MANUFACTURING PROCESS

MANUFACTURING PROCESS

Introduction to 

Basic Manufacturing

Processes and 

Workshop Technology

Click Below Video

Final Report: Competition - Engineering and Manufacturing

1.1 INTRODUCTION

Manufacturing is the backbone of any industrialized nation. Manufacturing and technical staff

in industry must know the various manufacturing processes, materials being processed, tools

and equipments for manufacturing different components or products with optimal process

plan using proper precautions and specified safety rules to avoid accidents. Beside above, all

kinds of the future engineers must know the basic requirements of workshop activities in

term of man, machine, material, methods, money and other infrastructure facilities needed

to be positioned properly for optimal shop layouts or plant layout and other support services

effectively adjusted or located in the industry or plant within a well planned manufacturing

organization.

The complete understanding of basic manufacturing processes and workshop technology

is highly difficult for any one to claim expertise over it. The study deals with several aspects

of workshops practices also for imparting the basic working knowledge of the different

engineering materials, tools, equipments, manufacturing processes, basic concepts of electromechanical controls of machine tools, production criteria’s, characteristics and uses of various testing instruments and measuring or inspecting devices for checking components or products manufactured in various manufacturing shops in an industrial environment. 

It also describes and demonstrates the use of different hand tools (measuring, marking, holding and supporting tools, cutting etc.), equipments, machinery and various methods of manufacturing that facilitate shaping or forming the different existing raw materials into suitable usable forms. It deals with the study of industrial environment which involves the practical knowledge in the area

of ferrous and non ferrous materials, their properties and uses. It should provide the knowledge

of basic workshop processes namely bench work and fitting, sheet metal, carpentry, pattern

making, mould making, foundry, smithy, forging, metal working and heat treatment, welding,

fastening, machine shop, surface finishing and coatings, assembling inspection and quality

control. It emphasizes on basic knowledge regarding composition, properties and uses of

different raw materials, various production processes, replacement of or improvement over

a large number of old processes, new and compact designs, better accuracy in dimensions,

quicker methods of production, better surface finishes, more alternatives to the existing

materials and tooling systems, automatic and numerical control systems, higher mechanization

and greater output.

1.2 SCOPE OF STUDY

Today’s competitive manufacturing era of high industrial development and research, is being

called the age of mechanization, automation and computer integrated manufacturing. Due to

new researches in the manufacturing field, the advancement has come to this extent that

every different aspect of this technology has become a full-fledged fundamental and advanced

study in itself. This has led to introduction of optimized design and manufacturing of new

products. New developments in manufacturing areas are deciding to transfer more skill to the

machines for considerably reduction of manual labor. The scope of the subject of workshop

technology and manufacturing practices is a extremely wide as it specifies the need of greater

care for man, machine, material and other equipments involving higher initial investment by

using proper safety rule and precautions. The through and deep knowledge in the course of

study of this important subject is therefore becoming essential for all kinds of engineers to

have sound foundation in their profession. Therefore the course of study of this subject

provides a good theoretical background and a sound practical knowledge to the engineering

students and workshop staff. One should also be aware of the following terms for better

understanding of the scope of the study

1.3 MANUFACTURING ENGINEERING

Manufacturing is derived from the Latin word manufactus, means made by hand. In modern

context it involves making products from raw material by using various processes, by making

use of hand tools, machinery or even computers. It is therefore a study of the processes

required to make parts and to assemble them in machines. Process Engineering, in its

application to engineering industries, shows how the different problems related to development

of various machines may be solved by a study of physical, chemical and other laws governing

the manufacturing process. The study of manufacturing reveals those parameters which can

be most efficiently being influenced to increase production and raise its accuracy. Advance

manufacturing engineering involves the following concepts—

1. Process planning.

2. Process sheets.

3. Route sheets.

4. Tooling.

5. Cutting tools, machine tools (traditional, numerical control (NC), and computerized

numerical control (CNC).

6. Jigs and Fixtures.

7. Dies and Moulds.

8. Manufacturing Information Generation.

9. CNC part programs.

10. Robot programmers.

11. Flexible Manufacturing Systems (FMS), Group Technology (GT) and Computer

integrated manufacturing (CIM).

Click Below

 Mokans Paper World

Paper Mart-TNPL Green Delight

1.4 PRODUCTION PROCESS

It is the process followed in a plant for converting semi- finished products or raw materials

into finished products or raw materials into finished products. The art of converting raw

Introduction 3

material into finished goods with application of different types of tools, equipments, machine

tools, manufacturing set ups and manufacturing processes, is known as production. Generally

there are three basic types of production system that are given as under.

1. Job production

2. Batch production

3. Mass production

Job production comprises of an operator or group of operators to work upon a single job

and complete it before proceeding to the next similar or different job. The production

requirement in the job production system is extremely low. It requires fixed type of layout

for developing same products.

Manufacturing of products (less in number say 200 to 800) with variety of similar parts

with very little variation in size and shape is called batch production. Whenever the production

of batch is over, the same manufacturing facility is used for production of other batch product

or items. The batch may be for once or of periodical type or of repeated kinds after some

irregular interval. Such manufacturing concepts are leading to GT and FMS technology.

Manufacturing of products in this case requires process or functional layout.

Where as mass production involves production of large number of identical products (say

more than 50000) that needs line layout type of plant layout which is highly rigid type and

involves automation and huge amount of investment in special purpose machines to increase

the production.

1.5 PROCESS PLANNING

Process planning consists of selection of means of production (machine-tools, cutting tools,

presses, jigs, fixtures, measuring tools etc.), establishing the efficient sequence of operation,

determination of changes in form, dimension or finish of the machine tools in addition to the

specification of the actions of the operator. It includes the calculation of the machining time,

as well as the required skill of the operator. It also establishes an efficient sequence of

manufacturing steps for minimizing material handling which ensures that the work will be

done at the minimum cost and at maximum productivity. The basic concepts of process

planning are generally concerned with the machining only. Although these concepts may also

be extended to other processes such as casting, forging, sheet metal forming, assembling and

heat treatment as well.

1.6 MANUFACTURING PROCESS

Manufacturing process is that part of the production process which is directly concerned

with the change of form or dimensions of the part being produced. It does not include the

transportation, handling or storage of parts, as they are not directly concerned with the

changes into the form or dimensions of the part produced.

PAPER MAKING PROCESS

1.7 CLASSIFICATION OF MANUFACTURING PROCESSES

For producing of products materials are needed. It is therefore important to know the

characteristics of the available engineering materials. Raw materials used manufacturing of

products, tools, machines and equipments in factories or industries are extracted from ores.

The ores are suitably converted the metal into a molten form by reducing or refining processes

4 Introduction to Basic Manufacturing Processes and Workshop Technology

in foundries. This molten metal is poured into moulds for providing commercial castings,

called ingots. Such ingots are then processed in rolling mills to obtain market form of

material supply in form of bloom, billets, slabs and rods. These forms of material supply are

further subjected to various manufacturing processes for getting usable metal products of

different shapes and sizes in various manufacturing shops. All these processes used in

manufacturing concern for changing the ingots into usable products may be classified into six

major groups as primary shaping processes, secondary machining processes, metal forming

processes, joining processes, surface finishing processes and processes effecting change in

properties. These are discussed as under.

1.7.1 Primary Shaping Processes

Primary shaping processes are manufacturing of a product from an amorphous material.

Some processes produces finish products or articles into its usual form whereas others do not,

and require further working to finish component to the desired shape and size. Castings need

re-melting of scrap and defective ingots in cupola or in some other melting furnace and then

pouring of the molten metal into sand or metallic moulds to obtain the castings. Thus the

intricate shapes can be manufactured. Typical examples of the products that are produced by

casting process are machine beds, automobile engines, carburetors, flywheels etc. The parts

produced through these processes may or may not require to under go further operations.

Some of the important primary shaping processes is:

(1) Casting, (2) Powder metallurgy, (3) Plastic technology, (4) Gas cutting, (5) Bending and

(6) Forging.

1.7.2. Secondary or Machining Processes

As large number of components require further processing after the primary processes. These

components are subjected to one or more number of machining operations in machine shops,

to obtain the desired shape and dimensional accuracy on flat and cylindrical jobs. Thus, the

jobs undergoing these operations are the roughly finished products received through primary

shaping processes. The process of removing the undesired or unwanted material from the

workpiece or job or component to produce a required shape using a cutting tool is known as

machining. This can be done by a manual process or by using a machine called machine tool

(traditional machines namely lathe, milling machine, drilling, shaper, planner, slotter). In

many cases these operations are performed on rods, bars and flat surfaces in machine shops.

These secondary processes are mainly required for achieving dimensional accuracy and a very

high degree of surface finish. The secondary processes require the use of one or more

machine tools, various single or multi-point cutting tools (cutters), job holding devices, marking

and measuring instruments, testing devices and gauges etc. for getting desired dimensional

control and required degree of surface finish on the workpieces. The example of parts produced

by machining processes includes hand tools machine tools instruments, automobile parts,

nuts, bolts and gears etc. Lot of material is wasted as scrap in the secondary or machining

process. Some of the common secondary or machining processes are—

(1) Turning, (2) Threading, (3) Knurling, (4) Milling, (5) Drilling, (6) Boring, (7) Planning,

(8) Shaping, (9) Slotting, (10) Sawing, (11) Broaching, (12) Hobbing, (13) Grinding, (14) Gear

cutting, (15) Thread cutting and (16) Unconventional machining processes namely machining

with Numerical Control (NC) machines tools or Computer Numerical Control (CNC) machines

tools using ECM, LBM, AJM, USM setups etc.

Introduction 5

1.7.3 Metal Forming Processes

Forming processes encompasses a wide variety of techniques, which make use of suitable

force, pressure or stresses, like compression, tension and shear or their combination to cause

a permanent deformation of the raw material to impart required shape. These processes are

also known as mechanical working processes and are mainly classified into two major categories

i.e., hot working processes and cold working processes. In these processes, no material is

removed; however it is deformed and displaced using suitable stresses like compression,

tension, and shear or combined stresses to cause plastic deformation of the materials to

produce required shapes. Such processes lead to production of directly usable articles which

include kitchen utensils, rods, wires, rails, cold drink bottle caps, collapsible tubes etc. Some

of the important metal forming processes are:

Hot working Processes

(1) Forging, (2) Rolling, (3) Hot spinning, (4) Extrusion, (5) Hot drawing and (6) Hot spinning.

Cold working processes

(1) Cold forging, (2) Cold rolling, (3) Cold heading, (4) Cold drawing, (5) Wire drawing,

(6) Stretch forming, (7) Sheet metal working processes such as piercing, punching, lancing,

notching, coining, squeezing, deep drawing, bending etc.

1.7.4 Joining Processes

Many products observed in day-to-day life, are commonly made by putting many parts together

may be in subassembly. For example, the ball pen consists of a body, refill, barrel, cap, and

refill operating mechanism. All these parts are put together to form the product as a pen.

More than 800 parts are put together to make various subassemblies and final assembly of

car or aero-plane. A complete machine tool may also require to assemble more than 100 parts

in various sub assemble or final assembly. The process of putting the parts together to form

the product, which performs the desired function, is called assembly. An assemblage of parts

may require some parts to be joined together using various joining processes. But assembly

should not be confused with the joining process. Most of the products cannot be manufactured

as single unit they are manufactured as different components using one or more of the above

manufacturing processes, and these components are assembled to get the desired product.

Joining processes are widely used in fabrication and assembly work. In these process two or

more pieces of metal parts are joined together to produce desired shape and size of the

product. The joining processes are carried out by fusing, pressing, rubbing, riveting, screwing

or any other means of assembling. These processes are used for assembling metal parts and

in general fabrication work. Such requirements usually occur when several pieces are to be

joined together to fabricate a desired structure of products. These processes are used developing

steam or water-tight joints. Temporary, semi-permanent or permanent type of fastening to

make a good joint is generally created by these processes. Temporary joining of components

can be achieved by use of nuts, screws and bolts. Adhesives are also used to make temporary

joints. 

Some of the important and common joining processes are:

(1) Welding (plastic or fusion), (2) Brazing, (3) Soldering, (4) Riveting, (5) Screwing,

(6) Press fitting, (7) Sintering, (8) Adhesive bonding, (9) Shrink fitting, (10) Explosive welding,

(11) Diffusion welding, (12) Keys and cotters joints, (13) Coupling and (14) Nut and bolt joints.

1.7.5 Surface Finishing Processes

Surface finishing processes are utilized for imparting intended surface finish on the surface

of a job. By imparting a surface finishing process, dimension of part is not changed functionally;

6 Introduction to

 Basic Manufacturing Processes and Workshop Technology

either a very negligible amount of material is removed from the certain material is added to

the surface of the job. These processes should not be misunderstood as metal removing

processes in any case as they are primarily intended to provide a good surface finish or a

decorative or protective coating on to the metal surface. Surface cleaning process also called

as a surface finishing process. Some of the commonly used surface finishing processes are:

(1) Honing, (2) Lapping, (3) Super finishing, (4) Belt grinding, (5) Polishing, (6) Tumbling,

(7) Organic finishes, (8) Sanding, (9) deburring, (10) Electroplating, (11) Buffing, (12) Metal

spraying, (13) Painting, (14) Inorganic coating, (15) Anodizing, (16) Sheradising, (17) Parkerizing,

(18) Galvanizing, (19) Plastic coating, (20) Metallic coating, (21) Anodizing and (22) Sand blasting.

1.7.6 Processes Effecting Change in Properties

Processes effecting change in properties are generally employed to provide certain specific

properties to the metal work pieces for making them suitable for particular operations or use.

Some important material properties like hardening, softening and grain refinement are needed

to jobs and hence are imparted by heat treatment. Heat treatments affect the physical

properties and also make a marked change in the internal structure of the metal. Similarly

the metal forming processes effect on the physical properties of work pieces Similarly shot

peening process, imparts fatigue resistance to work pieces. A few such commonly used processes

are given as under:

(1) Annealing, (2) Normalising, (3) Hardening, (4) Case hardening, (5) Flame hardening,

(6) Tempering, (7) Shot peeing, (8) Grain refining and (9) Age hardening.

In addition, some allied manufacturing activities are also required to produce the finished

product such as measurement and assembly.

1.8. PRODUCT SIMPLIFICATION AND STANDARDISATION

The technique of simplification and standardization of product is closely inter-related that

leads to higher efficiency in production, better quality and reduced production cost. Simplification

is a process of determining limited number of grades, types and sizes of a components or

products or parts in order to achieve better quality control, minimize waste, simplify production

and, thus, reduce cost of production. By eliminating unnecessary varieties, sizes and designs,

simplification leads to manufacture identical components or products for interchangeability

and maintenance purposes of assembly of parts. Standardization is the important step towards

interchangeable manufacture, increased output and higher economy. The technique of

standardization comprises of determining optimal manufacturing processes, identifying the

best possible engineering material, and allied techniques for the manufacture of a product and

adhering to them very strictly so long as the better standards for all these are not identified.

Thus definite standards are set up for a specified product with respect to its quality, required

equipment, machinery, labor, material, process of manufacture and the cost of production.

The identified standard with time for a specified product should never be taken as final for

ever because improvement is always possible. It must accommodate the outcome of all the

new researches in the manufacturing areas in order to keep pace with increasing global

competition. Improvements over the existing standards in all respects should always be

welcomed. The different standards prevailing in different industries may be of the types of

managerial, design, manufacturing and technical needs. Managerial standards are applicable

to administrative functions within industry. These include the company policy, accounting

procedures, personnel policies, performance evaluation, control of expenditures, safety aspects,

security procedures and regulations, etc. where as design, manufacturing and technical standards

are needed for manufacturing concepts of the industry. These include design and manufacturing

techniques, practices, materials and parts, supplies, methods of testing, drafting method,

abbreviations and symbols, specifications and nomenclature, etc.

1.9 INSPECTION AND QUALITY CONTROL

A product is manufactured to perform desired functions. It must have a specified dimension

such as length, width, height, diameter and surface smoothness to perform or accomplish its

intended function. It means that each product requires a defined size, shape and other

characteristics as per the design specifications. For manufacturing the product to the specified

size, the dimensions should be measured and checked during and after the manufacturing

process. It involves measuring the size, smoothness and other features, in addition to their

checking. These activities are called measurement and inspection respectively.

In the era of globalization, every industry must pay sufficient attention towards maintaining

quality because it is another important requirement or function of a production unit. If a

manufacturing concern wants to survive for longer time and to maintain its reputation among

the users, it should under all condition apply enough efforts not only to keep up the standard

of quality of its products once established but to improve upon the same from time to time.

For this, every manufacturing concern must maintain a full-fledged inspection and quality

control department which inspects the product at different stages of its production. Vigilant

inspection of raw materials and products depends upon the entire process of standardization.

The production unit of manufacturing concern must produce identical products. However a

minor variation may be allowed to a predetermined amount in their finished dimensions of

the products. The two extremities of dimensions of the product are called limits. All the parts

of which the finished dimensions lie within these limits are acceptable parts. This facilitates

easy and quicker production, easy inspection, requires less skill on the part of worker and

accommodates a slight inaccuracy in the machine as well, resulting in an over all reduction

in the production cost of the part.

1.10 MECHANIZATION AND AUTOMATION

Mechanization means something is done or operated by machinery and not by hand.

Mechanization of the manufacturing means is milestone oriented trend towards minimizing

the human efforts to the extent of its possibility, by adopting mechanical and electrical means

or methods for automating the different manufacturing processes. Such a trend may be in the

area of automating and mechanizing the processes of material handling, loading and unloading

of components, actual operations performed on the job or transportation, etc. But, no feedback

is provided by the process, operation or machinery. Extension of mechanization of the production

process is termed as automation and it is controlled by a closed loop system in which feedback

is provided by the sensors. It controls the operations of different machines automatically. The

automatic control may be applied for some operations or for all the operations of a machine

or group of machines. Accordingly the machine will be known as semi-automatic or fully

automatic. The term was identified shortly after the World War II at the Ford Motor Company

to describe the automatic handling of materials and parts between the process operations.

The word ‘automation’ is derived from the Greek word automatos meaning self-acting.

Automation can also be defined as the process of following a predetermined sequence of

operations with little or no human intervention, using specialized equipment and devices that

perform and control the manufacturing process. Automation is a word that has many meanings

in the industry today. Automatic machines of all kinds existed long before the term automation

was conceived. But, it should be noted that all automatic machines do not come under the

category of automation. Automation is a technology concerned with the application mechanical,

electronic, and computer based systems to operate and control production.

Every machine should involve some automation, may be to a lesser degree or to a higher

extent to which is mainly governed by economic considerations. Automation means a system

in which many or all of the processes in the production, movement, and inspection of parts

and material are performed under control by the self-operating devices called controllers. This

implies that the essential elements of automation comprise of mechanization, sensing, feedback,

and control devices. The reasons why one should go for automation are:

1. Increased productivity

2. Reduced cost of labor and dependence on labor shortages

3. Improved quality

4. Reduced in-process inventory

5. Reduced manufacturing time

6. Reduced dependence on operator skills

7. Increased safety or reduced risk of humans.

Automation can be classified into three categories, viz.

1. Fixed automation

2. Programmable automation

3. Flexible automation.

1.10.1 Fixed Automation

It is also known as hard automation which is utilized to produce a standardized product such

as gears, nuts and bolts, etc. Even though the operating conditions can be changed, fixed

automation is used for very large quantity production of one or few marginally different

components. Highly specialized tools, devices, equipment, special purpose machine tools, are

utilized to produce a product or a component of a product very efficiently and at high production

rates with as low unit costs as possible relative to other alternative methods of manufacturing.

Cement Manufacturing Process

1.10.2 Programmable Automation

In programmable automation, one can change the design of the product or even change the

product by changing the program. Such technique is highly useful for the low quantity

production of large number of different components. The equipments used for the manufacturing

are designed to be flexible or programmable. The production normally carried out in batches.

1.10.3 Flexible Automation

There is a third category possible between fixed automation and programmable automation

that is called flexible automation using Computer Aided Design (CAD) and Computer Aided

Manufacturing (CAD/CAM) activities. This is also called as flexible manufacturing system

(FMS). It allows producing different products on the same equipment in any order or mix. One

important example of programmable automation, in discrete manufacturing, is numerical

control. Robot is another example of programmable automation. Robot being integral part of 

FMS and Computer Integrated Manufacturing (CIM) system can do a large number of

manufacturing tasks for replacing the human labor.

In the present globalized manufacturing scenario, the advancements of hardware and

software concepts using the mechatronics for fast mechanization and automation of

manufacturing processes have become essential to be incorporated in the manufacturing

areas.

1.11 COMPUTER AIDED MANUFACTURING (CAM)

The computer aided manufacturing implies manufacturing itself, aided or controlled by

computers. In a wider sense, it denotes all the activities in the manufacturing environment

like use of computers in inventory control, project management, material requirement planning,

data acquisition, testing and quality control. Improved reliability in view of the better

manufacturing methods and controls at the manufacturing stage, the products thus

manufactured as well as of the manufacturing system would be highly reliable. Since most

of the components of a CAM system would include integrated diagnostics and monitoring

facilities, they would require less maintenance compared to the conventional manufacturing

methods. Because of the Computer Numerical Control (CNC) machines used in production

and the part programs being made by the stored geometry from the design stage, the scrap

level would be reduced to the minimum possible and almost no rework would be necessary.

Since all the information and controlling functions are attempted with the help of the computer,

a better management control on the manufacturing activity is possible. All the above advantages

when properly translated, would mean a lower total cost and consequently, higher final

earnings. Therefore any manufacturing activity in a production unit (job shop production or

mass scale manufacture) can get the benefits of Computer Aided Manufacturing. However,

better results can be obtained when the design and manufacturing activities are properly

integrated. Also, when there is a large variety of products or minor changes required in the

existing production programme, CAM can easily manage the necessary changes or alterations.

Following are the main advantages of using CAM.

1. Greater design freedom

Any changes that are required in design can be incorporated at any design stage without

worrying about any delays, since there would hardly be any in an integrated CAM environment.

2. Increased productivity

In view of the fact that the total manufacturing activity is completely organized through

the computer, it would be possible to increase the productivity of the plant.

3. Greater operating flexibility

CAM enhances the flexibility in manufacturing methods and changing of product lines.

4. Shorter lead time

Lead times in manufacturing would be greatly reduced.

The integration of CAD and CAM systems is called Computer Integrated Manufacturing

(CIM) system. The role of computer in manufacturing may be in two major groups namely

computer monitoring and control of the manufacturing process and manufacturing support

applications, which deal essentially with the preparations for act of manufacturing and post

manufacture operations. Computers are used in controlling machine tools and other material

handling equipments.

10 Introduction to Basic Manufacturing Processes and Workshop Technology

1.12 KINDS OF PRODUCTION SYSTEMS

The choice of production type dictates the machine requirements, organizational system to

a large extent, layout planning and inventory subsystems. Three main types of production are

job, batch and flow or process production. The simplest way is to classify based on production

and processes by lot size, namely single unit production, small lot production, moderate lot

production, large lot production, and continuous production. The second classification comprises

three categories, namely small size production of a large variety of products, medium-scale

production of a limited range of products, and a large-scale production of a small variety of

products. Obviously, this method is related to the number of product types and production lot

sizes, and is an effective means of analyzing modern production management. The third

classification is related to the size of the production system expressed through the number

of employees or the amount of fixed assets involved, namely small production unit employing

less than 30 employees, medium-small having 30 to 300 employees, medium with 301 to 2,000

employees and large with 2001 to 15,000 employees, and a giant corporation employing more

than 15,000 employees

Job shop production deals the manufacture of very small lots, often of single jobs. This

may be required in special situations for the purpose of proving a design, making prototypes,

in tool making or for special purpose applications. In view of the very small lot, no special

purpose machines or tooling can be economically justified. Hence, the manufacturing has to

be carried on with the general purpose machines and tooling, which is a very lengthy and

often an error prone process.

SUGAR MANUFACTURING PROCESS

1.13 MANUFACTURING SYSTEM

Manufacturing basically implies making of goods or articles and providing services to meet

the needs of mankind. It creates value by useful application of physical and mental-labor in

the process. It is a chain of interrelated activities of production process and other support

services activities of an manufacturing environment such as order processing, product design,

design and manufacturing of tools, die, mould, jigs, fixtures and gauges, selection of material,

planning, managing and maintaining control of the processes, production, and reliable quality

of processed product in a systematic and sequential manner with proper coordination,

cooperation and integration of the whole manufacturing system that will lead to economical

production and effective marketing of proposed product in the minimum possible time. It is,

therefore, evident that manufacturing today is not a one man activity as it was in the initial

stages, wherein all the physical and mental inputs were applied by a single craftsman. These

days it has become totally a team work which consists of several components interacting

together in a dynamic manner. This entire domain of manufacturing is known as Manufacturing

System, which takes the required inputs and delivers the products for the customer. It is,

therefore, evident that manufacturing today is not a one man activity as it was in the

preliminary stages, wherein all the physical and mental inputs were provided by a single

workman. Today it is a team work which consists of several components interacting together

in a dynamic manner to provide the required physical and mental inputs at appropriate stages

to impart desired results. This entire domain of manufacturing is known as Manufacturing

System, which takes the required inputs and delivers the products for the customer.

Manufacturing system requires a large number of activities, few independent and rests

mostly interrelated. The manufacturing activities in a manufacturing system jointly contribute

towards economic and qualitatively acceptable production of desired articles in minimum

possible time. As per the need of the customer, the products are identified and their demands

are determined roughly for market forecast by considering present and future competition.

Products that may render the desired service over its expected life satisfactorily as per

requirement of customers are identified in terms of their demand, conceived and developed

for securing orders by the sales department. Once the product design activity is over and the

design finalized from all angles, functional, aesthetic, material selection, safety, economy, etc.,

it is followed by preparation of production drawings of the product assembly and its components

including a bill of materials. This is the stage where a make or buy decision has to be taken

in order to decide as to which components are to be bought from outside and which are to

be manufactured within the concern. It is followed by process planning i.e. selection of the

best process and an its parameters, design of jigs, fixtures and dies, selection of tooling,

programming of tool path as per need, for the components to be produced in-house. An

important activity in process planning within the organization is also to involve latest research

and development findings, through which the old processes are improved and new one’s are

developed in order to ensure better quality and economic production. The interaction of

different manufacturing activities in a manufacturing system can also be further enhanced by

the use of computer and hence leading CIM. The real manufacturing or production activity

is carried out on the shop. The layout of the shop floor has a significant influence on the tools

required to be coordinated in order to an economical and high quality production of various

components. It should be such that it ensures timely movement of raw materials, dies

moulds, jigs and fixtures and finished components, adequate safety to men, material and

machinery, enables timely inspection and quality control and minimizes handling time for

material and parts, etc. During actual manufacturing a lot of different activities are called

management function. Various engineers play an important role in the organizational function

of a manufacturing concern. They are required to ensure proper movement of the material,

tools and parts as per their specialized jobs in industry.

1.14 PRODUCT DEVELOPMENT

A product development has to go through the following concepts of product engineering which

are given as under.

Product functions

1. Product specifications

2. Conceptual design

3. Ergonomics and aesthetics

4. Standards

5. Detailed design

6. Prototype development

7. Testing

8. Simulation

9. Design for manufacture

10. Design for assembly

11. Drafting.

Now let us consider the manufacturing environment of a given product. How does the

product idea originate. Market forces determine the need for a product. Expertise on the part

12 Introduction to Basic Manufacturing Processes and Workshop Technology

of the company estimates the likely demand and probable profitability and decides on the best

mode of designing and manufacturing the desired product.

Traditionally, after the design of the product, the part prints are released for production.

The production engineering section first considers the feasibility of production of the product.

Having ascertained its feasibility, process planning is done so that the product can be

manufactured at the lowest possible cost. Any redesign that is needed for improving the

producibility of the product without compromising on its functionality would have to be done

at this stage. Having decided on the process plan for manufacture, the necessary actions are

undertaken for its implementation. These are making of the tooling required, acquiring of

new equipment or tools, procurement of the raw materials, releasing of the detailed operational

instructions to the shop floor, etc. The conventional methods of manufacturing are generally

inefficient and dependent on operator skills. These methods consume more time, have high

costs, and give poor accuracy.

Product design is an activity which needs to be well organized and take into account all

influences that are likely to be responsible for the success of the product under development.

A product here means a single component which is functional in itself like a wrench or an

assembly of a large number of components all of which will contribute to the functioning of

the part such as an automobile engine. The complexity of the design process certainly increases

with the number and diversity of components present in the final part. Since there are such

a large number of influencing factors, it is impossible to specify a design procedure for each

component. Here we are interested in developing some common guidelines and steps that are

needed to proceed for a successful product design and manufacture.

From the above discussion it can inferred that products can be manufactured by more

than one processes. Therefore several alternatives for manufacturing products are available.

The selection of a suitable process is depended upon the factors including volume of production,

properties of the components, technical viability of process, economy involved and desired

quality. Based upon the volume of product the manufacturing activity can be identified in

terms of job shop production, batch production and mass production

1.15 COMPUTERS IN MANUFACTURING INDUSTRIES

Factors governing increased productivity, more accuracy, greater flexibility of shapes, and

reduced manufacturing costs are forcing the manufacturing concerns to use computers in

design, manufacturing and other allied functions of industrial activities. With an increase in

the need for quality manufacturing along with the factors such as short lead time and short

product lives and increasing consumer awareness as regards the quality of the product, it is

becoming increasingly important for the manufacturers to initiate steps to achieve all these.

The developments in microelectronics in the recent past have made higher computational

ability available at a low cost. Therefore, it becomes imperative that manufacturing takes

advantage of the availability of low cost and also using yet more powerful computers. Computers

have been in use in manufacturing industries since 1960. Initially they were in use only in

supportive functions such as inventory control purchase accounting, etc. In to day’s time,

computer applications have progressed considerably in all areas of design and manufacturing

involving CAD and CAM. This however needs to be emphasized that all the benefits of CAD

and CAM can be achieved only if these two important functions are effectively interfaced. This

interfacing is known as CAD/CAM. It involves the flow of information in both the directions.

With the result the parts and assemblies are designed keeping in view the limitations and

capabilities of the processes and materials. Consequently, newer and superior products can be

produced more quickly and at lower costs.

Today, computers are not only used in manufacturing but they play also an important

role in all manufacturing related activities such as business or financial management, factory

level production management, CIM technologies, CAD, feature and solid modelling, and

CAM, manufacturing information, manufacturing system. The important sub-activities of

industrial environment have been identified to support with the use of computer in the

manufacturing industries.

 These are given as under:

1. Business or Financial Management

1. Costing

2. Sales and Marketing

3. Purchase Order Control

4. Vendors

5. Subcontracting

6. Personnel.

2. Factory Level Production management

1. Planning

2. Production Management

3. Manufacturing production scheduling (MPS)

4. Material requirement planning (MRP)

5. Just in time (JIT)

6. Bill of Materials

7. Capacity Planning

8. Inventory Control.

3. CIM Technologies

1. Computer Networks

2. System Design and Analysis

3. Distributed Processing

4. Database Management Manufacturing

5. Modelling and Simulation

6. Expert Systems

7. Quality Engineering.

4. Computer Aided Design (CAD)

This area is also known Feature and Solid Modelling

1. Variational and Parametric

2. Modelling

3. Computer Graphics

4. Graphic Standards

14 Introduction to Basic Manufacturing Processes and Workshop Technology

5. Inter-graphics exchange specification (IGES)

6. Data exchange file (DXF)

7. Manufacturing Robot Programming

8. Design Analyses Tools

9. Programming

10. Finite element modelling (FEM)

11. Finite element analysis (FEA)

12. Simulation

13. Mechanisms

14. Test and Analysis

15. Design Tools Mechanical

16. Hydraulic, Electronics, etc.

5. Computer Aided Manufacturing (CAM)

This involves activities related to manufacturing information and manufacturing system

which are given as under—

Manufacturing Information

1. Generation

2. Process Planning

3. Production Planning

4. Computer numerical control (CNC) part Programming

5. Robot Programming

6. Coordinate measuring machine (CMM) Programming.

Manufacturing System

1. Production Activity

2. Machining

3. Assembly

4. Material Handling

5. Storage

6. Production Control

7. Loading

8. Scheduling

9. Balancing

10. Capacity Planning

11. Quality Control.

One of the most important components for getting various benefits associated with

computer applications in manufacturing is the common databases associated with all aspects

of manufacturing. In fact, all the modules in the CAM would actually be sharing the database

created in any module. Any module would be able to modify the data as required for that

particular application. This approach reduces the work involved in maintaining the product

database and at the same time includes the latest modifications for any aspect related to

manufacturing. In contrast to the common database approach, it is possible that sometimes

individual modules in the production aspects may be taken from different vendors. In this

case care need to be taken that information is properly transmitted between the modules and

the data updating in all the modules takes place properly and at the right time. Some of above

mentioned manufacturing activities are controlled by computers. These activities are commonly

identified using the following terms.

1. Computer Aided Design (CAD)

2. Computer Aided Engineering (CAE)

3. Computer Aided Design And Drafting (CADD)

4. Computer Aided Process Planning (CAPP)

5. Computer Aided Tool Design (CATD)

6. Computer Aided Manufacturing (CAM)

7. Computer Aided Numerical Control (NC) Part Programming

8. Computer Aided Scheduling

9. Computer Aided Material Requirement Planning, etc.

10. Flexible Manufacturing System (FMS)

11. Group Technology (GT)

12. Computer aided Testing (CAT).

1.16 QUESTIONS

1. How do you classify the manufacturing processes?

2. Distinguish between ‘primary’ and ‘secondary’ processes?

3. Discuss primary shaping processes. Give also a brief account of the primary shaping processes.

4. Explain the secondary or machining processes. Give also a brief account of these processes.

5. Describe and name the types of joining processes, surface finishing operations and the

processes employed for changing the properties of manufactured components.

6. Write a short note on assembly process.

7. Write short notes on:

(a) Simplification, (b) Standardization, (c) Inspection and quality control, (d) Interchangeability,

(e) Mechanization, (f) Automation, (g) Mechatronics.

8. What do you understand from the terms Manufacturing, Process plan, Maintenance?

9. Explain the term ‘Manufacturing System’. What all it encompasses and how an integrated

approach is made for making an economical and competitive product? Describe how the use

of computers helps in increasing manufacturing efficiency.

10. Explain the terms CAD, CAM, NC, CAD/CAM, MRP, FMS and CIM?

11. Write a short note on Group Technology?

12. Explain the influence exerted by the computers on the manufacturing scene?

13. Briefly explain the conventional process of the product cycle in the conventional manufacturing

environment.

16 Introduction to Basic Manufacturing Processes and Workshop Technology

14. What are the functions that get benefited by the use of computers in design and manufacturing

functions?

15. Briefly explain the various automation aspects used in manufacturing activities.

16. Write down the advantages which can be gained by the adoption of CAD?

17. Describe the advantages which can be gained by the adoption of CAM?

18. Write down the advantages which can be gained by the adoption of FMS?

19. Write down the advantages which can be gained by the adoption of manufacturing production

scheduling (MPS)?

20. Write down the advantages which can be gained by the adoption of Material Requirement

Planning (MRP)?

21. Explain the main advantages which can be gained by the adoption of CIM

Click Below Video

Fundamental of Manufacturing Process

Click Below LinkText Book of Manufacturing Process


Download
Basic Manufacturing Process

@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@

Next Issue

RENEWABLE ENERGY

Nuclear Power Plant

Flow Chart

Click Video-Nuclear Power Plant

Click Video-Nuclear Power Plant Safety