| 摘要 |
<p>1,209,693. Elastic laminates. MINNESOTA MINING & MFG. CO. 17 May, 1968 [19 May, 1967], No. 23694/68. Heading B5N. An elastic shirred material is resiliently extensible by at least 1/3 of its length and comprises spaced elastic yarns between two webs, at least one of which is a non-woven porous fibrous web, the whole being bonded and impregnated with a polymeric binder and the yarns being under partial tension in the bonded structure. The elastic yarns may be spenelex, polyurethane or rubber yarns and may be spaced at 2 to 8 yarns/inch. Both webs may be non-woven porous, fibrous webs, e.g. batts of rayon or polyester staple fibres or mixtures of these, or one web may be non- porous, e.g. polyethylene film, aluminium foil or a reflective film or foil. The product may be self-adherent under pressure, either at room temperature if natural rubber latex is used as binder, or at elevated temperature if a polyethyl acrylate dispersion is used. As shown to make the web elastic yarns 10 are unwound under tension provided by brake 12 and passed, with non-woven fibrous webs 15, 17 through squeeze rolls 19, 20, the latter dipping into binder mixture 22. The laminated web passes through drying oven 24, pull drums 25, 26, heating platens 28, 29 (which heat the web to 200- 250‹ F. under reduced tension so that the yarns partially contract and the webs pucker) and pull drum 30. Squeeze rolls 19, 20 rotate at greater surface speed than roll 11 to stretch yarns 10, this speed being maintained on drums 25, 26, but reduced in pull drum 30 and wind-up roll 32 to permit shrinkage of the web as shown. The finished product may be further shrunk by heat treatment.</p> |
