Gas plasma treatment to improve the bondability of a RTV silicone to foamed polypropylene

Conference · Sun Jul 01 04:00:00 EDT 1979

OSTI ID:5920138

Tira, J S

A chemically blown, injection molded polypropylene foam is used as a support collar. The polypropylene is foamed using 0.5 to 0.7 percent by weight of a nitrogen blowing agent. The collar will be used in an environment which requires that it be coated with a thermal protective material. A RTV coating of 0.0150 +- 0.005 in. (0.381 +- 0.127 mm) was selected as the thermal protective material. Control of the coating thickness on the polypropylene part is very important. After several methods were considered, it was decided that molding the silicone over the approximately 90 in/sup 2/ (581 cm/sub 2/) surface was the most efficient. Aluminum molds are used which have cavities slightly larger than the polypropylene part. Mixed and de-aired silicone is injected into the mold where it flows around the part and cures and bonds to the polypropylene. The two-part, vinyl-addition-type silicone was selected because of its reversion resistance, a low viscosity which allows it to be injected into the mold, and its ability to be cured in a confined space.

• Research Organization: Bendix Corp., Kansas City, MO (USA)
• DOE Contract Number: EY-76-C-04-0613
• OSTI ID: 5920138
• Report Number(s): BDX-613-2224(Rev.); CONF-790668-3(Rev.)
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360401* -- Polymers & Plastics-- Preparation & Fabrication-- (-1987)
ADHESION
BONDING
CHEMICAL COMPOSITION
COLLOIDS
CONTAMINATION
DEPOSITION
DIMENSIONS
DISPERSIONS
FABRICATION
FOAMS
JOINING
MOLDING
ORGANIC COMPOUNDS
ORGANIC POLYMERS
POLYMERS
POLYOLEFINS
POLYPROPYLENE
SILICONES
SILOXANES
SURFACE COATING
SURFACES
THICKNESS