| 摘要 |
<p>A method and apparatus are provided for continuously extruding, biaxially orienting and intermittently forming molded products from a web of thermoplastic material and further, continuously separating the products from the web selvage, stacking and handling the products and recycling the web selvage for further extrusion. The method and apparatus use intermittent molding devices into which configuration the biaxially oriented web is interfaced by a continuous to intermittent interfacing structure which preserves the dimensional and orientational integrity of the web and maintains thermal stability therein. An undulating peripheral surface on a dynamic storage or accumulator drum and associated transfer rollers cooperate with intermittently advanced feed belts in timed relationship with a reciprocating forming press to effectuate the interface and product forming portions of the process. Products are formed in the intermittently advanced lengths of the oriented web so that the stress placed on the thermoplastic material by the biaxial orientation is substantially maintained from the initiation of the orientation to the forming of the products therefrom. In some of the preferred embodiments the inertia at the interface between the undulating peripheral surface of the accumulator drum and the biaxial orientation apparatus is reduced to an optimal minimum. The present invention provides a system which is very facile and variable with regard to unique and unusual shapes. This invention provides a means for interfacing between a continuous extrusion and orienting mode and intermittent forming mode without either mode effecting the integrity of the other or the quality and integrity of the biaxially oriented thermoplastic material in the system.</p> |
