04155972 is referenced by 34 patents and cites 11 patents.

An improved method for molding a unitary molded product comprised of three separate plastic materials includes the first step of molding the generally highest melting point, most abrasive, most viscous plastic material to mold a first form. Subsequently, the next generally lower melting point material is molded using the first form as a mold. Finally, the generally lowest melting point material is molded. By molding in a designated order, it is possible to mold a single product comprised of multiple plastic materials without having the materials bleed into one another. Additionally, a variety of materials having distinct melting points may be used to make a unitary molded product.

Title
Multiple-shot method of molding plastic products
Application Number
5/830593
Publication Number
4155972
Application Date
September 6, 1977
Publication Date
May 22, 1979
Inventor
Thomas J Parrott
Rockford
IL, US
David A Hauser
Rockford
IL, US
Agent
Allegretti Newitt Witcoff & McAndrews
Assignee
Keystone Consolidated
IL, US
IPC
B29D 3/00
B29C 21/00
B29C 5/00
View Original Source