Plastic processing technologies extrusion

There are only a few technologies that in the process of their development have found such an extensive range of appUcation as that of extrusion technology. Its origin was in structural ceramics, yet nowadays the extruder is employed in such diverse industries as the plastics industry, the chemical and its related industries, foodstuffs industry, fodder concentrate industry, etc., both for extrusion as well as for preparation and other process technologies. 

Extruders are thermomechanical mixers that consist of one or more screws in a barrel. Extrusion technology was initially applied in the plastics processing area, and after years of development and application, it has become a well-elaborated tool with technical solutions available for other fields like the pharmaceutical industry (for the production of controlled-release formulations). 

Schott, N. R., Plastics Extrusion Processing Technology Seminar, University of Lowell, 1988. 

Polypropylene (PP) is a high-volume, low-cost plastic first commercialized in 1959 and produced by many companies. It is unusual in that it is processed in large quantities by all four major fabrication processes moulding, extrusion, film, and fibre technology. Major engineering plka-tions include pipe and automobile parts. It does not absorb water. 

Goldsworthy, W. B. (1979), New technology for continuous reinforced plastics processing It s called Pulforming , and it permits extrusion of variable cross-section parts, curves, or both . Modem Plastics, 56, 82-83. 

Polycarbonates can be processed with common plastic manufacturing processes. Technologies like injection molding, extrusion and casting bear good shaping opportunities. In comparison to transparent polymers like PMMA or PET, polycarbonates show extraordinary transparency, strength and endurance. 

Extrusion blow molding is by far the most important method, with reference to both the size of the product and the amount of plastics processed. With today s technology, pieces with volumes from 1 cm to 10 m can be blown. This enormous size range does include packaging, storage, and transport containers, but it mainly... 

The Optifoam process is developed by the Institute of Plastics Processing (IKV) in Aachen, Germany. The technology, which is available for injection molding [8] and extrusion [9], introduces the SCF into polymer at the nozzle. For extrusion, this occurs constantly and with injection molding, the SCF is delivered during the injection stroke. The Optifoam nozzle delivers the SCF to the passing polymer via a sintered metal coaxial device (Fig. 11.9). 

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