Molten theromplastic web feeding process
AssigneeA.A.R.C. (Management) Pty. Limited
InventorAnthony E. Flecknoe-Brown
Life of this patent
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Abstract
A web of molten thermoplastics material (4) from extruder die (3) is fed through a pair of temperature controlled rolls (5) having a gap (13) of width less than that of the web thickness leaving the extruder die (3) and is fed from the rolls (5) directly and continuously under uniform tension to a thermoforming machine (9) (10) as a formable web (6) of substantially uniform temperature through its thickness.
Claims8
A method of continuously thermoforming thermoplastic material wherein a web of said material issuing molten from an extruder is passed through a set of temperature controlled rolls and from there to a continuous thermoforming machine the improvement comprising:
- setting 2 rolls with a gap between them of predetermined uniform width less than the thickness of the web leaving the extruder so that a bank of thermoplastic material is formed before the gap said material leaving the rolls in a hot fluid condition;
- feeding, directly and continuously the material to the thermoforming machine as a formable web having a substantially uniform temperature through its thickness, the web of material between the rolls and the thermoforming machine being supported under uniform tension by imparting a constant extension to the material from a differential between the speed of the rolls and the speed of a plurality of moving moulds carrying the web through the thermoforming machine.
Dependencies are inferred from the claim text.