METHODS, APPARATUS AND SYSTEMS FOR REDUCING WARPAGE IN POLYMERS WITH CONTINUOUS FIBERS

• US 20130153121A1
• Filed: 12/19/2011
• Published: 06/20/2013
• Est. Priority Date: 12/19/2011
• Status: Active Grant

• Current Assignee: Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Original Assignee: Toyota Motor Engineering & Manufacturing North America Incorporated (Toyota Motor Corporation)
• Inventors: Gandhi, Umesh N.
• Granted Patent: US 9,527,250 B2
• Time in Patent Office: Days
• US Class Current: 156/85
• CPC Class Codes: B29C 70/56 Tensioning reinforcements before or during shaping
• CPC Class Codes: B32B 2262/101 Glass fibres
• CPC Class Codes: B32B 2305/08 Reinforcements
• CPC Class Codes: B32B 2305/10 Fibres of continuous length
• CPC Class Codes: B32B 27/12 next to a fibrous or filamentary layer
• CPC Class Codes: B32B 37/0015 to avoid warp or curl
• CPC Class Codes: Y10T 428/24942 including components having same physical characteristic in differing degree

Abstract

Apparatus, systems and/or methods are provided to substantially reduce warping of a reinforced polymer. For example, by pre-stressing a glass component proportional to the difference between coefficients of linear expansions of glass and polymers, warping may be reduced when the resulting glass-polymer compound is cooled.

Claims

1-10. -10. (canceled)

11. A method for reducing the warping of a molded polymer-continuous fiber compound, the method comprising:

pre-stressing a layer of continuous fiber;

molding the layer of continuous fiber to a layer of polymer including a heating process; and

cooling the layer of continuous fiber and the layer of polymer such that the resulting compound is substantially flat.

12. The method of claim 11, wherein cooling the layer of continuous fiber includes releasing of the pre-stress.

13. The method of claim 12, wherein cooling the layer of continuous fiber below a predetermined threshold temperature triggers release of the pre-stress.

14. The method of claim 13, wherein the release of the pre-stress causes the layer of continuous fiber to shrink.

15. The method of claim 11, further comprising determining the degree of pre-stressing based on a coefficient of a linear expansion of a material of the continuous fiber layer and a coefficient of a linear expansion of a material of the polymer.

16. The method of claim 11, further comprising the addition of an inorganic filler, an additive, or a modifier to the layer of continuous fiber or the layer of polymer.

17. A method of reducing the warping of a molded glass-reinforced polymer, the method comprising:

pre-stressing a continuous glass fiber tape by stretching and holding the continuous glass fiber tape horizontally and/or vertically by means of a device;

adding a heated polymer to the pre-stressed continuous glass fiber tape to form a fiber-reinforced-polymer (FRP) composite;

molding the FRP composite;

cooling the FRP composite; and

releasing the continuous glass fiber tape from the pre-stress applied causing the FRP composite to be substantially unwarped.

18. The method of claim 17, wherein cooling of the FRP composite below a predetermined threshold temperature triggers the releasing of the continuous glass fiber tape from the pre-stress.

19. The method of claim 17, further comprising determining the degree of pre-stressing based on a coefficient of a linear expansion of a material of the continuous glass fiber tape and a coefficient of a linear expansion of a material of the polymer.

20. The method of claim 17, further comprising the addition of an inorganic filler, an additive, or a modifier to the continuous glass fiber tape or the polymer.