| 摘要 |
Foamed plastics material (6) is extruded through a die head with an arrangement immediately outside the die gap for cooling the surface of the extrudate to prevent the foaming thereof. The normal die gap (8a) may be followed by a cooling house which delivers cold gas to the surface of the extrudate. The cooling housing is insulated from the die lips by insulating material 21. Materials are PVC, polystyrene, polyethylene, polypropylene, etc. Production of foamed plastics with an integral skin like covering which is molecularly an integral part of the underlying foamed resin. |
