Process for preparing extruded foam bodies

Details Process for preparing extruded foam bodies Process for preparing extruded foam bodies

B - Operations, Transporting

29

C

18/664

B29C 44/50 (2006.01) B29C 44/34 (2006.01) B29C 44/60 (2006.01) B29C 47/88 (2006.01) C08J 9/14 (2006.01) B29C 35/16 (2006.01)

Patent

CA 2019083

A process for preparing an extruded elongate foam body characterized as having minimal surface defects such as pearls, streaks, foamy appearance and corrugations and having a density of between about 0.9 and about 3.5 pounds per cubic foot which comprises the steps of (A) heat plastifying a mixture of at least one thermoplastic resin and at least one nucleating agent; (B) adding at least one blowing agent selected from the group consisting of chlorodifluoro-methane; 1,1-dichloro-2,2,2-trifluoroethane; 1-chloro-1,1-difluoroethane; 1,1,1,2-tetrafluoroethane; 1,1-di-chloro-1-fluoroethane; 1-chloro-1,2,2,2-tetrafluoroethane and mixtures of two or more thereof to the mixture; (C) forming a blowable resin mixture by uniformly mixing the blowing agent and the mixture of step (A) in the resin under a pressure sufficient to prevent blowing of the resin; (D) extruding the blowable resin mixture through a die (20), which has a die lip temperature maintained at about 50°F to about 170°F and into a region wherein the blowable resin mixture expands into a foam body; and (E) cooling the foam body. In one embodiment, the region of less than atmospheric pressure is formed by an elongated chamber (15) with the blowable resin mixture passing through a die at one end of such chamber and such foam body passing through a pool of water (17) at the opposite end of the chamber. The process results in the formation of extruded expanded thermoplastic resins such as polystyrene resins characterized as having relatively small average cell sizes such as from about 0.2 to about 0.5 mm., improved and higher compressive strengths, and higher cell volumes.

Affiliated with

Also associated with

Rating

Process for preparing extruded foam bodies does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Process for preparing extruded foam bodies, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Process for preparing extruded foam bodies will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFCA-PAI-O-1906889