PROGRESS IN POLYMER PROCESSING

The plastics industry shows undiminishing expansion. On the global scale it is the fastest growing industry. Even when, at the turn of the century, the consumption of commodity resins in the advanced countries levels off, the large capital investments in the developing countries will more than compensate for the local slowdown. Production of commodity polymers during the next five years is expected to grow at an annual rate of: PVC 2.8%, PS 3.2%, LDPE 3.2%, HDPE 4.7% and LLDPE 9%. For the engineering resins the rates are higher: POM 5.1%, PA 6.1%, MPPE 10.1%, PC 10.4% and Polyesters 13.5%. The most rapidly expanding are the multiphase polymeric materials: alloys, blends and composites whose growth rate will be about 14% per annum. In recent years the plastics industry experienced evolutionary rather than revolutionary growth. This is apparent for all factors. There are no new outstanding polymers but a continuous improvement and maturing of both production and utilization of the 5–10 years old resins, such as PEEK or LCP. In commodity resins the advances are achieved in the type of catalysts which allow synthesis of newer and better grades (e.g. flexomers). Similarly the processing equipment undergoes a gradual improvement, increased automatization and loop control as well as growth of size; injection of 100 kg per shot is a reality. The true advances are made in compounding and die design. For example, using the lubricated die one can extrude materials, e.g. UHMWPE, by the process which more resembles metal forming than classical plastics extrusion.