Formative years

Citation

Loughlin, C. (2001), "Formative years", Assembly Automation, Vol. 21 No. 4. https://doi.org/10.1108/aa.2001.033021daa.001

Formative years

Formative years

If you want to form a particular shape then several options are available to you. You can inject material into a moulding, machine a block of the chosen material, bend or distort an existing shape into the shape you want, use rapid prototype techniques to form the part in layers, or simply join other shapes together by gluing, welding or fastening.

Whichever of these methods you choose will be largely driven by economic factors. Injection moulding can be very cheap, but only if you can recover the high cost of the tooling over a great many units; machining is always expensive and is wasteful of raw materials. Bending is cheap but limited in its application, and forming using techniques such a spinning or the "dieless forming" (Kochan, 2001) is interesting but too slow for high volume manufacture. Rapid prototyping is improving all the time but is still reasonably slow and expensive and limited in choice of material, and joining assumes you have the component parts in the first place and a bullet-proof way of fixing them together.

All of the above techniques have been around for thousands of years, even rapid prototyping is just a high-tech version of papier-mâché. Of course we have become better at it and the materials and end products have improved, but the fundamental operations are unchanged.

Given that all of the above have various drawbacks, wouldn't it be nice if someone could come up with something better?

If you want to make a lot of anything you have two options: either have a method that makes them one at a time but very quickly, or a method that makes several in parallel but at a proportionately slower rate.

Nature has some pretty impressive ways of making a lot of something. If ducks are needed then two ducks produce six ducks which produce 18 ducks, and so on until the duck warehouse is full. Bacteria are even more impressive, with multiplication times in the order of seconds rather than months. Both of the above produce clones that are to all intents and purposes identical.

Wouldn't it be useful if we could have plastic or metal "DNA" and grow our shapes? Anyone who has ever grown a copper sulphate crystal in a saturated solution will have seen the effect of molecules bonding together in pre-defined orientations, but without the missing life force of DNA the shapes produced are rather limited.

I have no solutions to offer you, but only the thought that there must be a better way. Perhaps nanotechnology will give us the structural DNA desired above, or perhaps there is no alternative to the continued improvement of our existing practices. My money is on rapid prototyping but with significantly improved materials and much faster layering techniques. What do you think?

Clive Loughlin

Reference

Kochan, A. (2001), "Dieless forming", Assembly Automation, Vol. 21 No. 4, pp. 321-2.