APPARATUS FOR MANUFACTURING HOLLOW ARTICLES SUCH AS BOWLS TRAYS, CUPS AND SIMILAR ARTICLES

摘要

Freshly extruded thermoplastic sheet is manipulated by leading it downwards at an angle of 30-60 degrees to pass through a thermoforming tool with an inclined daylight. The edges of the sheet are gripped by finger grips which can allow the sheet to sag slightly as it moves towards the daylight and then draw it taut for mould closure. For mfr. of hollow articles from matls. with a relatively low strength of stiffness at near extrusion temps., e.g. polyolefins. By leading the matl. through part of an approximately catenary path less thickness which variation is induced by matl. flow or droop than in processes which lead the hot sheet across a horizontal gap or which cause it to support its own wt. during vertical motion.