BULK BAG LINER WITH RELIEF VALVE

Abstract

A bulk bag liner comprising a sidewall forming an enclosure having at least one relief valve mounted in the sidewall thereof for expelling excess gas from within the enclosure so as to prevent elevated pressure within the enclosure and reduce the chance that the liner will rupture.

Description

CLAIM OF PRIORITY

Applicant claims priority based on provisional application Ser. No. 60/747,387 filed May 16, 2006, the entire contents of which are incorporated herein by reference.

TECHNICAL FIELD

This invention relates to bulk bag liners, and more particularly to bulk bag liners having relief valves for expelling excess gas from within the bulk bag liners.

BACKGROUND AND SUMMARY OF THE INVENTION

It is well known in the art to use fluid impermeable liners within bulk bags when using bulk bags to store flowable materials that could permeate the walls of the bulk bags. Bulk bag liners are typically filled via an inlet spout at the top thereof and emptied via an outlet spout at the bottom or by perforating the film of a flat-bottomed liner.

One problem encountered when using bulk bag liners is that when the liners are filled with flowable materials the flowable materials tend to settle within the liners creating an air pocket near the top of the liners such that the liners may rupture either due to the elevated pressure or when other bags or items are stacked thereon. Another problem is that certain flowable materials, for example calcined clay, tend to produce gas that further increases the pressure within the liners and the chances of rupture, a phenomenon known as outgassing.

This invention addresses the foregoing problems. In accordance with its narrower aspects, the invention comprises the use of one-way relief valves in the sidewalls of bulk bag liners to relieve pressure generated by filling the liners and/or by outgassing from the flowable materials contained by the liners.

The relief valves utilized in the manufacture of the invention are known in the art and include means for expelling excess gas from within the liners and also for preventing gas from entering the liners from the atmosphere. In one embodiment the valve comprises a flap that opens only upon actuation by pressure within the liner. Further, the relief valves contain filter means for preventing particulate within the liners from contacting and clogging or otherwise rendering inoperable the means for expelling gas from within the liners. In one embodiment the filter means comprises a mesh layer having sufficiently small pores to prevent particulate matter from passing therethrough. Further, in one embodiment of the invention the relief valves are positioned substantially near the inlet spouts of the bulk bag liners because the contents of the liners tend to settle creating gas pockets near the tops of the liners.

BRIEF DESCRIPTION OF THE DRAWINGS

A more complete understanding of the present invention may be had by reference to the following Detailed Description when taken in connection with the accompanying Drawings, wherein:

FIG. 1 is perspective view of a bag liner comprising one embodiment of the present invention;

FIG. 2 is a perspective view from inside the bag liner shown in FIG. 1 of a relief valve comprising one aspect of the present invention;

FIG. 3 is a perspective view of the relief valve shown in FIG. 2 from outside the bag liner shown in FIG. 1; and

FIG. 3A is a perspective view of an alternate configuration of a relief valve from outside a bag liner.

DETAILED DESCRIPTION

Referring to the drawings, and in particular to FIG. 1, one embodiment of the invention is illustrated. The bulk bag liner 10 comprises a sidewall 12 formed from a multi-layered film. The sidewall 12 has a top end 14 and a bottom end 16 and forms an enclosure therebetween.

An inlet spout 18 is positioned at the top end 14 and is connected in fluid communication with the enclosure to facilitate filling of the bulk bag liner 10. An outlet spout 20 is positioned at the bottom end 16 and is also in fluid communication with the enclosure to facilitate emptying the bulk bag liner 10. A relief valve 22 is mounted in the sidewall 12 substantially near the inlet spout 20 for expelling gas that is accumulated within the enclosure near the top end 14. Although the embodiment shown comprises only one relief valve 22, the sidewall 12 may comprise multiple relief valves 22 positioned about the sidewall 12 as needed for different applications and particulates to be placed within the bag liner 10. In addition, the liner may comprise a flat-bottom without a discharge spout instead of the outlet spout 20 as needed for certain applications and particulates to be placed therein.

FIG. 2 illustrates a perspective view of the relief valve 22 from inside the bag liner 10. The relief valve 22 comprises a housing 24, and a filter 26 for preventing particulate matter from passing through the valve 22. FIG. 3 illustrates a perspective view of the relief valve 22 from outside the bag liner 10. The relief valve may comprise a plurality of vents 30 perforated into the housing 24 for allowing air to expel from the enclosure. The valve may be a multi-part valve commercially available such as those available from Keamark, Inc. FIG. 3A illustrates a filter 22a identical in function and structure to filter 22 except the filter 22a may comprise a different configuration of vents 30a perforated into the sidewall 12 within the perimeter of housing 24a.

The multi-layered film comprising the sidewall 12 may comprise a fluid impermeable material such as aluminum foil or 6-millimeter linear low-density polyethylene (LLDPE) along with a reinforcing material such as polyethylene terephthalate (PET) and layers of a sealing material such as high-density polyethylene, low-density polyethylene, and/or low-density polyethylene.

Although preferred embodiments of the invention have been illustrated in the accompanying Drawings and described in the foregoing Detailed Description, it will be understood that the invention is not limited to the embodiments disclosed, but is capable of numerous rearrangements, modifications, and substitutions of parts and elements without departing from the spirit of the invention.

Claims

1. A bulk bag liner comprising:

a sidewall formed from a fluid impermeable material and having a top and a bottom end;

the sidewall defining an enclosure;

an inlet spout in fluid communication with the enclosure, the inlet spout positioned at the top end thereof;

at least one relief valve mounted in the sidewall substantially near the inlet spout and comprising means for expelling gas from the enclosure and means for preventing particulate matter from passing through the valve.

2. The bulk bag liner according to claim 1 further comprising an outlet spout positioned at the bottom end of the sidewall, the outlet spout in fluid communication with the enclosure.

3. The bulk bag liner according to claim 1 wherein the means for expelling gas from the enclosure comprises a plurality of vents perforated in a housing comprising the valve.

4. The bulk bag liner according to claim 1 wherein the means for expelling gas from the enclosure comprises a plurality of vents perforated in the film beneath and within the perimeter of the valve.

5. The bulk bag liner according to claim 1 wherein the means for preventing particulate matter from passing through the valve comprises a filter.

6. A bulk bag liner comprising:

a sidewall having a top and a bottom end, the sidewall formed from a multi-layer film comprising a fluid impermeable layer, at least one reinforcing layer, and at least one sealing layer;

the sidewall defining an enclosure;

an inlet spout in fluid communication with the enclosure, the inlet spout positioned at the top end thereof;

at least one relief valve mounted in the sidewall substantially near the inlet spout and comprising means for expelling gas from the enclosure and means for preventing particulate matter from passing through the valve.

7. The bulk bag liner according to claim 6 further comprising an outlet spout positioned at the bottom end of the sidewall, the outlet spout in fluid communication with the enclosure.

8. The bulk bag liner according to claim 6 wherein the means for expelling gas from the enclosure comprises a plurality of vents perforated in a housing comprising the valve.

9. The bulk bag liner according to claim 6 wherein the means for expelling gas from the enclosure comprises a plurality of vents perforated in the film beneath and within the perimeter of the valve.

10. The bulk bag liner according to claim 6 wherein the means for preventing particulate matter from passing through the valve comprises a filter.

11. The bulk bag liner according to claim 6 wherein the fluid impermeable layer comprises aluminum foil.

12. The bulk bag liner according to claim 6 wherein the fluid impermeable layer comprises linear low-density polyethylene.

13. The bulk bag liner according to claim 6 wherein at least of the reinforcing layers comprises polyethylene terephthalate.

14. The bulk bag liner according to claim 6 wherein at least one of the sealing layers comprises high-density polyethylene.

15. The bulk bag liner according to claim 6 wherein at least one of the sealing layers comprises low-density polyethylene.

16. The bulk bag liner according to claim 6 wherein at least one of the sealing layers comprises linear low-density polyethylene.