| 摘要 |
944,434. Agglutinated fibrous materials. OWENS-CORNING FIBERGLAS CORPORATION. April 12, 1960 [April 24, 1959], No. 33233/62. Divided out of 944, 433. Heading D1R. A panel 76 formed of bonded vitreous fibres has recesses 16, 18 in opposed surfaces 20, 22 thereof, the recesses 16 being staggered with respect to the recesses 18 and the fibres between the recesses 16, 18 and areas 24, 23 respectively of the surfaces 22, 20 respectively being compacted to a greater density than those of the remainder of the panel. The fibres are preferably glass having a diameter between 0À00012 and 0À00022 inches. A web is formed beneath a hood and is impregnated with a heat-curable binder between 9 and 26% by weight of the bonded fibres. The binder may be a combination of melamine formaldehyde and phenol formaldehyde in the approximate proportions of 1 : 2, an epoxy resin, urea formaldehyde resin or polyester resin. A blank is cut from the impregnated web and moulded to form the panel 76 in a press, Fig. 2, having frusto-conical pins 59, 64 on moulding members 58, 62. The upper platen 61 is moved downwardly on guides 69 by a cylinder 68. The members 58, 62 are heated either electrically or by steam to a temperature of 400‹F. to cure the binder. In a panel of “ inch thickness, the areas 23, 24 are spaced with their centres ¢ inch apart and the compacted regions have a thickness of 0À0625 inch and a density between 16 and 32 lb. per cubic foot. |
