PADDED POSTAL BAG

Abstract: A padded postal bag comprises Kraft paper outer skins (1 and 2) with an internal impact absorbing lining comprising sheets (3 and 4) and sheets (5 and 6), each sheet having air filled capsules (7) provided on a surface. The sheet (3) has the capsules adjacent the planar surface of sheet (4) and the sheet (5) has the capsules adjacent the planar surface of sheet (6). Thus smooth surfaces to the inside (8) of the bag are provided. The peripheral closed sides (9) of the bag are heat sealed using pressure to fuse the sheets (3, 4, 5, 6) and the outer skins (1 and 2) together. The opening to the bag has a flap and the sheets (3 and 4) are fused to skin (1) whilst the sheets (5 and 6) are fused to skin (2) thus allowing the contents to be inserted into the inside (8).

Description: Padded postal bag This invention relates to improvements in packaging and is primarily, but not essentially, concerned with packaging compπsing postal bags which are padded to provide protection for the contents Materials are known for packaging purposes which comprise a plastics material with a large number of bubbles or capsules on one surface filled with air Such materials may be provided as a lining on the inner surfaces of an envelope In such constructions it is difficult to increase the degree of padding and hence the impact resistance whilst still retaining sufficient strength and having each capsule filled with air at near ambient pressures There is also a tendency for the capsules to burst when localised impact occurs, particularly if the contents are πdged and angular It is an object of this invention to provide an improved packaging matenal and an envelope structure incorporating same which has superior characteristics as far as protection of the contents is concerned and without substantial weight increase In accordance with this invention there is provided packaging material formed from a sheet material having a plurality of projections formed by regularly spaced air filled capsules each occupying discrete areas on said sheet, said packaging material comprising two or more of said sheets superposed with a side of one sheet lying coplanar with and adjacent a side of the another sheet In accordance with this invention there is also provided packaging material formed from a sheet material with a first side being substantially planar and a second side having a plurality of projections formed by regularly spaced air filled capsules each occupying discrete areas on said sheet, said packaging material comprising two or more of said sheets superposed with the first side of one sheet lying coplanar with and adjacent the second side of the another sheet Preferably the two sheets forming the packaging matenal are secured together either at regular spaced discrete locations or at the boundary edges This invention also provides a bag, enclosure or envelope wherein at least one internal surface is lined with or formed from said packaging material arranged such that a first side of a sheet forms the internal surface Preferably both facing or all the internal surfaces will include the sheets In a preferred construction the two superposed sheets forming he packaging are connected It is preferable for the capsules on adjacent sheets to be generally in alignment that is one capsule on one sheet lies in coincidence with another on another sheet It has been found surprisingly, that this arrangement allows the sheets to slide over one another by a limited amount and for the capsules on one sheet to partly fill the gaps on the other sheet This provides an unexpected cushioning effect greater than would be expected from the aggregate properties of the two sheets and giving much improved cushioning against sustained pressure with reduced capsule bursting The sheets used may be so-called barner sealed which includes a layer of nylon material preventing diffusion of air from the capsules or non-barrier sealed which is more appropriate to the short life of postal bags It has been found that with the capsule side of one sheet against the flat side of the second sheet the two sheets slide and better accommodate and cushion the contents The two capsule sides could be positioned in face to face contact as an alternative In an alternative construction a single sheet may be provided with capsules on each side In yet another construction the capsules on each sheet, or on opposed sides of the one sheet have different dimensions This invention also provides a method of making a postal bag or the like enclosure wherein the two sheets are brought together and in contact with the bag outer skin material and thereafter heat sealed around the overlapped edges to form the sides and bottom of the bag, the heat sealing forming an integral structure More specifically this invention provides a method for the manufacture of a postal envelope or bag comprising the steps: a) laying a first sheet of packaging material having a first planar side and a second air filled capsule side onto an outer envelope sheet, b) laying a second sheet of said packaging material onto the first sheet, to form a first envelope component, c) laying a second envelope component of similar construction to said first component onto the said first component wherein the two second sheets of packaging material are in face to face relationship, d) applying heat and pressure along boundaries defining the periphery of the envelope to collapse the capsules and fuse to the sheets into bonded relationship, and e) cutting through the structure along the boundaries to provided individual envelopes. This invention will be further described and illustrated with reference to an embodiment shown by way of example in the drawings. In the drawings Fig.1 shows a typical postal bag incorporating this invention, Fig.2 shows a fragmentary cross-sectional perspective view of the postal bag, and Fig.3 shows a fragmentary plan view with the layers successively peeled away. Referring to the drawings an envelope or postal bag comprises two outer skins formed by sheets 1 and 2 of paper or plastics material The sheet 2 is extended to form a flap 2a which may be overlapped with the sheet 1 to close the open mouth 2b of the bag using adhesive or mechanical fastenings As shown in Figs 2 and 3 the inside of the bag thus formed has adjacent, and possibly connected to, each outer sheet 1 and 2 two further sheets of packaging material 3,4 and 5,6. Each of these sheets 3,4 and 5,6 include capsules 7 on their one surfaces which define air filled capsules As may be seen this provides a smooth inside 8 to the bag. All the sheets 1,2,3,4,5,6, are brought together at the three closed peripheral edges 9 forming the sides and end of the bag and then joined by heat sealing under pressure or with the use of adhesives. As shown in Fig. 2 the material sheets 3,4,5 and 6 are flattened and then fused together at 9a and together with the outer sheets 1 and 2 At the open end of the bag 2b sheets 3 and 4 are fused to the sheet 1 and sheets 5 and 6 are fused to the sheet 2 thus providing an opening to the inside 8 The material 1 and 2 may be a plastics laminated Kraft paper which will then bond with the sheets 4 and 6 under heat sealing. It will be understood that the heat sealing will squash the capsules 7 at the edges 9 The construction provides a much improved degree of padding having excellent impact resistance and enhanced strength and a particular feature is the planar surface of one sheet 4,6 being adjacent the capsulated surface of the other sheet 3,5 The overall construction and method of making the bag or envelope is similar to known arrangements except that the two sheets 3,4 and 5,6 are fed from rolls of matenal and brought together If preferred the adjacent sheets 3,5 and 4,6 can be formed from a continuous sheet which is folded on itself at one, or possibly more, of the side edges It is also possible to produce a sheet with the capsules to one side over part of the width and to the other side over another adjacent part of the width whereby the sheet can be folded at an edge to form adjacent sheets 3,4 and 5,6 In practical constructions the capsule diameter is between 2 and 30mm with the capsule height being between 1 and 10mm In general terms the ratio of diameter to height of the capsules will be between 2 1 and 3 1 It is convenient for the inner surfaces of the bag to be smooth but for some applications where it may be preferable for loose contents to be restrained the capsules may face the inside Although heat bonding is preferred other mechanical connections can be used such as staples or stitching More specifically, therefore, this invention provides a padded postal bag comprises Kraft paper outer skins 1 and 2 with an internal impact absorbing lining comprising sheets 3 and 4 and sheets 5 and 6 each sheet having air filled capsules 7 provided on a surface. The sheet 3 has the capsules adjacent the planar surface of sheet 4 and the sheet 5 has the capsules adjacent the planar surface of sheet 6. Thus smooth surfaces to the inside 8 of the bag are provided. The peripheral closed sides 9 of the bag are heat sealed using pressure to fuse the sheets 3,4,5,6 and the outer skins 1 and 2 together. The opening to the bag has a flap and the sheets 3 and 4 are fused to skin 1 whilst the sheets 5 and 6 are fused to skin 2 thus allowing the contents to be inserted into the inside 8.

Claims: CLAIMS 1. A packaging material formed from a sheet material having a plurality of projections formed by regularly spaced air filled capsules each occupying discrete areas on said sheet, said packaging material comprising two or more of said sheets superposed with a side of one sheet lying coplanar with and adjacent a side of the another sheet. 2 A packaging material formed from a sheet material with a first side being substantially planar and a second side having a plurality of projections formed by regularly spaced air filled capsules each occupying discrete areas on said sheet, said packaging material comprising two or more of said sheets superposed with the first side of one sheet lying coplanar with and adjacent the second side of the another sheet 3 A postal bag or envelope wherein an internal surface thereof is lined with a packaging material according to Claim 1 or 2. 4 A postal bag or envelope according to Claim 3, wherein the opposed facing internal surfaces are lined with the said packaging material 5 A postal bag or envelope according to Claim 3 or 4, comprising outer paper sheets, preferably with plastic coated inner surfaces, each with an internal lining comprising the packaging material, the outer sheets and the packaging material being joined by heat bonding around peripheral edges. 6 A postal bag or packaging material according to any preceding Claim, wherein the two sheets of packaging material are secured together at regular spaced locations or at the peripheral boundary edges only. 7 A postal bag or packaging material according to any preceding Claim, wherein the first side of a sheet, being the non-capsule side, forms the internal surface of the bag 8 A method for the manufacture of a postal envelope or bag comprising the steps a) laying a first sheet of packaging material having a first planar side and a second air filled capsule side onto an outer envelope sheet, b) laying a second sheet of said packaging material onto the first sheet, to form a first envelope component, c) laying a second envelope component of similar construction to said first component onto the said first component wherein the two second sheets of packaging material are in face to face relationship, d) applying heat and pressure along boundaries defining the periphery of the envelope to collapse and fuse the sheets into bonded relationship, and e) cutting through the structure at the boundaries to provided individual envelopes 9. A padded postal bag comprising Kraft paper outer skins with an internal impact absorbing lining comprising sheets of material each of which has air filled capsules provided on a surface, each outer skin having two such sheets forming the lining thereon with the one sheet having the capsules adjacent the planar surface of the second sheet and arranged to preferably present the smooth surfaces to the inside of the bag, the peripheral closed sides of the bag being heat sealed using pressure to fuse the sheets and connect the outer skins together, an opening to the bag having a flap and the sheets being fused to respective skins at the opening thus allowing access to the inside of the bag. 10. A packaging material or postal bag in accordance with any preceding Claim, wherein the two superposed sheets are formed from a single sheet of material which has been folded back on itself or retroverted to define two or more layers. 11 A packaging material or postal bag in accordance with any preceding Claim, wherein the capsules on one sheet have a different dimension to those on the other superposed sheet. 12 A packaging material or postal bag in accordance with any preceding Claim, modified in that a single composite sheet includes capsules on both sides 13. A packaging material or postal bag in accordance with any preceding Claim, wherein the capsules on the one sheet align with the capsules on the other sheet when the sheets are superposed. 14. A packaging material substantially as herein described and illustrated with reference to the drawings. 15. An envelope or postal bag as described herein and exemplified with reference to the drawings. 16. A method of making an envelope or bag substantially as described herein and exemplified. t l

Inventors: MAXWELL JOHN ANDREW, MAXWELL, JOHN, ANDREW
Applicants: ABBOTT S PACKAGING LTD, MAXWELL JOHN ANDREW, ABBOTT'S PACKAGING LTD., MAXWELL, JOHN, ANDREW
Application year: 1997
Main classification: B65D81
IPC codes: B65D81