Web with sealed pockets

Abstract

A web is formed from two sheets of polymeric material. An upper sheet includes pockets of any form. A lower sheet is subsequently bonded to the upper sheet which causes the sealing of each of the pockets. A web thus formed may be laminated with a metallic foil or metallized polymeric film. Such a web may also be laminated with a similar web in a face to face relationship so that the pockets interdigitate.

Description

TECHNICAL FIELD

[0001] The invention pertains to webs or sheets that include sealed pockets. More particularly, the invention pertains to laminates formed from such webs.

BACKGROUND ART

[0002] International Patent Application No. PCT/AU98/00494 (International Publication No. WO99/00161) discloses a protector pad which is formed from a web which is fabricated to include a number of sealed bubbles which provide a shock absorbing effect. That document is included herewith by reference.

[0003] The present invention proposes certain improvements which allow the invention to be employed in new fields and in new ways.

DISCLOSURE OF INVENTION

[0004] Accordingly, there is provided a web, comprising:

[0005] two sheets of polymeric material;

[0006] a first sheet having an array of pockets formed into it;

[0007] a second sheet bonded to the first sheet so as to seal the pockets.

[0008] In another embodiment of the invention, a laminate is formed from two webs, each comprising overlying sheets of flexible material sealed together with a plurality of spaced apart, non-connected, air-filled pockets. Each web further comprises a flat side and a pocketed side. The pocketed sides of each web are joined, interdigitated or tessellated to form a laminate having two flat sides.

[0009] In other embodiments of the invention, the laminate formed by joining the two webs is laminated with a metallic foil or metallised polymeric film.

BRIEF DESCRIPTION OF THE DRAWINGS

[0010] FIG. 1 is a plan view of one embodiment of a web formed in accordance with the teachings of the present invention,

[0011] FIG. 2 is an end view of one embodiment of a laminate formed in accordance with the teachings of the present invention,

[0012] FIG. 3 is a schematic top plan view illustrating the arrangement of pockets in the laminate of FIG. 2.

MODES FOR CARRYING OUT THE INVENTION

[0013] As shown in FIG. 1, a web 10 is formed from two sheets of polymer material. An upper sheet 11 includes vacuum-formed pockets 12. The pockets 12 may take any shape and are shown as being square for the purposes of the present example. Accordingly, the perimeter 13 of each pocket may take practically any form. The upper surface 14 and perimeter walls 15 of each pocket are integrally formed by a vacuum or other moulding process into the upper sheet 11. The upper sheet 11 is subsequently bonded to a lower sheet 16, which operation causes the sealing of each of the pockets 12. With reference to FIG. 1 it can be seen that the pockets 12 form a regular two-dimensional array which may be conveniently viewed as having any number of rows R and columns C. Pockets 12 in any row or column have the same spacing, but adjacent rows R (or columns C, or both) are offset by an amount O so as to form a regular array of pockets 12 and gaps 17.

[0014] In preferred embodiments of the invention a gap 17 is formed between adjacent pockets 12. The gap 17 is large enough to accommodate a pocket 12.

[0015] As shown in FIG. 2, two webs 11, 20 may be assembled and optionally joined to form a laminate 21. Owing to the arrangement of the webs 11 disclosed with reference to FIG. 1, the pockets 12 face one another, interdigitate or tessellate to form a compact structure. As shown in FIG. 2 and with respect to a row of pockets 12, pockets of the top layer are seen as alternating with pockets of the bottom layer. The webs 11, 20 may be sealed together, or not.

[0016] FIG. 3 illustrates a laminate 21 with internal pockets 12 of the variety depicted in FIG. 2. It will be appreciated that the array of pockets is shown as relatively closely packed with only small gaps G between any two adjacent pockets 12. It will appreciated that the size and spacing of the pockets may be altered to achieve different packing densities, laminate stiffness, impact or sound absorbing qualities. Neither the gaps 17, nor the pockets 12 need all be the same size so long as the pockets interdigitate or tessellate to form a compact structure with parallel outside surfaces 23, 24.

[0017] Another embodiment of the invention is suggested in FIGS. 1 and 2. In this embodiment, the outside surface of one web 23 or both 23, 24 are provided with enhanced properties by further lamination with a metallic foil or metallised polymeric film 30. The application of, for example, an aluminium foil or aluminium powder coated polyester film 30 provides improved insulation and provides for the reflection of radiant heat energy.

[0018] The structures of the present invention have a wide variety of uses. Single webs of the type depicted in FIG. 1 may be used for vibration isolation, impact protection and as noise insulation. A web of this type further laminated with the metal foil or film 30 serves as a better thermal insulator. Webs which are laminated together 21 as shown in FIG. 2, may be used as sound or noise insulation and may be engineered with a fixed, predetermined gap A between webs which optimises noise abatement and particular frequencies or otherwise provides for better insulation. The gap A may be filled with a foam or gas (air or other gas) or liquid.

[0019] While the present invention has been disclosed with reference to particular details of construction, these should be understood as having been provided by way of example and not as limitations to the scope or spirit of the invention. In particular, the dimension, shape and depth of the pockets is not considered essential to the utility of the invention. Similarly, the materials of construction and the precise methods of lamination are not considered essential.

Claims

1. A web, comprising: two sheets of polymeric material; a first sheet having an array of pockets formed into it; a second sheet bonded to the first sheet so as to seal the pockets.

2. The web of claim 1, further comprising: a metallic foil or metallised polymeric film bonded to an outside surface of the second sheet.

3. The web of either of claims 1 or 2, wherein: adjacent pockets are spaced apart from one another enough to accommodate a pocket.

4. The web of any one of claims 1 to 3, wherein: the pockets are arranged into an array of rows and columns and adjacent rows or columns are offset with respect to one another.

5. In combination, a first web of any type claimed in any one of claims 1 to 4 and a second web of any type claimed in any one of claims 1 to 4, wherein: the two webs are assembled to form a laminate; the pockets of each web facing one another and interdigitating.

6. The combination of claim 5, wherein: the pockets of each web tessellate.

7. The combination of either of claims 5 or 6, wherein: the pockets of both webs form a compact structure.

8. The combination of any one of claims 5 to 7, wherein: the two webs are joined together.

9. The combination of claim 8, wherein: the two webs are spaced apart by a gap of fixed dimension.

10. The combination of claim 9, wherein: the gap is filled with a substance selected from the group comprising: foam, liquid or gas other than air.

11. A web, substantially as hereinbefore disclosed with reference to any one of the drawing figures.

12. Two webs, substantially as hereinbefore disclosed with reference to either of FIG. 2 or 3.