Improvements in the Manufacture of Sound-Insulation Material

摘要

1,181,454. Coated felts. B. RUDLOFF. 6 April, 1967 [23 May, 1966], No. 15783/67. Heading B2E. [Also in Division B5] A process for the continuous manufacture of sound-insulation material comprises charging a layer of nonwoven material with two different powdered resins having different melting points, one having a melting point at 60‹C., and the other having a melting point between 130‹ and 140‹C; baking the charged nonwoven material to impart mechanical strength to it by fusing of the first resin; applying a coating of 0.5 to 1 mm in thickness of a rubber or bituminious or plastics thermofusible material to the non- woven material; tunnel drying the material at 60‹C; and rolling or cutting to size the material so formed. The material may subsequently be affixed to a surface to be soundproofed by applying the material to the surface and baking at 130-140‹C for 20-30 minutes to fuse the second resin and bond the material to the surface. In carrying out the method a felt is charged with powdered esterified colophonyl having a melting point of 60‹C and with powdered p.v.c., or polyethylene having a melting point of 130- 140‹C and is heated at 60‹C for 4 minutes to fuse the first resin. The agglomorated felt so formed is unwound from a roller R and passes between pairs of rollers A, A', B, B', C. C' the lower ones of which apply to the felt a coating of bitumen, rubber, or p.v.c. from a tank D which may be heated. The coating material may contain high density materials such as barium sulphate or asbestos. The coated felt is then dried in a tunnel S (not shown) at 60‹C. In alternative embodiments the felt is coated on its upper face only by reverse roller coating, or on its upper face by spraying and its lower face by rollers, or on both faces at once by immersion. The materials may be used in soundproof vehicles or buildings, and may be air-permeable or liquid proof.