| 摘要 |
733,924. Forming fibre mats. OWENS-CORNING FIBERGLAS CORPORATION. June 23, 1952 [June 29, 1951], No. 15778/52. Classes 120(1) and 120(3). [Also in Group VIII] A method of forming a fibre mat comprises the continuous steps of attenuating streams of fusible fibre-forming material to fibres, collecting the fibres in thin layers, continuously laminating the layers to form a composite web, and folding the composite web on itself in successively displaced folds to build up a mat of a multiplicity of strata all extending in the same general direction as the major faces of the mat. As shown, fibres of glass, thermoplastic resin, or other fusible fibre-forming material, produced in hoods 20, Fig. 1, by blowers 22 acting on streams of molten material issuing from feeders 18, are collected beneath a chamber 24 in thin layers on the foraminated surfaces of two rotary suction drums 26, 27, Fig. 7. The drums are supported at one end on central driving shafts and at the other end on rollers 52, suction ducts 30, 31 leaving the drums at the latter end and leading to a blower 34 discharging into a cyclone separator 40 which vents through a chamber 46 ; fibres separated from the air stream are returned by a blower 49 through ducts 45, 50 to chamber 24. The fibre layers entrained on drums 26, 27 are laminated at the nip thereof to form a double-layer web 29 which is doffed from the drums with the aid of air jets 76. Web 29 is loaded with powdered binder, e.g. phenol formaldehyde resin in partially cured form, by means of powder dispensing troughs 80, 81 and foraminated suction drums 88, 89 ; the powder is distributed within the web by means of beaters having flexible web-engaging elements 108, e.g. of rubber. Air from drums 88, 89 passes through a cyclone separator 100, any powder separated from the air being collected for re-use in a receptacle 104. The web is then lapped transversely, by means of alternating air jets 115, 116 or by mechanical means, onto a moving flexible foraminous conveyer 110 beneath which is a suction chamber 135. Conveyer 110 is carried by a frame 127 which is angularly adjustable so that the folds of web, which form a continuous laminar mat M, are substantially horizontal. Mat M is compacted by an endless belt-like assembly of compacting rolls 158 travelling at a linear rate slightly greater than that of conveyer 110 and is carried by conveyers 180, 187 and 198, between crushing rollers 190 which break up the fibres and reduce the resiliency of the mat, to an oven 202 where the resin binder is cured. In modifications, (a) a second web, similar to web 29, is lapped on top of a mat such as M to form a compound web, (b) two webs, similar to web 29, are combined prior to beaters 108 to form a four-layer web which is lapped as previously, (c) the web is lapped longitudinally, instead of transversely, of conveyer 110. |
