High speed bag forming, sealing and filling machine, method of operation, and multi-layer film therefor

摘要

The multi-layer film structure having an inner sealing layer which comprises metallocene resin, a core which includes polypropylene copolymer and an outer layer and wherein the multi-layer film structure has a thickness within a range between about 50 and 70 microns (2.0-2.75 mil). By utilizing this thin film with specific properties the sealers may be operated at lower temperatures thereby resulting in an energy saving and they produce seals having improved seal strength of 30% to 50% as compared with known prior mono-layer polyethylene film. The seal initiation temperature is reduced by 10° C. to 15° C. and the film exhibits an improved machine direction tensile strength of 25% to 40% and an improvement of 30% to 50% in puncture resistance as compared with a 76 microns (3 mil) mono-layer polyethylene film. This results in a reduction in the sealing cycle time and an increase in the throughput of the machine. This results in a liquid pouch having a substantial improvement in drop test performance, puncture resistance and seal strength. The machine accomplishes better seals with less energy, requires less downtime for roll changes and maintenance and increase throughput.