Mineral fillers are widely used in the plastics industry to enhance polymer properties and reduce ingredient costs. However, as the author of this paper demonstrates, over-use of these fillers can be a false economy. The volume cost of a raw material input is the purchase cost of a unit volume of the material. It is extremely important to understand the volume cost of polymers and their additives as this plays a key role in their selection for a particular application. Price is one of the first characteristics of a polymer that a designer looks at before specifying it as the material of construction. Prices vary from time to time, sometimes wildly, but tend to maintain their proportion in respect to other polymers. Recent prices of the commodity thermoplastics, using average prices, is shown in Table 1 of this article. While it would appear that UPVC is by far the cheapest polymer, the question is: Why does it have such limited applications in, for example, moulded products? These, and other questions are answered in this article.
