IP Library › Patent Application 19400342
Patent Application
App. No. 19/400,342

METHOD OF PRODUCTION OF FABRIC BAGS OR CONTAINERS USING HEAT FUSED SEAMS

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Quick Facts
Patent No.
US None
App. No.
19/400,342
Abstract

A method of producing flexible polypropylene fabric bags with heat fused seams comprising providing fabric pieces, wherein each fabric piece has a coated side and an uncoated side; positioning fabric pieces so that a coated side of one fabric piece faces a coated side of another fabric piece; selecting an area of fabric to be joined for forming a seam or joint; applying heat to the area to be joined that is less than the melting point of the fabrics, for forming one or more seams or joints and wherein the heat fused seams or joints of a resulting polypropylene bag retains at least 85% of the fabric strength without using sewing machines.

Claims (45)

1 - 24 . (canceled)

25 . A bulk bag, of a type that can hold 2,000 to 4,400 pounds of bulk material, comprising:

a) a bag folded configuration that is adapted to expand to a bag open configuration;

b) a first bag portion comprising woven plastic fabric with a first coating at least in a first joint area on an inner side or an outer side of the first bag portion, and wherein the first coating has a melting point that is lower than a woven plastic fabric melting point;

c) the first bag portion further comprising,

i) a first open end,

ii) a first folded configuration including a first left fold, able to be formed by drawing a first left side panel of the first bag portion inward, and including a first pair of outer left edges, and wherein the first folded configuration has a first right fold, able to be formed by drawing a first right side panel of the first bag portion inward, and including a first pair of outer right edges, and

iii) a first expanded configuration;

d) a second bag portion comprising the woven plastic fabric with a second coating at least in a second joint area that is either on an inner surface of the second bag portion if the first coating is on the outer side of the first bag portion, or is on an outer surface of the second bag portion if the first coating is on the inner side of the first bag portion, and wherein the second coating is different from the first coating, and

e) the second bag portion further comprising,

i) a second open end,

ii) a second folded configuration, including a second left fold, able to be formed by drawing a second left side panel of the second bag portion inward, and including a second pair of outer left edges, and

wherein the second folded configuration has a second right fold, able to be formed by drawing a second right side panel of the second bag portion inward, and including a second pair of outer right edges, and

iii) a second expanded configuration;

f) a heat-sealed joint coupling the first bag portion to the second bag portion at a location where the first bag portion overlaps the second bag portion, the heat-sealed joint having the following directly adjacent layers: (i) the woven plastic fabric of the first bag portion, (ii) the first coating, (iii) the second coating, and (iv) the woven plastic fabric of the second bag portion;

g) wherein the first folded configuration of the first bag portion enables the first bag portion to be overlapped with the second bag portion while the second bag portion is in the second folded configuration to form an overlapped configuration with eight folded layers wherein the first coating and the second coating are in contact with one another amongst the eight folded layers, and wherein some surfaces of the first bag portion are in contact with one another and some surfaces of the second bag portion are in contact with one another in the overlapped configuration; and

h) wherein the melting point of the first coating enables a bond to be formed between the first coating and the second coating amongst the eight folded layers to form the heat-sealed joint, and wherein application of heat to the folded layers to the melting point of the first coating is able to melt the first coating without melting the woven plastic fabric, without bonding surfaces of the first bag portion that are in contact, and without bonding surfaces of the second bag portion that are in contact, so that after formation of the heat-sealed joint, the bag can expand from the bag folded configuration to the bag open configuration.

26 . The bulk bag of claim 25 wherein the first bag portion is a bottom portion and the second bag portion is a body portion.

27 . The bulk bag of claim 25 wherein the first bag portion is a top portion and the second bag portion is a body portion.

28 . The bulk bag of claim 25 wherein the second bag portion is a top spout portion and the first bag portion is a top portion.

29 . The bulk bag of claim 25 wherein the second bag portion is a discharge tube portion and the first bag portion is a bottom portion.

30 . The bulk bag of claim 29 wherein the heat-sealed joint is a bottom load bearing joint.

31 . The bulk bag of claim 25 wherein the heat-sealed joint retains at least 85% of the woven plastic fabric strength.

32 . The bulk bag of claim 25 wherein the heat-sealed joint retains at least 90% of the woven plastic fabric strength.

33 . The bulk bag of claim 25 wherein the heat-sealed joint retains at least 96% of the woven plastic fabric strength.

34 . The bulk bag of claim 25 wherein the heat-sealed joint retains at least 100% of the woven plastic fabric strength.

35 . A bulk bag, of a type that can hold 2,000 to 4,400 pounds of bulk material, comprising:

a) a first portion comprising woven polypropylene fabric and including a first joint area with a first coating at least in the first joint area, and

having a first folded configuration in which the first coating is on an inner surface or an outer surface of the first portion, and

the first coating having a melting point that is lower than a woven polypropylene fabric melting point;

b) a second portion comprising the woven polypropylene fabric and a second joint area with a second coating at least in the second joint area,

wherein the second coating is different from the first coating and comprises a majority percentage of polypropylene, and

the second portion having a second folded configuration in which the second coating is on an inner side of the second portion if the first coating is on the outer surface of the first portion, or

in which the second coating is on an outer side of the second portion if the first coating is on the inner surface of the first portion;

c) a heat-sealed joint that couples the first portion to the second portion, wherein the melting point of the first coating enables the heat-sealed joint to be formed while the first portion is in the first folded configuration and overlapped with the second portion while in the second folded configuration, in an overlapped configuration, and under heat and pressure, because the first coating is able to be heated to a temperature that is able to melt the first coating so the first coating can bond to the second coating without melting the woven polypropylene fabric, and such that surfaces of the first portion that are in contact in the overlapped configuration are not bonded together and surfaces of the second portion that are in contact in the overlapped configuration are not bonded together; and

d) wherein the heat-sealed joint has the following directly adjacent layers: (i) the woven polypropylene fabric of the first portion, (ii) the first coating, (iii) the second coating, and (iv) the woven polypropylene fabric of the second portion.

36 . The bulk bag of claim 35 wherein the heat-sealed joint is able to be formed amongst eight folded layers in the overlapped configuration.

37 . The bulk bag of claim 35 wherein the heat-sealed joint retains at least 85% of the woven polypropylene fabric strength.

38 . The bulk bag of claim 35 wherein the heat-sealed joint retains at least 90% of the woven polypropylene fabric strength.

39 . The bulk bag of claim 35 wherein the heat-sealed joint retains at least 96% of the woven polypropylene fabric strength.

40 . The bulk bag of claim 35 wherein the heat-sealed joint retains at least 100% of the woven polypropylene fabric strength.

41 . The bulk bag of claim 35 wherein the first portion is a bottom portion and the second portion is a body portion.

42 . The bulk bag of claim 35 wherein the first portion is a top portion and the second portion is a body portion.

43 . The bulk bag of claim 35 wherein the second portion is a top spout portion and the first portion is a top portion.

44 . The bulk bag of claim 35 wherein the second portion is a discharge tube portion and the first portion is a bottom portion.