NZ200084A - Packaging bag with valve to close and open aperture(s)in bag wall - Google Patents

Description

2 00084 % NEW ZEALAND PATENTS ACT 1953 IU-9^ 1 ml No.: 200084 Date: 22 March 1982 COMPLETE SPECIFICATION "Improvements in or relating to a bag and valve arrangement" HE, U.E.B. INDUSTRIES LIMITED, a Company duly incorporated under the laws of New Zealand of 1-11 Short Street, Auckland, New Zealand, hereby declare the invention for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement: 200084 This invention relates to a bag and valve arrangement.

It is an object of the present invention to provide a bag and valve arrangement which will at least provide the public with a useful choice.

Accordingly, the invention consists in a bag and valve arrangement comprising a bag having an aperture or localized set of apertures in the wall thereof, a valve consisting of a panel of sintered polymer material located across said aperture or apertures and a membrane across said panel and said aperture or Or%uf> apertures such that gas flow in one direction ^fcondo to draw)said membrane towards said aperture or apertures and said panel and to substantially close said aperture or apertures and gas flow in the opposite direction allows said aperture or apertures to be opened to gas flow.

To those skilled in the art to which the invention relates, many changes in construction and widely differing embodiments and applications of the invention will suggest themselves without departing from the scope of the invention as defined in the appended claims. The disclosures and the descriptions herein are purely illustrative and are not intended to be in any sense limiting.

Two alternative forms of the invention will now be described with reference to the accompanying drawings in which: Figure 1 is a diagrammatic plan view of one form of the bag and valve arrangement according to the invention; Figure 2 is a diagrammatic cross section through the valve part of the bag and valve depicted in Figure 1; • 200084 Figure 3 shows a diagrammatic plan view of a second embodiment of bag and valve arrangement according to the invention; and Figure 4 shows a cross section through the valve part of the bag and valve shown in Figure 3. ——— / / / 2 000 8 4 Referring firstly to figures 1 and 2 of the drawings, a bag 5 is provided having an open mouth 6 and being joined at 7 along the remaining borders. The bag may be formed in any suitable material, for example, FVC, however the invention is applicable to other forms of bag including the multiwalled paper variety.

In one of the walls of the bag 5 is provided one or a localized set of apertures 8 and a valve in the form of a panel 9 of sintered polymer material is positioned so as to cover the aperture or apertures 8. In the embodiment depicted in figures % 1 and 2 the panel 9 is fixed to the outside of the bag and fixing is effected in any desired manner, for example by heat welding or by the use of adhesives.

A membrane is preferably associated with the bag so as to overlie panel 9 in a manner such that gas flowing in one direction tends to draw the membrane onto the panel and thus inhibit or prevent gas flow but so that gas flow in the opposite direction will tend to move the membrane away from the panel to allow gas flow. This may be achieved by fixing a section 10 of flexible gas impermeable material to the exterior of the bag, for example by heat welding at 11 so as to overlie panel 9. As shown the membrane 10 is in the form of a pocket fixed on three sides about panel 9, the open side 12 defining a gas passage 13.

The membrane can be formed of any suitable plastics material such as for example FVC.

Referring now to figures 3 and 4 one alternative arrangement of bag and valve is depicted in which bag 20 having closed sides 21 and an open side defining mouth 22 is provided with a panel k - i - 2 0008 4 23 of sintered polymer material fixed to the interior of one wall thereof. Provided in the bag wall where the same overlies panel 23 is one or more apertures. As shown the aperture comprises a simple slit 24 provided in the bag wall.

If it is desired to prevent gas flowing from the exterior of the bag 14 to the interior thereof, through panel 23 then slit 24 can be simply covered by a suitable membrane. By way of example the membrane could comprise a length of adhesive tape as indicated by reference numeral 25 in figure 4.

The sintered polymer panel 9 or 23 may be formed, for example, from polythene or polypropylene and a range of suitable materials is made by the Porex Company. The materials are classifed according to pore size and a suitable material for each application is selected according to what material is to be packaged in bags 5 or 20 and according to what venting rate is required.

The use of the invention is as follows: In use the bag 5 or 20 is filled with a non-liquid material that it is desired to package for example powdered milk, although of course other materials could be packaged therein.

The mouth 6 or 22 of the bag may then be closed for example by heat sealing and a low pressure source such as a vacuum pump applied either to the mouth 12 or the pocket formed by the membrane 10. Alternatively the vacuum source could be placed in the form of a cup over slit 24 so that air is exhausted from the bag through the aperture or apertures 8 or slot 24 and through the sintered polymer panel 9 or 23. Once the air has been 200084 substantially removed the low pressure vacuum pump or the like can be removed and if desired or necessary the mouth 12 can be sealed again for example by heat sealing or slit 24 covered by tape 25. It will be appreciated that with the embodiment depicted in figures 1 and 2, before heat sealing any tendency of gas to flow into the bag through the sintered polymer panel 9 and the apertures 8 will tend to cause the membrane 10 to be drawn onto the sintered polymer panel 9 and bag 5 thereby restricting gas flow and the membrane 10 will at that stage tend to be held in position by differential gas pressure thereacross.

Thus it can be seen that at least in the preferred form of the invention a bag and valve arrangement is provided which has the advantage that a plastics material may be used for the packaging in a manner such that gas entrapped with the product including gas such as air sorbed into the product can be removed after sealing of the bag. Thus tendency for powdered or small granular material to be drawn to the mouth of the bag during the removal of air therefrom is reduced.

It is a further advantage of the preferred form of the invention that with many powdered or granular materials this method of exhausting the air from the bag will allow the powdered material to compact thereby reducing the effective size of the package and improving stackability of the package.

Furthermore the use of a sintered polymer allows relatively well defined permeability to be achieved and also allows a relatively well defined particle size to be prevented from pasage through the sintered polymer.

V- 2 OOQ 8 4 With the tendency to compact it is envisaged that this will enable powdered materials to be packaged in the plastic liner and then paper wrapped rather than is necessary to now insert the bag either before or after filling into a preformed paper bag. ri 200084

Claims (6)

WHAT WE CLAIM IS:

1. A bag and valve arrangement comprising a bag having an aperture or localized set of apertures in the wall thereof, a valve consisting of a panel of sintered polymer material located across said aperture or apertures and a membrane across said panel and said aperture or apertures such that gas flow in one direction to-ads t>o draw said membrane towards said aperture or apertures and said panel and to substantially close said aperture or apertures and gas flow in the opposite direction allows said aperture or apertures to be opened to gas flow.

2. An arrangement as claimed in Claim 1 wherein said membrane is in the form of a flexible non-gas permeable material adhered or otherwise affixed to the outer surface of the walls of said bag about said aperture or apertures and said panel.

3. An arrangement as claimed in Claim 2 wherein said membrane is in the form of a pocket,.

4. An arrangement as claimed in any one of the preceding Claims . wherein said membrane is of a plastics material.

5. A bag and valve arrangement^when constructed arranged and operable substantially as hereinbefore described with reference to Figures 1 and 2 of the accompanying drawings. jQu• cjtamvif w- I

6. A bag and valve arrangement^when constructed arranged and operable substantially as hereinbefore described with reference to Figures 3 and 4 of the accompanying drawings. DATED THIS /^DAY OF A. J. PARK & SON h8f PER AGENTS FOR THE APPLICANT -8-