Patent GB-921132-A (GB)
Title: Fibrous boards
IPC: E04B1/84
Filed: 1961-06-29
Abstract: 921,132. Laminates and laminating. OWENS-CORNING FIBERGLAS CORPORATION. June 29, 1961 [June 30, 1960], No. 23562/61. Class 140. [Also in Group X] A fibrous wall or ceiling board has a soundattenuating porous body of bonded mineral fibres and a vibratable, impervious plastic film adhered to one face of the body, the said body having such sensitive compressibility and resilience that it permits, by corresponding compression and expansion, the adhered plastic film to respond, vibrationally, to sound waves impinging against the film, whereby sound waves are transmitted by the vibrating film into the porous body for attenuation thereby. The fibres may be of glass. A suitable binding agent comprises a combination of melamine and phenol formaldehyde resins; other suitable agents are epoxy, urea and polyester resins. The preferred plastic film is constituted of unplasticized polyvinyl chloride, but polythene, plasticized p.v.c., polyvinylidine chloride, ny- Ion, polycarbonate or polyvinyl fluoride may be used. The board is made by bonding mineral fibres together to form a low-density pack, splitting the pack horizontally, as by sawing, to form two smooth surfaces, and bonding the films to these surfaces. As shown, Fig. 1, a continuous pack 20 of bonded fibrous glass which has been compressed between conveyer flights 22 and 23 and dimensionally stabilized by curing of the binder component in oven 21 is delivered to conveyer 25 whereon it is horizontally split in half by band saw 28, turning on drums 29. The upper split portion 30 turns upwardly under guide roller 33 and then across guide rollers 34 and 35 and is cut by knife 38 into lengths suitable for successive winding on a series of mandrels 36. The material thus rolled may subsequently be processed in the same manner as the lower split portion 40 as hereinbelow described. Portion 40 moves forward past edge-trimming discs 42 and longitudinal slitting disc 43, being supported on roller 44, and the longitudinally divided strips are then cut into individual boards 50 by knife 47, the boards being carried forward on conveyer 48 whence they are collated and laid for transporation on pallets 52. As shown in Fig. 2, boards 50 from pallet 52 are laid on conveyer 54 running between end drums 56. To remove loose fibres resulting from the action of the band saw, the boards are passed beneath vacuum hood 62 between rolls 60 and 64. Plastic film 66 from supply roll 68 passes downwardly over coating roller 70 whereby adhesive 71 from tank 72 is applied to its under side. Suitable adhesives are solutions, dispersions or emulsions of butadienestyrene, nitriles or neoprenes. An adhesive of butadiene-styrene with a petroleum solvent base may be used. Heated air from manifold 78 volatilizes the major portion of the solvent leaving the adhesive in a tacky condition, the sheet being supported by rolls 80 against the force of the air. The coated sheet then passes under guide rollers 82, being thereby positioned upon the series of boards 50, and is held against the face of the travelling boards by woven-wire conveyer 84, conveyer 54 being supported from beneath by steel herring-bone assembly 85. The boards and sheet then pass beneath pressure roller 86 and beneath chopper 88 which is actuated to cut the sheet along the transverse edges of adjoining boards. The finished boards 90 may be placed in cartons 92 on packaging conveyer 94. Fig. 3 shows diagrammatically the finished board 90 comprising a porous body of bonded mineral fibres 50, and plastic film 66 adhered to one face thereof by adhesive 71.