Method of production of fabric bags or containers using heat fused seams

Patent metadata

Field	Value
Publication number	US-10974869-B2
Application number	US-201816126635-A
Country	US
Kind code	B2
Filing date	Sep 10, 2018
Priority date	Jun 5, 2013
Publication date	Apr 13, 2021
Grant date	Apr 13, 2021

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.

First claim

The invention claimed is:

1. A woven plastic fabric bulk bag with stitch-free heat sealed joints comprising:
a) a container folded configuration that is adapted to expand to an open configuration;
b) a first container portion having a first open end, a first folded configuration, and a first expanded configuration, and the first container portion comprising woven plastic fabric with a first coating at least in a first joint area on one side of the first container portion, the first coating comprising propylene-based plastomers, propylene-based elastomers or a combination thereof;
c) a second container portion having a second open end, a second folded configuration, and a second expanded configuration, and the second container portion comprising woven plastic fabric with a second coating at least in a second joint area on one side of the second container portion, the second coating being different from the first coating and comprising a majority percentage of polypropylene; and
d) a heat sealed joint coupling the first container portion to the second container portion, the heat sealed joint having the following directly adjacent layers: (i) woven plastic fabric of the first container portion, (ii) first coating, (iii) second coating, and (iv) woven plastic fabric of the second container portion; and
wherein the heat sealed joint is formed by:
i) overlapping the first and second open ends of the first container portion and the second container portion while the first container portion is in the first folded configuration and the second container portion is in the second folded configuration to define an overlapped configuration, and wherein in the overlapped configuration, there are a pair of outer left edges and a pair of outer right edges, each of the pair of outer left edges being a fold wherein a left side panel of the folded first container portion and of the folded second container portion are drawn inward, and each of the pair of outer right edges being another fold wherein a right side panel of the folded first container portion and of the folded second container portion are drawn inward;
ii) applying heat and pressure to the first and second container portions in the overlapped configuration to form a bond between the first coating and the second coating of the first and second container portions that are in contact and to form a container folded configuration wherein the heat sealed joint is formed amongst folded layers of the overlapped configuration, and wherein at least a substantial portion of first container portion surfaces that are in contact with each other are not bonded and at least a substantial portion of second container portion surfaces that are in contact with each other are not bonded so that the container can expand from the container folded configuration to the open configuration after the heat sealed joint is formed.

2. The bulk bag of claim 1 wherein the first container portion is a bottom portion and the second container portion is a body portion.

3. The bulk bag of claim 1 wherein the first container portion is a top portion and the second container portion is a body portion.

4. The bulk bag of claim 1 wherein the second container portion is a top spout portion and the first container portion is a top portion.

5. The bulk bag of claim 1 wherein the second container portion is a discharge tube portion and the first container portion is a bottom portion.

6. The bulk bag of claim 1 wherein the bulk bag can hold 2,000 to 4,400 pounds of bulk materials.

7. The bulk bag of claim 6 wherein the heat sealed joint is a bottom load bearing joint.

8. The bulk bag of claim 1 wherein the heat sealed joint retains at least 85% of the fabric strength.

9. The bulk bag of claim 1 wherein the heat sealed joint retains at least 90% of the fabric strength.

10. The bulk bag of claim 1 wherein the heat sealed joint retains at least 96% of the fabric strength.

11. The bulk bag of claim 1 wherein the heat sealed joint retains at least 100% of the fabric strength.

12. A woven polypropylene fabric bulk bag of the type that can hold 2,000 to 4,400 pounds of bulk material, with stitch-free heat fused joints comprising:
a) a first bulk bag portion including a first joint portion with a first coating at least in the first joint portion, and having a first folded configuration, the first coating comprising propylene-based plastomers, propylene-based elastomers or a combination thereof;
b) a second bulk bag portion comprising a second joint portion with a second coating at least in the second joint portion, wherein the second coating is different from the first coating and comprising a majority percentage of polypropylene, and the second bulk bag portion having a second folded configuration;
c) a heat sealed joint that couples the first bulk bag portion and the second bulk bag portion together,
wherein the heat sealed joint is formed while the first and second bulk bag portions are in the first folded configuration and the second folded configuration with the first joint portion and the second joint portion overlapped so that the first coating of the first joint portion is in contact with the second coating of the second joint portion,
wherein the heat sealed joint is formed by applying heat and pressure to the overlapped first joint portion and second joint portion so that at least the first coating melts and a bond is formed between the first coating and the second coating,
wherein the heat sealed joint has the following directly adjacent layers: (i) woven polypropylene fabric of the first bulk bag portion, (ii) first coating, (iii) second coating, and (iv) woven polypropylene fabric of the second bulk bag portion; and
wherein when forming the heat sealed joint, first bulk bag portion surfaces under heat and pressure are in contact with one another and second bulk bag portion surfaces under heat and pressure are in contact with one another, and heat sealed joints are not formed between at least some of the first bulk bag portion surfaces that are in contact with one another and at least some of the second bulk bag portion surfaces that are in contact with one another.

13. The polypropylene fabric bulk bag of claim 12 wherein the heat sealed joint retains at least 85% of the fabric strength.

14. The polypropylene fabric bulk bag of claim 12 wherein the heat sealed joint retains at least 90% of the fabric strength.

15. The polypropylene fabric bulk bag of claim 12 wherein the heat sealed joint retains at least 96% of the fabric strength.

16. The polypropylene fabric bulk bag of claim 12 wherein the heat sealed joint retains at least 100% of the fabric strength.

17. A flexible woven polypropylene fabric bulk bag with stitch-free heat sealed joints, of the type that can hold 2,000 to 4,400 pounds of bulk material, comprising:
a) a first bag portion comprising woven polypropylene fabric and including a first coating in a first joint portion, the first coating comprising propylene-based plastomers, propylene-based elastomers or a combination thereof;
b) a second bag portion comprising woven polypropylene fabric and including a second coating in a second joint portion, the second coating comprising a majority percentage of polypropylene and wherein the second coating is different from the first coating;
c) a heat sealed joint including a bond formed between the first and second coatings, said bond formed by heat sealing wherein heat is applied at a temperature to melt the first coating to form the bond between the first coating and the second coating; and
d) the

Assignees

• Ameriglobe Llc
• Dow Global Technologies Llc

Inventors

• Dunlap Clifford
• Schnaars Sr Daniel R
• Kardos Lori
• Patel Rajen

Classifications

• A41H43/04 Primary

  Joining garment parts or blanks by gluing or welding (mending garments by adhesives or adhesive patches A41H27/00) {; Gluing presses} · CPC title

• B31B2160/30

  pointed or tapered · CPC title

• B32B2307/31

  Heat sealable · CPC title

• B29C66/73921

  characterised by the materials of both parts being thermoplastics · CPC title

• B29C66/8322

  Joining or pressing tools reciprocating along one axis · CPC title