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Pressure Controlled Venting of Structural Foam Molds

IP.com Disclosure Number: IPCOM000065981D
Original Publication Date: 1979-Jan-01
Included in the Prior Art Database: 2005-Feb-19

Publishing Venue

IBM

Related People

Authors:
Bement, RA Feeman, DE [+details]

Abstract

Injection under pressure of thermoplastic foam into a closed structural mold cavity requires venting of the cavity unless it has previously been evacuated. Such venting is typically accomplished by cutting shallow channels 11 (e.g., 0.1 mm X 20 mm) from the cavity to the exterior at various points around the peripheral area of the mold 10. High and low pressure areas in the cavity 12, as a function of, for example, distance from the injection orifice 13. cause uneven density in the hardened material, although higher pressure can contribute to better surface finish.