SEALABLE CONTAINER LININGS AND SEALABLE CONTAINERS

Abstract

A sealable container includes a substantially rigid housing having an inner surface and an opening and a liner including: a) a collar formed at least from a fluoropolymer material and sized and shaped to removably engage the opening in the housing; and b) a flexible bag, having an opening, sealed to the collar, and including a composite of an abrasion resistant reinforcing material and an inner fluoropolymer material that is substantially inert to content in the container and compatible with the fluoropolymer material of the collar, the bag being sized and shaped to pass through the opening in the housing and expand such that the abrasion resistant reinforcing material can be in contact with at least a substantial portion of the inner surface of the housing.

Description

TECHNICAL FIELD

This disclosure relates to sealable container linings and sealable containers utilizing sealable container linings.

BACKGROUND

Very pure chemicals such as organic solvents, in particular, must be placed in containers for transport that satisfy a number of needs. The containers must withstand the potential for damage through ordinary commercial transportation means, must be liquid tight, and must be inert to the chemicals or solvents within the container. A representative type of transport container is disclosed in U.S. Pat. No. 4,741,457, for example. Another type of transport container is the NOWPak® Drum Dispense System manufactured by ATMI Packaging.

Very pure chemicals or solvents transported in smaller containers, such as 10 to 20 liters, typically may be transported from the point of filling to the ultimate customer destination without problems such as leakage, contamination or the like. However, when the size of the container increases to larger quantities, such as 100 liters to 200 liters or even more, which is quite desirable from an economic and efficiency standpoint, there is a significant increase in the amount of leakage and contamination of the container contents.

The problems appear to be that small holes propagate in the container lining during transport which permits leakage and/or contamination of the contents. Also, there tends to be an increased occurrence of problems associated with the connection between the flexible liner of the container and the liner ring seated in the container opening. Thus, there is a need to provide a container that can safely and effectively transport liquid chemicals by ordinary transportation means without leakage and without contamination of the container contents.

SUMMARY

Provided herein is a sealable container including a substantially rigid housing having an inner surface and an opening, and a liner including: a) a collar formed at least from a fluoropolymer material and sized and shaped to removably engage the opening in the housing; and b) a flexible bag, having an opening, sealed to the collar, and including a composite of an abrasion resistant reinforcing material and an inner fluoropolymer material that is substantially inert to the contents of the container and compatible with the fluoropolymer material of the collar, the bag being sized and shaped to pass through the opening in the housing and to expand such that an outer surface of the flexible bag can be in contact with at least a substantial portion of the inner surface of the housing.

Also provided is a sealable container lining including a collar formed at least from a fluoropolymer material and sized and shaped to removably engage an opening in a liner housing, and a flexible bag, having an opening, sealed to the collar, and including a composite of an abrasion resistant reinforcing material and an inner fluoropolymer material that is substantially inert to the contents of the container and compatible with the fluoropolymer material of the collar, the bag being sized and shaped to pass through the opening in the liner housing and to expand such that an outer surface of the flexible bag can be in contact with at least a substantial portion of an inner surface of the housing.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a schematic cross section of a container suitable for transporting liquids such as pure chemicals or solvents.

FIG. 2 is a schematic cross section of a portion of the container liner.

FIG. 3 is a schematic cross section of another liner.

FIG. 4 is a schematic cross section of yet another liner.

FIG. 5 is an exploded schematic cross section of a neck portion of a container of FIG. 1.

DETAILED DESCRIPTION

It will be appreciated that the following description is intended to refer to specific representative examples of structure selected for illustration in the drawings and is not intended to define or limit the disclosure, other than in the appended claims.

Without being bound by any particular theory, it is believed that one problem with leakage and contamination associated with larger size containers lies with the fact that the containers are typically only filled to about 90% of their ultimate capacity prior to transport to their ultimate destination. This partial filling allows for temperature changes that occur during transportation to permit expansion and contraction of the material within the liner. Leaving about 10% of the total capacity of the liner unfilled permits such expansion without danger of the flexible liner bursting or rupturing due to excessive pressure. However, when the contents of the container are at less than their full expansion capacity, such as at 90%, or 92% or 93%, for example, there is sufficient space for the liquids to move within the liner either gently depending on the handling circumstances, or comparatively violently.

Given the volume of the liquid and its accompanying mass, the movement within the flexible liner can cause the formation of pinholes or even small tears in the relatively thin flexible liner, typically having a thickness of about 2 to 10 mils. Such movement of liquid within a container relative to the liner may occur when the container is transported by forklift, hand truck or even in a moving vehicle. This movement causes the liquid to move within or “slosh” around the container, particularly where there is space at the upper portion of the liner and where the neck of the liner is not fully expanded into contact with the inner surface of the container, thereby causing the upper portion of the liner to intermittently and repeatedly move along the inner surface of the container or fold over onto itself. As a result of the movement along the inner surface, the liner develops pinholes from the abrasive movement and/or folds onto itself creating sharp creases which itself may cause additional pinholes. Moreover, such movement of the liquids can place stress at the connection between the flexible liner and its collar seated on the opening of the liner housing.

It has been discovered that solutions to this problem include providing a sealable and flexible container lining which includes a collar formed from a fluoropolymer material which is sized and shaped to removeably engage the opening in the container housing; and a flexible liner bag having an opening that is sealed to the collar. The flexible liner bag comprises a composite of an abrasion resistant reinforcing material and an inner fluoropolymer material that is substantially inert to the contents of the container and compatible with the fluoropolymer material of the collar. The bag is sized and shaped to pass through the opening in the housing and may expand such that an outer surface of the flexible bag can be in contact with at least a substantial portion of the inner surface of the housing. Using an inner fluoropolymer material as the interior flexible liner is desirable as it is inert to many chemicals typically used in larger containers such as a wide variety of organic solvents.

On the other hand, the abrasion resistant reinforcing material provides abrasion resistance and strength to the exterior portion of the liner to prevent the formation of pinholes and tears typically caused by the movement of liquid within standard liners.

The inner fluoropolymer material may be selected from a wide variety of fluoropolymer materials. Representative examples include at least one material selected from PFA (perfluoroalkoxy), PTFE (polytetrafluoroethylene), ECTFE (ethylene chlorotrifluoroethylene), FEP (fluorinated ethylene propylene) and ETFE (ethylene tetrafluoroethylene). These are merely representative fluoropolymer materials and other known fluoropolymer materials may be used as desired.

The abrasion material reinforcing material can be selected from a wide variety of abrasion resistant materials such as, for example, at least one selected from fiberglass webs, LDPE, polyamides and the like provided in various forms such as, for example, fibers, yarns, particles, aggregates, fabrics and the like. Various types of NYLON® material may be used as preferred polyamides.

The flexible liner collar should also be formed at least from a fluoropolymer material. The fluoropolymer material may be the same as or different from that of the inner fluoropolymer material of the flexible liner bag. Preferred materials include PFA and PTFE, for example.

An unexpected problem has also been discovered when connecting the flexible liner bag having the abrasion resistant material to the liner collar. This connection must be liquid tight and resistant to the stresses applied to that connection point as the liquid moves within the liner. While the abrasion resistant reinforcing material solves the tearing problem by adding strength to liners, introducing the abrasion resistant reinforcing material into the liner, however, can cause a new problem—the ability to successfully connect the flexible bag to the collar. This is because the abrasion resistant reinforcing material typically has physical characteristics such as softening or melting temperatures different from the fluoropolymer material of the collar, thereby making it more difficult to have a reliable seal or connection point between those two components. For example, when the abrasion resistant reinforcing material is a fiberglass web, that web material has very different chemical and physical characteristics and would not likely be as easily sealed to the collar. Despite the incompatibility of those materials, it was discovered that it is possible to reliably seal the composite material of the flexible bag to the collar by conventional, known means such as heat welding, as one example.

Turning now to the drawings, FIG. 1 shows a sealable container 10 which includes a substantially rigid housing 12 and a flexible liner 14 sized and shaped to fit within the housing 12. The housing 12 includes an upper flange 16 which essentially assists in protecting the neck portion of the housing and a lower flange 18 that helps to stabilize the bottom of the container 10. The substantially rigid housing 12 can be made from any number of high strength materials such as fiberglass materials, hard plastics, various metals such as stainless steel or the like.

FIG. 1 shows the liner 14 in a fully expanded configuration wherein the liner is adjacent essentially to the entirety of the inner surface of housing 12. The liner 14 comprises a collar 20 and a flexible bag 22. The flexible bag 22 may be a composite that can be formed in several configurations. A particularly advantageous configuration is a plurality of layers. Representative, non-limiting examples include the configurations shown in FIGS. 2 and 3, for example. In that regard, FIG. 2 shows a two layer configuration wherein an inner fluoropolymer material is shown as layer 24 and the abrasion resistant reinforcing material is shown as layer 26. These are distinct layers laminated together by any known means. FIG. 3 shows the same distinct layers 24 and 26. However, a distinct adhesive layer 28 is sandwiched between layers 24 and 26.

FIG. 4 shows a composite wherein the layers are not distinct in the same manner as in FIGS. 2 and 3. The inner fluoropolymer material and the abrasion resistant reinforcing material are combined into a single layer 30 which, in this instance, has an upper portion 32 that is primarily formed of the inner fluoropolymer material and a lower portion 34 that is primarily the abrasion resistant reinforcing material. This structure may be made by known methods such as, for example, by casting the fluoropolymer material over the abrasion resistant material or impregnating the fluoropolymer material into the abrasion material. Other configurations with additional and/or different distinct or non-distinct layers or combinations thereof are contemplated.

The flexible bag 22 is typically a thin bag having a wall thickness of about 0.002 inches (0.0508 mm) to about 0.010 inches (0.254 mm) although other thicknesses may be used. A wall thickness of about 0.004 inches (0.1016 mm) is preferred. The wall thickness of the overall bag can be influenced by the number of layers as shown in FIGS. 2-4. Also, the thicknesses of the various layers can be varied with respect to one another. The configuration shown in FIG. 4 is typically the thinnest of the layers or configurations of the flexible bag since the fluoropolymer material in that instance may be cast over at least one side of the abrasion resistant material, which provides maximum functionality with minimum thickness.

FIG. 5 shows an exploded view of a neck portion 36 of housing 12 and liner 14. Flexible liner 14 includes not only flexible bag 22, but also collar 38. Collar 38 may, for example, be heat welded to the inner fluoropolymer material of flexible bag 22. The collar 38 is seated on opening 40 of neck portion 36. The neck portion 36 has a plurality of threads 42 which engage threads 44 of cap 48.

This arrangement allows for the flexible liner 14 to be inserted through opening 40 and have collar 38 seated in a fixed position at opening 40 so that it will not move during transportation. It also serves as a point to anchor the flexible liner 14 for potential expansion into substantially complete contact with the inner surface of housing 12. Cap 48 sealingly engages the flange portion 46 of collar 38 and compresses flange portion 46 between cap 48 and opening 40. This creates a reliable seal during transportation.

Thus, the user procures an empty housing 12, inserts flexible liner 14 through opening 40, fills flexible liner 14 to a preferred capacity such as about 90%, and then seals the container for transport. This system is able to reliably transport containers full of liquids such as pure chemicals, organic solvents or the like in large quantities such as 100 to 200 liters or more without developing pinholes in the flexible bag 22 or tears between the collar 38 and flexible bag 22.

Although apparatus and methods have been described in connection with specific forms thereof, it will be appreciated that a wide variety of equivalents may be substituted for the specified elements described herein without departing from the spirit and scope of this disclosure as described in the appended claims.

Claims

1. A sealable container comprising:

a substantially rigid housing having an inner surface and an opening; and

a liner comprising: a) a collar formed at least from a fluoropolymer material and sized and shaped to removably engage the opening in the housing; and b) a flexible bag, having an opening, sealed to the collar, and comprising a composite of an abrasion resistant reinforcing material and an inner fluoropolymer material that is substantially inert to contents of the container and compatible with the fluoropolymer material of the collar, the bag being sized and shaped to pass through the opening in the housing and expand such that an outer surface of the bag can be in contact with at least a substantial portion of the inner surface of the housing.

2. The sealable container of claim 1, wherein the inner fluoropolymer material is formed from at least one material selected from the group consisting of PFA (perfluoroalkoxy), PTFE (polytetrafluoroethylene), ECTFE (ethylene chlorotrifluoroethylene), FEP (fluorinated ethylene propylene) and ETFE (ethylene tetrafluoroethylene).

3. The sealable container of claim 1, wherein the collar and the inner fluoropolymer material are heat welded together.

4. The sealable container of claim 1, wherein the abrasion resistant reinforcing material is at least one selected from the group consisting of a fiberglass web, an LDPE layer and a polyamide layer.

5. The sealable container of claim 1, further comprising an adhesive layer positioned between the abrasion resistant reinforcing material and the inner fluoropolymer material.

6. The sealable container of claim 1, wherein the bag has a thickness of about 0.002 inches (0.0508 mm) to about 0.010 inches (0.254 mm)

7. The sealable container of claim 1, wherein the inner fluoropolymer material is cast over at least one side of the abrasion resistant reinforcing material.

8. A sealable container lining comprising:

a collar formed at least from a fluoropolymer material and sized and shaped to removably engage an opening in a liner housing; and

a flexible bag, having an opening, sealed to the collar, and comprising a composite of an abrasion resistant reinforcing material and an inner fluoropolymer material that is substantially inert to contents of the lining and compatible with the fluoropolymer material of the collar,

the bag being sized and shaped to pass through the opening in the housing and to expand such that an outer surface of the bag can be in contact with at least a substantial portion of an inner surface of the housing.

9. The liner of claim 8, wherein the inner fluoropolymer material is formed from at least one material selected from the group consisting of PFA (perfluoroalkoxy), PTFE (polytetrafluoroethylene), ECTFE (ethylene chlorotrifluoroethylene), FEP (fluorinated ethylene propylene) and ETFE (ethylene tetrafluoroethylene).

10. The liner of claim 8, wherein the collar and the inner fluoropolymer material are heat welded together.

11. The liner of claim 8, wherein the abrasion resistant reinforcing material is at least one selected from the group consisting of a fiberglass web, an LDPE layer and a polyamide layer.

12. The liner of claim 1, wherein the bag has a thickness of about 0.002 inches (0.0508 mm) to about 0.010 inches (0.254 mm)

13. The liner of claim 8, wherein the inner fluoropolymer material is cast over at least one side of the abrasion resistant reinforcing material.

14. A sealable container for solvents comprising:

a substantially rigid housing having an inner surface and an opening; and

a liner comprising: a collar formed at least from a fluoropolymer material which is at least one selected from the group consisting of PFA and PTFE and sized and shaped to removably engage the opening in the housing; and a flexible bag, having a thickness of about 0.002 inches (0.0508 mm) to about 0.010 inches (0.254 mm) and an opening, heat sealed to the collar, and comprising a composite of an abrasion resistant reinforcing material which is at least one selected from the group consisting of a fiberglass web, an LDPE layer and a polyamide layer, and an inner fluoropolymer material that is substantially inert to contents of the liner, compatible with the fluoropolymer material of the collar and is at least one selected from the group consisting of PFA (perfluoroalkoxy), PTFE (polytetrafluoroethylene), ECTFE (ethylene chlorotrifluoroethylene), FEP (fluorinated ethylene propylene) and ETFE (ethylene tetrafluoroethylene), the bag being sized and shaped to pass through the opening in the housing and to expand such that the abrasion resistant reinforcing material can be in contact with at least a substantial portion of the inner surface of the housing; and a sealing member sized and shaped to attach the collar to the opening in the housing and sealingly close the flexible bag such that the collar is not movable and the contents of the liner are held in the container.