Patent ID: 6237308
Filing Date: 2001-05-29
Classification: B29C,B29L,B32B,B65B

Abstract:
A method of forming, sealing and filling a pouch with a consumable liquid at high speed, said method comprising the steps of:i) providing, in roll form, a multi-layer film sheet having an inner sealing layer, an outer layer and a core sandwiched therebetween, said sealing layer comprises about 40 to 100% weight percent of a metallocene resin having a density of between about 0.902 and 0.9122, and about 0 to 60 weight percent of a low density polyethylene or a mixture of low density polyethylene and linear low density polyethylene, said outer layer comprises a low density polyethylene or a mixture of low density polyethylene and linear low density polyethylene, said core comprising a mixture of about 20 to 90 weight percent of a polypropylene copolymer and about 10 to 80 weight percent of a low density polyethylene or a mixture of low density polyethylene and linear low density polyethylene, said multi-layer film structure having a thickness within a range between about 50 and 70 micronsii) drawing said film sheet, by drawing means, over a pouch former to form a plastic film tube having an overlapped vertical film edge,iii) sealing said overlapped vertical edge with a vertical sealer to form a vertical seal,iv) effecting a horizontal seal across said plastic film tube with a horizontal sealing jaw and at a predetermined location below said vertical sealer, and simultaneously severing said tube to form a top horizontal seal for a filled pouch and a bottom horizontal seal for a pouch being filled, said horizontal and vertical seals having an improved seal strength of 30% to 50% as compared with a 76 microns (3 mil) mono-layer polyethylene film and a 10.degree. C. to 15.degree. C. reduction in seal initiation temperature, an improved tensile strength of 25% to 40%, and an improvement of 30% to 50% in puncture resistance while reducing the sealing cycle time, andv) continuously feeding a consumable liquid within said plastic film tube below said vertical sealing jaw and above said transverse sealing jaw.