GB911157A - A condensed filamentous mat and method for making same - Google Patents

Abstract

911,157. Fabrics of adhesive-bonded threads; wadding. AMERICAN AIR FILTER CO. Inc. June 10, 1960 [June 25, 1959], No. 20449/60. Classes 42 (2) and 140. [Also in Groups IX and XXIII] A filamentous mat is composed of a plurality of monofilaments which are arranged in overlying layers, the monofilaments of one layer being arranged in groups in crossed relationship with the mono-filaments of adjacent layers, each group comprising at least one border of relatively closely-spaced monofilaments forming a flat ribbon and a plurality of relatively widely-spaced monofilaments adjacent said border. The mat may be made by traversing a filament feeder axially back and forth along a drum and rotating the drum a multiplicity of times during each traverse of the feeder, gathering a portion of the filaments in a zone intermediate said feeder and said drum into one or more substantially planar concentrated groups of individual and separate filaments lying closely together relative to the spacing of said filaments as discharged from said feeder, feeding said gathered portion of closely spaced filaments on to said drum in relatively closely spaced ribbon-like forms and simultaneously feeding the remaining portion of the filaments directly from said feeder on to said drum adjacent said closely spaced filaments in relatively widely spaced form approximately equalling the spacing between individual filaments discharged from said feeder. As shown in Figs. 1 and 2, glass filaments 17 are discharged through spinnerets in orifice plate 16 of glass furnace 10 which is mounted in rails 14 and adapted to be driven with a reciprocating movement as indicated by the double-headed arrow in Fig. 1. As the furnace assembly is reciprocated, drum 2, mounted on supports 4 and 6 and driven by belt 8 is rotated a multiplicity of times during each traverse of the furnace. A central and minor portion of filaments 17 is fed directly on to drum 2 while the axially outer filament portions are collated into two substantially planar or ribbon-like filament groups 41 by opposed spools 18, which groups are also simultaneously fed on to the rotating drum. As the furnace traverses, the filaments are laid in helical turns having an angular disposition first in one direction and then in the opposite direction. Binder is sprayed from applicator 66 as the filaments are being spun onto the drum. The cylindrical mat formed on the drum is slit axially and removed from the drum, thus constituting a planar condensed mat 68 (Fig. 8). Mat 68 is stretched axially to form an elongate expanded web having a thickness appreciably greater than the desired final thickness. The expanded web is carried by conveyer 71 through an oven 72 to cure and harden the binder. Pressureplate 74 compresses the expanded web to the desired thickness and the web is subsequently cut to desired width by slitting apparatus 76 and cut to desired length by cutter 78. Specification 891,715 is referred to.