Method and apparatus for producing plastic bags
AssigneeMiller Weldmaster Corporation
InventorBrian D. Henry
Life of this patent
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Abstract
A gusset preheating assembly and a method of using the same. The assembly includes a heating gun assembly mounted on a frame. Spreader rods open up a gap in a bag's gusset and nozzles blow warmed air into the gap. Orthogonally arranged first and second hydraulic members are operatively engaged with heating gun assembly and are activated to move the heating gun assembly vertically or horizontally. Hot air blowing into the gap from the nozzle relaxes the gusset. Pressure is applied to the relaxed gusset, thereby reducing the thickness of the gusset region of the bag. The reduction in thickness makes it possible to increase the number of gusseted bags that are packaged in a container or on a roll.
Claims9
A method of producing plastic bags, said method comprising:
- forming a gusset in each of two opposing sides of a plastic sheet, wherein each gusset includes a first folded layer and a second folded layer of plastic and the first folded layer is separated from the second folded layer by a gap;
- passing the gusseted sheet into a gusset preheating assembly;
- introducing a nozzle of a heating gun assembly into the gap;
- blowing hot air into the gap from the nozzle;
- heating the first folded layer and second folded layer with the hot air to a temperature that is sufficient to warm but not melt the plastic thereof;
- removing the heating gun assembly from the gap;
- relaxing the gusset;
- applying pressure to the relaxed gusset;
- causing the gap to collapse and become reduced in size, wherein the heat and pressure is insufficient to seal the first folded layer and the second folded layer to each other;
- and
- feeding the sheet with the relaxed gussets into a cutting operation or into a rolling operation.
Dependencies are inferred from the claim text.