Method for making plastic bags
OwnerHans G. Jentschinventor
Life of this patent
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Abstract
The invention provides a novel method of making a plastics bag and a novel plastics bag, the method comprising folding a sheet of plastics material to form a U-shaped blank, welding the longitudinal edges of the blank, and providing either two or four weld seams at the base of the bag to provide a bottom wall defined at least in part by said seams, said seams serving to give the bag stability whereby it may be stood on said bottom wall. The top of the bag may be closed in various ways, for example by straight or inclined weld seams and a funnel like pouring spout may be provided if desired.
Claims10
A method of making a plastics container having a bottom wall in a W-shaped configuration from a single sheet or film of plastics material, comprising the steps of:
- a. folding a laminated sheet or film blank having at least one layer of weldable plastics material upon itself to provide two superjacently disposed blank sections in a U-shaped configuration;
- b. forming a tuck at the base of said U-shaped portion to impart a W-shaped configuration thereto to enable formation of said bottom wall;
- c. welding the bottom creases resulting from said W-shaped folding to form weld seams defining in part said bottom;
- d. forming longitudinal weld seams of said blank sections by applying first welding jaws at both exterior sides of the superjacent portions along each longitudinal seam, leaving a sealable opening formed by the upper edges of said container blank sections;
- and after cutting
- e. overwelding the longitudinal weld seams at the outer edges thereof by applying further welding jaws at both exterior sides of said weld seams so that the layers of weldable plastics material are melted together thereby completely sealing the container relative to the exterior.
A method of making a plastics container having a bottom wall upon which the container may be stood in an upright position, comprising the steps of:
- a. providing a blank in the form of a rectangular sheet of laminated film having at least one surface layer of weldable material;
- b. folding said blank upon itself to provide two blank sections, the sections being at least partially disposed superjacently, at least portions of the longitudinal edges of the blank sections being superjacent;
- c. welding together the superjacent portions of each longitudinal edge of the blank;
- d. applying two further welds or weld seams in the zone of the bottom surface of the container, said further welds or weld seams at least partially defining the bottom wall of the container;
- and
- e. overwelding at least some of the weld seams at the outer edges thereof so that the layers of weldable plastics material are melted together which completely seals the container relative to the exterior.
A method of making a plastics bag having a bottom wall upon which the bag may be stood in an upright position, comprising the steps of:
- a. providing a blank in the form of a rectangular sheet of laminated film having at least one surface of weldable plastics material;
- b. folding said blank once upon itself to provide two blank sections, the sections being disposed superjacently;
- c. welding together the superjacent portions of each longitudinal edge of the blank to form longitudinal weld seams thus producing a bag having two side walls, a bottom edge which is closed seamlessly and a top which is open;
- d. gripping the bag by each of said side walls and drawing the side walls apart to form two further side walls and a bottom wall, two double walled flaps thus being formed which extend outwardly of the bag, each flap having one wall thereof extending from one of said two further side walls and another wall extending from said bottom wall;
- e. welding together the said walls of each flap to form a weld seam at a position spaced from the free end of each flap and adjacent the bottom wall, and cutting off the portion of each flap disposed beyond the weld seam;
- and
- f. rewelding at least some of the weld seams at the outer edges thereof so that the layers of weldable plastics material are melted together which completely seals the container relative to the exterior.
Dependencies are inferred from the claim text.