Process of making a consolidated part

• US 5,380,480 A
• Filed: 08/04/1993
• Issued: 01/10/1995
• Est. Priority Date: 08/04/1993
• Status: Expired due to Term

• Current Assignee: Fiberite, Inc.
• Original Assignee: E. I. du Pont de Nemours and Company (Corteva, Inc.)
• Inventors: Tam, Albert S., Okine, Richard K.
• Primary Examiner(s): Tentoni, Leo B.
• Application Number:
  US08/099,845
• Time in Patent Office: 524 Days
• Field of Search: 264/257, 264/258, 264/320, 264/322, 264/316, 156/212, 156/222, 156/224, 156/308.2, 156/309.9
• US Class Current: 264/316
• CPC Class Codes: B29C 51/085 with at least one of the shaping surfaces being made of resilien material, e.g. rubber
• CPC Class Codes: B30B 15/061 Cushion plates

Abstract

A thermoplastic composite sheet is used as a tool or tool liner for thermoforming thermoplastic composite sheets into parts having uneven sections. A more uniform consolidation of the part is achieved that has not been previously attainable in open mold processing at high forming temperatures.

Claims

1. A method for forming a consolidated part having interior and peripheral surfaces from a thermoplastic resin sheet having a high melt-forming temperature in an open mold press comprising:

applying a compliant layer to at least one face of said sheet said compliant layer being a reinforced thermoplastic resin matrix having a melt-forming temperature substantially the same as said sheet and a melt viscosity less than said resin sheet;

placing the sheet and the layer in the press, heating the sheet and the layer to the melt-forming temperature of the sheet, closing the press to form the part;

applying pressure by means of the press to flow said compliant layer to provide uniform contact between said compliant layer, said press and said part whereby a low flow resistance of the compliant layer over the interior surface of the part allows the compliant layer to transmit said pressure against said part to consolidate the part and a high flow resistance of the compliant layer over the peripheral surface of the part allows the compliant layer to build and maintain said pressure with a minimum of compliant layer squeeze-out from the press;

cooling the part; and

removing the part from the press.

2. The method of claim 1, said press having opposed surfaces movable toward each other for consolidating said part, said compliant layer being one of said surfaces rather than being applied to one face of the sheet.

3. The method of claim 1, including preheating said sheet and said compliant layer prior to placing said sheet in said press.

4. The method of claim 1, said thermoplastic resin matrix of said compliant layer being reinforced with fibers.

5. The method of claim 1, said thermoplastic resin matrix of said layer being reinforced with hollow glass microspheres.

6. The method of claims 1, 2, 3, 4 or 5 wherein said thermoplastic resin sheet is reinforced with fibers.