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EP-4741142-A1 - MOLD ASSEMBLY FOR A VACUUM FORMING PROCESS AND A METHOD OF ELONGATING MEMBRANES OF THE MOLD ASSEMBLY

EP4741142A1EP 4741142 A1EP4741142 A1EP 4741142A1EP-4741142-A1

Abstract

A mold assembly for a vacuum forming process and a method of elongating membranes of the mold assembly for the vacuum forming process. A permeable layer is disposed across a surface of a mold body such that the permeable layer overlaps a groove defined in the surface of the mold body. Membranes are disposed across the permeable layer and the mold body. A vacuum is activated to expel a gaseous fluid out of a space between the mold body and one of the membranes which creates compaction pressure during compaction that causes the membranes to elongate and transform the composite blank material into the composite preform. A pump is activated to inject a flow of fluid between the permeable layer and one of the membranes via the groove to control the compaction pressure during elongation of the membranes as the gaseous fluid is expelled out of the space.

Inventors

  • SERENCSITS, William Louis
  • FRY, JESSICA OFFUTT
  • PETERS, BRIAN TIMOTHY

Assignees

  • The Boeing Company

Dates

Publication Date
20260513
Application Date
20251112

Claims (15)

  1. A method of elongating membranes (32, 34) of a mold assembly (10) for a vacuum forming process, the method comprising: disposing a permeable layer (30) across a surface (26) of a mold body (16) such that the permeable layer (30) overlaps a groove (28) defined in the surface (26) of the mold body (16), wherein the mold body (16) transforms a composite blank material (12) into a composite preform (14); containing the composite blank material (12) between the membranes (32, 34), wherein the membranes (32, 34) are disposed across the permeable layer (30) and the mold body (16); activating a vacuum (36) to expel a gaseous fluid out of a space (38) between the mold body (16) and one of the membranes (32, 34) which creates compaction pressure during compaction that causes the membranes (32, 34) to elongate and transform the composite blank material (12) into the composite preform (14); and activating a pump (54) to inject a flow of fluid between the permeable layer (30) and one of the membranes (32, 34) via the groove (28) to control the compaction pressure during elongation of the membranes (32, 34) as the gaseous fluid is expelled out of the space (38).
  2. The method according to claim 1, wherein disposing the permeable layer (30) across the surface (26) of the mold body (16) further comprises: attaching the permeable layer (30) to the mold body (16) such that the permeable layer (30) overlaps the groove (28).
  3. The method according to claim 1 or 2, wherein the membranes (32, 34) comprise a first membrane (32) and a second membrane (34) that contains the composite blank material (12); wherein disposing the membranes (32, 34) across the permeable layer (30) and the mold body (16) further comprises: disposing the first membrane (32) across the permeable layer (30) and the mold body (16); attaching the first membrane (32) to the mold body (16) beyond the permeable layer (30); and attaching the second membrane (34) to the mold body (16) beyond the permeable layer (30).
  4. The method according to claim 3, wherein containing the composite blank material (12) between the membranes (32, 34) further comprises: containing the composite blank material (12) between the first membrane (32) and the second membrane (34).
  5. The method according to claim 3 or 4, wherein attaching the second membrane (34) to the mold body (16) beyond the permeable layer (30) further comprises: attaching the second membrane (34) to the mold body (16) beyond the composite blank material (12) and the first membrane (32).
  6. The method according to any one of claims 1 to 5, wherein the space (38) and the groove (28) are in fluid communication with each other; and wherein activating the pump (54) to inject the flow of fluid between the permeable layer (30) and one of the membranes (32, 34) occurs before the membranes (32, 34) adhere to the surface (26) of the mold body (16) beyond the groove (28).
  7. The method according to any one of claims 1 to 6, wherein the membranes (32, 34) continue to elongate along the surface (26) of the mold body (16) during activation of the vacuum (36) that expels the gaseous fluid out of the space (38).
  8. The method according to any one of claims 1 to 7, wherein the membranes (32, 34) comprise a first membrane (32) and a second membrane (34) that contains the composite blank material (12); and wherein the method further comprises activating a vacuum (52) to expel gaseous fluid out of an area (50) between the first membrane (32) and the second membrane (34).
  9. The method according to any one of claims 1 to 8, wherein a predetermined amount of the gaseous fluid is removed from the space (38) during activation of the vacuum (36); wherein a predetermined amount of the flow of fluid is injected into the space (38) during activation of the pump (54); and wherein the predetermined amount of the gaseous fluid removed from the space (38) is greater than the predetermined amount of the flow of fluid injected into the space (38).
  10. The method according to any one of claims 1 to 9, further comprising: deactivating the pump (54) to stop the flow of fluid entering the space (38) via the groove (28) when the membranes (32, 34) elongate beyond the permeable layer (30).
  11. The method according to any one of claims 1 to 10, further comprising: deactivating the vacuum (36) to stop flow of the gaseous fluid out of the space (38) after transforming the composite blank material (12) to the composite preform (14); and removing the completed composite preform (14) from the membranes (32, 34).
  12. A mold assembly (10) for a vacuum forming process that transforms a composite blank material (12) into a composite preform (14), the mold assembly (10) comprising: a mold body (16) having a surface (26) defining a groove (28); a permeable layer (30) disposed across the surface (26) of the mold body (16) such that the permeable layer (30) overlaps the groove (28) defined in the surface (26) of the mold body (16); a plurality of membranes (32, 34) configured to contain the composite blank material (12) between the membranes (32, 34), wherein the membranes (32, 34) are disposed across the permeable layer (30) and the mold body (16); a vacuum (36) configured to be selectively activated to expel a gaseous fluid out of a space (38) between the mold body (16) and one of the membranes (32, 34) which creates compaction pressure during compaction that causes the membranes (32, 34) to elongate and transform the composite blank material (12) into the composite preform (14); and a pump (54) configured to be selectively activated to inject a flow of fluid between the permeable layer (30) and one of the membranes (32, 34) via the groove (28) to control the compaction pressure during elongation of the membranes (32, 34) as the gaseous fluid is expelled out of the space (38).
  13. The mold assembly (10) according to claim 12, wherein: the membranes (32, 34) include a first membrane (32) and a second membrane (34) configured to contain the composite blank material (12); and the first membrane (32) is disposed across the permeable layer (30) and the mold body (16).
  14. The mold assembly (10) according to claim 13, wherein the groove (28) and the space (38) are in fluid communication with each other below the first membrane (32).
  15. The mold assembly (10) according to any one of claims 12 to 14, wherein: the permeable layer (30) is formed of a material having a first coefficient of friction; the membranes (32, 34) are formed of a material having a second coefficient of friction; and the first coefficient of friction is less than the second coefficient of friction.

Description

CROSS-REFERENCE This Patent Application claims priority to U.S. Provisional Patent Application No. 63/719206, filed on November 12, 2024, and entitled "MOLD ASSEMBLY FOR A VACUUM FORMING PROCESS AND A METHOD OF ELONGATING MEMBRANES OF THE MOLD ASSEMBLY." BACKGROUND Current forming processes for composite materials may utilize deformable membranes and a vacuum to form a full stack of material at once. To form complex configurations using composite materials, some composite materials have small segments of fiber material that are hand laid such that the fiber direction does not deviate from a set standard amount. This process may be time consuming. Furthermore, due to the complex geometry to be achieved during the forming process, the deformable membranes may not be able to elongate to the required length. Therefore, to assist in elongating the deformable membranes, lubricants or surface treatments may be implemented, but this may cause contamination of the environment. SUMMARY Therefore, it is desirable to develop a mold assembly and a method that improves manufacturing processes of elongating membranes for forming a composite preform, and other benefits are discussed herein. The present disclosure pertains to a method of elongating membranes of a mold assembly for a vacuum forming process, as defined in the appended independent claim 1. The present disclosure also pertains to a mold assembly for a vacuum forming process that transforms a composite blank material into a composite preform, as defined in the appended independent claim 12. The detailed description and the drawings or FIGS. are supportive and descriptive of the disclosure, but the claim scope of the disclosure is defined solely by the claims. While some of the best modes and other configurations for carrying out the claims have been described in detail, various alternative designs and configurations exist for practicing the disclosure defined in the appended claims. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic perspective view of a mold assembly including a permeable layer and a groove disposed under the permeable layer relative to the view.FIG. 2 is a schematic enlarged fragmented view of a surface of a mold body defining a groove and the permeable layer disposed over the groove.FIG. 3 is a schematic fragmented view of a component blank material disposed between membranes prior to elongation.FIG. 4 is a schematic fragmented view of the component blank material disposed between the membranes during elongation, in which a pump is activated to inject a flow of fluid into a space via the groove.FIG. 5 is a schematic illustration of the membranes fully elongated and transforming the composite blank material into the composite preform with at least one radii. The present disclosure may be extended to modifications and alternative forms, with representative configurations shown by way of example in the drawings and described in detail below. Inventive aspects of the disclosure are not limited to the disclosed configurations. Rather, the present disclosure is intended to cover modifications, equivalents, combinations, and alternatives falling within the scope of the disclosure as defined by the appended claims. DETAILED DESCRIPTION Those having ordinary skill in the art will recognize that all directional references (e.g., above, below, upward, up, downward, down, top, bottom, left, right, vertical, horizontal, etc.) are used descriptively for the FIGS. to aid the reader's understanding, and do not represent limitations (for example, to the position, orientation, or use, etc.) on the scope of the disclosure, as defined by the appended claims. Moreover, terms such as "first," "second," "third," and so on, may be used to describe separate components. Such terminology may include the words specifically mentioned above, derivatives thereof, and words of similar import. Furthermore, the term "substantially" can refer to a slight imprecision or slight variance of a condition, quantity, value, or dimension, etc., some of which are within manufacturing variance or tolerance ranges. As used herein, an element or step recited in the singular and preceded by the word "a" or "an" should be understood as not necessarily excluding the plural of the elements or steps. That is, "a", "an", "the", "at least one", and "one or more" are used interchangeably to indicate that at least one of the items is present and more than one may be present, unless stated otherwise. Further, any reference to "one configuration" is not intended to be interpreted as excluding the existence of additional configurations that also incorporate the recited features. Moreover, unless explicitly stated to the contrary, configurations "comprising" or "having" an element or a plurality of elements having a particular property may include additional elements not having that property. The phrase "at least one of" as used herein should be construed to include the non-exclusive logical "or"