Both co-rotating and counter-rotating twin-screw extruders have compounded vinyls and made vinyl end products. Because their melt moduli can be high and their heat stability can be low vinyls are generally processed at lower screw speeds than polyolefins, for example. When classical twin-screw extruders process vinyls at high screw speeds they tend to generate unwanted viscous heating, more than they do with lower viscosity polymers. This is partly the fault of the classical screws discipline which has been generally available. This paper introduces approaches to making twin extruders do their jobs more efficiently to permit higher screw speeds and throughputs, whether in compounding, finished product extrusion or a mixture of the two.
| Number of Pages : | 9 |
| Published : | 06/01/1997 |
