GB2321958A - Heat insulating bag - Google Patents

Abstract

A heat insulating bag includes a bag body (10) having at least a base wall (12) and a surrounding wall (13). Each of the base wall (12) and the surrounding wall (13) includes an outermost transparent layer (124, 134) made of a heat sealable plastic sheet material, a printed layer (121, 131) underlying the outermost transparent layer, an innermost layer (123, 133) made of a heat-sealable water-proof plastic sheet material, and an intermediate layer (122, 132) made of a heat insulating foam and provided between the innermost layer and the printed layer. The bottom edge (136) of the surrounding wall is heat sealed to the peripheral edge (125) of the base wall. An openable closure member (30) is attached to the surrounding wall (13). The heat insulating bag is free of stitching seams and is thus waterproof.

Description

HEAT INSULATING BAG The present invention relates to a heat insulating bag, more particularly to a water-proof heat insulating bag having heat insulating multilayer walls which are heat-sealed to one another.

Conventional heat insulating bags generally have flexible multilayer walls or laminates which include an insulating foam layer sandwiched between two fabric sheets made of natural or synthetic fabric materials.

Zippers are attached to the bags at their openings for releasably closing the bags. Such bags are generally formed by sewing or stitching so that sewing or stitching seams exist at the adjoining ends of the bag walls. Owing to the presence of stitching seams, such bags are not water-tight, though insulating.

An heat insulating bag was therefore suggested to include an inner waterproof plastic pouch inside the bag. The pouch is fastened to the inner side of the bag by means of interengageable fastening strips called

VelcroLstraps. However, the bag still have the following drawbacks: (1) The bag is formed by sewing with a considerable number of sewing stitches, thereby slowing the manufacturing rate and increasing the manufacturing cost.

(2) When a relatively cold or refrigerated object is put in the bag, the moisture condensed at the outer surface of the inner pouch can leak through the stitching seams of the bag.

(3) Since the seams and the fabric zipper are airpermeable, the heat insulating effect of the bag is still unsatisfactory.

(4) Since an additional inner pouch is required in the conventional heat insulating bag, the manufacturing process for making the bag is complicated.

The main object of the present invention is to provide a heat insulating bag which is free of stitching seams and which is not only waterproof but also heat insulating.

Accordingly, the heat insulating bag according to one aspect of the present invention includes a bag body having a base wall with a peripheral edge and a surrounding wall having a top edge and a bottom edge.

The heat insulating bag further includes a cover which has a peripheral portion. Each of the base wall, the surrounding wall and the cover includes an outermost transparent layer made of a heat sealable plastic sheet material, a printed layer underlying the outermost transparent layer, an innermost layer made of a heatsealable water-proof plastic sheet material, and an intermediate layer made of a heat insulating foam and provided between the innermost layer and the printed layer. The bottom edge of the surrounding wall is heat sealed to the peripheral edge of the base wall. The peripheral portion of the cover has a part heat-sealed to the top edge of the surrounding wall. The heat insulating bag further includes an openable closure member for closing a top opening defined by the top edge of the surrounding wall.

Other features and advantages of the present invention will become apparent in the following detailed description of the preferred embodiments with reference to the accompanying drawings, of which: Figure 1 is a perspective view illustrating the heat insulating bag according to a preferred embodiment of the present invention in an open position; Figure 2 is a cross-sectional view of the heat insulating bag of the preferred embodiment of Figure 2; Figures 3 and 4 illustrate the interengageable zipper engagement members of a zipper used in the preferred embodiment; and Figure 5 shows another embodiment of the invention in an open conaition.

Referring to Figures 1 and 2, the heat insulating bag 100 according to a preferred embodiment of the present invention includes a bag body 10, a cover 20 and a closure member.

The bag body 10 in the present embodiment is rectangular in shape and includes a base wall 12 with a peripheral edge 125 and a surrounding wall 13 having a top edge 135 and a bottom edge 136. The base wall 12 and the surrounding wall 13 cooperatively confines a receiving space 11 with a top opening 111. The base wall 12 includes an outermost transparent layer 124 made of a heat-sealable water-proof plastic sheet material, a printed layer 121 underlying the outermost transparent layer 124, an innermost layer 123 made of a heat-sealable water-proof plastic sheet material, and an intermediate layer 122 made of a flexible heat insulating foam and provided between the innermost layer 123 and the printed layer 121. The innermost layer 123 can be made of a flexible or semi-rigid plastic sheet material. The printed layer 121 is provided with printed designs thereon for aesthetic purposes. The transparent layer 124 is capable of protecting the printed layer 121 and enhancing the water-proof effect of the printed layer 121. The surrounding wall 13 also includes an outermost transparent layer 134 made of a heat-sealable waterproof plastic sheet material, a printed layer 131 underlying the outermost transparent layer 134, an innermost layer 133 made of a heat-sealable water-proof plastic sheet material, and an intermediate layer 132 made of a flexible heat insulating foam and provided between the innermost layer 133 and the printed layer 131 of the surrounding wall 13. The innermost layer 133 can be made of a flexible or semi-rigid plastic sheet material. The printed layer 131 is provided with printed designs thereon for aesthetic purposes. The transparent layer 134 is capable of protecting the printed layer 131 and enhancing the water-proof effect of the printed layer 131. The bottom edge 136 of the surrounding wall 13 is heat sealed to the peripheral edge 125 of the base wall 12 via a high frequency sealing process.

The cover 20 has a rectangular shape conforming to the bag body 10. The cover 20 includes a top portion 21 and a peripheral portion 22 with a predetermined height. The cover 20 includes an outermost transparent layer 214 made of a heat-sealable water-proof plastic sheet material, a printed layer 211 underlying the outermost transparent layer 214, an innermost layer 213 made of a heat-sealable water-proof plastic sheet material, and an intermediate layer 212 made of a flexible, heat insulating foam and provided between the innermost layer 213 and the printed layer 211. The innermost layer 213 can be made of a flexible or semirigid plastic sheet material. The printed layer 211 is provided with printed designs thereon for aesthetic purposes. The transparent layer 214 is capable of protecting the printed layer 211 and enhancing the water-proof effect of the printed layer 211. The peripheral portion 22 of the cover 20 has a part 24 heat-sealed to the top edge 135 of the surrounding wall 13 of the bag body 10.

The closure member in the present embodiment is in the form of a zipper 30 and is provided at the top opening 111 of the bag body 10 for fastening releasably and sealingly the remaining part of the peripheral portion 22 of the cover 20 to the top edge 135 of the surrounding wall 13 of the bag body 10. The zipper 30 has a first strip 32 which is made of a plastic sheet material and which is heat-sealed to the peripheral portion 22 of the cover 20 by means of a high-frequency sealing process, and a second strip 31 which is made of a plastic sheet material and which is heat-sealed to the top edge 135 of the surrounding wall 13 of the bag bodylo by means of a high-frequency sealing process.

The first strip 32 and the second strip 31 have overlapping portions which are respectively formed with interengageable zipper engagement members. The zipper 30 further has a handle member 33 which is operable to engage and disengage the zipper engagement members of the first and second strips 32, 31.

Referring to Figure 3 and 4, the first strip 32 of the zipper 30 has a substantially inverted figure three-shaped hook formation which includes an upper hook projection 321 with an inwardly bending end portion 321b, and a lower hook projection 322 which extends downwardly from the upper hook projection 321 and which has an inwardly bending end portion 322b. The secord strip 31 of Zr zipper 30 has a substantially figure three-shaped groove formation which includes an upper groove 332 arc 2 lower groove 311 for engaging the upper and lower nook projections 321, 322 c the inverted figure three-shaped hook formation, respectively.

Since the peripheral portion 22 of the cover 20 has a part 2 healed sealed to the top edge 135 of the surrounding wall 13 of the bag bod 10 and since the heat-sealed first and second strips 32, 31 of the zipper 30 has overlapping and interengaging portions which extends along the edge of the surrounding wall 13, the top opening of the bag body 10 can be closed in a fluid tight manner.

Referring to Figure 5, a heat insulating bag 100A according to a second preferred embodiment includes a bag body 10A which has a round base wall 12A with a peripheral edge 121A, a surrounding wall 13A which is composed of front and rear parts 13B and 13C that are heat-sealed together. The surrounding wall 13A has a top edge that defines a top opening IllA and a bottom edge heat sealed to the peripheral edge 121A of the base wall 12A. The base wall 12A and the surrounding wall 13A cooperatively confine a receiving space llA.

The surrounding wall 13A includes an outermost transparent layer 134A made of a heat sealable waterproof plastic sheet material, a printed layer 131A underlying the outermost transparent layer 134A, an innermost layer 133A made of a flexible or semi-rigid heat sealable water-proof plastic sheet material, and an intermediate layer 132A made of a heat insulating foam and provided between the innermost layer 133A and the printed layer 131A. The structure of the base wall 12A is similar to that of the surrounding wall 13A.

The heat insulating bag l00A further has a closure member 30A for closing the top opening lllA. The closure member 30A is in the form of a zipper having a first strip 32A and a second strip (not shown) which are both made of heat-sealable plastic sheet material.

The first strip 32A is heat sealed to the end portion of the rear part 13C of the surrounding wall 13A at seam 14. The second strip (not shown) is heat sealed to the top end.portion of the front part 13B of the surrounding wall 13A. The construction of the zipper engagement members of the zipper 30A conforms to that of the zipper 30.

As mentioned above, the heat insulating bag according to the present invention includes multilayer wall components and zipper strips which are heat-sealed to each other by means of a high-frequency sealing process so as to achieve a water-proof effect. Since time and labor-consuming sewing works are not necessary, the manufacturing cost can thus be reduced.

The bag body 10 of the heat insulating bag of the present invention can also be used outdoors as a container to fetch water since the bag body 10 is water-proof.

Claims (6)

1. CLAIMS: 1. A heat insulating bag characterized by: a bag body 10, 10A having a base wall 12, 12A with a peripheral edge 125 and a surrounding wall 13, 13A having a top edge 135 and a bottom'edge 136, and a top opening 111, lllA defined by said top edge; each of said base wall 12, 12A and said surrounding wall 13, 13A including an outermost transparent layer 124, 134, 134A, made of a heat sealable water-proof plastic sheet material, a printed layer 121, 131, 131A underlying said outermost transparent layer, an innermost layer 123, 133, 133A made of a heat-sealable water-proof plastic sheet material, and an intermediate layer 122, 132, 132A made of a heat insulating foam and provided between said innermost layer and said printed layer; said bottom edge 136 of said surrounding wall 13, 13A being heat sealed to said peripheral edge 125, 121A of said base wall; and a closure member 30, 30A attached to said surrounding wall 131, 13A for closing said top opening 111, 1llA, said closure member being openable for access to the inside of said bag body.
2. 2. The heat insulating bag according to Claim 1, characterized in that said closure member is in the form of a zipper 30, 30A which has first and second strips 32, 31 with overlapping portions formed interengageable zipper engagement members, respectively, at least one of said first and second strips 32, 31 being attached to said bag body 10, l0A by a heat sealing process.
3. 3. The heat insulating bag according to Claim 2, characterized in that one of said zipper engagement members has a substantially inverted figure threeshaped hook formation 321, 322, the other one of said zipper engagement membershaving a substantially figure three-shaped groove formation 311, 312 to engage said inverted figure three-shaped hook formation 321, 322.
4. 4. The heat insulating bag according to Claim 1, characterized in that said innermost layer 123, 133, 133A is semi-rigid.
5. 5. The heat insulating bag according to Claim 1, characterized in that said innermost layer 123, 133, 133A is flexible.
6. 6. The heat insulating bag as substantially hereinbefore described with reference to the drawings.