Method for making all plastic valved bags

Claim 1

THE METHOD FOR THE PRODUCTION OF AN ALL-PLASTIC VALVED BAG WHICH COMPRISES (A) EXTRUDING, ONTO A FLAP OF A SHEET OF A THERMOPLASTIC RESINOUS MATERIAL FROM WHICH THE WALLS OF THE BAG ARE TO BE FORMED, ESSENTIALLY PARALLEL AND CLOSE TO THE EDGE OF THE FLAP THAT IS TO BE INCLUDED IN A VERTICAL SIDE SEAM OF THE BAG, A STRAND OF A MOLTEN THERMOPLASTIC RESIN THAT IS COMPATIBLE WITH THE THERMOPLASTIC RESIN OF WHICH SAID SHEET IS MADE, (B) APPLYING TO THE THUS EXTRUDED MOLTEN STRAND WHILE THE STRAND IS STILL WARM AND PLASTIC, A VALVE SLEEVE CONSISTING OF AN ESSENTIALLY RECTANGULAR SHEET OF A THERMOPLASTIC RESINOUS SHEET MATERIAL THAT IS COMPATIBLE WITH THE THERMOPLASTIC RESIN FROM WHICH THE SHEET THAT IS TO FORM THE WALLS OF THE BAG IS MADE, WHICH RECTANGULAR SHEET HAS BEEN FOLDED OVER ONCE UPON ITSELF IN SUCH A MANNER THAT THE EDGE THAT IS FOLDED OVER IN ESSENTIALLY CONTERMINOUS WITH THE HORIZONTAL TOP EDGE OF THE SHEET FROM WHICH THE WALLS OF THE BAG ARE TO BE FORMED, AND THE VERTICAL OPEN SIDE ENDS OF THE VALVE SLEEVE NEAREST THE EDGE OF THE SHEET ARE ESSENTIALLY CONTERMINOUS WITH THE VERTICAL EXTRUDED STRAND OF MOLTEN COMPARTIBLE THERMOPLASTIC RESIN, (C) PRESSING THE FLAP AT THE OUTER EDGE OF THE VALVE SLEEVE INTO CONTACT WITH THE UNDERLYING EXTRUDED STRAND OF MOLTEN COMPATIBLE THERMOPLASTIC RESIN WHILE THE STRAND IS STILL WARM AND PLASTIC, THEREBY JOINING THE VALVE SLEEVE TO THE SHEET FROM WHICH THE WALLS OF THE BAG ARE TO BE FORMED, (D) FOLDING THE SHEET INTO AN ESSENTIALLY FLAT BAG TUBE IN WHICH THE FLAP TO WHICH THE VALVE SLEEVE IS JOINED AND THE VALVE SLEEVE ARE SUPERIMPOSED OVER AND IN

Claim 2

THE METHOD FOR THE PRODUCTION OF AN ALL-PLASTIC VALVED BAG WHICH COMPRISES (A) EXTRUDING, ONTO A FLAP OF A SHEET OF A THERMOPLASTIC RESINOUS MATERIAL FROM WHICH THE WALLS OF THE BAG ARE TO BE FORMED, ESSENTIALLY PARALLEL AND CLOSE TO THE EDGE OF THE FLAP THAT IS TO BE INCLUDED IN A VERTICAL SIDE SEAM OF THE BAG, A STRAND OF A MOLTEN THERMOPLASTIC RESIN THAT IS COMPATIBLE WITH THE THERMOPLASTIC RESIN OF WHICH SAID SHEET IS MADE, (B) APPLYING TO THE THUS EXTRUDED MOLTEN STRAND WHILE THE STRAND IS STILL WARM AND PLASTIC, A VALVE SLEEVE CONSISTING OF AN ESSENTIALLY RECTANGULAR SHEET OF A THERMOPLASTIC RESINOUS SHEET MATERIAL THAT IS COMPATIBLE WITH THE THERMOPLASTIC RESIN FROM WHICH THE SHEET THAT IS TO FORM THE WALLS OF THE BAG IS MADE, WHICH RECTANGULAR SHEET HAS BEEN FOLDED OVER ONCE UPON ITSELF IN SUCH A MANNER THAT THE EDGE THAT IS FOLDED OVER IN ESSENTIALLY CONTERMINOUS WITH THE HORIZONTAL TOP EDGE OF THE SHEET FROM WHICH THE WALLS OF THE BAG ARE TO BE FORMED, AND THE VERTICAL OPEN SIDE ENDS OF THE VALVE SLEEVE NEAREST THE EDGE OF THE SHEET ARE ESSENTIALLY CONTERMINOUS WITH THE VERTICAL EXTRUDED STRAND OF MOLTEN COMPARTIBLE THERMOPLASTIC RESIN, (C) PRESSING THE FLAP AT THE OUTER EDGE OF THE VALVE SLEEVE INTO CONTACT WITH THE UNDERLYING EXTRUDED STRAND OF MOLTEN COMPATIBLE THERMOPLASTIC RESIN WHILE THE STRAND IS STILL WARM AND PLASTIC, THEREBY JOINING THE VALVE SLEEVE TO THE SHEET FROM WHICH THE WALLS OF THE BAG ARE TO BE FORMED, (D) FOLDING THE SHEET INTO AN ESSENTIALLY FLAT BAG TUBE IN WHICH THE FLAP TO WHICH THE VALVE SLEEVE IS JOINED AND THE VALVE SLEEVE ARE SUPERIMPOSED OVER AND IN