A brief consideration of the relationship between production tasks, design requirements, economic viability and quality aspects.

After the mechanical production of a workpiece, engineers, designers, production directors, salespeople and buyers must decide "What happens to the surface?" If a decorative component is involved, everyone is initially in agreement: "It needs to look good at an affordable price!" But what tasks result from this and what options are available? Many methods of decorative surface finishing and coating are currently used in metalworking: mass-finishing, grinding, brushing, smoothing/polishing, electro-plating, powder-coating, painting, shot-blasting with diverse media and others. So there is no shortage of options. But how and by what criteria can we decide what to do?

Decorative is defined in the dictionary as follows: ...ornamental, effective; serving to make a person or thing more attractive ...That sounds good to begin with, but elicits a number of questions on closer consideration. What makes a surface effective? How can we make something more attractive? Who decides what looks attractive and who is ultimately prepared to pay for this? What exactly is "more attractive": A polished surface? A painted one? A chrome-plated one? A shot-blast one? A brushed one? A gold-plated one? Depending on the material, sector, application or trend, numerous variants may come into play. These must be evaluated in regard to feasibility and profitability, but above all an answer needs to be found to the question: What do we actually want or what might the customer like?

In the past, there were clear trends such as fashion, but those days are long gone. If you ask four people about a product design nowadays, you will get four different opinions, even though all of them live in similar social circumstances. From "over-the-top" or "interesting" through to "magnificent" - anything is possible. No matter whether the surface of a mobile phone, a car tire or an item of jewellery, the way the decorative effect is evaluated can be very different. This has led to a situation today where many products are offered with a wide range of different surfaces. Even if not always customised, end customers have the option of a wider choice, letting them feel they can individually shape their product. In terms of production technology, this luxury must be able to be reproduced and implemented on a solid economic basis. Reliable and feasible methods with manageable risks and calculable expense therefore have to be found.

An example can be cited to illustrate what important factors have to be answered: When manufacturing candlesticks which we later wish to sell to end customers at Harrods for a lot of money, there are two basic options:

1. The manufacturer invests considerable money in high-quality base material (stainless steel, brass...) and has manageable expenditure to give the surface a decorative finish after machining, because the surface already exhibits a good structure on account of the material anyway.

2. The manufacturer invests as little as possible in the base material (plastic, zinc die casting...), but subsequently invests a great deal of money to improve the lower-quality material by means of a complex decorative surface.

Both variants have their merits and it is the task of everyone involved to weigh up what strategy makes sense. The critical consumer might well think twice about what is under an electroplated surface and could be horrified if that material is plastic or the cheapest cast metal. Frequently the sums do not add up in variant 2. If elaborate and multistage refinement processes are so complex that defective production results, the manufacturing costs for variant 2 often exceed those for variant 1.

Looking at all the different aspects, it quickly becomes clear that decorative surfaces are not to be underestimated. As early as the design phase, it is necessary to think long and hard about the surface finishing options and associated tasks with the aim of planning effectively. Tremendous frustration always entails if construction, production and design are inadequately coordinated and procurement suddenly discovers that a product can no longer be manufactured economically.

It is therefore a communicative task that needs to be resolved in sufficient time to avoid unpleasant consequences later. If all goes well with the surface, all will go well with the customer!

Good Vibrations by Dirk Gather Contributing Editor MFN and General Manager of GZO GmbH, Germany

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