| 摘要 |
In order to produce a flat stitched butt seam in a textile web, the exposed portions of the sewing thread are pressed into the faces of the fabric, and are adhesively heat sealed to the faces of the fabric by a thermoplastic component of the sewing thread. The thread comprises at least 1% of a thermoplastic component having a flow temperature of between preferably 125 and 200 degrees, and at least 30% of a component which neither flows not deteriorates when heated to said temperature. The seam is subjected to a pressure of from 25 to 200 lb per sq. inch, preferably from 50 to 100 lb per sq. inch, depending on the materials, to embed the exposed threads into the web, the seam area is heated, while under pressure, to a temperature at least 25 degrees C. above said flow temperature, the temperature is maintained for up to one minute normally from 2 to 35 seconds, and the seam is then permitted to cool. If the thermoplastic component is non-fibrous, it may comprise from 1 to 40%, preferably from 3 to 30%, and may be present either as a coating on a thread, or by being distributed around the individual fibres of the second component. It may include plasticized, partially polymerized phenolformaldehyde resins, polyurethanes, polyvinyl acetates, polyvinyl butyrates, polyvinyl chlorides, acrylic monomers and methacrylic polymers. If the thermoplastic component is fibrous, it may comprise from 20 to 70%, preferably 50%, and may be in filament, multi-filament or staple form, separate from or blended with the second fibrous component. It may include polypropylene, polyethylene, polyvinyl alcohol, polyvinyl acetate, cellulose acetate and other thermoplastic derivatives of cellulose, polyvinyl butyrates and the lower melting nylons. If the textile web is to be subsequently subjected to a heating operation, the thermoplastic component may be a material which becomes thermo-setting upon heating, such as the aminoplats and phenoplasts. Preferably the second fibrous component is non-thermoplastic, e.g. cotton, rayon or wool, but nylons, ethylene glycol, terephthalic polyesters, acrylics and other relatively high melting thermoplastic materials can be used when the flow temperature is at least 25 DEG C. above the flow temperature of the first component. U.S.A. Specification 3,600,434 is referred to. |
