Apparatus for extrusion of thermoplastic handrail

摘要

A method and apparatus for extrusion of an article is provided. A die assembly can apply flows of thermoplastic material to an array of reinforcing cables to form a composite extrusion. A slider fabric can be bonded to one side of the composite extrusion. After exiting the die assembly, the slider fabric can act to support the extrudate as it passes along an elongate mandrel, which can cause the base of the slider fabric to change shape from a flat profile to the final internal profile of the article. The extruded article can then be cooled to solidify the material. The die can include cooling for the slider fabric and means for promoting penetration of the thermoplastic into reinforcing cables.

主权项

1. A die assembly for extruding an article comprising a thermoplastic polymer and a stretch inhibitor, the die assembly comprising:
a first inlet for a first thermoplastic polymer; an entrance for the stretch inhibitor; a first combining zone wherein the first thermoplastic supplied above and below the stretch inhibitor, whereby the stretch inhibitor is embedded in the first thermoplastic polymer; an outlet; an element of restricted flow cross-section located upstream from the outlet relative to the movement of the article and the stretch inhibitor through which the first thermoplastic polymer and the stretch inhibitor pass, whereby the element of restricted flow cross-section generates back pressure to promote penetration of the first thermoplastic polymer into the stretch inhibitor; a second combining zone and a second inlet for a second thermoplastic polymer located downstream from the element of restricted flow cross-section, wherein in the second combining zone, the second thermoplastic polymer is combined with the flow of the first thermoplastic polymer and the stretch inhibitor, on one side thereof; an inlet slot for an elongate web of fabric, for bonding to one side of the thermoplastic polymer; and an extrudate support block, the die assembly being configured so that the fabric passes over the extrudate support block and supports the extrudate, the extrudate support block comprising at least one inlet and at least one outlet for cooling fluid.