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Electric Shielding for Foam Molded Applications

IP.com Disclosure Number: IPCOM000088110D
Original Publication Date: 1977-Apr-01
Included in the Prior Art Database: 2005-Mar-04
Document File: 2 page(s) / 71K

Publishing Venue

IBM

Related People

McDonald, RJ: AUTHOR [+2]

Abstract

A two-shot injection molding apparatus (Fig. 1) includes first and second injection chambers 6 and 7, respectively, which may be selectively connected to the mold cavity 8 by a chamber sequencing valve 9. The mold cavity 8 is defined by a pair of mold portions 10 and 11, which are maintained in a closed relationship during the molding cycle by a press-clamp mechanism 12.

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Electric Shielding for Foam Molded Applications

A two-shot injection molding apparatus (Fig. 1) includes first and second injection chambers 6 and 7, respectively, which may be selectively connected to the mold cavity 8 by a chamber sequencing valve 9. The mold cavity 8 is defined by a pair of mold portions 10 and 11, which are maintained in a closed relationship during the molding cycle by a press-clamp mechanism 12.

A molded part having an exterior skin of a desired plastic material and an inner core of foamed, conductive material (Fig. 4) may be formed using the apparatus and sequence of steps illustrated in Figs. 1 through 3. The material which is to form the part surface is contained in injection chamber 6 and initially injected (Fig. 1). The second charge contained in injection chamber 7 is a material compatible with the material in injection chamber 6 which has been blended with conductive filler material to provide the required conductive properties when mixed with the proper foaming agent and in the expanded state. The material from injection chamber 7 is next injected (Fig. 2) to form an inner conductive core with a terminal injection (Fig. 3) of material from injection chamber 6 to effect a continuous surface of the material from chamber 6 on the completed part (Fig. 4).

The inner core of the completed part (Fig. 4) affords electrical shielding, and grounding of such core portion would be provided by an attached conductor of suitable design.

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