WARP-KNIT SUPPORT TAPE FOR LOOP AND HOOK FASTENERS

Abstract: A warp-knit support tape (l0) for hook and loop fasteners is disclosed which comprises a pile portion (ll) including a foundation of tricot stitches (l4) and single cord stitches (l5) and a multiplicity of pile-loops (l7) formed from chain stitches (l6). The tricot and single cord stitches are formed of crimped yarns, and there is additionally laid in a plurality of warp members (20) made of an elastic material (2l) to allow the tape (l0) to stretch particularly in its longitudinal direction.

Description: This invention relates generally to hook and loop fasteners and has particular reference to a stretchable warp-knit loop-carrying support tape engageable with a mating hook-carrying support tape. Certain prior art tapes for hook and loop fasteners have been proposed that are stretchable in the longitudinal direction. To the knowledge of the present inventor, however, there is no satisfactory prior art which teaches producing economically and efficiently a warp-knit tape which is stretchable longitudinally as desired for application to hook and loop fasteners. Japanese Patent Publication 55-38l2l discloses a woven tape for hook and loop fastener which incorporates an elastic yarn to render the tape stretchable as shown in Figure 6 of the accompanying drawings. Such prior art stretchable tapes are in the form of a relatively narrow strip, and attempts to make stretchable hook and loop fastener tapes of sufficient width from woven material have involved considerable manufacturing problems. The present invention seeks to provide a stretchable support tape for hook and loop fasteners which can be produced highly economically and efficiently. The present invention further seeks to provide a stretchable support tape which plays the loop part of a hook and loop fastener and which is formed by warp-­ knitting to increased width. These and other objects and features of the invention will be better understood from the following detailed description taken in conjunction with the accompanying drawings in which like reference numerals refer to like parts throughout the several views. According to the present invention, there is provided a warp-knit support tape for hook and loop fasteners which comprises a pile portion constructed with tricot stitches and single cord stitches, both stitches being formed of crimped yarns and chain stitches formed into pile-loops, and warp members of an elastic material laid in warpwise by idle swing. Figure l is a schematic diagram illustrating the construction of a warp-knit support tape embodying the invention; Figures 2a - 2d inclusive are diagrammatic representations of the various stitches incorporated in the support tape of Figure l; Figure 3 is a cross-sectional view of the support tape of Figure l; Figure 4 is a view similar to Figure 3 but showing the tape after being treated; Figure 5 is a view similar to Figure 4 but showing the tape in confronting relation to its mating hook part of a hook and loop fastener; and Figure 6 is a schematic representation on enlarged scale of a prior art woven support tape for hook and loop fasteners. Referring now to the drawings and Figure l in particular, there is shown a preferred form of a warp-knit support tape l0 to be used as a loop or female part of a hook and loop fastener. The support tape l0 consists of a pile portion ll and selvage portions l2 and l3 extending warpwise on opposite sides of the pile portion ll. The pile portion ll of the tape l0 is constructed with tricot stitches l4, single cord stitches l5, both stitches being interlaced to make up a foundation of the tape l0, and chain stitches l6 which form a multiplicity of pile-loops l7. For the tape l0 to be stretchable, the tricot stitches l4 and the single cord stitches l5 are crimped by suitable treatment. The tricot stitches l4 are of Link No. l-2/l-0/l-2/l-0 or 2-3/l-0/2-3/l-0, and the single cord stitches l5 are of Link No. 0-l/4-3/0-l/4-3, as shown in Figures 2b and 2c, respectively. The chain stitch l6 is of an open lap and represented by Link No. l-0/0-0/0-l/l-l or l-0/0-0/0-0/0-l/l-l/l-l, as shown in Figure 2a, and threads therefor are positively overfed beyond the normal rate of feed of threads for the remaining stitches and formed by sinker looping into pile-loops l7 extending over every other course. The pile-loops l7 are arranged to extend longitudinally of the tape l0 alternately along the right and left sides of wales l8 as shown in Figure 3, whereby increased opportunity is provided for the loops l7 to engage the hooks l9 on the mating tape as shown in Figure 5. The chain stitches l6 forming the pile-loops l7 are made of multifilamentary threads which may be also crimped. Designated at 20 is a warp member made of a covered yarn such as synthetic rubber yarn, Spandex yarn or other elastic yarn which is laid in by idle swing and has Link No. 0-0/l-l/0-0/l-l or 0-0/2-2/0-0/2-2 as shown in Figure 2d. The warp member 20 is knitted in place while being stretched and is allowed to shrink when removed from the knitting machine, and it may be laid in over each wale or over every other or more wales depending upon the construction and extent of stretch of the tape l0 desired. The selvages l2 and l3 extended over three wales l8 on opposite sides of the tape l0 as shown in Figure l and are constructed with the same knit threads as the pile portion ll except for the absence of pile-loops l7. The inclusion of warp members 20 enhances stretchability of the tape l0 particularly in the longitudinal direction which is preferrably from l.5 to 2 times. Figure 4 shows the loop-carrying or female support tape l0 after being finished. This finishing treatment includes heat-setting, dying, brushing and coating. Brushing is done to comb up and separate the pile-loop l7 into filamentary condition so as to facilitate their engagement with the hooks l9 on the male support tape l0′ as shown in Figure 5. The tape l0 is coated underside with a suitable elastic material 2l to anchor the pile-loops l7 in place against dislocation from the web of the tape l0, the elastic material 2l being silicone rubber, polyurethane foam, other elastic rubber or resin materials. As will appear apparent to one skilled in the art, the tape l0 is sewn or otherwise attached along the selvages l2 and l3 onto a garment article.

Claims: 1. A warp-knit support tape (l0) for hook and loop fasteners which comprises a pile portion (ll) constructed with tricot stitches (l4) and single cord stitches (l5), both stitches being formed of crimped yarns and chain stitches (l6) formed into pile-loops (l7), and warp members (20) of an elastic material laid in warpwise by idle swing. 2. A warp-knit support tape according to claim l, wherein said tape (l0) is coated underside with an elastic coating (2l). 3. A warp-knit support tape according to claim l, wherein said chain stitches (l6) are formed of multifilamentary yarns. 4. A warp-knit support tape according to claim l, said tape (l0) is finished by brushing to comb up and separate said pile-loops (l7) into filamentary condition.

Inventors: MATSUDA, YOSHIO
Applicants: YOSHIDA KOGYO K.K.
Application year: 1986
Main classification: D04B21
IPC codes: D04B21, A44B18