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Introduction to Basic Manufacturing Processes and ... - always yours

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<strong>Introduction</strong> 7<br />

security procedures <strong>and</strong> regulations, etc. where as design, manufacturing <strong>and</strong> technical st<strong>and</strong>ards<br />

are needed for manufacturing concepts of the industry. These include design <strong>and</strong> manufacturing<br />

techniques, practices, materials <strong>and</strong> parts, supplies, methods of testing, drafting method,<br />

abbreviations <strong>and</strong> symbols, specifications <strong>and</strong> nomenclature, etc.<br />

1.9 INSPECTION AND QUALITY CONTROL<br />

A product is manufactured <strong>to</strong> perform desired functions. It must have a specified dimension<br />

such as length, width, height, diameter <strong>and</strong> surface smoothness <strong>to</strong> perform or accomplish its<br />

intended function. It means that each product requires a defined size, shape <strong>and</strong> other<br />

characteristics as per the design specifications. For manufacturing the product <strong>to</strong> the specified<br />

size, the dimensions should be measured <strong>and</strong> checked during <strong>and</strong> after the manufacturing<br />

process. It involves measuring the size, smoothness <strong>and</strong> other features, in addition <strong>to</strong> their<br />

checking. These activities are called measurement <strong>and</strong> inspection respectively.<br />

In the era of globalization, every industry must pay sufficient attention <strong>to</strong>wards maintaining<br />

quality because it is another important requirement or function of a production unit. If a<br />

manufacturing concern wants <strong>to</strong> survive for longer time <strong>and</strong> <strong>to</strong> maintain its reputation among<br />

the users, it should under all condition apply enough efforts not only <strong>to</strong> keep up the st<strong>and</strong>ard<br />

of quality of its products once established but <strong>to</strong> improve upon the same from time <strong>to</strong> time.<br />

For this, every manufacturing concern must maintain a full-fledged inspection <strong>and</strong> quality<br />

control department which inspects the product at different stages of its production. Vigilant<br />

inspection of raw materials <strong>and</strong> products depends upon the entire process of st<strong>and</strong>ardization.<br />

The production unit of manufacturing concern must produce identical products. However a<br />

minor variation may be allowed <strong>to</strong> a predetermined amount in their finished dimensions of<br />

the products. The two extremities of dimensions of the product are called limits. All the parts<br />

of which the finished dimensions lie within these limits are acceptable parts. This facilitates<br />

easy <strong>and</strong> quicker production, easy inspection, requires less skill on the part of worker <strong>and</strong><br />

accommodates a slight inaccuracy in the machine as well, resulting in an over all reduction<br />

in the production cost of the part.<br />

1.10 MECHANIZATION AND AUTOMATION<br />

Mechanization means something is done or operated by machinery <strong>and</strong> not by h<strong>and</strong>.<br />

Mechanization of the manufacturing means is miles<strong>to</strong>ne oriented trend <strong>to</strong>wards minimizing<br />

the human efforts <strong>to</strong> the extent of its possibility, by adopting mechanical <strong>and</strong> electrical means<br />

or methods for au<strong>to</strong>mating the different manufacturing processes. Such a trend may be in the<br />

area of au<strong>to</strong>mating <strong>and</strong> mechanizing the processes of material h<strong>and</strong>ling, loading <strong>and</strong> unloading<br />

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

is provided by the process, operation or machinery. Extension of mechanization of the production<br />

process is termed as au<strong>to</strong>mation <strong>and</strong> it is controlled by a closed loop system in which feedback<br />

is provided by the sensors. It controls the operations of different machines au<strong>to</strong>matically. The<br />

au<strong>to</strong>matic control may be applied for some operations or for all the operations of a machine<br />

or group of machines. Accordingly the machine will be known as semi-au<strong>to</strong>matic or fully<br />

au<strong>to</strong>matic. The term was identified shortly after the World War II at the Ford Mo<strong>to</strong>r Company<br />

<strong>to</strong> describe the au<strong>to</strong>matic h<strong>and</strong>ling of materials <strong>and</strong> parts between the process operations.<br />

The word ‘au<strong>to</strong>mation’ is derived from the Greek word au<strong>to</strong>ma<strong>to</strong>s meaning self-acting.<br />

Au<strong>to</strong>mation can also be defined as the process of following a predetermined sequence of<br />

operations with little or no human intervention, using specialized equipment <strong>and</strong> devices that

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