Forecasting
·        Product Design
o                   Expert systems
o                   Design considerations
·        Group Technology (GT)
o       Reasons for adopting GT
o       Benefits of GT
§                     Benefits in product design
§                     Standardization of tooling and setup
§                     More efficient material handling
§                     Increased economies of batch-type production
§                     Easier scheduling
§                     Reduced work-in-process and lead time
§                     Faster and more rational process planning

Production Engineering
·        Manufacturing engineering
Process planning engineering
The planning process
Process planner qualifications
Automation of process planning
Geometric tolerance stacking
o       Tool design engineering
o       NC programming engineering
·        Industrial engineering

Computer Fundamentals
·        Microcomputers
·        Minicomputers
·        Mainframe computers
·        Distributed processing

Computer Numerical Control
·        Control features
o       Types of interpolation (linear, circular, helical & parabolic)
o       CSFM programming
o       Parametric programming
o       Digitizing programming
o       Centerline programming
o       Adaptive control
o       Over travel monitoring
o       Mathematical capability
·        Management features

Distributive Numerical Control (DNC)
·        Conventional system
·        CNC “behind the reader” system
·        DNC minicomputer system

Integrated Machine Tool Control Systems
·        Communication protocols and MAP
·        Factory floor networks
·        Cell controllers


UNIT 4: MANUFACTURING PLANNING, CONTROL AND SCHEDULING IN CIM ENVIRONMENT

Objectives:
a)     Develop a general understanding of manufacturing planning and control in a CIM environment
b)     Employ scheduling strategies employed in a CIM enterprise
c)      Describe inventory management techniques as applied to CIM
d)     Explore different forecasting techniques used in modern manufacturing
e)     Describe quantitative methods, software applications, and financial management employed in a CIM environment

REHG & KRAEBBER, CHAPTER 6: INTRODUCTION TO PRODUCTION/OPERATIONS PLANNING



The planning functions have formal interfaces with both the design and production departments and informal relationships with most of the enterprise. The operations management functions are a critical part of the CIM implementation.

Operations management:
Has the responsibility for the administration of enterprise systems used to create good or provide services.
For example, the factory management must design new products, redesign current models, test designs, order raw materials, determine product mix and quantity to produce, schedule the production machines, maintain production hardware and software, and adjust fixed and variable resources to meet changes in the market.

Manufacturing planning and control:
All planning has a time horizon, e.g. number of days, months or years
Enterprise planning is divided into three levels
The strategic plan is generally long range: one year to many years
The strategic plan is performed at highest level in management
The aggregate plan has an intermediate-length time horizon of about two to eight months
The aggregate plan emphasizes levels of employment, output, inventories, back orders, and subcontractors
The goal of aggregate planning is the generation of a production plan that utilizes the enterprise resources efficiently to meet customer demand
The production plan and forecasted customer demand provides the aggregate information from which the disaggregate master production schedule (MPS) is produced
The development of MPS data is the start of disaggregate planning
The disaggregate plan provides short-range planning with detailed plans that include machine loading, part routing, job sequencing, lot sizes, safety stock, and order quantities.
The disaggregate plan has the shortest time horizon
o       The term disaggregate means to separate into component parts
At disaggregate planning level, an aggregate plan is disaggregated into all the various models and options necessary to meet customer demand
The first step in disaggregation is the creation of MPS from the aggregate production plan
The material requirement planning (MRP) strategy in the manufacturing planning and control (MPC) system is a very useful tool at the disaggregate level
MRP system addresses the need for parts management of complex products and product mixes with high rates of production
MRP process starts with the MPS providing the quantity of each model or part required (gross requirement) per period
The bill of materials (or BOM in the form of product structure diagram) and current inventory provide critical information for an effective MRP system
The product structure diagram illustrates clearly the sequence required to build the product, with the 0 level representing the finished product
The bill of materials provides the MRP system with the part number and quantity of all parts required to build and assemble the product
The inventory control system supplies the MRP system with the projected on-hand balance of all parts and materials listed on the BOM
The MRP run produces the requirements for purchasing and production that are needed to complete the master schedule

Part routing, lead times and capacity planning:
·        The routing sheet specifies each production operation and the work center location
·        Lead time includes four elements: run time, setup time, move time and queue time (setup time, move time and queue time add no value)
·        Capacity requirement planning (CRP) works with the system data to calculate the labor and machine time requirements needed to complete the master production schedule

Production activity control:
·        Production activity control or shop-floor control manages the detailed flow of materials inside the production facility
·        It uses three different processes for scheduling production in manufacturing: Gantt charts, priority rules for sequencing jobs at work center, and finite loading
·        Finite and infinite loading techniques are similar to daily production schedule process

Rehg & Kraebber, Chapter 7: Detailed Planning and Production-Scheduling Systems



·  The manufacturing planning and control (MPC) process in the CIM enterprise is responsible for the aggregate and disaggregate planning of production and scheduling of manufacturing resources
·  The aggregate plan starts with a production plan stated in broad product specifications
·  The first disaggregate plan, broken into specific product models, is called the master production schedule (MPS)
·  The MPS states the production plan for each model for several production periods in the MPS record
·  The output of the MPS record provides the data for the material requirements planning (MRP) scheduling system
·  Much of the contents of this chapter was covered in Tech 147

Rehg & Kraebber, Chapter 8: Enterprise Resource Planning and Beyond


·  APICS Dictionary defined enterprise resource planning (ERP) as a method for the effective planning and control of all resources needed to take, make, and account for customer orders in a manufacturing, distribution, or service company
·  ERP is one of the newer system concepts that focuses on the integration of business systems
·  These integrated systems support all of the functional departments in the enterprise: sales and order entry, engineering, manufacturing, finance and accounting, distribution, order planning and execution, and the supply chain flow
·  Tech 149 team project can take advantage of this philosophy in its concurrent engineering approach
·  Since businesses are increasingly focusing on customers, customer relationship management (CRM) systems are being developed to help companies manage the information they have about their customers, the products these customers buy, and the way the customers prefer to do business
·  Some related aspects of ERP include:
o       Product data management (PDM)
o       Information technology issues (data collection issues and system integration problems)
o       The role of the internet
o       Sample ERP systems include: PeopleSoft, SAP R/3, Oracle, Sterling, Legacy, and JBA (see page 337)

Rehg & Kraebber, Chapter 9: The Revolution in Manufacturing


·        Several technologies and philosophies have revolutionized manufacturing in recent years. Some of these are covered in this chapter

Just-In Time (JIT) Manufacturing:
·        Just-In-Time manufacturing (JIT) encompasses every aspect of manufacturing, from design engineering to delivery of the finished goods, and includes all stages in the processing of raw material
·        JIT is much more that material-ordering plan that schedules deliveries at the time of need
·        JIT focuses on the elimination of the seven wastes found in manufacturing practices, namely:
1.      Waste of overproduction
2.      Waste of waiting
3.      Waste of transportation
4.      Waste of processing
5.      Waste of stocks
6.      Waste of motion
7.      Waste of making defective products
·        Elements of JIT include:
o       Technology management
1.      Structured flow manufacturing
2.      Small lot production
3.      Setup reduction
4.      Fitness for use
o       People management
1.      Total employee involvement
2.      Control through visibility
3.      Housekeeping
4.      Total quality focus
o       Systems management
1.      Level load and balanced flow
2.      Preventive maintenance
3.      Supplier partnerships
4.      Pull system

Kanban (Card):
·        Kanban is a Japanese word that means “card”
·        These cards in effect replace all work orders and inventory move tickets
·        Within the MPC system, kanban controls the flow of production material
·        One- and two-card kanban systems are in common use
·        Kanban supports a pull (JIT) system

Drum-Buffer-Rope System

Lean Production
Other Related Materials:

Material requirements planning:
·  Understanding the MRP record: Some definitions:
o       Period number (time duration used in MRP planning process; one period represents a day, week, or month)
o       Part number (identifies the specific part being planned for)
o       Gross requirements (equals the anticipated future demand for an item per period)
o       Scheduled receipts (all orders released to manufacturing or to suppliers through purchase orders)
o       Projected on hand (the calculated inventory for the item projected through all the periods on the record)
o       Planned order receipts (indicate when a planned order would be received if the planned order release date is exercised)
o       Planned order releases (the suggested order quantity, release date, and due date generated by using MRP software)
o       Lead time (time between release of an order and the completion or delivery of the order)
o       Lot size (the required minimum order quantity determined by the economics of the production process)
o       Safety stock (the lowest level of inventory allowed in the projected on-hand line; protect against variations in delivery

MRP calculations
·  The product structure diagram and the MRP record:
o       The MPS is used to determine the MRP gross requirement quantities in each period
o       Every box in the product structure diagram is covered by an MRP record
o       The MRP records are linked
o       The planned order releases from one record flow into the gross requirements of the record at the next lower level

The benefits of MRP:
·     Improved customer service
·     Reduction in past due orders
·     Better understanding of capacity constraints
·     Significant increases in productivity
·     Reduction in lead time
·     Reduction in the inventory for finished goods, raw materials, component parts, and safety stock
·     Reduction in work-in-process (WIP)
·     Elimination of annual inventory
·     Significant drops in annual accounting adjustment for inventory problems
·     Usually, a doubling of inventory turns
·  MPC has responsibility for the planning and control of the shop floor, production materials, production scheduling, quality process, and facilities planning
·  MPC performs two distinct functions: 1) Manufacturing planning, and 2) Manufacturing control

Planning in the MPC:
·  High-level planning for the business
·  Forecasting future demand
·  Planning for production
o       Chase production strategy
o       Level production strategy
o       Mixed production strategy
o       The MPS technique
o       MPS time-phased record
o       The MRP technique
o       Inventory management (raw materials, component parts, work-in-process, or finished goods and products)

Product data management:
·        Bill of materials
o       Originates from design
o       Includes quantity, part number, and specifications of each part
o       Parts are either manufactured or purchased
o       Represented in MPC as product structure diagram or indented BOM

Unit 5: Automated Manufacturing

Objectives:
a)     Apply industrial controls, programmable logic controllers, and industrial robots in a CIM environment
b)     Describe the theory of operation, programming, and the practical application of PLCs and robots
c)      Describe fundamentals of data communications and local area networks as they relate to the various levels of communications between shop floor computers, PLCs, robots, CNC machine tools and automatic identification equipment
d)     Integrate commonly used industrial control devices, including CAD/CAM, computer-assisted numerical control programming, computer-assisted quality control, and automatic identification

·        Reasons for automation in the factory include:
o       Reduced labor costs
o       Sales growth
o       Better quality
o       Reduced inventory
o       Increased worker productivity
Two types of automation are fixed and flexible systems
Current factory technology includes:
o       Computer networks including ERP
o       Data collection and reporting
o       Automated material handling
o       Cells and work centers
o       Automated inspection and testing
o       The paperless factory
o       Robots

REHG & KRAEBBER, CHAPTER 11: PRODUCTION SUPPORT MACHINES AND SYSTEMS


Industrial Robots:

A robot is an automatically controlled, programmable, multipurpose, manipulating machine with several programmable axes, which may be either fixed in place or mobile for use in industrial automation applications.
Key word are reprogrammable and multipurpose
The basic robot system consists of manipulator, power supply, controller, end effectors, interfacing or required equipment such as devices and sensors and any communications interface that is operating and monitoring the robot, equipment and sensors
The mechanical arm is driven by electric motors, pneumatic devices, or hydraulic actuators
Six motions are identified: Arm sweep, shoulder swivel, elbow extension, pitch, yaw, and roll.
Robotic arm geometry classification includes the following: Cartesian geometry, cylindrical geometry, spherical geometry, and articulated geometry.
End effector or end-of-arm tooling must be provided for robots to have production capability
The controller is a special-purpose computer with a central processing unit which controls the robot’s arm and the work cell in which it is operating.
Robots are programmed by keying in or selecting menu commands in the controller language, moving the robot arm to the desired position in the work cell, and recording the position in the program often with a teach pendant.
Programming methods include:
Active robot teaching (teach pendant)
Passive robot teaching (lead-through)
Off-line robot programming
Robot applications include: Material processing, material handling, and assembly and fabrication.
Selecting and justifying robot application requires a detailed design process and cost analysis.
Justifying a robotic system is performed using this model: [P = I/(S-E)]

Automated material handling:


Material-handling process for parts and raw materials should be automated only after every unnecessary inch of material transport distance has been removed from the production process.
The work simplification and analysis process that precedes the design and selection of material-handling automation starts with a diagram of the production flow, using process flow analysis symbol shown on page 461.
The transfer mechanism used to move parts between work cells and stations serves two main functions: 1) move the part in the most appropriate manner between production machines, and 2) orient and position the part with sufficient accuracy at the machine to maximize productivity and quality.
Automated transfer systems include:
Continuous transfer such as overhead monorail
Intermittent or synchronized transfer such as the walking beam transfer system
Asynchronous transfer or power-and-free systems as in conveyor and pallet system.

Automatic guided vehicles (AGV):


·        An AGV is a vehicle equipped with automatic guidance equipment capable of following prescribed guide paths and may be equipped for vehicle programming and stop selection, blocking, and any other special function required by the system.
·        AGV types include: Towing vehicles, unit load vehicles, pallet truck vehicles, fork lift vehicles, light load vehicles, and assembly line vehicles.
·        AGV systems must perform five functions, namely: Guidance, routing, traffic management, load transfer, and system management.
·        AGV systems must be justified based on the current and future material-handling requirements.

Automated storage and retrieval systems (AS/RS)
Materials to be stored and retrieved include: 1) raw materials, 2) unsold finished products, 3) production parts, 4) purchased parts and subassemblies used in the assembly of products, 5) rework and scrap that result from production operations, 6) spare parts for repair of production machines and facilities, and 7) general office supplies including tools and instruments.
AS/RS is a combination of equipment and controls that handles, stores, and retrieves materials with precision, accuracy, and speed under a defined degree of automation.

REHG & KRAEBBER, CHAPTER 13: QUALITY AND HUMAN RESOURCE ISSUES IN MANUFACTURING


Deming’s 14 points for management
Total quality management (TQM)
Quality tools and processes (for quiz 3)

OTHER MATERIALS
FMS Benefits
Producing a family of parts
Random launching of parts
Reduced manufacturing lead time
Reduced work-in-process
Reduced operator requirements
Expandability
Increased machine utilization
Reduced capital equipment costs
Responsiveness to change
Ability to maintain production
Product quality improvement
Reduced labor costs
Better management control

Components of the Flexible Manufacturing System
FMS workstations:
FMS for prismatic parts
FMS for rotational parts
Robots
Fixtures and pallets
Tooling
Operators
Inspection system
Coolant and chip handling systems
Cleaning stations
FMS off-line operations
Control station
·        Material handling system:
o       Parts delivery:
                                    -Material handling outside the FMS
                                    - Material handling inside the FMS
                                    -Conveyor systems
                                    -Cutting tool delivery
o       Load/unload stations:
                                    -Handling equipment
                                    -Operator control
o       Buffer storage