Process for molding thin-walled skins

Patent metadata

Field	Value
Publication number	US-11007693-B2
Application number	US-201815899511-A
Country	US
Kind code	B2
Filing date	Feb 20, 2018
Priority date	Feb 20, 2018
Publication date	May 18, 2021
Grant date	May 18, 2021

Abstract

A method of forming a thin-walled skin includes coating at least one side of a mold cavity of a molding tool, evacuating air from the mold cavity, and filling the mold cavity with a molten polymeric resin. Among other optional variations of the disclosed method, an inert gas is injected into the molten polymeric resin simultaneously with the step of filling the mold cavity with a molten polymeric resin. As a result, high quality, large, thin-walled skins are produced by the teachings of the present disclosure.

First claim

What is claimed is:

1. A process of forming a thin walled skin having a thickness of about 1.0 mm (0.04 in) or less, the process comprising:
coating at least one side of a mold cavity of a molding tool;
evacuating air from the mold cavity; and
filling the mold cavity with a molten polymeric resin while simultaneously injecting an inert gas into the molten polymeric resin.

2. The process according to claim 1 , wherein the inert gas is nitrogen gas or carbon dioxide (CO 2 ) in a supercritical state.

3. The process according to claim 2 , wherein an amount of the inert gas is about 0.25% of a mass of the thin-walled skin.

4. The process according to claim 1 , wherein a vacuum is held in the mold cavity during the filling the mold cavity.

5. The process according to claim 4 , wherein a seal is provided between adjacent parts of the molding tool.

6. The process according to claim 5 , wherein the molding tool comprises two halves.

7. The process according to claim 1 , wherein the mold cavity is filled with the molten polymeric resin by injection molding.

8. The process according to claim 1 , wherein a ratio of the thickness of the skin to a length of the skin (t/L) is about 0.002 or less.

9. The process according to claim 1 , wherein the coating is selected from a group consisting of an electroless nickel coating, a Teflon coating, and a titanium coating.

10. The process according to claim 1 , wherein the coating is applied to only a core side of the molding tool.

11. The process according to claim 1 further comprising venting the mold cavity proximate predetermined end-of-fill locations.

12. An instrument panel of a motor vehicle having the skin formed by the process according to claim 1 .

13. A process of forming a skin having a thickness of about 1.0 mm (0.04 in) or less, the process comprising:
coating at least one side of a mold cavity of a molding tool;
evacuating air from the mold cavity and holding the mold cavity at a vacuum condition; and
simultaneously injecting the mold cavity with a molten polymeric resin and injecting an inert gas in a supercritical state into the mold cavity while holding the vacuum condition.

14. The process according to claim 13 , wherein a ratio of a thickness of the skin to a length of the skin (t/L) is about 0.002 or less.

15. The process according to claim 13 , wherein an amount of the inert gas is about 0.25% of a mass of the skin.

16. The process according to claim 13 further comprising venting the mold cavity proximate predetermined end-of-fill locations.

17. A process of forming a skin having a thickness of about 1.0 mm (0.04 in) or less, the process comprising:
applying a coating on only a core side of a molding tool;
evacuating air from a mold cavity of the molding tool and holding the mold cavity at a vacuum condition; and
simultaneously filling the mold cavity with a molten polymeric resin and injecting an inert gas in a supercritical state into the molten polymeric resin while holding the vacuum condition.

18. The process according to claim 17 , wherein an amount of the inert gas is about 0.25% of a mass of the skin.

Assignees

• Ford Motor Co

Inventors

• Marchetti Bernard Gerard
• Woods Derren
• Brown Bari
• Mowery Ryan

Classifications

• B29C37/0067

  Using separating agents during or after moulding; Applying separating agents on preforms or articles, e.g. to prevent sticking to each other (separating agents B29C33/60) · CPC title

• B29C45/34 Primary

  having venting means · CPC title

• B29C33/56 Primary

  Coatings {, e.g. enameled or galvanised}; Releasing, lubricating or separating agents {(in-mould coating B29C37/0028; using or applying separating agents B29C37/0067)} · CPC title

• B29C45/0025

  Preventing defects on the moulded article, e.g. weld lines, shrinkage marks (preventing defects on the preformed parts or layers B29C45/14836) · CPC title

• B29C45/26

  Moulds · CPC title