Method for the continuous formation of biaxially oriented thermoplastic materials and forming articles therefrom by intermittent forming means interfaced therewith

The method of extruding and orienting a web of thermoplastic material in a continuous mode and subsequently forming molded products therefrom in an intermittent mode without interruption of said continuous mode, comprising:

• extruding a web of thermoplastic material and presenting it continuously to an orientation means at an optimum orientation temperature;
• intermittently stretch orienting the web in a biaxial orienting means to a desired degree in the transverse and longitudinal dimensions thereof while said web is in a continuous longitudinal motion over predetermined intermittent throw lengths thereof;
• intermittently extracting the oriented predetermined throw lengths of the oriented web from the biaxial orienting means in synchronism with the intermittent actuations of the latter and ingesting the said throw lengths into a forming means;
• and
• intermittently forming products in said throw lengths of oriented web with said forming means while preserving the integrity of orientation therein.

The method of forming products of biaxially oriented thermoplastic material comprising:

• continuously extruding a web of thermoplastic material;
• biaxially stretching said web in an intermittently actuated biaxial orientation means in a continuous manner over a predetermined throw length of each actuation of said orientation means to effect biaxial orientation therein and dimension said web for subsequent forming;
• interfacing said continuously extruded web with said intermittently actuated orientation means in a dimensionally and thermally stable manner through a gravity formed accumulation loop sized in accordance with said predetermined throw length;
• substantially immediately and in synchronism with said orientation means transferring a said throw length of oriented web from said orientation means onto a downstream transfer means while maintaining the dimensional integrity of said web;
• and
• forming products in said intermittently advanced lengths of said web on said transfer means substantially immediately upon the completion of each advance to enhance thermal stability therein and preserve said orientation.

The method of extruding a web of thermoplastic material in a continuous mode and subsequently orienting and forming molded products therefrom in an intermittent mode without interruption of said continuous mode, comprising:

• extruding a web of thermoplastic material and presenting it continuously to an intermittently actuated orientation means at an optimum orientation temperature through a gravity formed accumulator loop accommodating a predetermined throw length of web;
• stretch orienting the said predetermined throw length of web to a desired degree in the transverse and longitudinal dimensions thereof while said web is in continuous longitudinal motion over a given intermittent actuation cycle of said orientation means;
• continuously interfacing and juxtaposing said oriented throw of web during said given actuation cycle with a downstream transfer means synchronized with said orientation means in a dimensionally and thermally stable engagement therewith to preserve the integrity of the orientation and the temperature therein and to establish an intermittent feed mode of said web downstream of said orientation means without disturbing the continuous mode upstream thereof;
• said downstream transfer means being the input of an intermittent thermoforming means;
• and
• intermittently forming products in said incremental lengths of oriented web within said thermoforming means substantially immediately upon receipt thereof to enhance the thermal stability of said web while preserving the integrity of orientation therein.