Selectively weakened stretched films

Patent metadata

Field	Value
Publication number	US-10005256-B2
Application number	US-201213523141-A
Country	US
Kind code	B2
Filing date	Jun 14, 2012
Priority date	Jun 14, 2012
Publication date	Jun 26, 2018
Grant date	Jun 26, 2018

Abstract

A film for a composite article may include a non-weakened portion and a weakened portion. The weakened portion may have at least one property that may be lower than the property of the non-weakened portion.

First claim

What is claimed is:

1. A non-fibrous film for a composite article, comprising:
a plurality of non-fibrous non-weakened portions extending along the length of the non-fibrous film;
a plurality of non-fibrous weakened portions having one of the following three arrangements:
(a) at least one of the non-fibrous weakened portions having a tortuous shape and being non-intersected by any transverse weakened segments along the length of the non-fibrous film;
(b) at least one of the non-fibrous non-weakened portions having a tortuous shape and being non-interrupted by any transverse weakened segments along the length of the non-fibrous film;
(c) some of the non-fibrous weakened portions being intersected by transverse weakened segments and at least one of the non-fibrous weakened portions being non-intersected by transverse weakened segments extending from opposite sides of the weakened portion at the same location thereon along the length of the non-fibrous film, the weakened portions being continuously straight along the length of the non-fibrous film;

wherein each transverse weakened segment is non-parallel to the weakened portions; and
the weakened portions having at least one property that has a value that is lower than the value of the property of the plurality of non-weakened portions.

2. The film of claim 1 , wherein:
the property comprises at least one of a tensile strength, a tensile modulus, and an ultimate strain.

3. The film of claim 1 , wherein:
the non-fibrous film comprises a stretched film having a stretched direction oriented generally parallel to a lengthwise direction of the weakened portions.

4. The film of claim 1 , wherein:
the non-fibrous film comprises a corrugated film having a corrugated cross-sectional shape.

5. The film of claim 1 , wherein:
the non-fibrous film has a film thickness in a range of from approximately 3 microns to 5000 microns.

6. The film of claim 1 , wherein:
at least one of the non-weakened portions has an elongated cross-sectional shape with an aspect ratio of a non-weakened portion width to a film thickness of approximately 3 to approximately 500.

7. The film of claim 1 , wherein the film is formed from at least one of:
a thermoplastic material, a thermosetting material, and a metallic material.

8. The film of claim 7 , wherein:
the non-fibrous film comprises a stretched film formed of thermoplastic material.

9. The film of claim 8 , wherein:
the stretched film is one of unidirectionally stretched and bidirectionally stretched.

10. The film of claim 1 , further comprising:
an adhesive layer located between at least one pair of the non-fibrous films.

11. A composite article, comprising:
a plurality of non-fibrous films arranged in a stacked formation;
at least one of the non-fibrous films having a plurality of non-weakened portions extending along the length of the non-fibrous film;
a plurality of non-fibrous weakened portions having one of the following three arrangements:
(a) at least one of the non-fibrous weakened portions having a tortuous shape and being non-intersected by any transverse weakened segments along the length of the at least one non-fibrous film;
(b) at least one of the non-fibrous non-weakened portions having a tortuous shape and being non-interrupted by any transverse weakened segments along the length of the non-fibrous film;
(c) some of the non-fibrous weakened portions being intersected by transverse weakened segments and at least one of the non-fibrous weakened portions being non-intersected by transverse weakened segments extending from opposite sides of the weakened portion at the same location thereon along the length of the at least one non-fibrous film, the weakened portions being continuously straight along the length of the non-fibrous film;

wherein each transverse weakened segment is non-parallel to the weakened portions; and
the weakened portions having at least one property that has a value that is lower than the value of the property of the plurality of non-weakened portions.

12. The composite article of claim 11 , further comprising:
an adhesive layer located between at least one pair of the plurality of non-fibrous films.

13. The composite article of claim 11 , wherein:
the property comprises a property including at least one of a tensile strength, a tensile modulus, and an ultimate strain.

14. The composite article of claim 11 , wherein:
at least one of the plurality of non-fibrous films comprises a stretched film having a stretched direction oriented generally parallel to a lengthwise direction of the weakened portion.

15. The composite article of claim 14 , wherein:
the stretched film is one of unidirectionally stretched and bidirectionally stretched.

16. The composite article of claim 11 , wherein:
the plurality of non-fibrous films comprise corrugated films arranged in the stacked formation.

17. The composite article of claim 16 , further comprising:
a pair of face sheets mounted on opposite sides of the stacked formation of the corrugated films.

18. A method of forming a film, comprising the steps of:
forming a non-fibrous film having a plurality of non-fibrous non-weakened portions extending along the length of the non-fibrous film, and a plurality of non-fibrous weakened portions having one of the following three arrangements:
(a) at least one of the non-fibrous weakened portions having a tortuous shape and being non-intersected by any transverse weakened segments along the length of the non-fibrous film;
(b) at least one of the non-fibrous non-weakened portions having a tortuous shape and being non-interrupted by any transverse weakened segments along the length of the non-fibrous film;
(c) some of the non-fibrous weakened portions being intersected by transverse weakened segments and at least one of the non-fibrous weakened portions being non-intersected by transverse weakened segments extending from opposite sides of the weakened portion at the same location thereon along the length of the non-fibrous film, the weakened portions being continuously straight along the length of the non-fibrous film;

wherein each transverse weakened segment is non-parallel to the weakened portions; and
configuring the non-fibrous film such that the weakened portions have at least one property having a value that is lower than the value of the property of the non-weakened portions.

19. The method of claim 18 , wherein:
the property comprises at least one of a tensile strength, a tensile modulus, and an ultimate strain.

20. The method of claim 18 , further comprising the step of:
forming the tortuous shape as lengthwise weakened segments that are offset from one another and which are interconnected by transverse weakened segments.

21. The method of claim 18 , further comprising the step of:
providing the non-fibrous film as a stretched film.

22. A method of forming a composite article, comprising the steps of:
providing a plurality of non-fibrous films, at least one of the films having a plurality of non-fibrous non-weakened portions extending along the length of the at least one non-fibrous film, and a plurality of non-fibrous weakened having one of the following three arrangements:
(a) at least one of the non-fibrous weakened portions having a tortuous shape and being non-intersected by any transverse weakened segments along the length of the non-fibrous film;
(b) at least one of the non-fibrous non-weakened portions having a tortuous

Assignees

• Wilenski Mark S
• Kozar Michael P
• Boeing Co

Inventors

• Wilenski Mark S
• Kozar Michael P

Classifications

• B32B2307/412

  Transparent · CPC title

• B32B38/0008

  Electrical discharge treatment, e.g. corona, plasma treatment; wave energy or particle radiation (heat treatment B32B38/0036) · CPC title

• B32B37/02

  characterised by a sequence of laminating steps, e.g. by adding new layers at consecutive laminating stations · CPC title

• B32B27/365

  comprising polycarbonates · CPC title

• B32B2307/50

  having particular mechanical properties · CPC title