Bi-directional flexible structure with angled perforations
The present disclosure relates to inflatable cushions. The inflatable cushions may include a first ply extensive in longitudinal and transverse directions, and a second ply extensive in the longitudinal and transverse directions. The second ply may be overlayed on and sealed to the first ply such that the plies define therebetween a plurality of inflation chambers. The inflation chambers may be inflatable with a fluid and operable to contain the fluid. At least the first or second ply may include a layer of a first polymer material that has a bi-directional orientation. One or more lines of weakness may be formed by a plurality of perforations that facilitate tearing through the plies to separate portions of the inflatable cushion. At least one of the perforations may have a tip that is oriented at an angle displaced to the transverse direction.
1. An inflatable cushion, comprising:
a first ply made of polymer material extensive in a longitudinal direction and a transverse direction;
a second ply made of polymer material extensive in the longitudinal direction and the transverse direction and overlaid on and sealed to the first ply such that the plies define therebetween a plurality of inflation chambers, which are inflatable with a fluid and operable to contain the fluid; and
one or more lines of weakness extending generally transversely across the plies and formed by a plurality of perforations in the plies that facilitate tearing through the plies to separate portions of the inflatable cushion, each of the perforations having a tip that is oriented at an angle displaced from the transverse direction, adjacent pairs of the perforations being spaced from one another such that a tie connection of the plies extends therebetween;
wherein the polymer material of at least the first or second ply comprises a material that has a bi-directional orientation such that the tie connections break when the plies are torn along the line of weakness, thereby reducing the tendency of a tear to propagate outside the line of weakness.
2. The inflatable cushion of claim 1 , wherein the plurality of perforations extend at least a portion of the way across a transverse direction of the plies.
3. The inflatable cushion of claim 1 , wherein the tip is oriented diagonally relative to the transverse direction.
4. The inflatable cushion of claim 1 , wherein at least one of the perforations has two end tips on opposite sides of said perforation.
5. The inflatable cushion of claim 1 , wherein at least one of the perforations includes a sharp bend, and the tip is disposed at the bend.
6. The inflatable cushion of claim 5 , wherein the at least one of the perforations is a chevron shaped slit of which the tip is an intermediary tip, and the at least one of the perforations further comprises two portions each having an end tip.
7. The inflatable cushion of claim 1 , the inflation chambers having a filling entrance for directing air into the inflation chambers, the inflation chambers being sealed to retain the fluid therein when the filling entrance is sealed.
8. The inflatable cushion of claim 1 , wherein a plurality of transverse seals extend transversely across the plies and are spaced from each other longitudinally to define longitudinally spaced boundaries of the fluid chambers.
9. The inflatable cushion of claim 1 , wherein both the first and second plies include the bidirectional material.
10. The inflatable cushion of claim 1 , wherein at least one of the plies is a monolayer of said material having the bi-directional orientation.
11. The inflatable cushion of claim 1 , wherein at least one of the plies is a multilayer ply that includes a seal layer of a first polymer material and a gas barrier layer of a second polymer material, wherein the first and second polymer materials are different from one another.
12. The inflatable cushion of claim 1 , further comprising an inflation region that extends longitudinally and in fluid communication with the inflation chambers to enable filling of the inflation chambers with fluid injected into the inflation region.
13. The inflatable cushion of claim 12 , wherein the inflation region is defined between the first and second plies.
14. The inflatable cushion of claim 1 , wherein the one or more lines of weakness extend transversely through the plies and less than completely across the plies.
15. The inflatable cushion of claim 1 , wherein at least one of the one or more lines of weakness extends completely across the cushion to sever cushion portions from one another upon tearing along the line of weakness.
16. An inflatable cushion comprising:
a first ply made of polymer material extensive in a longitudinal direction and a transverse direction;
a second ply made of polymer material extensive in the longitudinal direction and the transverse direction and overlaid on and sealed to the first ply such that the plies define therebetween a plurality of inflation chambers, which are inflatable with a fluid and operable to contain the fluid;
an inflation region that extends longitudinally and in fluid communication with the inflation chambers to enable filling of the inflation chambers with fluid injected into the inflation region; and
one or more lines of weakness are formed by a plurality of perforations that facilitate tearing through the plies to separate portions of the inflatable cushion, each of the perforations having a tip that is oriented at an angle displaced from the transverse direction, adjacent pairs of the perforations being spaced from one another such that a tie connection of the plies extends therebetween,
wherein the polymer material of at least the first or second ply comprises a material that has a bi-directional orientation such that the tie connections break when the plies are torn along the line of weakness, thereby reducing the tendency of a tear to propagate outside the line of weakness.
17. The inflatable cushion of claim 16 , wherein the plurality of perforations extend at least a portion of the way across a transverse direction of the plies.
18. The inflatable cushion of claim 16 , wherein the tip is oriented diagonally relative to the transverse direction.
19. The inflatable cushion of claim 16 , wherein at least one of the perforations has two end tips on opposite transverse sides of said perforation.
20. The inflatable cushion of claim 16 , wherein the inflation chambers include a filling entrance for directing air into the inflation chambers, the inflation chambers being sealed to retain the fluid therein when the filling entrance is sealed.
21. The inflatable cushion of claim 16 , wherein the perforations comprise perforations that are chevron shaped.
22. The inflatable cushion of claim 16 , wherein the first and second plies are formed from a tube of a layer of a first polymer material.
23. The inflatable cushion of claim 16 , wherein the first and second plies are formed of a single sheet of material that is folded in a c-fold.
24. The inflatable cushion of claim 16 , wherein the first and second plies each comprise two sheets of material.
25. The inflatable cushion of claim 16 , further comprising a plurality of one way valves that extend from the inflation region into the inflation chamber through a seal.
26. The inflation cushion of claim 16 , wherein at least ⅓ of the plurality of perforations include a tip that is displaced at an angle relative to the transverse direction.
27. The inflation cushion of claim 16 , wherein all or substantially all of the plurality of perforations include a tip that is displaced at an angle relative to the transverse direction.
28. The inflatable cushion of claim 1 , wherein, first and second transverse seals are disposed at opposite edges of the plies, and the inflation chambers extend from the first transverse seal to the second transverse seal.
29. The inflatable cushion of claim 1 , wherein:
each of the perforations is a slit that has first and second portions that extend from a respective first or second end to join one another at a tip,
each of the first and second portions extends from the respective end to the tip in a direction that is oriented at an angle displaced from the transverse direction, and
each tie connection extends between the first end of a slit and the second end of an adjacent slit.
30. The inflatable cushion of claim 29 , wherein the first and second ends of the slits are aligned with one another in the transverse direction.
31. The inflatable cushion of claim 16 , wherein the one or more lines of weakness extend transversely across the plies, substantially excluding in the inflation region.
32. The inflatable cushion of claim 1 , further comprising first and second intermediate sheets overlaid on each other and disposed between the first and second plies in a first region of the inflatable cushion, the intermediate sheets cooperatively defining a plurality of one way valves that extend into the inflation chambers to direct the fluid into the chambers and retain the fluid in the chambers, wherein the plurality of perforations extend into the first region of the inflatable cushion.
33. The inflatable cushion of claim 32 , further comprising an inflation channel that extends longitudinally between the first and second plies and is in fluid communication with the one way valves to direct the fluid to the valves to fill the inflation chambers.
34. The inflatable cushion of claim 16 , wherein each of the perforations have a tip that is oriented at an angle displaced by at least about 10° from the transverse direction.
35. The inflatable cushion of claim 16 , wherein each of the perforations have a tip that is oriented at an angle displaced by at least about 30° from the transverse direction.
36. The inflatable cushion of claim 16 , wherein the polymer material of at least the first or second ply having a bi-directional orientation comprises a blown polymer material.