| 摘要 |
<p>1,075,612. Laminates and laminating. MINNESOTA MINING & MANUFACTURING CO. July 6, 1964 [July 5, 1963], No. 27827/64. Heading B5N. A composite sheet comprises a layer of uniformly distributed, non-woven, linearly aligned, continuous high-strength filaments saturated with and held together by a thermosetting resin binder composition, preferably an epoxy resin and an overlay tissue of non-woven, randomly interlaced, smooth, organic staple fibres adhered to the resin-impregnated layer but at most only partially impregnated by the resin. The sheet may be stored in roll form. The resin composition has a viscosity of 1 million -35 million poises at room temperature and is capable of remaining so for months under storage conditions, but is fusible and heatcurable under heat and pressure to form a resin-bonded product. The volume ratio of filaments to resin lies within the range 65 to 35 and 35 to 65 and the thickness of the layer is not more than 20 mils (0À5 mm.) preferably less than 15 mils. The surface overlay, which has a weight of between 0À2 to 1 ounce per square yard and a thickness of not more than 5 mils, the thickness in mils being about 2 to 8 times the weight in ounces per square yard, may be in the form of a non-woven fleece, the fibres being of polyethylene terephthalate, polypropylene, P.V.C. or nylon. As shown, glass filaments are drawn from spools 10 through an eyelet board 11 in contiguous linearly-aligned relationship, between rolls 12 and through combs 13 and 14 which space the ends of the filaments to uniform density, e.g. 200 ends per inch (80 per cm.) The web passes through a bath of resin 16 and then through heated rolls 19 and 20 to remove excess resin after which it meets a woven issue 22 of randomly interlaced extruded staple fibres while passing between rolls 20 and 23 so spaced apart that the tissue becomes partially impregnated with resin. The composite sheet is cooled by air-jets 26 and wound into a roll at 27. The filaments in the impregnated layer may be glass, preferably having a priming of a silane or an organo-metallic complex, or of oriented polyethylene terephthalate, nylon or rayon. To make panels cross-laid cut lengths of the composite sheet are superposed and hot pressed.</p> |
