The Dow Chemical Company

Allen N. Niemi

William J. Schafer

Regan D. Wieland

Norbert L. Bradley

Norbert L Bradley

Ritchie A Wessling

Kenneth J Cleereman

Virgil W Coomer

Regan D Wieland

William J Schafer

Allen N Niemi

A method and apparatus for injection molding of ceramic suspensions is disclosed wherein an elastomeric bladder is disposed within a mold cavity of a mold. The elastomeric bladder, in a relaxed state, can be tubular or can be formed by bonding together sheets of material. A ceramic suspension is injected into the elastomeric bladder, whereby the elastomeric bladder is distended. Distention of the elastomeric bladder applies a significant force to the ceramic suspension for preventing jetting and formation of knit lines within the ceramic suspension. The ceramic suspension distends the elastomeric bladder until the mold cavity is filled. The ceramic suspension is then exposed to conditions sufficient to cause the injected ceramic suspension to form a molded ceramic greenware composite. The molded ceramic greenware composite can then be removed from the mold for drying and for debindering and densification to form a finished ceramic part.

Apparatus for injection molding a ceramic greenware composite without

A method and apparatus for injection molding of ceramic suspension is disclosed wherein an elastomeric bladder is disposed within a mold cavity of a mold. The elastomeric bladder, in a relaxed state, can be tubular or can be formed by bonding together sheets of material. A ceramic suspension is injected into the elastomeric bladder, whereby the elastomeric bladder is distended. Distention of the elastomeric bladder applied a significant force to the ceramic suspension for preventing jetting and formation of knit lines within the ceramic suspension. The ceramic suspension distends the elastomeric bladder until the mold cavity is filled. The ceramic suspension is then exposed to conditions sufficient to cause the injected ceramic suspension to form a molded ceramic greenware composite. The molded ceramic greenware composite can then be removed from the mold for drying and for debindering and densification to form a finished ceramic part.

Method of injection molding ceramic greenward composites without knit

A method and apparatus for injection molding a metal alloy wherein the alloy is maintained in a thixotropic, semi-solid state in a reciprocating extruder at temperatures above its solidus temperature and below its liquidus temperature in the presence of shearing and then injected as a thixotropic slurry into a mold to form a useful product. Following completion of the injection molding stroke the nozzle of the extruder is sealed by a solidifying a portion of the residue of the alloy remaining in the nozzle.

Method and apparatus for the injection molding of metal alloys

A scrap-free, substantially solid phase, relatively low temperature economical process for rapidly making plastic articles from resinous powders wherein the resultant articles can comprise various polymers including oriented polymers; polymers with a high practical heat distortion temperature; expanded polymers; ultra high molecular weight polymers; blended structures of two or more materials; or multilayered structures. The resinous powders are initially compressed into briquettes, which briquettes are heated to a temperature in the range from about the alpha transition temperature to less than the melting point or melt temperature of the polymer therein to both somewhat soften and sinter the briquettes. The sintered briquettes are forged under conditions which permit substantial plug flow deformation into preforms whereby fusion of the sintered resin powder particles occurs. The resulting preforms can then be cooled for later thermoforming or can be directly transferred to thermoforming molds for forming into desired shaped articles. It is also possible to form at least shallow cans, lids or other items directly in the forging step.

Scrapless forming of plastic articles

Process for forming a plastic article

Growing community of inventors

Sanford, MI, United States of America

Norbert L Bradley