초록 ▼

A mechanically expandable foam sheet has comprising a plurality of discrete slits therein that allow the foam sheet to be expanded from an unexpanded foam sheet configuration to an expanded foam sheet configuration. The expandable foam sheet has a density of from 14 g/liter to 48 g/liter in the unex

A mechanically expandable foam sheet has comprising a plurality of discrete slits therein that allow the foam sheet to be expanded from an unexpanded foam sheet configuration to an expanded foam sheet configuration. The expandable foam sheet has a density of from 14 g/liter to 48 g/liter in the unexpanded configuration and a thickness of from 6 mm to 50 mm. The slits are of a kind and of a size and arrangement that the expanded foam sheet locks into the expanded configuration by exhibiting a pressure-to-close of at least 5 gm/cm2. Each of the slits provides only a single free volume in the expanded foam sheet. An expandable foam sheet having serpentine-shaped expansion and locking arms is also disclosed, as are various cushioning articles comprising expanded foam sheet.

대표청구항 ▼

1. An expandable foam sheet comprising a plurality of discrete slits therein, the foam sheet being mechanically expandable from an unexpanded foam sheet configuration to an expanded foam sheet configuration, the expandable foam sheet having a density of from 14 g/liter to 48 g/liter in the unexpande

1. An expandable foam sheet comprising a plurality of discrete slits therein, the foam sheet being mechanically expandable from an unexpanded foam sheet configuration to an expanded foam sheet configuration, the expandable foam sheet having a density of from 14 g/liter to 48 g/liter in the unexpanded configuration and a thickness of from 6 mm to 50 mm, the slits being of a size and shape and arrangement so that the expanded foam sheet locks into the expanded configuration by exhibiting a pressure-to-close of at least 5 gm/cm2, with each of the slits providing only a single free volume in the expanded foam sheet. 2. The expandable foam sheet according to claim 1, wherein: (A) the unexpanded foam sheet configuration comprises a plurality of transverse stabilization walls X, each stabilization wall comprising a plurality of cavity wells along a first side thereof, and a plurality of cavity wells along a second side thereof, with the cavity wells being bounded on a first side by a first finger extending from and integral with the stabilization wall and being bounded on a second side by a second finger extending from and integral with the stabilization wall, the fingers extending between adjacent cavity wells on the same side of the stabilization wall, the cavity wells containing at least a portion of a finger from an adjacent stabilization wall extending thereinto, with the finger within the cavity well being hingedly attached to an associated pair of expansion-and-locking arms, including being hingedly attached to a first end of a first expansion-and-locking arm within said cavity well and hingedly attached to a first end of a second expansion-and-locking arm also within said cavity well, with the first expansion-and-locking arm having a second end that is hingedly attached to the first finger bounding the first side of the cavity well, and the second expansion-and-locking arm having a second end that is hingedly attached to the second finger bounding the second side of the cavity well; and(B) the expanded foam sheet configuration comprises the plurality of transverse stabilization walls X and a plurality of transverse locking arm walls Y, with the plurality of transverse stabilization walls X and the plurality of transverse locking arm walls Y alternating in X-Y-X-Y arrangement, with a single transverse stabilization wall being connected to a single transverse locking arm wall by a plurality of the fingers extending from and integral with the transverse stabilization wall, and with the locking arm walls comprising a plurality of pairs of first and second expansion-and-locking arms in inverted position, with said first and second expansion-and-locking arms in inverted position having emerged from the cavity well of the unexpanded foam sheet during expansion of the foam sheet so that said first and second expansion-and-locking arms are locked in the inverted position, with the plurality of cavity wells and the plurality of associated pairs of expansion-and-locking arms locked in inverted position surrounding a corresponding number of discrete free volumes within the expanded foam sheet. 3. The expandable foam sheet according to claim 2, wherein the unexpanded foam sheet has a density of from 16 g/liter to 36 g/liter. 4. The expandable foam sheet according to claim 2, wherein the expansion-and-locking arms are of non-uniform width and are wider in a middle region than at end regions at which the expansion-and-locking arms are hingedly attached to the fingers. 5. The expandable foam sheet according to claim 2, wherein each of the expansion-and-locking arms are of a substantially uniform width. 6. The expandable foam sheet according to claim 2, wherein each cavity well has a centrally-positioned finger therein. 7. The expandable foam sheet according to claim 2, wherein the foam sheet comprises at least one member selected from polyolefin, polyurethane, rubber, silicone resin, ethylene/methyl acrylate copolymer, ethylene/butyl acrylate copolymer, ethylene/acrylic acid copolymer, ethylene/methacrylic acid copolymer, ionomer resin, styrene/butadiene copolymer, styrene/butadiene/styrene random and block copolymer, styrene/isoprene/styrene random and block copolymer, and styrene/ethylene/butylene copolymer. 8. The expandable foam sheet according to claim 7, wherein the foam sheet comprises at least one member selected from ethylene homopolymer, ethylene/alpha-olefin copolymer, propylene homopolymer, propylene/alpha-olefin copolymer, and polyurethane. 9. The expandable foam sheet according to claim 2, wherein the unexpanded foam sheet has a thickness of from 6 millimeters to 38 millimeters. 10. The expandable foam sheet according to claim 2, wherein the expanded foam sheet exhibits a percent free volume of from 40 percent to 70 percent. 11. The expandable foam sheet according to claim 2, wherein the pressure-to-close of the expanded foam sheet is from 5 to 40 g/cm2. 12. The expandable foam sheet according to claim 2, wherein the expansion-and-locking arms have an axis that pivots at least 85 degrees between the unexpanded foam sheet configuration and the expanded foam sheet configuration. 13. The expandable foam sheet according to claim 2, wherein the pair of expansion-and-locking arms are symmetrical in shape and orientation in the unexpanded foam sheet. 14. The expandable foam sheet according to claim 2, wherein each of the first and second expansion-and-locking arms has at least one serpentine edge. 15. The expandable foam sheet according to claim 14, wherein the finger has an enlarged region at its tip that is wider than at least a portion of the remainder of the finger. 16. The expandable foam sheet according to claim 14, wherein the expansion-and-locking arms each have a total serpentine angle of from 20 to 250 degrees. 17. The expandable foam sheet according to claim 2, wherein in the unexpanded foam sheet, the hinged connection of the expansion and locking arms to the fingers has a hinge width of from 0.06 inch to 0.16 inch. 18. The expandable foam sheet according to claim 2, wherein at the ends of the fingers in the unexpanded foam sheet, the hinged connection of the first expansion-and-locking arm to the finger in the cavity well is separated from the hinged connection of the second expansion-and-locking arm to the finger in the cavity well by a hinge separation of from 0.06 inch to 0.16 inch. 19. The expandable foam sheet according to claim 2, wherein the unexpanded foam sheet comprises a plurality of rows of slits A and a plurality of rows of slits B, with each row of slits A having a plurality of A slits therein, and each row of slits B having a plurality of B slits therein, with each row of slits A alternating with each row of slits B in -A&B-A&B-A&B- arrangement, with each row of slits A being coupled with one adjacent row of slits B on a first side of said row of slits A, and each row of slits B being coupled with the adjacent row of slits A on a first side of said row of slits B, with each row of slits A comprising A slits with a concavity facing coupled row of slits B and each row of slits B comprising B slits with a concavity facing coupled row of slits A, with the A slits in each row A interlocking with two B slits in each row of slits B in that in each coupled row of slits A and B, the A slits have ends extending into the cavity wells of coupled B slits, and the B slits have ends extending into the cavity wells of coupled slits A, with the expansion-and-locking arms being formed by foam between the row of slits A and the coupled row of slits B, with the stabilization walls and fingers extending therefrom being formed by foam between adjacent but uncoupled rows of slits A and rows of slits B. 20. The expandable foam sheet according to claim 19, wherein each A slit in each row of slits A has a concavity facing B slits in the coupled row of slits B, with each slit in the row of slits A having a width-to-depth ratio of from 0.5 to 1.5, and each slit in the row of slits B having a width-to-depth ratio of from 0.5 to 1.5. 21. The expandable foam sheet according to claim 20, wherein each slit in the row of slits A has a depth of from 6 mm to 25 mm, and each slit in the row of slits B has a depth of from 6 mm to 25 mm. 22. The expandable foam sheet according to claim 20, wherein the A slits and the B slits have a width-to-depth ratio of from 0.8 to 1.3, with the coupled A and B slits being at least 60% interlocked with respect to each other, the A slits and the B slits having a convex region at a bottom of the concavity, the convex region in the A slits protruding toward the coupled B slits, and the convex region in the B slits protruding towards the coupled A slits, with the convex region at the bottom of the concavity being formed by a slit line having a centrally-positioned point that is the intersection of two linear slit lines intersecting at an angle of from 60 to 140 degrees, with the convex region extending across at least 40 to 80 percent of the width of the slit, the first expansion-and-locking arm having two serpentine edges and the second expansion-and-locking arm having two serpentine edges, the first and second expansion- and locking arms each having a total serpentine angle of from 35 to 50 degrees, the first and second expansion-and-locking arms each having a substantially uniform width of from 0.06 inch to 0.75 inch, the first and second expansion-and-locking arms pivoting through an angle of from 100 to 120 degrees as the expandable foam sheet is expanded from its unexpanded configuration to its expanded configuration with the expansion-and-locking arms in their inverted and locked position, with the first and second expansion-and-locking arms being hingedly connected to the fingers with hinges having a length of from 0.03 to 0.35 inch, the expandable foam sheet having a slit pattern with a repeat finger-to-finger distance of from 0.25 inch to 3 inches and a repeat stabilization wall-to-stabilization wall distance of from 0.25 inch to 3 inches in the unexpanded configuration. 23. The expandable foam sheet according to claim 20, wherein the A slits and the B slits have a width-to-depth ratio of from 0.9 to 1.4, with the coupled A and B slits being at least 70% interlocked with respect to each other, the first expansion-and-locking arm having two serpentine edges and the second expansion-and-locking arm having two serpentine edges, the first and second expansion- and locking arms each having a total serpentine angle of from 40 to 150 degrees, the first and second expansion-and-locking arms having a substantially uniform width of from 0.05 to 0.5 inches, the first and second expansion-and-locking arms pivoting through an angle of from 90 to 110 degrees as the expandable foam sheet is expanded from its unexpanded configuration to its expanded configuration with the expansion-and-locking arms in their inverted and locked position, with the first and second expansion-and-locking arms being hingedly connected to the fingers with hinges having a length of from 0.03 to 0.35 inch, the expandable foam sheet having a slit pattern with a repeat finger-to-finger distance of from 0.25 inch to 3 inches and a repeat stabilization wall-to-stabilization wall distance of from 0.25 inch to 3 inches in the unexpanded configuration. 24. The expandable foam sheet according to claim 19, wherein the A slits and the B slits each have an arcuate central portion without an inflection point and a linear end portion on each side of the arcuate central portion, the A slits and the B slits having a width-to-depth ratio of from 1 to 1.8, with the coupled A and B slits being at least 45% interlocked with respect to each other, the first expansion-and-locking arm having two arcuate edges without an inflection point and the second expansion-and-locking arm two arcuate edges without an inflection point, with the first and second expansion-and-locking arms being wider in their central region than at their end regions, the first and second expansion-and-locking arms pivoting through an angle of from 90 to 105 degrees as the expandable foam sheet is expanded from its unexpanded configuration to its expanded configuration, with the first and second expansion-and-locking arms being hingedly connected to the fingers with hinges having a length of from 0.07 to 0.25 inch, the expandable foam sheet having a slit pattern with a repeat finger-to-finger distance of from 0.3 inch to 1.4 inches and a repeat stabilization wall-to-stabilization wall distance of from 0.3 inch to 1.4 inches in the unexpanded configuration. 25. An expandable foam sheet comprising a plurality of discrete slits therein, the foam sheet being mechanically expandable from an unexpanded foam sheet configuration to an expanded foam sheet configuration, wherein: (A) the unexpanded foam sheet configuration comprises a plurality of stabilization walls X, each stabilization wall comprising a plurality of cavity wells along a first side thereof, and a plurality of cavity wells along a second side thereof, with the cavity wells being bounded on a first side by a first finger extending from and integral with the stabilization wall and being bounded on a second side by a second finger extending from and integral with the stabilization wall, the fingers extending between adjacent cavity wells on the same side of the stabilization wall, the cavity wells containing at least a portion of a finger from an adjacent stabilization wall extending thereinto, with the finger within the cavity well being hingedly attached to an associated pair of expansion-and-locking arms, including being hingedly attached to a first end of a first expansion-and-locking arm within said cavity well and hingedly attached to a first end of a second expansion-and-locking arm also within said cavity well, with the first expansion-and-locking arm having a second end that is hingedly attached to the first finger bounding the first side of the cavity well, and the second expansion-and-locking arm having a second end that is hingedly attached to the second finger bounding the second side of the cavity well, with the first expansion-and-locking arm having at least one serpentine edge and the second expansion-and-locking arm having at least one serpentine edge; and(B) the expanded foam sheet configuration comprises the plurality of stabilization walls X and a plurality of locking arm walls Y, with the plurality of stabilization walls X and the plurality of locking arm walls Y alternating in X-Y-X-Y arrangement, with a single stabilization wall being connected to a single locking arm wall by a plurality of the fingers extending from and integral with the stabilization wall, with the locking arm walls comprising a plurality of pairs of first and second expansion-and-locking arms in inverted position, with said first and second expansion-and-locking arms in inverted position having emerged from the cavity well of the unexpanded foam sheet during expansion of the foam sheet so that said first and second expansion-and-locking arms are locked in the inverted position, with the plurality of cavity wells together with the plurality of associated pairs of expansion-and-locking arms locked in inverted position surrounding a corresponding number of discrete free volumes within the expanded foam sheet; andthe expandable foam sheet having a density of from 14 g/liter to 100 g/liter in the unexpanded configuration and a thickness of from 6 mm to 160 mm, the slits being of a size and shape and arrangement so that the expanded foam sheet locks into the expanded configuration by exhibiting a pressure-to-close of at least 5 gm/cm2, with each of the slits providing only a single free volume in the expanded foam sheet. 26. The expandable foam sheet according to claim 25, wherein the first expansion-and-locking arm has two serpentine edges and the second expansion-and-locking arm has two serpentine edges, and the first and second expansion-and-locking arms have a total serpentine angle of from 20 to 250 degrees. 27. The expandable foam sheet according to claim 26, wherein a region at a tip portion of the fingers is wider than at least a portion of the remainder of the fingers. 28. A cushioning article, comprising an expandable foam sheet in expanded configuration, the foam sheet having a non-expandable foam sheet or film adhered thereto, the expandable foam sheet having a density of from 14 to 100 grams per liter in its unexpanded configuration and a thickness of from 3 mm to 100 mm, the expanded foam sheet having been made from an expandable foam sheet comprising a plurality of discrete slits therein, the foam sheet being mechanically expandable from an unexpanded foam sheet configuration to an expanded foam sheet configuration, the slits being of a size and shape and arrangement so that the expanded foam sheet locks into the expanded configuration by exhibiting a pressure-to-close of at least 5 gm/cm2, with each of the slits providing only a single free volume in the expanded foam sheet. 29. The cushioning article according to claim 28, wherein the expandable foam sheet has a density of from 14 g/liter to 48 g/liter in the unexpanded configuration and a thickness of from 6 mm to 50 mm. 30. The expandable foam sheet according to claim 2, wherein the expandable foam sheet has a finger-to-finger distance of from 0.25 to 3 inches. 31. The expandable foam sheet according to claim 2, wherein the expandable foam sheet has a finger-to-finger distance of from 0.3 to 1.5 inches. 32. The expandable foam sheet according to claim 2, wherein the expandable foam sheet has a finger-to-finger distance of from 0.35 to 1.35 inches. 33. The expandable foam sheet according to claim 2, wherein the expandable foam sheet has a finger-to-finger distance of from 0.5 to 1.1 inches.