| abstract |
An apparatus utilizing paired endless belts is provided as a low pressure die or sheet forming device and take-off system for forming extruded polymer melts into thermoplastic sheet; said sheet possessing isotropic characteristics, improved dimensional stability, and improved surface characteristics. A method is also provided that included: taking up a strand of extruded polymer melt between endless moving belts; maintaining the region of contact between the melt and said belts at a temperature that allows the melt to adhere to the belts; forming the melt strand into a web of the desired dimensions by compressing, spreading and flattening between said belts; gradient cooling the thermoplastic web between the belts under conditions to provide isotropic properties to the finished thermoplastic sheets before their separation from said belts. |