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CO-EXTRUSION BLOW MOLDING PROCESS & BLOW MOLDED CABINET

IP.com Disclosure Number: IPCOM000006219D
Original Publication Date: 1991-Jul-01
Included in the Prior Art Database: 2001-Dec-14
Document File: 3 page(s) / 135K

Publishing Venue

Motorola

Related People

Craig S. Zaplatynsky: AUTHOR

Abstract

PROBLEM STATEMENT To develop a cost effective plastic manufacturing process which produces plastic components that have an aesthetic outer surface and a secondary or interior surface of unique characteristics for specialized appli- cations such as RFI/EMI shielding applications.

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MOTOROLA INC. Technical Developments Volume 13 July 1991

CO-EXTRUSION BLOW MOLDING PROCESS & BLOW MOLDED CABINET

by Craig S. Zaplatynsky

PROBLEM STATEMENT

  To develop a cost effective plastic manufacturing process which produces plastic components that have an aesthetic outer surface and a secondary or interior surface of unique characteristics for specialized appli- cations such as RFI/EMI shielding applications.

BACKGROUND

  As new products proliferate today's markets, the need to find materials with improved or unique prop- erties becomes increasingly important. Materials which are commonly available often fall short of spec- ified requirements while many "exotic" materials are too costly to justify their use in most products. In some instances it may also be the process used to form these materials or multiple processes which are pro- hibitive in terms of cycle time and cost.

  The application of an inexpensive form of mate- rial processing, a modified form of blow, molding, would keep processing costs low through a wide range of production volumes. Using a unique combination of readily available materials, which provide neces- sary properties, would keep material costs down. The result would be attractive products which perform the same as those manufactured with expensive materials or multiple processes at a significantly reduced cost.

SOLUTION

This innovation is comprised of a blow molding die head, specially designed to form two independent

circular parisons of two types of plastic, one concen- tric within the other. The die head is supplied two types of molten plastics from separate screw feeders as shown in figure 1. As the two parisons are formed simultaneously (co-extruded) they are dropped between two mold halves. The mold halves are closed on the twin p...