Manufacturing

# 1.2 The manufacturing process

Let's first consider what is meant by the term 'manufacturing'. You probably have a general feeling for it already. The word 'manufacture' derives from two Latin words: manu (meaning 'by hand') and factum (meaning 'made'). We generally think of manufacturing taking place in a 'factory': an abbreviated form of the eighteenth-century word 'manufactory', which came from the same source. So manufacturing applies to artificial products: it does not apply to natural products which grow on the surface of our planet, can be found in the Earth's crust or exist in the atmosphere. On the contrary, such products are the source of what we call natural or physical resources and which are the starting point for all manufactured items.

Such resources are also often called raw materials, but this term is more generally used to describe the input for any manufacturing process. Similarly the term product can be used to describe the output of any manufacturing process. So, crudely, a raw material is anything that can be turned into something else and a product is anything for which there is a market. To a mining company, iron ore is a product: it mines its raw material directly from the Earth's mineral resources. An iron producer operating a blast furnace uses this iron ore as a raw material and smelts it into a product, pig iron, in a blast furnace. This pig iron is either solidified for later remelting in engineering foundries or else kept molten and passed on to steelworks. The output product from the blast furnace thus becomes the main raw material for the foundry or the steelmaker. The steelmaker turns the raw iron into steel sheet or bar. These steel products then go on to become the raw material for other manufacturers producing the enormous variety of useful products we see all around us; motor vehicles, domestic white goods (washing machines, refrigerators, etc.), wire coat hangers, pins, paper clips, and every conceivable item which contains steel. Even a tiny spring or a nut and bolt.

Such processing chains are an integral part of the manufacturing route for practically everything our society demands. It matters little whether it be nylon stockings, a plastic moulding for a roof gutter, a child's toy or a tube of adhesive (all of which all start out from oil), or a high voltage electrical insulator for overhead power lines, a spark plug, or a grinding wheel (all of which start out from the same ceramic material, alumina). Every manufacturing chain can be traced back to some natural raw material which has to be put through several, often many, different processes before the desired product is ready for sale in its final marketplace.

Figure 1 shows the raw materials that form part of the manufacturing process sequence needed to produce domestic copper plumbing fittings.

Figure 1 Copper – raw material or product?
Figure 1
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The ore is first mined and then smelted into copper, which is usually supplied as rolled bar. Finally the plumbing fittings are produced by combinations of the processes of extrusion and forming (which we will come back to later in this course). Of course, unless you are a DIY enthusiast, you may not even think of the plumbing fitting as the product you use. Central heating parts are bought by the plumber. But for each part of this chain, every person or organisation involved up until the final user will consider themselves to have suppliers of raw materials and consumers of their products.

## Exercise 1

All products require raw materials in some form. Identify the raw materials for the following processes: think in terms of the input materials to the process, rather than the original resources.

1. The manufacture of ammonia.

2. The manufacture of ballpoint pens.

3. The manufacture of copper pipe for central heating systems.

4. The manufacture of loaves of sliced white bread.

5. The manufacture of personal computers.

6. The manufacture of Open University course blocks.

## Discussion

Some raw materials are easier to identify than others.

1. Nitrogen and hydrogen.

2. Up to four different sorts of plastic for the barrel, lid, ink tube and plug; brass for the ball holder, tungsten for the ball.

3. Copper, probably as ingots that can be drawn into rods and then into pipes.

4. Flour, water, yeast (plus additives such as vitamins and so-called 'improvers'), plastic film or waxed paper for the wrapping, printing inks, adhesive tape for the closure.

5. Manufacture of PCs is very much an assembly job, so the raw materials are all the internal components, the housings, the mechanical connectors, the connecting leads, etc.

6. Paper, card, staples (or adhesive) and inks, obviously, but do you count the intellectual and creative efforts as inputs?

OpenLearn - Manufacturing
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