| 摘要 |
951,198. Fibrous fabric, treating. R. FREUDENBERG, H. FABRICIUS, H. E. FREUDENBERG, K. KRAFT, O. SCHILDHAUER, P. WENTZLER, H. FREUDENBERG, and D. FREUDENBERG, [trading as C. FREUDENBERG . June 17, 1960 [June 25,1959; Nov. 18, 1959], No. 21293/60. Headings D1L and D1R. A method of producing a number of spaced apertures through a non-woven fibre fleece comprises passing a stream of gas of sufficient velocity to displace individual fibres of the fleece through a perforate surface and through the web against an imperforate backing surface while maintaining the web between the perforate surface and the imperforate backing surface. The gas may be air and the fleece consist at least partially of fibres of a thermoplastic material in which case the gas may be heated to a temperature above the softening point of the thermoplastic. The fleece may be composed of cardable fibres and may be impregnated with a banding agent before gas is passed through it. Referring to the drawings, Fig. 1 shows the imperforate surface formed by roller 1, the perforate surface formed by endless felt 11 of wire or plastic mesh running over rollers 2 while compressed air is blown through tube IV fitted with gas jets. When large holes are required in fleeces composed of short fibres the imperforate backing may have depressions as shown in Figs. 2a, 2b and 2c. U.S.A. Specifications 2,717,795, 2,719,802, 2,719,803 and 2,719,806 are referred to. |
