Plastic article or earthenware shaping or treating: apparatus – With apparatus assembly or dismantling means or with idle part – For extrusion or injection type shaping means
Patent
1988-11-02
1991-11-19
Tentoni, Leo B.
Plastic article or earthenware shaping or treating: apparatus
With apparatus assembly or dismantling means or with idle part
For extrusion or injection type shaping means
264572, 425546, 425567, 425568, 425812, B29C 4520, B29C 4534, B29D 2200
Patent
active
050662147
ABSTRACT:
A method and apparatus for making a plastic injection molded part with a smooth surface or skin and a hollow core wherein thermoplastic material is injected as a molten stream into the mold cavity through a sprue bushing fixed in the mold. Simultaneously, an unmeasured quantity of inert gas is introduced through an adapter into the molten stream at the sprue bushing substantially coaxially with the melt stream and ata pressure sufficient to penetrate the thermoplastic material to form a gas cavity in the molten material in the mold. For retrofitting an existing mold, an adapter can be added to the existing sprue bushing. During plastic injection and cooling in the mold the gas is maintained at a high pressure, preset, constant and adequate to maintain the plastic against the mold surface until it is self-supporting. The gas is exhausted from the mold, back through the sprue bushing and adapter, before the mold is opened. Adequate preset high pressure is maintained at the gas supply by a large cylinder having a positive displacement member therein that is controlled by a pressure sensor in the gas pressure line to the mold to maintain preset adequate gas pressure within the cavity.
REFERENCES:
patent: 3687582 (1972-08-01), Hendry et al.
patent: 4101617 (1978-07-01), Friederich
patent: 4136220 (1979-01-01), Olabisi
patent: 4474717 (1984-10-01), Hendry
patent: 4740150 (1988-04-01), Sayer
patent: 4781554 (1988-11-01), Hendry
patent: 4855094 (1989-08-01), Hendry
Baxi Indra R.
Erikson Erik E.
Encore Molding Systems, Inc.
Gossett Dykema
Tentoni Leo B.
LandOfFree
Injection molding apparatus does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Injection molding apparatus, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Injection molding apparatus will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-1367170