Five-ply laminated multi=channel plastics pipe for carrying fluids in vehicle

摘要

Laminated, multichannel plastics pipe consists of m internal, circular, channels and n layers, the size of which is determined by the main dimensions (inside dia. of channels, outside dia. of pipe, number of channels, number of layers, channel wall thickness, web thickness, channel distribution). It is made by co-extrusion and used in vehicles for brake fluid, compressed air, hydraulic fluid, fuel and coolant pipes. Its walls include diffusion-inhibiting, reinforcing, foamable and flame-retarding layers or layer(s) with a combination of at least 2 of these properties. The pipe (15) or its components are made from specified materials and has specified geometry. The materials, from the inside outwards, are: an inner layer (1) of thermoplastic polymer moulding compsn. (I); an adhesive layer (2) of moulding compsn. (II) contg. at least 50 wt.% thermoplastic polymer and at most 50 wt.% thermoplastic copolymer; a diffusion layer (3) of thermoplastic polymer moulding compsn. (III); a foam layer (4) of partly crosslinked thermoplastic polymer moulding compsn. (IV) contg. blowing agent(s) with reaction temp. higher than the processing temp.; and an outside layer (5) of partly crosslinked thermoplastic polymer moulding compsn. (V) contg. flame retardant additive(s). The geometry is such that the axes (12) of the channels (13) are on geometrically defined line(s), the sheath has a geometrically defined curve and it is circular (10) and the cross-sectional areas of the m channels are identical.