Fabric material

Description

[0001] The present invention relates to fabric materials and particularly to woven fabric materials including tapes of stretchable synthetic resinous material. The present invention is an improvement in and modification of one aspect of the invention disclosed in our co-pending European Patent Application No. 82.3036322.

[0002] In the said co-pending patent application there is disclosed in relation to Figures 1 and 2 a woven construction formed from flat polypropylene tapes which constitute both the warp and weft elements of a base fabric material. The weft tapes are produced with longitudinal zones of weakness which are localised weakened areas extending longitudinally in each weft tape before the tape is woven into the base fabric material. After weaving these weft tapes with longitudinally extendable warp tapes the woven fabric material is heated to a temperature at which the synthetic resinous material becomes softened, and is tensioned in the warp direction to stretch the fabric in the warp direction to approximately twice its original length.

[0003] As the heated warp tapes are stretched and extend longitudinally they interact on the weft tapes with which they are in frictional contact so that the weft tapes tend to split, either continuously or intermittently, along the weakened areas or zones into strips which are pulled apart. When the degree of stretch of the warp tape is sufficient, each longitudinally weakened weft tape splits into a series of narrow strips so that the number of weft tapes in the fabric is multiplied. On subsequent cooling of the stretched fabric under tension, the warp tapes bond to the subdivided weft tapes at the intersections to give a final product which is a stretched fabric with a high degree of dimensional stability.

[0004] Instead of providing continuous longitudinally extending localised weakened areas, for example continuous grooves extending longitudinally in the weft tape, the method according to the present invention provides for the formation of discontinuous longitudinally extending localised weakened areas in each weft tape.

[0005] The discontinuous longitudinally extending localised weakened areas may be arranged in groups of such areas with untreated portions of the tape between each group. Alternatively the discontinuous longitudinally extending localised weakened areas may be staggered so that most, if not all, of the length of the tape has one or more longitudinally extending area of laterally localised weakening within it.

[0006] When a woven fabric with weft tapes having discontinuous longitudinally extending localised weakened areas is heated and stretched under tension in the warp direction, the weft tapes tend to split at these discontinuous weakened areas so that each weft tape is broken down into a series of interconnected strips. The strips are pulled apart from one another by frictional contact with the warp tapes so that each weft tape takes on the appearance of a network, which may be regular or irregular depending on the arrangement of the discontinuous weakened areas in the original weft tape.

[0007] If the degree of stretch of the warp tapes is very high, the splits formed at the discontinuous weakened areas may be propagated lengthwise so that substantial lengths, and possibly the whole length, of the weft tapes are subdivided into separate weft tapes.

[0008] The treatment of the woven fabric formed with weft tapes as described is carried out substantially as described in our said co-pending European Patent Application No. 82.3036322 and the resulting product has similar advantages to those described for the product of the said co-pending patent application, including greater tenacity of the fabric (in grammes/dtex) in the warp direction, greater area of fabric for a given quantity of material, and good dimensional stability of the fabric when stretching of the fabric is undertaken under conditions permitting bonding of the warp and weft tapes at their intersections.

[0009] Instead of using the tapes with the discontinuous longitudinally extending localised weakened areas as weft tapes, they may be used as warp tapes in a fabric which is stretched transversely instead of longitudinally.

Claims

1. A method of manufacturing a fabric material comprising the steps of forming a woven base fabric of warp and weft tapes, stretching the base fabric to stretch longitudinally either the warp or the weft tapes and thereby obtain a stretched fabric having greater area than the original base fabric, characterised in that the other of the warp and weft tapes include discontinuous longitudinally extending zones of weakness and that, during stretching, at least some of the other tapes split at the zones of weakness.

2. A method according to Claim 1, characterised in that the weft tapes include discontinuous longitudinally extending localised weakened areas.