Stabilized dry preform and method

Patent metadata

Field	Value
Publication number	US-9381675-B2
Application number	US-201113307654-A
Country	US
Kind code	B2
Filing date	Nov 30, 2011
Priority date	Nov 30, 2011
Publication date	Jul 5, 2016
Grant date	Jul 5, 2016

Abstract

A method of forming a preform may include providing a layer of tackified fibrous material containing structural fibers and resin. The layer may be passed through a forming die set having a die cross-sectional shape. The thermoplastic resin may be heated. The layer may be formed into the die cross-sectional shape. The thermoplastic resin may be allowed to solidify in a manner such that a preform is formed having the die cross-sectional shape.

First claim

What is claimed is:

1. A method of forming a preform, comprising the steps of:
providing a layer of tackified fibrous material containing structural fibers and resin commingled or intimately blended with the structural fibers, the resin being in solid form and being approximately 1 to 10 percent by volume of the layer of tackified fibrous material;
passing the layer through a forming die set having a die cross-sectional shape;
heating the resin;
softening the resin in response to heating the resin such that the resin flows within the fibrous material;
forming the layer into the die cross-sectional shape;
allowing the resin to solidify in a manner such that a preform is formed in the die cross-sectional shape, the solidified resin retaining the die cross-sectional shape of the preform; and
retaining a porous nature in the fibrous material after forming the preform.

2. The method of claim 1 wherein the resin is a thermoplastic resin, the step of allowing the resin to solidify includes:
allowing the thermoplastic resin to cool such that the thermoplastic resin solidifies.

3. The method of claim 1 wherein:
the layer of tackified fibrous material contains approximately 2 to 4 percent by volume of resin.

4. The method of claim 1 , wherein the forming die set comprises a stationary die set, the step of passing the layer through the forming die set comprises:
continuously pultruding the layer through the stationary die set using a pulling mechanism.

5. The method of claim 1 , wherein the forming die set comprises a movable die set, the step of passing the layer through the forming die set comprises:
sequentially forming the layer into the die cross-sectional shape by successively clamping sections of the layer between the movable die set.

6. The method of claim 1 , wherein the step of heating the resin comprises at least one of the following:
conductive heating;
radiation heating; and
inductive heating.

7. The method of claim 1 wherein the step of heating the layer comprises at least one of the following:
heating a material roll of the layer of fibrous material;
heating the forming die set and the layer in response to the layer passing therethrough.

8. The method of claim 1 wherein the step of providing the layer of tackified fibrous material comprises:
providing the layer of fibrous material from a refrigerated material roll; and
heating the layer of fibrous material to tackify the layer.

9. The method of claim 1 , further comprising the steps of:
positioning the preform with additional fibrous material;
infusing the preform and the additional fibrous material with a matrix material; and
curing the matrix material to form the final composite article.

10. The method of claim 9 , wherein the final composite article has a fiber-volume fraction in a range of from approximately 30 to 70 percent.

11. The method of claim 1 , wherein:
the die cross-sectional shape varies over a length of the forming die set.

12. The method of claim 11 , wherein:
the die cross-sectional shape is tapered from an entrance to an exit of the forming die set.

13. The method of claim 1 , further comprising the steps of:
infusing the preform with a matrix material; and
curing the matrix material to form the final composite article.

14. The method of claim 13 , wherein:
the final composite article comprises a component of at least one of an aircraft and a spacecraft.

15. The method of claim 1 , wherein the resin is a thermoplastic resin having at least one of the following characteristics when in the presence of a matrix material:
at least partially soluble in the matrix material;
reactive with the matrix material; and
remaining in a phase that is different than the phase of the matrix material during curing of the matrix material.

16. The method of claim 1 , further comprising the steps of:
providing at least two layers of fibrous material;
assembling the layers into a layer assembly; and
passing the layer assembly through the forming die set.

17. The method of claim 16 , wherein:
each one of the layers includes fibers; and
the fibers in at least one of the layers having a different orientation than the fibers in another one of the layers.

18. The method of claim 16 , further comprising at least one of the following steps:
drawing at least two of the layers from single-ply material rolls;
drawing at least two of the layers from a multi-ply material roll.

19. The method of claim 1 , wherein the resin is a thermoplastic resin, the method further comprising the steps of:
stacking at least two of the preforms into a preform stack;
heating the preform stack to a temperature causing a reduction in viscosity of the thermoplastic resin;
applying a compressive force to the preform stack; and
allowing the thermoplastic resin to solidify to form a solidified preform assembly.

20. The method of claim 1 , wherein the layer of fibrous material has as at least one of the following configurations:
fabric; and
organized tows.

21. A method of forming a composite article, comprising the steps of:
providing at least one layer of fibrous material containing structural fibers and resin commingled or intimately blended with the structural fibers, the resin being in solid form and being approximately 1 to 10 percent by volume of the layer of tackified fibrous material;
passing the layer through a forming die set having a die cross-sectional shape;
heating the resin with a heating device;
softening the resin in response to heating the resin such that the resin flows within the fibrous material;
forming the layer into the die cross-sectional shape;
allowing the resin to solidify in a manner such that a preform is formed in the die cross-sectional shape, the solidified resin retaining the die cross-sectional shape of the preform, the preform retaining a porous nature in the fibrous material after solidification of the resin and forming into the preform;
positioning the preform with additional fibrous material;
infusing, due to the porous nature of the fibrous material, the preform and the additional fibrous material substantially uniformly with liquid matrix material after forming the preform into the die cross-sectional shape; and
curing the liquid matrix material to form a final composite article.

Assignees

• Tsotsis Thomas Karl
• Young Gerould K
• Boeing Co

Inventors

• Tsotsis Thomas Karl
• Young Gerould K

Classifications

• B29B11/16 Primary

  comprising fillers or reinforcement {(non-woven fabrics per se D04H1/00, D04H3/00)} · CPC title

• B29C70/52

  Pultrusion, i.e. forming and compressing by continuously pulling through a die · CPC title

• B29K2101/12

  Thermoplastic materials · CPC title

• B29C48/908

  characterised by calibrator surface, e.g. structure or holes for lubrication, cooling or venting · CPC title

• B29C48/906

  using roller calibration · CPC title