| 摘要 |
921,650. Finishing fabrics. HESS, GOLDSMITH & CO. Inc. July 26, 1961 [Aug. 31, 1960], No. 27008/61. Class 42 (1). A process for desizing a sized glass fibre fabric comprises heating an advancing length of the fabric to a temperature sufficiently high to volatilize the size from the fabric, maintaining the fabric at this temperature for a time sufficient to volatilize at least 75% of the size, so diffusing the volatilized zize with air as to prevent ignition thereof adjacent the fabric, and subsequently raising the temperature of the fabric to a temperature sufficiently high to set the fibres thereof and volatilize substantially all the residual size thereon while diffusing the volatilized residual size with air to prevent ignition thereof in the vicinity of the fabric. The initial heating of the fabric is to a temperature between 800‹ F. and 1100‹ F. and the setting temperature is between 1280‹ F. and 1400‹ F. Preferably, one or more intermediate zones are provided to gradually raise the fabric temperature to the latter range to prevent thermal shock to the fabric. In some cases about 85-95% of the size is removed during the initial heating. In this zone the volatilized size is so diffused, preferably by providing a draught, as to produce a mixture thereof with air which mixture is too lean to ignite. A major portion of the size vapour is removed so that only a minor portion thereof enters the second zone. The process may be carried out in a vertical muffle furnace comprising at least three zones each of which is provided with vapour exhausting means. In a modification, the process is carried out in a muffle furnace comprising a single zone which subjects the advancing fabric to gradually increasing temperatures. U.S.A. Specifications 2,633,428, 2,665,125, 2,845,364 and 2,970,934 are referred to.
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