B - Operations – Transporting – 29 – C
Patent
B - Operations, Transporting
29
C
18/642
B29C 44/22 (2006.01) B29C 47/06 (2006.01) F16L 9/12 (2006.01) B29C 47/00 (2006.01)
Patent
CA 1109619
ABSTRACT Disclosed is a method of making a lightweight, rigid thermoplastic pipe having solid interior and exterior surfaces and a foamed interior, comprising heating a first thermoplastic material in a first extruder, heating a second thermoplastic material containing a heat decomposable chemical foaming agent in a second extruder to a temperature of about at least 400°F, feeding said first thermoplastic material and said second thermoplastic material simultaneously and respectively to multiple and separate passages of a pipe shaping tool, dividing said first thermoplastic material into two streams to form the interior and exterior surfaces of the pipe, the chemical foaming agent of said second thermo- plastic material decomposing as a result of said heating step but said second thermoplastic material remaining in a foam- able but unfoamed state due to pressures within said second extruder and the pipe shaping tool until the pressure is reduced as the second thermoplastic material leaves said tool, whereby the solid interior and exterior surfaces of the pipe and the foamed interior thereof are formed simultaneously. Exemplified is the manufacture of graft ABS pipe having solid interior and exterior surfaces and a foamed interior.
302380
Brozenick Norman J.
Hornbeck Robert L.
Borg-Warner Chemicals Inc.
Macrae & Co.
LandOfFree
Method of making lightweight, rigid thermoplastic pipe does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Method of making lightweight, rigid thermoplastic pipe, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Method of making lightweight, rigid thermoplastic pipe will most certainly appreciate the feedback.
Profile ID: LFCA-PAI-O-118548