Patent GB-932793-A (GB)
Title: An improved weather resistant sheet for roofs and walls
IPC: E04C2/18
Filed: 1960-06-07
Abstract: 932,793. Coated fabrics; laminates and laminating; agglutinated fibrous materials. OWENSCORNING FIBERGLAS CORPORATION. June 7, 1960 [June 8, 1959], No. 19964/60. Classes 42 (2) and 140. A weather-resistant sheet for roofs and walls comprises a porous mat, composed at least partly of randomly oriented glass fibres enclosed and interpenetrated by a matrix composed at least partly of asphalt, the mat being coextensive with and adjacent to one surface of the matrix, a thicker layer of the latter being on the other side of the mat. The glass fibres may be bonded with a synthetic resinous material such as a phenolic resin, or an asphalt-epoxy resin mixture which may also be used as the asphaltic impregnating and coating material. The product may be made by impregnating a glass fibre mat with heated asphaltic material, cooling, and coating with additional material at a temperature sufficient to bond with but not penetrate the impregnant. The web may comprise a mat of fibrous glass in which the fibres are continuous and randomly oriented and grouped into twisted or untwisted strands. Randomly oriented individual discontinuous fibres may be interspersed with the strands and, in addition, continuous fibres extending longitudinally of the sheet and the fibres. The weather-resistant sheet may comprise a pair of webs of the fibrous glass embedded in the asphaltic matrix. As shown (Fig. 4), streams of molten glass flow from the lips 31 of a feeder and are disrupted into discontinuous fibres 22 by blowers 32. The fibres 22 fall downwardly on to foraminous conveyer 39 and are divided into two groups by a partition 33 in the form of a narrow tent-like construction. In the underlying space within the separator continuous glass strands 21 are deposited on the underlayer of discontinuous fibres 22 on conveyer 39 in parallel alignment from tubes 36, leading from sources of strand not shown, and are drawn forward by frictional adherence of the strands to the conveyer. Also in the space within the separator further continuous glass strands 20 are ejected from blowing tubes 38 which deposit them in random distribution on conveyer 39. As the latter moves further forward the overlayer of discontinuous fibres 22 is deposited thereon between separator 33 and hood 35. The mass of fibres is supplied with a binding agent from a source not shown and conveyed through a curing oven not shown. As shown (Fig. 5) a glass fibre mat 43 as produced by the method of Fig. 4 is drawn from a supply roll by feed rolls 50 and passes between coating squeeze rolls 51, 52 which apply molten asphalt from reservoir 53. A portion of the asphalt passes through the porous mat which is thereby impregnated through the upper side from the underside. Additional asphalt may be deposited on the upper side from a source 55. A blade 54 removes excess asphalt from the underside of the mat, which is then cooled by sprays of water 56 and subsequently by air circulated between cooling hoods 57. Additional molten asphalt 42, from a source 62, is next deposited on the mat and a second mat of glass fibres 41 is applied directly over the newly spread asphalt layer by passage between squeeze rolls 61. A portion of the asphalt is squeezed through the mat 41. A further layer of molten asphalt is then deposited on the mat 41 from a source 63 and spread bypassage between rolls 64. Protective and decorative mineral granules 44 such as crushed stone are then deposited on the upper coating of asphalt from a hopper 66, or several such hoppers for colour blending, the granules being metered by a fluted roll 67. The composite assembly then passes around drum 68 and a parting agent e.g. mica particles or sand, is deposited on the underside from a hopper 71 over a vibrating member 70. The assembly then passes round a drum 73, between pairs of press rolls 76 and 77, through a cooling station comprising a number of slower moving rollers 80 which allow the material to hang in loops, and then between pulling rolls 82, slither rolls 83, drive rolls 84 and cutter rolls 86 to a conveyer belt 87 whence the product, in the form of cut roofing shingles, is stacked on a bed 90. The material may be so cut that the continuous glass strands in the fibrous layers lie laterally instead of longitudinally in the product. Fig. 2 shows the construction of the shingle in greater detail, comprising glass fibre mats 11 and 13 enclosed by asphalt 12 and with granules 14 of crushed mineral material set in the asphalt overlying the upper mat of glass fibres. The lower fibrous layer may be of other than glass fibres, e.g. of fibres of synthetic resin. For roofing felt the spacing of the fibrous layers may be reduced and/or a more flexible asphaltic composition may be used. One or more strengthened nailing bands may be formed in the product by providing additional nozzles similar to those at 38, Fig. 4, which supply additional continuous but randomly oriented glass threads in the areas to be strengthened. Specification 770,535 and U.S.A. Specification 2,875,503 are referred to.