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EP-4368376-B1 - FORMING THERMOPLASTIC STRUCTURE STAMPING BLANK USING AUTOMATED FIBER PLACEMENT DEVICE

EP4368376B1EP 4368376 B1EP4368376 B1EP 4368376B1EP-4368376-B1

Inventors

  • LACALLE, Javier

Dates

Publication Date
20260513
Application Date
20231114

Claims (15)

  1. A method for forming a thermoplastic structure (70), comprising: providing a substrate (30), the substrate (30) including a substrate thermoplastic (50) and a plurality of substrate fibers (48) disposed within the substrate thermoplastic (50), and the plurality of substrate fibers (48) arranged in a substrate pattern; depositing a first layer (28; 28A) on the substrate using an automated fiber placement device (24), the first layer including a first layer thermoplastic (58) and a plurality of first layer fibers (56) disposed within the first layer thermoplastic (58), and the plurality of first layer fibers arranged in a first layer pattern that is different than the substrate pattern; and stamping a blank (22; 22') into the thermoplastic structure (70), the blank (22; 22') including the substrate (30) and the first layer (28; 28A) where the first layer thermoplastic (58) is consolidated with the substrate thermoplastic (50), characterized in that a first of the plurality of substrate fibers (48) follows a straight trajectory within the substrate thermoplastic (50); and a first of the plurality of first layer fibers (56) follows a non-straight trajectory within the first layer thermoplastic (58).
  2. The method of claim 1, wherein the plurality of substrate fibers (48) are uniformly spaced within the substrate thermoplastic (50); and at least some of the plurality of first layer fibers (56) are non-uniformly spaced within the first layer thermoplastic (58).
  3. The method of claim 1 or 2, wherein the substrate (30) comprises a two-dimensional laminate.
  4. The method of any preceding claim wherein the substrate (30) is configured as a pre-consolidated laminate.
  5. The method of any preceding claim, wherein the substrate pattern is a unidirectional pattern of the plurality of substrate fibers (48).
  6. The method of any preceding claim, wherein the substrate (30) comprises a sheet of prepreg material; and the first layer (28; 28A) is deposited on the sheet of prepreg material.
  7. The method of any preceding claim, wherein the first layer thermoplastic (58) is consolidated with the substrate thermoplastic (50) during the depositing of the first layer (28; 28A) using the automated fiber placement device (24).
  8. The method of any of claims 1 to 6, further comprising consolidating the first layer thermoplastic (58) with the substrate thermoplastic (50) following the depositing of the first layer (28; 28A).
  9. The method of any preceding claim, wherein the first layer (28; 28A) is deposited on a select portion of the substrate (30).
  10. The method of any preceding claim, further comprising removing at least a portion (62) of the substrate (30) not covered by the first layer (28; 28A).
  11. The method of any preceding claim, wherein: the substrate (30) has an outer peripheral substrate geometry; and the first layer (28; 28A) has an outer peripheral first layer geometry that is different than the outer peripheral substrate geometry.
  12. The method of any preceding claim, further comprising: depositing a second layer (28B) on the first layer (28A) using the automated fiber placement device (24); the second layer (28B) including a second layer thermoplastic and a plurality of second layer fibers disposed within the second layer thermoplastic; and the blank further including the second layer (28A) where the second layer thermoplastic is consolidated with the first layer thermoplastic (58).
  13. The method of claim 12, wherein the depositing of the second layer (28B) on the first layer (28A) is on a select portion of the first layer (28A).
  14. The method of claim 12 or 13, wherein the plurality of second layer fibers are arranged in a second layer pattern that is different than at least one of the substrate pattern or the first layer pattern.
  15. The method of any of claims 1 to 11, further comprising: providing a second substrate (30), the second substrate (30) including a second substrate thermoplastic and a plurality of second substrate fibers disposed within the second substrate thermoplastic, and the plurality of second substrate fibers arranged in a second substrate pattern; depositing a second layer (28) on the second substrate (30) using the automated fiber placement device (24), the second layer (28) including a second layer thermoplastic and a plurality of second layer fibers disposed within the second layer thermoplastic, and the plurality of second layer fibers arranged in a second layer pattern that is different than the second substrate pattern; stacking the second substrate (30) with the second layer (28) onto the substrate (30) with the first layer (28; 28A) to provide a multi-layer stack; and consolidating the multi-layer stack together to provide the blank (22).

Description

BACKGROUND This disclosure relates generally to forming a thermoplastic structure and, more particularly, to forming the thermoplastic structure by stamping a stamping blank. A structure may be formed by stamping a fiber-reinforced polymer stamping blank. The stamping blank may be configured as a consolidated laminate of multiple layers. Each laminate layer may include a standard woven mesh, unidirectional or other types of fibers embedded within a polymer matrix. While the standard woven mesh of fibers and generic, constant thickness laminates may be readily available and inexpensive, it may be difficult provide the stamped structure with optimal fiber placement and orientation. There is a need in the art therefore for an improved method for forming a fiber-reinforced polymer structure with tailored fiber placement and/or orientation. FR 3 020 779 A1 discloses a prior art method for producing preforms by application and forming of oriented fibers. US 2018/229452 A1 discloses a prior art method of making thermoplastic composite structures and prepreg tape used therein. US 2019/329460 A1 discloses a prior art method for manufacturing fiber-reinforced plastic. DE 10 2016 106258 A1 discloses a prior art fiber layer for curved fiber composite laminates and a method for depositing fanned fiber layers. DE 102013 105080 A1 discloses a prior art process for producing semi-finished products or components made of fiber-reinforced thermoplastic and semi-finished products produced by the process and component produced therefrom. SUMMARY OF THE DISCLOSURE According to an aspect of the present disclosure, a method is provided for forming a thermoplastic structure as recited in claim 1. Features of embodiments are set forth in the dependent claims. The foregoing features and the operation of the invention will become more apparent in light of the following description and the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic illustration of a system for forming a fiber-reinforced thermoplastic stamping blank.FIG. 2 is a schematic illustration of an automated fiber placement (AFP) device forming the stamping blank.FIG. 3 is a schematic illustration of certain components of the formation system forming the stamping blank.FIG. 4 is a flow diagram of a method for forming a thermoplastic structure.FIG. 5 is a schematic illustration of a fiber-reinforced thermoplastic substrate on a substrate support.FIG. 6 is a schematic illustration of a portion of the thermoplastic substrate with unidirectional fibers.FIG. 7 is a schematic illustration of a portion of the thermoplastic substrate with woven fibers, which falls outside the wording of the claims.FIG. 8 is a perspective schematic illustration of one or more fiber-reinforced thermoplastic layers (collectively shown) on the thermoplastic substrate.FIG. 9 is a schematic illustration of the thermoplastic layer(s) on the thermoplastic substrate.FIGS. 10A and 10B are schematic illustrations of portions of thermoplastic layers with various inter-fiber spacings and/or draping patterns.FIG. 11 is a schematic illustration of the stamping blank with multiple thermoplastic layers having different configurations.FIG. 12 is a schematic illustration of the stamping blank with a trim line.FIG. 13 is a schematic illustration of the stamping blank during a stamping process.FIGS. 14A and 14B are schematic illustrations depicting alternative steps for forming the stamping blank. DETAILED DESCRIPTION FIG. 1 is a schematic illustration of a system 20 for forming a (e.g., a two-dimensional (2D)) fiber-reinforced thermoplastic stamping blank 22, which stamping blank 22 may be stamped into a (e.g., three-dimensional (3D)) fiber-reinforced thermoplastic structure. The thermoplastic structure may be configured as or may be part of a structure of an airframe for an aircraft. The thermoplastic structure may alternatively be configured as or may be part of a structure of a propulsion system for the aircraft. The present disclosure, however, is not limited to the foregoing exemplary thermoplastic structure configurations nor to aircraft applications. The formation system 20 may include a material deposition device such as an automated fiber placement (AFP) device 24. The formation system 20 of FIG. 1 also includes a deposition device manipulator 26. Referring to FIG. 2, the AFP device 24 is configured to deposit (e.g., place, dispense, apply, lay, etc.) one or more layers 28A-E (generally referred to as "28") of fiber-reinforced thermoplastic material over and onto a fiber-reinforced thermoplastic substrate 30 with one or more fully consolidated or partially consolidated thermoplastic plies, or another object. The AFP device 24 may also be configured to consolidate (or alternative tack) the respective stamping blank members 28 and 30 together during the deposition of the thermoplastic layer(s) 28. The AFP device 24 of FIG. 2, for example, includes a substrate support 32 (see FIG.