Carbon fiber reinforcements for sheet molding composites

Patent metadata

Field	Value
Publication number	US-9815224-B2
Application number	US-201514672703-A
Country	US
Kind code	B2
Filing date	Mar 30, 2015
Priority date	Mar 30, 2015
Publication date	Nov 14, 2017
Grant date	Nov 14, 2017

Abstract

A method of processing a carbon fiber tow includes the steps of providing a carbon fiber tow made of a plurality of carbon filaments, depositing a sizing composition at spaced-apart sizing sites along a length of the tow, leaving unsized interstitial regions of the tow, and cross-cutting the tow into a plurality of segments. Each segment includes at least a portion of one of the sizing sites and at least a portion of at least one of the unsized regions of the tow, the unsized region including and end portion of the segment.

First claim

What is claimed is:

1. A method of processing a carbon fiber tow comprising the steps of:
a) providing a carbon fiber tow comprising a plurality of carbon filaments;
b) depositing a sizing composition at spaced-apart sizing sites along a length of said tow, leaving unsized interstitial regions of said tow; and
c) cross-cutting said tow into a plurality of segments, each of said segments defining an end portion, each of said segments comprising at least a portion of one of said sizing sites and at least a portion of at least one of said unsized regions of said tow, said unsized region including said end portion.

2. A method of processing a carbon fiber tow in accordance with claim 1 further comprising the additional step between step b) and step c) of surface-activating said unsized regions of said tow with oxygen-associated groups so that surfaces of said filaments become polar and repel each other after the cross-cutting step.

3. A method of processing a carbon fiber tow in accordance with claim 1 wherein each of said segments defines two end portions, and wherein each of said segments comprises one of said sizing sites and a portion of two of said unsized regions of said tow, said unsized region portions respectively including said two end portions.

4. A method of processing a carbon fiber tow in accordance with claim 1 further comprising the additional, subsequent step d) of dispersing said plurality of said segments in a resin matrix so that said resin matrix penetrates interstices between said filaments.

5. A method of processing a carbon fiber tow in accordance with claim 1 wherein each of said segments defines two end portions, and wherein each of said segments comprises one of said sizing sites and a portion of one of said unsized regions of said tow, said unsized region portion and said one sizing site each respectively including one of said end portions.

6. A method of processing a carbon fiber tow in accordance with claim 1 wherein depositing step b) includes depositing a sizing composition at equally spaced-apart sizing sites along a length of said tow.

7. A method of processing a carbon fiber tow in accordance with claim 1 wherein depositing step b) includes depositing a sizing composition with two or more applicators.

8. A method of processing a carbon fiber tow in accordance with claim 1 wherein depositing step b) includes depositing a sizing composition with segmented rollers.

9. A method of processing a carbon fiber tow in accordance with claim 1 wherein depositing step b) includes depositing a sizing composition with an eccentric roller.

10. A method of processing a carbon fiber tow in accordance with claim 1 further comprising the additional step between step b) and step c) of drying said sizing spots at a temperature of between 40° C. to 80° C. for a time period of between 0.5 min to 10 min.

Assignees

• Ut Battelle Llc

Inventors

• Ozcan Soydan
• Paulauskas Felix L

Classifications

• C08J2363/00

  Characterised by the use of epoxy resins; Derivatives of epoxy resins · CPC title

• C08J5/042

  with carbon fibres · CPC title

• B29K2063/00

  Use of {EP, i.e.} epoxy resins {or derivatives thereof}, as moulding material · CPC title

• B29B15/125 Primary

  by dipping · CPC title

• C08J2331/02

  Characterised by the use of omopolymers or copolymers of esters of monocarboxylic acids · CPC title