RTM (resin transfer molding)—method with intermediate fibrous layer

Patent metadata

Field	Value
Publication number	US-12172394-B2
Application number	US-201514966338-A
Country	US
Kind code	B2
Filing date	Dec 11, 2015
Priority date	Dec 15, 2014
Publication date	Dec 24, 2024
Grant date	Dec 24, 2024

Abstract

The present invention relates to a method for the production of a fiber composite part, with a fibrous blank ( 6 ) being inserted into a mold ( 1 ) and the mold ( 1 ) being closed, and a matrix being injected into the closed mold ( 1 ), which is characterized in that at least sectionally an intermediate fibrous layer ( 15 ) is arranged locally fixed between the outer shell surface ( 7 ) of the fibrous material blank ( 6 ) and the inner shell surface ( 5 ) of the mold ( 1 ), so that the flow rate of the resin is reduced due to the randomly arranged fibers ( 15 ).

First claim

The invention claimed is:

1. A resin transfer molding (RTM) method for the production of a fiber composite part comprising,
inserting a fiber preform blank with an outer shell surface into a closed mold with an inner shell surface,
arranging an intermediate fibrous layer in channels for resin flow and located between the outer shell surface of the fiber preform and the inner shell surface of the closed mold, wherein the intermediate fibrous layer generated by roughening the outer shell surface of the fiber preform blank by a scraper, or by way of a flocking process, thereby generating individual filaments and/or fiber strands projecting and pointing away from the outer shell surface of the fiber preform blank to cause a reduction in the flow rate of a resin system through the intermediate fibrous layer between the outer shell surface of the fiber preform blank and the inner shell surface of the mold,
injecting the resin system into the closed mold, and
developing a homogenous resin front through the fiber preform blank and the intermediate fibrous layer arranged in the channels.

2. The method according to claim 1 wherein, the intermediate fibrous layer is arranged in cavities between the outer shell surface of the fiber preform blank and the inner shell surface of the closed mold.

3. The method according to claim 1 wherein, the intermediate fibrous layer is arranged in cavities aligned at an angle from 0 degree to 90 degrees with reference to a direction of a compression stroke of the mold.

4. The method according to claim 3 wherein, the cavities extend at an angle from 0 degree to 80 degrees with reference to a direction of the compression stroke of the mold.

5. The method according to claim 1 wherein, the closed mold comprises a mold cavity, with a resin injection aperture located in a central section of the mold cavity and ventilation apertures provided at ends of the mold cavity, through which excess pressure, which has developed due to the resin injection, is released.

6. The method according to claim 1 wherein, in areas with less surface pressure between the mold and the fiber preform blank, when the mold is closed, a higher density of randomly aligned fibers and/or longer randomly aligned fibers is provided than in areas with higher surface pressure.

7. The method according to claim 1 , wherein the generated individual filaments and/or fiber strands have a length from 0.1 mm to 75 mm.

8. The method according to claim 7 wherein, filaments and/or fiber strands are generated at a length from 1 mm to 20 mm.

9. The method according to claim 1 including heating the mold, or sectionally heating the mold to different temperatures and/or sections of the mold are heated at different points in time.

10. The method according to claim 1 wherein, a leaf spring is produced for a motor vehicle.

Assignees

• Benteler Sgl Gmbh & Co Kg
• Benteler Automobiltechnik Gmbh

Inventors

• Kaiser Dominik

Classifications

• B29L2031/774

  Springs · CPC title

• B29C70/547

  using channels or porous distribution layers incorporated in or associated with the product · CPC title

• B29C70/48 Primary

  and impregnating the reinforcements in the closed mould, e.g. resin transfer moulding [RTM] {, e.g. by vacuum} · CPC title

• B29C45/73

  of the mould {(B29C45/2642 and B29C45/2737 take precedence)} · CPC title

• B29C45/14786

  Fibrous material or fibre containing material, e.g. fibre mats or fibre reinforced material · CPC title