GB1169034A - Method of Coating Mineral Fibers with Binding or Sizing Materials - Google Patents

Abstract

1,169,034. Coating mineral fibres. CELOTEX CORP. 8 Nov., 1966, No. 50066/66. Headings D1P and D1R. [Also in Division C1] Mineral fibres are coated with a liquid binder, e.g. phenol formaldehyde resin, or sizing material by forming individual mineral fibres from molten slag, atomizing the binder or sizing material to form fine droplets such that more than 90% of the droplets are smaller than 0.11 inches in diameter and not less than 0.01 inches in diameter and coating the fibres with the atomized binder or sizing material. A resin bonded mineral fibre board may be produced by forming an interfelted blanket of the coated fibres and curing the binder under heat and pressure to rigidity the blanket. The binder may be applied to the fibres immediately after they are formed or at any point along their path within two feet after they are formed. In Fig. 1 slag 11 melted at temperatures of about 2600‹F is applied over a trough 14 to a rotor 10 the upper face 17 of which is cut away to leave a cup-shaped depression 18 for receiving molten slag which is centrifugally thrown over lip 20 when the rotor is rotated by shaft 22. Steam supplied through pipe 36 is blown from the holes drilled round the underside of steam ring 35 under pressure past the lip 20 and attenuates the molten slag centrifugally thrown off the lip into thin streams of molten slag to form fibres which are collected on conveyor 40. Binder is fed from supply source 31 by pump 30 through tube 25 to nozzle 28, a rotary joint 32 being connected between shaft 22 and the upper section of tube 25 so that the lower end of the tube 25 may rotate without rotation of its upper end. The nozzle may comprise a threaded base portion and a helical shaped vane extending axially from the threaded base portion and spiralling inwardly its inner wall having an inward axial taper to form a bore in a conical or bullet shape so that the crosssection of the bore is reduced in the direction of flow through the nozzle. The spray of binder may be in the form of a sheet substantially planar and perpendicular to the lower end of the tube 25 or may form a cone whose inside angle is 120‹ or 270‹. Alternatively a non-rotating nozzle may be used. In a further alternative binder is supplied through an outside spray ring 80 supplied through tube 81.