Impact-resistant molded composites and methods therefor

Patent metadata

Field	Value
Publication number	US-12017420-B2
Application number	US-202117373566-A
Country	US
Kind code	B2
Filing date	Jul 12, 2021
Priority date	Jul 10, 2020
Publication date	Jun 25, 2024
Grant date	Jun 25, 2024

Abstract

A method for improving the impact resistance of a fiber-composite part includes positioning fibers within an expected impact region of the part, wherein at least a portion of most of the positioned fibers is oriented to be within about 45 degrees of parallel to an impact vector of an impact that occurs at the impact region. At least some of the fibers in the impact region should have relatively high impact resistance, such as glass fiber or aramid fiber, and the matrix in the impact region should have relatively high impact resistance.

First claim

What is claimed:

1. A method comprising:
positioning an assemblage of feed constituents in a mold, the assemblage of feed constituents including fibers and resin in the form of at least one of (i) a plurality of preforms and (ii) a plurality of misaligned preforms, the misaligned preforms being characterized by a selective misalignment of a minor portion of fibers therein amongst a majority of unidirectionality aligned fibers therein, wherein the fibers will not flow during compression molding due to a length thereof, and wherein as positioned and aligned in the mold, at least a first portion of each fiber of a first plurality of fibers sourced from some of the preforms or some of the misaligned preforms will be substantially parallel to an impact vector for an impact occurring at a first location along a rounded corner, wherein the first plurality of fibers are glass fibers or aramid fibers, and wherein the impact vector is normal to the tangent of the rounded corner at the first location; and
compression molding the assemblage of feed constituents to form a fiber-composite part having the fibers in which the first portion thereof is substantially parallel to the impact vector.

2. The method of claim 1 comprising forming the assemblage of feed constituents.

3. The method of claim 1 wherein the assemblage of feed constituents comprises the plurality of preforms, wherein at least some of the preforms have about a 180-degree bend along a length thereof, and wherein the first plurality of fibers is sourced from said some preforms, and the first portion of each fiber that is substantially parallel to the impact vector is located at the bend in each fiber.

4. The method of claim 1 wherein the assemblage of feed constituents comprises the plurality of misaligned preforms, wherein the minor portion of fibers that are selectively misaligned in each misaligned preform includes fibers that are spiraled around other fibers within the misaligned preform, wherein the first plurality of fibers is sourced from the misaligned preforms, and the first portion of each fiber that is substantially parallel to the impact vector is located along the fibers that are spiraled.

5. The method of claim 1 wherein the fiber-composite part comprises a rib, wherein the assemblage of feed constituents includes the plurality of preforms, wherein positioning the assemblage of feed constituents comprises aligning, in the mold, at least some of the preforms parallel to a long axis of the rib.

6. The method of claim 5 wherein the fibers in the preforms aligned with parallel to the long axis of the rib are carbon fibers.

7. The method of claim 5 comprising forming a region of fiber-free thermoplastic matrix external to the rib and adjacent to a surface of the rounded corner of the rib, wherein the surface adjacent to the fiber-free thermoplastic matrix is opposite to a surface of the rib where the impact occurs.

8. The method of claim 1 wherein the resin from the plurality of preforms or the plurality of misaligned preforms that is positioned proximate to the rounded corner is a thermoplastic polymer selected from the group consisting of thermoplastic polyurethane, polycarbonate, polyphenylene oxide, and polyphenylene ether.

9. A method comprising:
forming an assemblage of feed constituents, wherein the assemblage includes fibers and resin in the form of a plurality of preforms, wherein at least one of the preforms of the plurality includes fibers that are suitably short to flow with resin during compression molding to form a fiber-composite part having a rounded corner;
positioning, in a mold cavity that includes a rounded corner, the assemblage of feed constituents such that the preform having the suitably short fibers is proximal to the rounded corner of the mold cavity;
opening, in the mold cavity, a vent by actuating a slider associated with the vent, the vent having a location that is proximal to a center of a length of a curved surface defining the rounded corner; and
compression molding the assemblage of feed constituents, wherein the open vent causes the short fibers to flow towards the vent along with a flow of resin thereto, so that, in the fiber-composite part being formed, the short fibers substantially align with an axis that is normal to the tangent of the curved surface defining the round corner at the location of the vent.

10. A method comprising:
forming an assemblage of feed constituents for compression molding a fiber-composite part having a rounded corner, wherein the assemblage includes fibers and resin in the form of a plurality of misaligned preforms, wherein the misaligned preforms are characterized by selective misalignment of some of the fibers within a segment of mostly unidirectionally aligned fibers;
positioning, in a mold cavity that includes a rounded corner, the assemblage of feed constituents such that at least a portion of each of the misaligned preforms are curved along a long axis thereof to align with and substantially match a curvature of the rounded corner of the mold cavity;
compression molding the assemblage of feed constituents to form the fiber composite part having the rounded corner.

11. The method of claim 10 wherein the fiber composite part comprises a first linear surface and a second linear surface, which are oriented at about ninety degrees relative to one another, wherein the first linear surface terminates at a first end of the rounded corner and the second linear surface terminates at a second end of the rounded corner, and wherein each of the misaligned preforms include two linear portions, one of such linear portions disposed on each side of the portion of the misaligned preform that is curved, wherein the linear portions of the misaligned preforms align with and parallel respective first and second linear surfaces.

Assignees

• Arris Composites Inc

Inventors

• Kirkland Kenneth
• Mannhalter Bert D
• Perkins J Scott
• Escowitz Ethan
• Reese Riley

Classifications

• B29C70/06

  Fibrous reinforcements only · CPC title

• B29C70/86

  Incorporated in coherent impregnated reinforcing layers, {e.g. by winding} · CPC title

• B29K2307/04

  Carbon · CPC title

• B29K2101/12

  Thermoplastic materials · CPC title

• B29L2031/7162

  Boxes, cartons, cases · CPC title