Title:
Flexible independent multi-layer container and method for forming
Kind Code:
A1


Abstract:
Flexible independent multi-layer container and method for forming the flexible independent multi-layer container for retention and delivery of flowable materials having independent layers freely movable between each other and sealed off from each other with at least one fitting formed there through and compression seals formed between the flanges of the fitting and the flexible material of the independent multi-layer container by the at least one fitting formed there through for sealing the at least one fitting in place and for forming a compression seal between the independent multi-layer of the flexible materials and for forming a flexible multi-layer container.



Inventors:
True, Charles W. (Houston, TX, US)
Application Number:
11/124982
Publication Date:
11/09/2006
Filing Date:
05/09/2005
Primary Class:
Other Classes:
383/109, 383/118
International Classes:
B65D30/08; B65D30/02; B65D33/16
View Patent Images:
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Primary Examiner:
HELVEY, PETER N.
Attorney, Agent or Firm:
THE WENDT FIRM, P.C. (Austin, TX, US)
Claims:
That claimed is:

1. A flexible multi-layer container for retention and delivery of flowable materials having independent layers freely movable between each other and sealed off from each other with at least one fitting formed there through and compression seals formed with the at least one fitting formed there through comprising; a. At least a 1st bag layer formed from a compressible and elastically flexible material having the ability to expand within the elastic limits of said flexible material upon receiving flowable materials, b. At least a 2nd bag layer formed from a compressible and elastically flexible material sized relative to said at least 1st bag layer for allowing said at least 1st bag layer formed from an elastically flexible material to smoothly expand within the elastic limits of said flexible material upon receiving flowable materials and for causing said at least 2nd bag layer to be smoothly expanded within its elastic limits, and c. At least one fitting means formed through said at least 1st and 2nd bag layers formed having a flange member internal of said at least 1st bag layer formed and a flange external of said at least 2nd bag layer formed for forming a compression seal between said flanges and said compressible and elastically flexible material by compressing the compressible and elastically flexible material of said at least 1st and 2nd bag layer materials sufficiently for forming a compression seal there between and for sealing said at least one fitting means in place and for forming a flexible multi-layer container.

2. A flexible multi-layer container for retention and delivery of flowable materials of claim 1 comprising, a. At least a 3rd bag layer formed from a flexible material having strength and abrasion resistant properties sized relative to said at least 1st and 2nd bag layers for allowing said at least 1st and 2nd bag layers formed from flexible materials to smoothly expand within their elastic limits and for causing said 3rd bag layer to expand within its flexible limits.

3. A flexible multi-layer container for retention and delivery of flowable materials of claim 2 wherein said at least one fitting means formed through said bag layers further comprises, a. A 1st flanged member internal of said at least 1st bag layer having sufficient flange surface for engaging said at least 1st bag layer formed from the inside surface of said at least 1st bag layer; b. A 2nd flanged member external of said at least 3rd bag layer having sufficient flange surface for engaging said at least 3rd bag layer formed from the external surface of said at least 3rd bag layer and for functional engagement with said 1st flanged portion means; and c. Means for driving said 1st and 2nd flanged members toward each other and said at least 1st, 2nd and 3rd bag layers for forming a compression seal there between and sealing said at least one fitting means in place and for forming a flexible multi-layer container.

4. A flexible multi-layer container for retention and delivery of flowable materials of claim 3 wherein said 1st and 2nd flanged portion means further comprises, a. A sufficient surface on said 1st flanged member portioned on said inside surface of said at least 1st bag layer for providing a seating surface against said inside surface of said at least I st bag layer and b. A sufficient surface on said 2nd flanged member having a gripping surface positioned on said outside surface of said at least 3rd bag layer for holding said bag layers surface against movement and for engaging said flanged surfaces toward each other and against said at least 1st, 2nd and 3rd bag layer surfaces for forming a compression seal and holding said at least 1st, 2nd, and 3rd bag layer materials against movement creep.

5. A flexible multi-layer container for retention and delivery of flowable materials of claim 4 wherein said 2nd flanged member gripping surface further comprises, a. concentric grooved surfaces on said flanged portion against said outside surface of said 3rd bag layer for holding said bag layers surfaces against movement creep and for being driven toward said 1st flange member and against said at least 1st, 2nd and 3rd bag layer surfaces for forming a compression seal and holding said at least 1st, 2nd, and 3rd bag layer materials against movement creep.

6. A flexible multi-layer container for retention and delivery of flowable materials of claim 4 wherein said means for driving said at least 1st, 2nd and 3rd bag layer layers to form a compression seal there between and holding said at least 1st, 2nd, and 3rd bag layer materials against movement creep comprises, a. At least two apertures through said at least 1st, 2nd, and 3rd bag layers and said 2nd flanged member, b. At least two fastener receiving means within said 1st flanged member, and c. At least two fastener means through said at least two apertures in said 2nd flanged member, said at least 1st, 2nd, and 3rd bag layers and into said at least two fastener receiving means within said 1st flanged member for compressing said 1st and 2nd flanged members toward each other and against said at least 1st, 2nd, and 3rd bag layer materials there between as said fasteners are tightened for forming a compression seal at said at least 1st, 2nd, and 3rd bag layer materials and for preventing movement creep of said at least 1st, 2nd, and 3rd bag layers at said formed compression seal.

7. A flexible multi-layer container for retention and delivery of flowable materials of claim 6 wherein said means for driving said at least 1st, 2nd and 3rd bag layer layers to form a compression seal there between comprises, a. At least two apertures through said at least 1st, 2nd, and 3rd bag layers and said 1st and 2nd flanged member, and b. At least two fastener means through said at least two apertures for compressing the 1st and 2nd flanged members toward each other and against said at least 1st, 2nd, and 3rd bag layer materials there between as said fasteners are tightened for forming a compression seals at said 1st, 2nd, and 3rd bag layer materials and for preventing movement creep at said at least 1st, 2nd, and 3rd bag layer materials from pulling out of said sealing engagement and for forming a compression seals at said 1st, 2nd, and 3rd bag layer materials.

8. A flexible multi-layer container for retention and delivery of flowable materials of claim 7 wherein said at least 2nd bag layer further comprises, a. Aligning means on said at least 2nd bag layer connected to said at least 3rd bag layer for holding said at least 1st and 2nd bag layers in alignment with said at least 3rd bag layer as said at least 1st and 2nd bag layers are allowed to smoothly expand within their elastic limits within said at least 3rd bag layer and cause said at least 3rd bag layer to expand within its flexible limits.

9. A flexible multi-layer container for retention and delivery of flowable materials of claim 8 wherein said aligning means further comprises, a. Tab members connected to said at least 2nd bag layer and projecting therefrom and connected to said 3rd bag layer for causing said at least 1st and 2nd bag layers to align with said at least 3rd bag layer as said 1st and 2nd bag layers smoothly expand within their elastic limits and cause said at least 3rd bag layer to expand within its flexible limits.

10. A flexible multi-layer container for retention and delivery of flowable materials of claim 9 wherein said 1st and 2nd compressible and elastically flexible material further comprise, a. A material of a thickness at its thinnest sufficient for allowing compression into a compression seal, and b. A material of a thickness at its thickest sufficient for allowing compression into a compression seal and for preventing creep of said material at the point of compression into a seal about said at least one fitting means.

11. A flexible multi-layer container for retention and delivery of flowable materials of claim 10 wherein said at least 1st and 2nd compressible and elastically flexible materials at its thinnest and thickest further comprises, a. A thinness of no less than 04 mils, and b. A thickness of no more than 80 mils.

12. A flexible multi-layer container for retention and delivery of flowable materials of claim 11 wherein said at least 1st and 2nd compressible and elastically flexible materials at its thinnest and thickest further comprises, a. A thinness of no less than 06 mils, and b. A thickness of no more than 70 mils.

13. A method of forming a multi-layer container for retention and delivery of flowable material comprising; a. Forming at least a 1st seal on one end of a tube of a compressible and elastically flexible material, b. Indexing on said tube for the position of a fitting having an orifice and a flange surface for aligning an aperture to be made at said orifice, c. Making at least one hole in said tube at said indexed position sufficient for the orifice of the fitting and for leaving said elastically flexible material in contact with said flange of said fitting, d. Holding said flanged surface of said fitting against said inside surface of said tube about said hole made at said indexed position, e. Forming a 2nd seal on the other end of said tube of said compressible and elastically flexible material for forming at least a 1st bag layer, f. Positioning said 1st bag layer into a second tube of a compressible and elastically flexible material, g. Forming a 1st seal on one end of said second tube of a compressible and elastically flexible material, h. Indexing on said second tube for the position of said fitting for aligning an aperture to be made there through with said at least 1st bag layer aperture, i. Making at least one hole in said second tube at said indexed position sufficient for the orifice of said fitting and for leaving said elastically flexible material in alignment with said at least 1st bag layer material about said aperture, j. Forming a 2nd seal on the other end of said second tube to form a 2nd bag layer independent of said 1st bag layer and sufficiently distant therefrom to allow said 1st bag layer to smoothly expand within said 2nd bag layer within its elastic limits and for causing said 2nd bag layer to smoothly expand within its elastic limits, k. Positioning said at least 1st and 2nd bag layers into a 3rd bag layer material having strength and abrasion resistant properties and a flexible limit, l. Indexing on said 3rd bag layer material for the position of said fitting for aligning aperture with said aperture of said at least 1st and 2nd bag layers, m. Making a hole in said 3rd bag layer material at said indexed position for the orifice of said fitting and for leaving said 3rd bag layer material in alignment with said at least 1st and 2nd bag layer material about said apertures, n. Forming a 3rd bag layer about said at least 1st and 2nd bag layers with sufficient distance from said at least 1st and 2nd bag layers to allow said at least 1st and 2nd bag layers to smoothly expand within each other and to smoothly expand within said at least 3rd bag layer to its flexible limits, o. Holding said 2nd flanged surface of said fitting against said outside surface of said at least 3rd bag layer, p. Inserting fasteners through said apertures in said flanged surfaces and said at least 1st, 2nd, and 3rd bag layers and q. Forcing said 1st flanged and 2nd flanged members of said fitting against said at least 1st, 2nd, and 3rd bag layer portions between said 1st and 2nd flanged portions by fastening said fasteners for forming a compression seal there between and for preventing movement creep of said at least 1st, 2nd, and 3rd bag layers at said fitting for forming a flexible multi-layer container for retention and delivery of flowable materials.

14. A method of forming a multi-layer container for retention and delivery of flowable material of claim 13 wherein said forcing of said 1st flanged and 2nd flanged members of said fitting against said at least 1st, 2nd, and 3rd bag layers further comprises, a. Fastening said fasteners with a force of 75 inch/lbs to 400 inch/lbs for forming a compression seal and for preventing movement creep of said at least 1st, 2nd, and 3rd bag layers and pulling away from said at least one fitting.

15. A method of forming a multi-layer container for retention and delivery of flowable material of claim 14 wherein said forcing of said 1st flanged and 2nd flanged members of said fitting against said at least 1st, 2nd, and 3rd bag layers further comprises, a. Fastening said fasteners with a force of 80 inch/lbs to 305 inch/lbs for forming a compression seal and for preventing movement creep of said at least 1st, 2nd, and 3rd bag layers and pulling way from said at least one fitting.

16. A flexible multi-layer container for retention and delivery of flowable materials having independent layers freely movable between each other and sealed off from each other with at least one fitting formed there through and compression seals formed at the at least one fitting formed there through comprising; a. At least an interior bag layer formed from a compressible and elastically flexible material having the ability to expand within the elastic limits of said flexible material upon receiving flowable materials, b. At least an exterior bag layer formed from a flexible material having strength and abrasion resistant properties sized relative to said at least interior bag layers for allowing said at least interior bag layers formed from flexible materials to smoothly expand within its elastic limits and for causing said exterior bag layer to expand within its flexible limits, and c. At least one fitting means formed through said at least interior and exterior bag layers formed having a flange member internal of said at least interior bag layer formed and a flange external of said at least exterior bag layer formed for forming a compression seal between said flanges and said compressible and elastically flexible material by compressing the compressible and elastically flexible material of said at least interior and exterior bag layer materials sufficiently for sealing said at least one fitting means in place and for forming a flexible multi-layer container.

17. A flexible multi-layer container for retention and delivery of flowable materials of claim 16 wherein said at least one fitting means formed through said bag layers further comprises, a. A 1st flanged member internal of said at least interior bag layer having sufficient flange surface for engaging said at least interior bag layer formed from the inside surface of said at least interior bag layer, b. A 2nd flanged member external of said at least exterior bag layer having sufficient flange surface for engaging said at least exterior bag layer formed from the external surface of said at least exterior bag layer and for engaging with said 1st flanged portion means, and c. Means for driving said 1st and 2nd flanged members toward each other and said at least interior and exterior bag layers for forming a compression seal there between and sealing said at least one fitting means in place and for forming a flexible multi-layer container.

18. A flexible multi-layer container for retention and delivery of flowable materials of claim 17 wherein said 1st and 2nd flanged portion means further comprises, a. A sufficient surface on said 1st flanged member portioned on said inside surface of said at least interior bag layer for providing a seating surface against said inside surface of said at least interior bag layer, and b. A sufficient surface on said 2nd flanged member having gripping surface positioned on said outside surface of said at least exterior bag layer for holding said bag layers surface against movement and for engaging said flange surfaces toward each other and against said at least interior and exterior bag layer surfaces for forming a compression seal and holding said at least interior and exterior bag layer materials against movement creep.

19. A flexible multi-layer container for retention and delivery of flowable materials of claim 18 wherein said 2nd flanged member gripping surface further comprises, a. Concentric grooved surfaces on said flanged portion against said outside surface of said exterior bag layer for holding said bag layers surfaces against movement creep and for being driven toward said 1st flange member and against said at least interior and exterior bag layer surfaces for forming a compression seal.

20. A flexible multi-layer container for retention and delivery of flowable materials of claim 18 wherein said means for driving said at least interior and exterior bag layer layers for forming a compression seal there between comprises, a. At least two apertures through said at least interior and exterior bag layers and said 2nd flanged member, b. At least two fastener receiving means within said 1st flanged member and, c. At least two fastener means through said at least two apertures in said 2nd flanged member, said at least interior and exterior bag layers, and into said at least two fastener receiving means within said 1st flanged member for compressing the 1st and 2nd flanged members against each other and said at least interior and exterior bag layer materials there between as said fasteners are tightened for forming a compression seal at said at least interior and exterior bag layer materials and for preventing movement creep at said formed compression seal.

21. A flexible multi-layer container for retention and delivery of flowable materials of claim 20 wherein said means for driving said at least interior and exterior bag layers to form a compression seal there between comprises, a. At least two apertures through said at least interior and exterior bag layers and said 1st and 2nd flanged member and, b. At least two fastener means through said at least two apertures for compressing the 1st and 2nd flanged members against each other and said at least interior and exterior bag layer materials there between and for preventing movement creep resistance against said at least interior and exterior bag layer materials from pulling out of said sealing engagement and for forming compression seals at said interior and exterior bag layer materials.

22. A flexible multi-layer container for retention and delivery of flowable materials of claim 21 further comprising, a. At least an intermediate bag layer formed from a compressible and elastically flexible material sized relative to said at least interior bag layer for allowing said at least interior flexible bag layer formed from an elastically flexible material to smoothly expand within the elastic limits of said flexible material upon receiving flowable materials and for causing said at least intermediate bag layer to be smoothly expanded within its elastic limits.

23. A method of forming a multi-layer container for retention and delivery of flowable material comprising; a. Forming at least a 1st seal on one end of a tube of a compressible and elastically flexible material, b. Indexing on said tube for the position of a fitting having an orifice and a flange surface for aligning an aperture to be made at said orifice, c. Making at least one hole in said tube at said indexed position sufficient for the orifice of the fitting and for leaving said elastically flexible material in contact with said flange of said fitting, d. Holding said flanged surface of said fitting against said inside surface of said tube about said hole made at said indexed position, e. Forming a 2nd seal on the other end of said tube of said compressible and elastically flexible material for forming at least an interior bag layer, f. Positioning said at least interior bag layers into a exterior bag layer material having strength and abrasion resistant properties and a flexible limit, g. Forming a 1st seal on one end of said exterior bag layer material, h. Indexing on said exterior bag layer material for the position of said fitting for aligning an aperture to be made with said aperture of said at least interior bag layers, i. Making at least one hole in said exterior bag layer material at said indexed position for the orifice of said fitting and for leaving said exterior bag layer material in alignment with said at least interior bag layer material about said aperture, j. Forming a 2nd seal on said exterior bag layer for forming an exterior bag layer about said interior bag layers with sufficient distance from said at least interior bag layers to allow said at least interior bag layers to smoothly expand within said exterior bag layer to its flexible limits, k. Holding said 2nd flanged surface of said fitting against said outside surface 30 of said at least exterior bag layer, l. Inserting fasteners through said apertures in said flanged surfaces and said at least interior and exterior bag layers, and m. Forcing said 1st flanged and 2nd flanged members of said fitting against said at least interior and exterior bag layer portions between said 1st and 2nd flanged portions by fastening said fasteners for forming a compression seal there between and for preventing movement creep of said at least interior, and exterior bag layers at said fitting for forming a flexible multi-layer container for retention and delivery of flowable materials.

24. A method of forming a multi-layer container for retention and delivery of flowable material of claim 23 further comprising; a. Positioning said interior bag layer formed in steps (a) thru (e) into a second tube of a compressible and elastically flexible material, b. Forming a 1st seal on one end of said second tube of a compressible and elastically flexible material, c. Indexing on said second tube for the position of said fitting for aligning aperture with said aperture of said at least interior bag layer, d. Making a hole in said second tube at said indexed position sufficient for the orifice of said fitting and for leaving said elastically flexible material in alignment with said at least interior bag layer material about said aperture, e. Forming a 2nd seal on the other end of said second tube for forming an intermediate bag layer independent of said interior bag layer and sufficiently distant therefrom to allow said interior bag layer to smoothly expand within said intermediate bag layer within its elastic limits and for causing said intermediate bag layer to smoothly expand within its elastic limits, f. Positioning said at least interior and intermediate bag layers into an external bag layer material having strength and abrasion resistant properties and a flexible limit and completing steps (f) thru (m) of claim 23.

26. A method of forming a multi-layer container for retention and delivery of flowable material of claim 25 wherein said forcing of said 1st flanged and 2nd flanged members of said fitting against said at least interior, intermediate, and external bag layers further comprises, a. Fastening said fasteners with a force of 75 inch/lbs to 400 inch/lbs for forming a compression seal and for preventing movement creep of said at least interior, intermediate, and external bag layers and pulling away from said at least one fitting.

27. A method of forming a multi-layer container for retention and delivery of flowable material of claim 26 wherein said forcing of said 1st flanged and 2nd flanged members of said fitting against said at least internal, intermediate, and external bag layers further comprises, a. Fastening said fasteners with a force of 80 inch/lbs to 315 inch/lbs for forming a compression seal and for preventing movement creep of said at least internal, intermediate, and external bag layers and pulling away from said fitting.

Description:

FIELD OF THE INVENTION

This invention relates to the field of flexible multi-layer containers and methods for making the flexible multi-layer containers. The flexible multi-layer containers are used for transport and storage of flowable materials generally of container sized volumes, but can be used with smaller volumes. The flexible containers are readily foldable and can be unfolded and used to convert normally dry containers used in shipping into wet or flowable material containers or they may be used as stand alone containers. The flexible multi-layer containers are for retention and delivery of flowable materials and have independent layers which are freely movable between each other and are sealed off from each other, but have seals formed at fittings which are attached to these containers for filling, discharge, sampling, etc. These independent layers are generally sealed off from each other as the containers of this field of invention provide secondary containment of their content from leaking out and/or contamination within by penetration. Further in this field of invention these containers and fittings are readily reuseable/recyclable.

BACKGROUND OF THE INVENTION

The prior art has been in search of flexible containers for use in the shipment and storage of flowable materials, such as liquids, slurries, etc. and methods for making them which do not leak or fail in use and can be re-used multiple times. Some such prior art containers have been used solely for storage in stationary locations, which is a less rigorous use, because stationary use does not have the dynamic loading forces caused by motion in the shipping process on the flexible materials and the interface between the flexible materials and fittings mounted to these flexible containers. However, even stationary storage has dynamic loading forces caused by the liquid pulses of loading and unloading of these stationary flexible containers. These loading forces have caused prior art tanks to leak or fail.

The prior art has resorted to many different processes for solving the leak problems associated with these flexible tanks. In some cases the prior art tanks or containers used heat-welding technology for sealing the containers and attaching the fittings to the flexible bodies of the containers. The problem of using heat welding is that it requires precise application of heat and pressure for a period of time and must be done in a very controlled environment. The order of difficulty of all these variables in the process of heat welding goes up dramatically in relation to the number of layers of material that is being heat welded at one time. If the heat welding process generates too much heat at the surface layer being welded the plastic material can become crystallized and become brittle which can cause failure of the weld and the container. If the heat welding process generates too little heat at the mid-layers being welded the plastic materials may not be sufficiently welded and the defective weld fails and the tank leaks. These defects in many cases would not be evident at the time of manufacture, but would become obvious when the container was loaded or shipped and the container fails completely or leaked product being shipped.

Other prior art has attempted to add chemical welding to the heat and pressure welding process of flexible materials used in the formation of flexible tanks and for attaching the fittings to the containers and tanks, but this has proved to be as unsuccessful as just the heat and pressure welding. These failures occur especially when the prior art containers are subjected to violent hydraulic motion, which is encountered in fluid shipments of containers. It should be realized that the containers are not baffled and the fluid inside can have full range of motion inside such containers, which can be 40 feet long and can produce great pressure on the flexible containers.

Further the prior art discovered that even if all the chemical, heat and pressure variables were perfect, failure to form a weld in the flexible container materials and securing the fitting could still occur because of body oil of workers, dust, powder or even light difference over the surfaces to be welded could cause failure.

The prior art provided mechanical members in addition to the welding process whether chemical and/or heat and pressure welding to form a seal for the securing the container and tank at the point where the fittings are mounted. In these applications the flexible materials were sealed about the hole made in the flexible materials where the fitting was to be inserted into the container and then the fitting was mechanically clamped on to the flexible tank or container. The sealed flexible materials about the hole did not rely on the mechanical clamping to seal the multiple layers about the hole nor did the mechanical clapping prevent the flexible materials forming the multiply layers from preventing movement creep in the flexible containers when they were filled and the flexible materials stretched or expanded because of filling or motion.

In yet other prior art flexible containers the fittings were created with specialized collars which could have the various layers of the flexible material being used for forming the flexible containers fitted about the collars both above and below and then chemically and/or heat and pressure welded to seal the fitting in place on the flexible tank or container. These welds of flexible material to more rigid materials of these collars created not only the typical problems of chemical, heat and pressure welds, but also stress razor points at the interface between the collar and the layers of materials being used in the flexible tank or container. These stress razor points produced failures when loading and/or discharging these tanks and containers, plus having failures during shipment thereof caused by dynamic wave actions in these flexible containers or tanks. Further these specialized collars tended to be some what rigid and hindered folding of the flexible containers for shipment.

The prior art in an effort to overcome some of these leak problems, at the fittings in flexible containers especially in severe operating conditions, attempted to develop additional special fitting, such as concentric cord and wire reinforced “doilies” about fittings which are used with flexible containers. These reinforced “doilies” then were chemically and/or heat and pressure welded to bind the flexible materials of various layers of flexible containers to these doilies. Finally, a metal clamp down was provided with fastener members who were fastened into the fitting, but not into the flexible materials of the flexible containers. This prior art was designed to provide hard non-compressible members to clamp down upon for a secure hold. This prior art was aimed at the problem of movement creep or “pulling out” of the flexible materials from the fittings. It never the less did not solve the problem of the failures of the flexible materials at the interface between the flexible materials and the more rigid fittings which occurred because of the wave action and other causes in the transport of these flexible containers and which occur at the time of loading and/or discharging from these containers.

Other prior art just formed a chemical weld and/or heat and pressure seal about the place in the wall of the flexible materials of the container and then put a fitting there through and attached the fitting with a screw down collar clamp. The screw down collar clamp attached the fitting securely about the chemical weld and/or heat and pressure seal already formed. However this type of fitting mount was subject to failure because of motion creep or out ward pulling forces which are generated by the stretching of the flexible materials used in the walls of the containers as they are filled or as motion waves are created in these containers shipment.

In addition to the above, the prior art used a flexible container of various materials having both the flexible material and reinforced material to prevent leaks so that when failures occurred in one layer of material, it did not get out of the container. Some of these flexible materials had woven fibers put into the inner layers of the flexible materials used to form layers of a flexible container, but these fibers created voids and provided friction points against the other smooth layers of flexible material. These voids and friction points caused creases and tucks in the smooth layer materials and became stress razors or pinching points for causing pinholes in the smooth layers of the flexible materials. Once a hole was formed then the woven fiber provided channels to allow the product to leak to other layers of the container or the container to leak.

The prior art has also tried using very thick flexible materials for providing strength, but these materials added weight to the containers and were not very flexible. Further these very thick flexible materials had a tendency to not fold out or fill smoothly and, if they did not, then stress pinches in the flexible material would cause these materials to have pin whole leaks through them. Once a leak occurs and the fluid product gets passed the thick flexible materials, which was provided for strength, the pressure of the fluid is transferred through to the next layer of flexible materials, which can lead to failure of the container. Further, if a thin walled flexible material of less than 15 mills thickness was used with a very thick flexible material as the inner layer then when this type container is discharged the pump suction at its intake can suck this thin walled flexible material into the intake and cut or damage that flexible material which would prevent the container further use.

Also the prior art used thick single flexible materials with re-enforcing materials built into the single flexible layers with compression seals and chemical welds to make tanks, but these tanks are very heavy and the re-enforcing materials are bound together with the tank materials to be come one layer of materials. In addition to being heavy these type tanks provided no environmental containment and the failure of the single wall was complete failure of these tanks. Also these tanks were in additional to being heavy, they were inflexible and could not be folded back on themselves for shipping multiple tanks in a shipping container.

As the prior art has added technology to solve these problems in multi layer flexible containers, the method of their manufacture became more complicated and more expensive. In many cases the added technology did not solve the problems of container failures in either shipment or static storage.

In addition to environmental containment problems, these prior art containers had recyclability problems because the fittings were so integrated into the materials, which might have been recyclable, that it was prohibitively expensive to recycle them.

The increases in shipping cost has demanded that the prior art flexible containers be easily folded and tightly packed to get as many folded containers shipped as possible to a site and then filled to save on the increasing costs of transportation. These prior art tanks with the bulky fitting and thick reinforced materials were not tightly foldable and were expensive to ship, which has made them less desirable.

The prior art did not recognize that the energy passed through the surface of flexible materials as these flexible tanks are moved and transported nor did they recognize the handling energies which are created upon filling and discharging materials from these flexible containers. As these fitting are directly in the path line of the energy being passed through the surface of the flexible container materials, many failures occurred at the interfaces between the flexible material and the fitting.

OBJECTS OF THIS INVENTION

The object of this invention is to create a flexible multi-layer container and to create a method for making a flexible multi-layer container for use in shipment and storage of flowable materials, such as liquids, slurries, mashes, etc which do not leak or fail in use and can be re-used repeated times.

Also an object of this invention is to provide a flexible container which may serve as a stationary tank or container and handle the dynamic loading forces caused by liquid pulses created during loading and unloading of these flexible multilayer containers with out leaking or failing.

Yet another object of the method of this invention is to use chemical and/or heat welding process on these compressible and elastic flexible material in their formation where as few layers are welded at once as possible. In a preferred embodiment, only one layer of the material is chemically and/or heat welded at once in the formation of these flexible containers for the prevention of crystallized materials being formed and for obtaining a good seal. At the point where the fittings are mounted through the walls of the flexible containers, no welding occurs between the compressible and elastic flexible materials and the fittings, which eliminates any crystallized materials formation. At these points only a compression seal is formed to fix the fitting in place and seal the compressible elastic flexible materials to form a flexible container, therefore brittleness does not occur and the compressible flexible material maintains it full range of flexibility.

Also an object of the method of this invention is to provide simplified steps for the formation of this flexible container which provide relatively easy control of the variables which can cause a chemical and/or heat weld to fail, such as body oil of workers, dust, powder, etc. and at the same time provide a method which provides a flexible container not subject to failure in its operation.

Yet another object of this invention is the formation of containers which can be used in the shipment of liquids and which can handle or withstand the violent hydraulic forces caused by the motion, which is encountered in shipping fluid in flexible containers. This invention can endure the forces produced in shipment of a 40 foot flexile container without baffles therein.

Still a further object of this invention is a flexible container with fitting provided through the compressible elastic flexible multiple layer materials of the flexible container of this invention which do not have to have special collars for chemical or heat welding them to form seals for securing the fittings and for forming a seal between the multiple layer materials at the fitting for forming a flexible container with fittings.

A still further object of this invention is a flexible container with fitting provided through the compressible elastic flexible multiple layer materials of the flexible container of this invention which do not have specially prepared coils or ridge materials against which fittings can be mechanically clamped to hold the flexible materials against movement creep or pulling out motions by the flexible materials of these containers.

It is the object of this invention to provide fittings which have flanged surfaces for holding the compressible elastic flexible multiple layer materials of the flexible containers of this invention with sufficient force to have the compressible elastic flexible multiple layer materials form compression seals for sealing the fittings and the multiple layers of material for forming a flexible container. Further these flanges may have surfaces which assist in holding the multiple layers against motion creep or pulling the flexible material out of the flanged surfaces forming the compression seal. Also to assist against motion creep or pulling out of the flanged surfaces by multiple layers forming the compression seal are fasteners which pass through the multiple layers being held as a compression seal and are used with the flanges for tightening down the flanges for forming the compression seal between the flanges and the multiple layers.

Another object of this invention is to allow the smooth filling out of the internal layers of the flexible materials before fully engaging the next layer of flexible materials so that no stress razors or pinching points occur to eliminate the cause of hole formation in the smooth layers of the flexible materials and then driving the next layer of smooth flexible material to expand smoothly, driven by the layer below it after it is smoothly expanded with in its elastic limits.

Still a further object is to provide the outer most layer with a reinforcing fiber layer for abrasion resistance and having the smoother layers inside it so that if a failure occurs internal of the multiple smooth layers of material the reinforcing fiber layer will not serve as a channel to allow the product to leak to the other layers of the container or propagate tank failure or leaking.

It is the object of this invention to use relatively thin layers of the compressible elastic flexible material layers, but not so thin that a compression seal may not be formed and not so thick as to cause or allow the movement to creep or pulling out forces to cause the failure of the materials and to cause leaking of the flexible container at its fittings.

Also an object of this invention is to use multiple layers of relatively thin compressible elastic flexile materials to form these containers and to achieve the strength of a thick single flexible material with re-enforcing materials built into it. By using these independent layers in tight mechanical relationship with each other, the container formed with these multiple layers of compressible elastic flexible materials achieve superior strength without becoming inflexible. These tanks or containers are easily folded back on themselves for shipping multiple tanks in a shipping container. Further these multiple layered containers provide environmental containment by being composed of multiple layers should one layer develop a leak as well.

Also an object of this invention is to provide a flexible container that is recyclable because its fittings are easily removed for reuse and are not bounded to the flexible multiple layers but the fitting seal the multiple layers to provide secondary containment against leaks in this flexible container at the fitting and the independent layers provide containment throughout the flexible container.

Still a further object of this invention is to provide a highly flexible container which is relatively inexpensive and which is not bulky and easily folds into a small space for being shipped to a location for filling.

BRIEF DESCRIPTION OF THE DRAWINGS

The flexible multi-layer container and the methods for making the flexible multi-layer container of this invention may be practiced in certain physical forms and arrangements and adjustments of the variable parts herein described, but preferred embodiments of which will be described in detail in the specification and illustrated in the coming drawings which will form a part hereof.

FIG. 1 is a drawing of the flexible multi-layer container of this invention, containing flowable materials, formed from independent layers freely movable between each other and sealed off from each other with the at least one fitting formed there through for forming compression seals with the compressible and elastically flexible multi-layer materials at the at least one fitting.

FIG. 2 is a top drawing view of the flexible multi-layer container of this invention, void of flowable materials therein, formed from independent layers freely movable between each other and sealed off from each other with the at least one fitting formed there through for forming compression seals with the compressible and elastically flexible multi-layer materials at the at least one fitting.

FIG. 3 is a cross-section drawing of the flexible multi-layer container of this invention with at least a 1st bag layer formed from a compressible and elastically flexible material smoothly expanded within elastic limits upon having received some flowable materials, but before causing the at least a 2nd bag layer to be expanded.

FIG. 4 is a cross-section drawing of the flexible multi-layer container of this invention with the at least a 2nd bag layer formed from a compressible and elastically flexible material sized relative to the at least 1 st bag layer formed from flexible material for allowing the at least 1st bag layer to smoothly expanded within elastic limits and for causing the 2nd bag layer to be expanded with in its elastic limits upon the 1st bag layer expanding, upon receiving flowable materials.

FIG. 5 is a cross-section drawing of the flexible multi-layer container of this invention with at least a 3rd bag layer formed from a flexible material having strength and abrasion resistant properties sized relative to the at least 1st and 2nd bag layers for allowing the 1st and 2nd bag layers formed from flexible materials to smoothly expand within their elastic limits and for causing the at least 3rd bag layer to be expanded within its flexible limits upon the 1st and 2nd bag layers expanding, upon receiving flowable materials.

FIG. 6 is an exploded drawing of the flexible multi-layer container of this invention, showing the 1st flanged member of the at least one fitting internal of the at least 1st bag layer, and showing the 2nd flanged member of the at least one fitting external of the 2nd bag layer and showing the fasteners for passing through the aperture in the 1st and 2nd flange member and through the 1st and 2nd bag layers for forming a compression seal with the 1st and 2nd bag layers and holding 1st and 2nd bag layers against movement creep upon said fasteners being fastened.

FIG. 7 is an exploded drawing of the flexible multi-layer container of this invention, showing the at least 1st flanged member of the at least one fitting internal of the at least 1st bag layer, and showing an at least 2nd bag layer and at least a 3rd bag layer and the at least 2nd flanged member of the at least one fitting external of the at least 3rd bag layer for forming a compression seal with the 1st, 2nd, and 3rd bag layers and holding the 1st, 2nd, and 3rd bag layer's against movement creep upon said fasteners being fastened.

FIG. 8 is a cross-sectional view taken through FIGS. 1 and 7 of the at least one fitting with the fasteners fastened through the at least 1st flanged member and 2nd flange member for forming a compression seal between the 1st, 2nd, and 3rd bag layers and holding the 1st, 2nd, and 3rd bag layers against movement creep. This cross-section also shows the orifice in the at least one fitting for filling and emptying the flexible multi-layer container.

FIG. 9 is a representational view of the 2nd flanged member of the at least one fitting member, showing the sufficient surface of the 2nd flanged member and gripping surface for holding the 1st, 2nd, and 3rd bag layers and forming a compression seal and holding of the 1st, 2nd , and 3rd bag layers against movement creep.

FIG. 10 is a representational view showing the beginning steps of the method of this invention for forming flexible multi-layer containers for containing flowable materials, formed from independent layers freely movable between each other and sealed off from each other starting with a tube of a compressible and elastically flexible material.

FIG. 11 is a representational view showing the forming of a first seal on one end of the tube of FIG. 10 and indexing where the at least the 1st flange of the at least one fitting is to be located and showing holes sufficient for the orifice of the fitting and for leaving elastic flexible material with holes for fastener but in contact with the 1st flange of the fitting and the 1st flange of the fitting held in place inside the tube of FIG. 10.

FIG. 12 is a representational view showing a second seal formed on the other end of the tube of FIG. 11 tube for forming at least a 1st bag layer from the tube of FIG. 10.

FIG. 13 is a representational view showing the beginning steps forming a second bag layer by placing the first bag layer of FIG. 12 inside a tube of a compressible and elastically flexible material.

FIG. 14 is a representational view showing the forming of a first seal on one end of the tube of FIG. 13 and indexing where the 1st flange of the at least one fitting is located to align the hole sufficient for the orifice of the fitting and remaining elastic material with holes for fasteners but to be in contact with the material of the 1st bag layer.

FIG. 15 is a representational view showing a second seal on the other end of the tube of FIG. 14 for forming at least a 2nd bag layer from the tube of FIG. 13.

FIG. 16 is a representational view showing the 2nd bag layer of FIG. 15, but having tab members connected to the 2nd bag layer and projecting there from.

FIG. 17 is a representational view showing the beginning steps for forming a 3rd bag layer by placing the 1st and 2nd bag layer of FIG. 16 inside a tube of a flexible material having strength and abrasion resistant properties sized relative to said 1st and 2nd bag layers for allowing the at least 1st and 2nd bag layers to smoothly expand within their elastic limits and for causing the 3rd bag layer to expand within its flexible limits.

FIG. 18 is a representational view showing the forming of a first seal on one end of the tube of FIG. 17 which attaches the tab members thereto and indexing where the at least 2nd flange of the at least one fitting is to be located and showing a hole sufficient for the orifice of the fittings and aligned with the at least 1st flange internal of the at least 1st bag layer and aligned with the remaining elastic material with holes for fasteners but to be in contact with the material of the 3rd bag layer.

FIG. 19 is a representational view showing a second seal on the other end of the tube of FIG. 18 for forming at least a 3rd bag layer from the tube of FIG. 17 and attaching the tab members thereto.

FIG. 20 is an exploded drawing of another embodiment of the flexible multi-layer container of this invention using co-extruded materials, showing the at least 1st flanged member of the at least one fitting internal of the at least an interior bag layer formed from a compressible and elastically flexible material, and showing the at least 2nd flanged member of the at least one fitting external of the at least exterior bag layer formed from a co-extruded flexible material having strength and abrasion resistant properties and showing the fasteners for passing through the aperture in the 1st and 2nd flange member and through the interior and exterior bag layers for forming a compression seal and holding the interior and exterior bag layers against movement creep upon the fasteners being fastened.

FIG. 21 is an exploded drawing of the flexible multi-layer container of this invention using co-extruded materials, showing the at least 1st flanged member of the at least one fitting internal of the at least interior bag layer, and showing an at least intermediate bag layer formed from a co-extruded compressible and elastic flexible material between the interior and exterior bag layers and the at least 2nd flanged member of the at least one fitting external of the at least exterior bag layer for forming a compression seal and holding the interior, intermediate and exterior bag layers against movement creep upon the fasteners being fastened there through.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

The present invention relates to flexible multilayer containers for retention and delivery of flowable materials having independent layers freely movable between each other and sealed off from each other by each independent layer being sealed to form a bag with at least one fitting formed there through and compression seals formed with the at least one fitting formed there through generally referred to at reference number 10 of FIG. 1. In at least one embodiment as shown in FIG. 1, the flexible multilayer container 10 is shown being filled with a flowable material and with at least one fitting 11 positioned on the top. In FIG. 2 the flexible multilayer container 10 is shown void of flowable materials but is shown as see through to show the independent layers as separate and freely movable between each other and sealed off from each other and have tabs 15. From FIG. 2 it can be seen that each bag layer is sized to allow it to smoothly expand within its elastic limits and then engage the next bag layer and also smoothly expand the next bag layer or layers, but still be within the elastic limits of all the bag layers. In FIG. 2 of this embodiment is shown a 1st bag layer 12, a 2nd bag layer 13, and a 3rd bag layer 14 with at least one fitting 11. These bag layers must be of sufficient thickness to give proper strength to a bag layer but not so thick as to be inflexible and not compressible. On the other hand no matter their strength they can not be so thin as to not be compressible for forming or acting as compression seals. To better understand this invention reference should be had to FIGS. 3, 4, and 5 which show the transition from FIG. 2 to FIG. 1 of this flexible multilayer container 10.

Referring to FIG. 3, the 1st bag layer 12 is formed from a compressible and elastically flexible material, such as polyethylene of 15 mils thickness, having the ability to expand within its elastic limits upon receiving flowable materials. This 1st bag layer 12 as shown in FIG. 3 is allowed to expand until it has smoothly expanded within its elastic limits prior to engaging the 2nd bag layer 13 as shown in FIG. 3. The 2nd bag layer 13 is mechanically separate as an independent layer from the 1st bag layer 12. Thus the 1st bag layer is formed as a smoothed walled container with no stress razors or pinching points to cause hole formation in this 1st bag layer 12 because it does not engage the 2nd bag layer 13 until it has fully formed as a smoothed walled container with in the 2nd bag layer 13 before it causes the 2nd bag layer to smoothly expand.

Referring to FIG. 4, the 2nd bag layer 13 is formed from a compressible and elastically flexible material, such as polyethylene of 15 mils thickness, having the ability to expand within its elastic limits, but is sized to allow the 1st bag layer to smoothly expand before it engages the 2nd bag layer 13 for then causing the 2nd bag layer 13 to smoothly expanded within its elastic limits upon being engaged by the 1st bag layer 12. Thus the 2nd bag layer 13 is formed as a smoothed walled container with no stress razors or pinching points to cause hole formation in the 2nd bag layer 13 because it does not engage the 3rd bag layer 14 until it has fully formed as a smoothed walled container within the 3rd bag layer.

Referring to FIG. 5, the 3rd bag layer 14 is formed from a flexible material having strength and abrasion resistant, such as polypropylene woven fiber of 4 oz. to 16 oz. weight thickness, and sized to allow the 2nd bag layer 13 to smoothly expand within it elastic limits and be guided by tabs 15 before it engages the 3rd bag layer 14 for then causing the 3rd bag layer 14 to smoothly expand within its limits upon being engaged by the 2nd bag layer 13 for forming a flexible multilayer container 10. By each bag layer being expanded within its elastic limits into the next bag layer a flexible multilayer container 10 is formed which can handle violent hydraulic forces caused by motion in shipping fluids in these flexible containers as if they where made of much thicker flexible materials, but yet these flexible containers are much lighter and more flexible containers which allows them to be easily folded into small space for being shipped to a location for filling. Also these flexible containers are generally lighter than thicker walled flexible tanks.

These independent bag layers are formed from a compressible and elastically flexible material having the ability to expand within the elastic limits upon receiving flowable materials but must have at least one fitting 11 for receiving and discharging flowable materials. As shown in FIGS. 6 and 7, by these bag layers being independent of each other, there must be provision for mounting at least one fitting member 11 through each independent bag layer and forming a seal between each of these bag layers at the at least one fitting 11 to prevent leaks and make these containers useable. Any seal formed at the at least one fitting member 11 in the at least 1st bag layer is also subject to expansion within the elastic limits of the flexible material upon receiving the flowable materials which causes the stresses or movement creep associated with those elastic forces on filling or from violent movement forces produced at the fitting on such a container. Further, the at least 2nd bag layer 13, as shown in FIGS. 6 and 7, is formed from a compressible and elastically flexible material sized relative to the at least 1st bag layer 12 for allowing the at least 1st bag layer 12 formed to smoothly expand within the elastic limits of the flexible material upon receiving flowable materials and for causing the at least 2nd bag layer 13 to be smoothly expanded with in its elastic limits also put stresses or movement creep associated with those elastic forces whether on filling or from violent movement forces produced in shipment on the at least 2nd bag layer 13 also. These forces of stress or movement creep are increased at the at least one fitting member 11 formed especially through the interface at least 1st and 2nd bag layers 12 and 13 formed at the at least one fitting 11. In this embodiment, as shown in FIG. 6, the at least one fitting member 11 to deal with the forces of stress or movement creep has a 1st flange member 16 internal of the at least 1st bag layer 12 formed and a 2nd flange member 17 external of the at least 2nd bag layer 13 formed for forming a compression seal between the flanges and the compressible and elastically flexible material. These flanges 16 and 17 have apertures 18 through them for accepting fasteners 22 for compressing the compressible and elastically flexible material of the at least 1st and 2nd bag layer material 12 and 13, between the 1st and 2nd flange members 16 and 17 sufficiently for forming a compression seal there between and for sealing the at least one fitting member 11 in place and thus forming a flexible multi-layer container 10. As those skilled in the art of seals and seal formation will recognize, if the material to be used as a seal is not compressible enough it will fail to form a seal. If the material is compressible enough, but is under compressed or over compressed the seal to be formed will fail. Further in the seals of this invention formed in this compression state must also deal with movement creep, which is the tendency for these elastically flexible materials to pull out from these fittings when violent motion occurs in shipment, which generates dynamic pressure spikes applied across the planes or surface of these elastically flexible materials. So the forces used on the fasteners 22 to form these compression seal must be adjusted for these materials and their applications, and the preferred range of 315 inch/lbs to 80 inch/lbs has been found to work, but a broader range of 400 inch/lbs. to 75 inch/lbs. has also been determined to work on most materials.

In yet another embodiment, this invention, as shown in FIG. 7, relates to including at least a 3rd bag layer 14 formed from a flexible material having strength and abrasion resistant properties and sized relative to the at least 1st and 2nd bag layers 12 and 13 for allowing the at least 1st and 2nd bag layers 12 and 13 formed from flexible materials to smoothly expand within their elastic limits and for causing the 3rd bag layer 14 to expand within its flexible limits. Also this invention relates to the at least one fitting member 11 having 1st and 2nd flanged members 16 and 17 having sufficient flange surface areas 19 and 20 for engaging the at least 1st bag layer formed 12 from the inside surface of the at least 1st bag layer 12 and sufficient flange surface 20 for engaging the at least 3rd bag layer 14 from the external surface of the at least 3rd bag layer 14 to form compression seals through the 1st, 2nd, and 3rd bag layer 12, 13, and 14 at the at least one fitting member 11. In some embodiments as shown in FIGS. 8 and 9 the flanged surfaces 19 and 20 in addition to having sufficient flanged surfaces 19 and 20 to create compression seals and hold against creep movement, they may also have provided gripping surfaces 21 such as shown in FIGS. 8 and 9 to aid in forming a compression seal and holding against creep movement of the materials at the fitting member 11 when fasteners 22 are tightened down. As shown in FIGS. 8 and 9 the gripping surface 21 is concentric circular grooves or ridges, but as those skilled in the art would know many non-smooth surfaces could be used to form a gripping surface to aid the compression seal for holding the materials against creep movement.

These fasteners 22, are provided for passing through apertures 18 in the flanges 16 and 17 and holes 23 of the at least 1st, 2nd, and 3rd bag layers 12, 13, and 14 for functionally drawing the flanges 19 and 20 against the 1st, 2nd, and 3rd bag layers 12, 13, and 14 to form compression seals and for penetrating the 1st, 2nd, and 3rd bag layers 12, 13, and 14 through holes 23. Both the compression and penetrating as shown in FIG. 8 are used for preventing movement creep of the at least 1st, 2nd, and 3rd bag layers 12, 13, and 14 materials at the compression seal formed at the at least one fitting 11. As those skilled in the art of seals and seal formation will recognize, if the material to be used as a seal is not compressible enough it will fail to form a seal. If the material is compressible enough, but is under compressed or over compressed the seal to be formed will fail. Further, the seals formed in this invention must also deal with movement creep, which is the tendency for these elastically flexible materials to pull out from these fittings when violent motion occurs in shipment or other forces act on these materials. So the forces used on these fasteners 22 to form these compression seals must be adjusted for the material used and the preferred range of 315 inch/lbs. to 80 inch/lbs. with a broad range of from 400 inch/lbs. to 75 inch/lbs. has been determined to work with most such materials.

In some applications as shown in FIG. 2, where different materials are used in the bag layers having different surface frictions, as for example between the 2nd bag layer 13 made of polyethylene and 3rd bag layer 14 made of polypropylene, it has been found that to aid in the formation of smoothly expanding within elastic limits of 2nd bag layer 13 without forming stress razor or pinching points between the material of 3rd bag layer 14, that tabs 15 are provided on the 2nd bag layer 13 and fastened to the 3rd bag layer 14 for guiding alignment while the 2nd bag layer 13 is smoothly expanding within it elastic limits. These tabs 15 thus keep the 2nd bag layer 13 in rough alignment with the 3rd bag layer 14 as the 2nd bag layer 13 is smoothly expanding, but the 3rd bag layer 14 is still loose around the 2nd bag layer 13 until it expands into the 3rd bag layer 14 for causing the 3rd bag layer 14 to expand within its flexible limits for forming a flexible multilayer container 10.

In yet another embodiment of this invention as shown in FIG. 20 at least an interior bag layer 24 is formed as at least a single bag layer which is physically independent from other bag layers, but interior bag layer 24 may be made of co-extruded multiple layers, which in FIG. 20 are represented as having two layers 25 and 26 of compressible and elastically flexible materials being used as an interior bag layer 24. Whether a single layer of co-extruded multiple layers or a single 1st bag layer, these bag layers must be subject to the formation of a compression seal between the 1st flange member 16 and 2nd flange member 17 of the fitting 11. In that regard the combined thickness of the co-extruded materials, which in this embodiment are represented by layer 25 and 26, must be in the broad range of being no less thick than 04 mils and no thicker than 80 mils with a preferred range of no less thickness than 06 mils and no thicker than 70 mils. Further these co-extruded materials must be capable of being sealed or welded to form a interior bag layer 24, so in many embodiments these layers 25 and 26 will be of relatively thin materials for forming a good weld, but when combined as co-extruded materials they will fall within the above ranges. Also in this embodiment there is at least an exterior bag layer 29 formed as at least as a single layer which is physically independent but may be made of co-extruded or woven multiple layers, which in FIG. 20 are represented as having two layers 30 and 31 of flexible materials having strength and abrasion resistance properties being used as an exterior bag layer 29. Whether a single layer of co-extruded multiple layers or a single bag layer they are sized relative to each other for allowing the interior bag layers 24 to smoothly expand within its elastic limits and for causing the exterior bag layer 29 to expand within its flexible limits, and allow at least one fitting 11 to be formed through the interior and exterior bag layers 24 and 29 for forming a compression seal between 1st and 2nd flanges 16 and 17 for sealing the at least one fitting 11 in place and for forming a flexible multi-layer container 10.

In yet other embodiment of this invention as shown in FIG. 21 at least an intermediate bag layer 32 is formed as at least a single bag layer which is physically independent from other bag layers, but the intermediate bag layer 32 may be made of co-extruded multiple layers, which in FIG. 21 are represented as having two layer 33 and 34 of compressible and elastically flexible materials. Whether composed of an interior bag layer 24, and an external bag layer 29 or having the intermediate bag layer 32 there would be provided at least one fitting member 11, which forms a compression seal about these layers for sealing these bag layers off from each other and mounting the at least one fitting member 11.

From all the forgoing embodiments described it should be apparent that these flexible containers would be recyclable because their fittings 11 are easily removed for re-use by removing the fasteners 22 and simply mechanically separating the 1st and 2nd flange members 16 and 17 from the multiple layers, as there is no welding or chemical fastening between these 1st and 2nd flange member 16 and 17 of fittings 1 1 and the flexible multi-layer bag materials. Further as the multiple bag layers are formed as independent bags sealed off from each other and sealed off from each other at the compression seals formed through them at the fitting 11 these flexible multilayer container provide environmental containment against leaks should one multiple bag layer fail.

At least one method embodiment for forming the flexible container 10 of this invention is shown in FIGS. 10 through 19. Starting at FIG. 10 with at least a 1st tube 35 of compressible and elastically flexible material, a 1st seal 36 is formed on one end of the tube as shown in FIG. 11. Then in FIG. 11, it can be seen that a 1st flange member 16 of the at least one fitting 11 is inserted and held for indexing of its orifice 37 and fastener apertures 18 in 1st flange member 16 are to be put through the 1st tube 35 while one end of the 1st tube 35 is held open. After indexing on the 1st tube 35 for the position of the orifice 37 through the 1st flange member 16 and fastener apertures 18 positions, then holes are made in the 1st tube 35 at the indexed positions in the elastically flexible material in contact with the 1st flange member 16 of the at least one fitting 11. Once the holes have been made the 1st flange member 16 of the at least one fitting 11 is held in place against the inside surface of the 1st tube 35 about the fastener and orifice holes made at the indexed position as shown in FIG. 11. Then as shown in FIG. 12 a seal is formed on the other end 39 of the 1st tube 35 of the compressible and elastically flexible material for forming at least a 1st bag layer 12. Those skilled in the art will appreciate that the quality control of forming a single weld through as single tube will provide a higher quality seal and improve the chance of not having a weld failure. The next step, as shown in FIG. 13, is positioning the 1st bag layer 12 into a second tube 40 of a compressible and elastically flexible material, which tube is sized to be larger than the 1st bag layer 12. Then as shown in FIG. 14 forming a 1st seal 41 on one end of the second tube 40 of a compressible and elastically flexible material, and then indexing on the second tube 40 for alignment with the position of the 1st flange member 16 of the at least one fitting 11 both for aligning the orifice 37 and fastener apertures 18 with those of the at least 1st bag layer 12. Once indexed, then making holes in the second tube 40 at the indexed positions sufficient for the orifice 37 of the 1st flanged member 16 of the at least one fitting 11 and fastener apertures 18 but leaving the elastically flexible maternal in alignment with the at least 1st bag layer 12 material about the orifice 37 and aperture holes 18. Then, as shown in FIG. 15, forming a 2nd seal on the other end 42 of the second tube 40 to form a 2nd sealed tube bag layer 13 sufficiently distant from the 1st bag layer 12 to allow the 1st bag layer 12 to smoothly expand within the 2nd bag layer within its elastic limits and for causing the 2nd bag layer to smoothly expand within it elastic limits when filled. In some embodiments of this method as show in FIG. 16 tabs 15 are attached to the 2nd bag layer and the at least 1st and 2nd bag layers 12 and 13 would be positioned, as shown in FIG. 17 inside a third tube 43 of material having strength and abrasion resistant propertied and a flexile limit. Then as shown in FIG. 18, indexing the third tube 43 material for the position of 1st flange member 16 of the at least one fitting 11 for aligning the orifice 37 with the apertures made in the 1st and 2nd bag layers 12 and 13. Once aligned and indexed, holes are made in the 3rd tube 43 material at the indexed position for the orifice 37 and fastener apertures 18 of the 1st flanged member 16 of the at least one fitting 11 and fastener apertures 18 but leaving the 3rd tube 43 material in alignment with the 1st and 2nd bag layer 12 and 13 materials. Then one end 44 of 3rd bag layer 14 is sealed which fixes tabs 15. Then as shown in FIG. 19, the 3rd tube 43 is sealed 45 which fixes tabs 15 and tub 43 is formed in to a 3rd bag layer 14 about the 1st and 2nd bag layers 12 and 13 with sufficient distance from the at least 1st and 2nd bag layers 12 and 13 to smoothly expand within each other and to smoothly expand within the at least 3rd bag layer 14 to expand the at least 3 bag layer 14 to its flexible limits. Then as shown in FIG. 19 the 2nd flanged member 17 of the at least one fitting 11 is held against the outside surface of the at least 3rd bag layer 14 and fasteners 22 are inserted through the fastener apertures 18 in the 1st and 2nd flanged member 16 and 17 and the at least 1st, 2nd and 3rd bag layers 12, 13, and 14 for forcing the 1st and 2nd flanged members 16 and 17 having flanged surfaces 19 and 20 of the at least one fitting 11 against the at least 1st, 2nd, and 3rd bag layer 12, 13, and 14 positioned between the 1st and 2nd flanged surfaces 16 and 17 for fastening the fasteners 22, for forming a compression seal there between and for prevention of movement creep of the at least 1st, 2nd and 3rd bag layers 12, 13, and 14 at the at least one fitting 11 for forming a flexible multi-layer container for retention and delivery of flowable materials. The range of fastening force can be from 75 inch/lbs to 400 inch/lbs, but as those skilled in the art will appreciate it will vary within that range depending upon the material being used. It has been found that a range of from 80 inch/lbs to 315 inch/lbs will work with polyethylene and polypropylene materials, but again depending on the thicknesses and weights of these materials falling between 04 mils to 80 mils and a preferred range of 06 mils to 70 mils and weights of 04 oz. to 16 oz. Also the 1st and 2nd flanged surface 19 and 20 must have sufficient surface to provide a sufficient seating surface against the bag layer materials to form a compression seal, and if different flanged surfaces are used it may vary the fastening forces as those skilled in the art will appreciate.

From the above method it can be seen that when forming a seal on the bag layers, which can be a heat weld and/or chemical, the welds are formed with only one layer of material being welded at one time to provide the highest quality seal possible and when a seal is formed across multiple layers a compression seal is formed through these bag layers. That the fitting 11 being formed in the bag layers to fasten the at least one fitting and the bag layer off from each other and against creep movement of the bag layers is the compression seal. However, if a bag layer is formed of co-extruded materials with independent layers these individual layers are very thin such that their collective layers are within the range of 04mils to 80 mils or the preferred range of 06 mils to 70 mils then these co-extruded materials may be treated as a 1st bag layer, but in fact they may be an interior bag layer, intermediate bag layer, and exterior bag layer.

While the referenced embodiments of the invention of this flexible container and the method for there formation has been disclosed it will be appreciated that other embodiments and process may be used without departing form the sprit of the invention and from the methods herein claimed.