Patent ID: 6378562
Filing Date: 2002-04-30
Classification: B32B,F16L,Y10S,Y10T

Abstract:
An elongated multi-layer tubing for connection to a motor vehicle system to handle fluids containing hydrocarbons, having a defined length, the elongated tubing comprising:a first layer disposed radially innermost and having a first inner surface capable of prolonged exposure to a fluid containing hydrocarbons and a first outer surface spaced a first predetermined radial thickness from the inner surface, the first layer consisting essentially of an extrudable, melt-processible thermoplastic; a second layer having a second predetermined radial thickness at most equal to the thickness of the first layer, the second layer homogeneously connected to the first layer and consisting essentially of an extrudable, melt-processible thermoplastic capable of sufficiently permanent laminar adhesion with the first layer to prevent delamination during a desired lifetime of said tubing, at least one of the first and second layers resistant to permeation by hydrocarbons, the second layer having an associated second inner face and an associated second outer face, the associated first and second faces defining a second predetermined radial thickness, wherein the second predetermined radial thickness varies less than 0.19 mm over the length of the tubing; and a third layer having a third predetermined radial thickness greater than the thickness of the first layer, the third layer homogeneously connected to the second layer and consisting essentially of an extrudable, melt-processible thermoplastic capable of sufficiently permanent laminar adhesion to the second layer to prevent delamination during said desired lifetime of said tubing; wherein the tubing has a passive hydrocarbon permeation rate, an elongation at break an ability to resist impacts, a tensile strength, and a burst strength, within predetermined parameters.