| 摘要 |
<p>1291361 Laminates EI DU PONT DE NEMOURS & CO 17 Feb 1970 [28 Feb 1969] 7659/70 Heading B5N [Also in Division D1]. A bonded non woven sheet of continuous polyester filaments, at least 80% of which are polyethylene terepthalate, has a net irreversible thermal shrinkage (as defined) in the lengthwise and widthwise directions of 1À2-5% when heated to 170‹ C. and cooled, and has a maximum heat releasable shrinkage temperature (as defined) of greater than 90‹C. The sheet can be bonded by cospun polyester copolymer filaments heated with hot air. The sheet is made by stretching the sheet between 1À2 and 5% simultaneously in both length and width, heating the stretched sheet to 135‹ C., cooling to room temperature and releasing the stretching tension. The above non woven sheet is used to produce a sponge rubber faced carpet underlay by forming a foamable and curable rubber layer, heating the rubber layer, laying the sheet on top of the layer at a temperature of 90-150‹ C. but at or below the temperature at which the sheet exhibits maximum shrinkage and then heating the combination to 170-190‹ C. to foam and cure the rubber and adhere it to the sheet. The rubber layer can be natural, reclaimed or synthetic rubber, vinyl chloride polymer and copolymers or polyurethane.</p> |
