Method for producing multilayer tailored fiber placement (tfp) preforms using meltable fixing fibers

• US 20040074589A1
• Filed: 11/07/2003
• Published: 04/22/2004
• Est. Priority Date: 12/08/2000
• Status: Active Grant

• Current Assignee: EADS Deutschland GmbH (Airbus SE)
• Original Assignee: EADS Deutschland GmbH (Airbus SE)
• Inventors: Filsinger, Juergen, Gessler, Andreas
• Granted Patent: US 7,942,993 B2
• Time in Patent Office: Days
• US Class Current: 156/155
• CPC Class Codes: B29C 70/202 arranged in parallel planes or structures of fibres crossing at substantial angles, e.g. cross-moulding compound [XMC] B29C70/207 takes precedence
• CPC Class Codes: B29C 70/226 the structure comprising mainly parallel filaments interconnected by a small number of cross threads

Abstract

A method is described whereby multilayer tailored fiber placement (TFP) preforms of any desired thickness may be easily produced without fixing threads or intermediate layers interfering. To this end, the invention provides that reinforcing fibers (1) are sewn onto a substrate (2) using a chemically or thermally meltable fixing thread (3) thus resulting in the formation of a reinforcing fiber structure (5a). The fixing thread (3) firstly serves to fix the reinforcing fibers (1) on the substrate (2) and is subsequently melted so that the fixing thread (3) disintegrates while pre-fixing the reinforcing fibers (1) and does not influence the mechanical properties of the reinforcing fiber structure (5a).

Claims

1. A method for producing multilayer TFP preforms, in particular for the production of multilayer TFP preforms of any desired thickness and without interfering intermediate layers,

wherein reinforcing fibers (1) are sewn onto a substrate (2) using a chemically or thermally meltable fixing thread (3), so that a reinforcing fiber structure (5a) is produced, the fixing threads (3) first being used to fix the reinforcing fibers (1) to the substrate (2) and then being melted so that the fixing thread (3) dissolves while the reinforcing fibers (1) are pre-fixed and does not affect the mechanical properties of the reinforcing fiber structure (5a).

2. The method for producing multilayer TFP preforms as recited in claim 1, characterized by the steps:

stacking of at least two reinforcing fiber structures (5a) to form a multilayer stack structure (6a);

melting the fixing thread (3);

impregnating and curing the stack structure (6a).

3. The method for producing multilayer TFP preforms as recited in claim 2,

wherein the melting of the fixing thread (3) takes place during the impregnation and curing process of the stack structure (6a) by chemical reaction with the material to be impregnated.

4. The method for producing multilayer TFP preforms as recited in claim 2,

wherein the melting of the fixing thread (3) takes place through the application of external heat, the fixing yarn (3) being heated to a temperature above its melting point.

5. The method as recited in claim 4,

wherein the application of heat is utilized during the impregnation and curing process to melt the fixing thread (3).

6. The method for producing multilayer TFP preforms as recited in claim 1, characterized by the steps:

melting the fixing thread (3) by the application of external heat after the reinforcing fibers (1) are sewn onto the substrate (2) so that the reinforcing fibers (1) are pre-fixed by the adhesive action of the molten fixing fiber (3) and the reinforcing fiber structure (5a) has an adequate stability;

stacking a plurality of reinforcing fiber structures (5a) to form a stack structure (6a);

impregnating and curing the stack structure (6a).

7. The method for producing multilayer TFP preforms as recited in one of claims 2 through 6,

wherein outward facing substrates (2) of the stack structure (6a) formed are removed by tearing off or peeling.

8. The method for producing multilayer TFP preforms without intermediate layers as recited in claim 1, characterized by the steps:

melting the fixing thread (3) by the application of external heat after the reinforcing fibers (1) are sewn onto the substrate (2) so that the reinforcing fibers (1) are pre-fixed by the adhesive action of the molten fixing fiber (3) and the reinforcing fiber structure (5a) has an adequate stability;

tearing off or peeling the substrate (2) from the reinforcing fiber structure (5a), resulting in a reinforcing fiber structure without a substrate (5b);

stacking a plurality of reinforcing fiber structures without a substrate (5b) to form a stack structure (6b);

impregnating and curing the stack structure (6b).

9. The method as recited in one of the preceding claims,

wherein the chemically or thermally meltable fixing thread (3) is a thermoplastic thread or a hot melt yarn.

10. The method as recited in claim 9,

wherein the thermally meltable fixing thread (3) is a copolyamide multifilament hot melt yarn.

11. The method as recited in one of the preceding claims,

wherein the reinforcing fibers (1) are force-flux oriented or situated in a quasiisotropic manner on the substrate (2).