초록 ▼

In a process for extruding a low density foam, a foamable thermoplastic elastomer such as a thermoplastic rubber is selected. The selected thermoplastic elastomer is then fed into a heated extruder barrel where it is compressed and melted by the action of a screw. A blowing agent consisting of water

In a process for extruding a low density foam, a foamable thermoplastic elastomer such as a thermoplastic rubber is selected. The selected thermoplastic elastomer is then fed into a heated extruder barrel where it is compressed and melted by the action of a screw. A blowing agent consisting of water is introduced into the melted thermoplastic elastomer. The melted thermoplastic elastomer and the water are thoroughly mixed and then cooled to a uniform, predetermined temperature. The mixture is then forced through a die to form an extruded foam profile.

대표청구항 ▼

[ We claim:] [1.] A method for extruding a thermoplastic elastomer seal comprising the steps of:selecting a foamable thermoplastic elastomer composition comprising a blend of between 25 to 75 percent by weight of a thermoplastic polyolefin resin and, correspondingly, 75 to 25 percent by weight of a

[ We claim:] [1.] A method for extruding a thermoplastic elastomer seal comprising the steps of:selecting a foamable thermoplastic elastomer composition comprising a blend of between 25 to 75 percent by weight of a thermoplastic polyolefin resin and, correspondingly, 75 to 25 percent by weight of a monoolefin copolymer rubber;compressing and heating the thermoplastic elastomer composition in a mixing vessel to a temperature above the melting point of the thermoplastic resin;introducing into the heated thermoplastic elastomer composition while under pressure within the mixing vessel a blowing agent consisting essentially of water in an amount sufficient to produce closed cell foaming of the thermoplastic elastomer composition;mixing and heating the thermoplastic elastomer composition including melted thermoplastic resin and the water in the mixing vessel;forcing the heated composition and water through a die opening shaped like a cross-section of a seal to form an extruded seal of substantially closed-cell foam thermoplastic elastomer substantially impervious to the passage of fluid therethrough; andcooling the extruded seal.