초록 ▼

A laminate of thermoplastic polymeric films comprises a fluted ply A and non-fluted ply B, adhered to one another in bonded zones along some of the flute crests the fluted ply A. The wavelength of the flutes is preferably no more than 3 mm. Ply A has a generally uniform thickness or can have attenua

A laminate of thermoplastic polymeric films comprises a fluted ply A and non-fluted ply B, adhered to one another in bonded zones along some of the flute crests the fluted ply A. The wavelength of the flutes is preferably no more than 3 mm. Ply A has a generally uniform thickness or can have attenuated zones of lessor thickness extending parallel to the flute direction, each bonded zone being located mainly within an attenuated zone. The flutes can be sinuous with crests on both sides of ply A and can be adhered on each side to a ply B. The flutes can be filled with filler material, including reinforcement strands, and one or both sides can be perforated. The method and apparatus employ aligned grooved fluting rollers and a grooved laminating roller.

대표청구항 ▼

The invention claimed is: 1. A laminate comprising at least one ply A and at least one ply B each formed of at least one monofilm or multifilm and comprising a thermoplastic polymer material of which the polymer material of at least one ply A is cold-orientable has a wavy or fluted configuration wh

The invention claimed is: 1. A laminate comprising at least one ply A and at least one ply B each formed of at least one monofilm or multifilm and comprising a thermoplastic polymer material of which the polymer material of at least one ply A is cold-orientable has a wavy or fluted configuration while at least one ply B is not waved, the fluted ply A being adhesively bonded to a first side of at least one ply B in bonded zones along at least some of the crests of the flutes of a first side of the fluted ply A, the thickness of the fluted ply A being of a variable thickness established by solid-state attenuation of the fluted ply A in transversely spaced apart elongated first attenuated zones extending parallel to the length of the flutes, to thereby reduce the thickness of the fluted ply A in the first attenuated zones from that in non-attenuated zones, where each bonded zone being mainly located within a first attenuated zone. 2. The laminate according to claim 1, wherein the the fluted ply A exhibits within the non-bonded zones an average yield tension parallel to the flute direction which at an extension velocity of 500%/min is not less than 30 Nmm2. 3. The laminate according to claim 1, wherein a wavelength of the flutes of the fluted ply A is no greater than 50 times a greatest thickness of the fluted ply A within a flute. 4. The laminate according to claim 1, wherein a dimension of the bonding zones transverse to the fluted direction is at least 15% of the wavelength of the flutes. 5. The laminate according to claim 4, wherein a transverse dimension of the non-bonded zones of the fluted ply A as measured along the curvature thereof between edges of two adjacent bonded zones is at least 10% greater than the linear distance between the edges. 6. The laminate according to claim 1, wherein the fluted ply A within each non-bonded zone and other than in the solid-state attenuated zones is molecularly oriented in a direction at least substantially parallel to a direction of the flutes. 7. The laminate according to claim 6, wherein at least one ply B is molecularly oriented with an orientation within each non-bonded zones perpendicular to the flute direction being greater than the average orientation of the ply A in the same direction, the two orientations being determined by shrinkage measurements. 8. The laminate according to claim 7, wherein a yield tension of the fluted ply A and at least one of the ply B in directions parallel to and transversely to the flute direction, respectively, are at least 30 Nmm2, as determined on narrow strips within the non-bonded zones at an extension velocity of 500% /mm. 9. The laminate according to claim 1, wherein the ply B has a lower coefficient of elasticity than the fluted ply A, both measured perpendicular to the flute direction. 10. The laminate according to claim 7, wherein the polymer material for the ply B and the depth of fluting in the fluted ply A are so selected that when the laminate is stretched perpendicular to the flute direction sufficient to remove the fluting from the fluted ply A, ply B remains free of significant plastic deformation. 11. A the laminate according to claim 1, wherein at least two films in the plies each have a main direction of orientation and are arranged in the laminate with the main directions thereof crossing one another. 12. The laminate according to claim 1, wherein if first attenuated zones extend beyond the corresponding bonded zone into a non-bonded zone of ply A, then at least 50% of a width of the adjacent non-bonded zone is not attenuated, this width being measured along a curvature thereof. 13. The laminate according to claim 1, having only a single fluted ply A wherein the flutes have a generally sinuous configuration with crests projecting on opposite sides of the central plane of the ply A and a single flat ply B is laminated to the attenuated crests of fluted ply A on one side thereof. 14. The laminate according to claim 1, wherein the fluted ply A further includes second attenuated zones elongated in the direction of the flutes but having a narrower transverse dimension than that of the first attenuated zones including the bonded zones. 15. The laminate according to claim 1, further comprising a second non-waved monofilm or multifilm formed ply C comprising a thermoplastic polymer material, where the ply C is bonded to the crests of a second side of the ply, optionally through a lamination layer. 16. A the laminate according to claim 1, further comprising a second monofilm or multifilm formed ply D comprising a thermoplastic, cold-orientable polymer material, where the ply D has a waved flute configuration and some of crests on a first side of the ply D are bonded to a second side of ply B, optionally through a lamination layer. 17. The laminate according to claim 1, wherein the crests of at least some of the flutes of the fluted ply A have flattened regions at spaced apart intervals along the length thereof and are bonded to the ply B to form each of the flattened flutes into a row of narrow pockets closed at their ends. 18. The laminate according to claim 17, wherein at least a plurality of mutually adjacent flutes of the fluted ply A have the flattened regions at corresponding lengthwise locations therealong to thereby form a series of transverse rows of flattened regions extending at least partially across the fluted ply. 19. The laminate according to claim 1, wherein the bonding of the crests of the ply A to the first side of the ply B takes place by means of at least one lamination layer. 20. The laminate according to claim 1, wherein the polymer material of all the plies comprises mainly a polyolefin. 21. The laminate according to claim 1, wherein the the first attenuated zones of the ply A have a minimum thickness of the the first attenuated zones is less than 75% of a maximum thickness of the ply A in the non-bonded zones of the ply A. 22. The laminate according to claim 1, wherein the the ply A has a main direction of orientation, extending generally parallel to the longitudinal direction of the flutes and the ply B has a main direction of orientation that make an angle to the main direction of orientation of the ply A. 23. The laminate according to claim 15, wherein the plies B and C each has its own main direction of orientation and the plies B and C are arranged in the laminate so that the main direction of orientation of the ply B criss-crosses the main direction of orientation of the ply C. 24. The laminate according to claim 23, wherein the ply A in its unoriented state exhibits a coefficient of elasticity which is less than a coefficients of elasticity of the plies B and C in their unoriented states. 25. The laminate according to claim 1, wherein the polymer material of the ply A and its state of orientation are selected such that the average coefficient of elasticity thereof as measured in a non-bonded zone in a direction parallel to the flutes thereof is at least 700 Mpa. 26. The laminate according to claim 1, wherein at least some of channels defined by the flutes of the ply A and the first side of the ply B bonded thereto contain a filling material selected from particles, fibers, filaments, and liquids. 27. The laminate according to claim 26, wherein the material is a preservative for goods intended to become packed in or protected by the laminate selected from the group consisting of an oxygen scavenger or ethylene scavenger, a biocide, a corrosion inhibitor and a fire extinguishing agent. 28. The laminate according to claim 27, wherein the channels include perforations established in the flutes or non-waved film material to enhance the effect of the preservative. 29. The laminate according to claim 26, wherein the filling material comprises reinforcement strands. 30. The bag made from a laminate according to claim 1 which is constituted of a single fluted ply A and a single flat ply B bonded together in sheet-form, the bag having its opposite side walls made of the sheet-form laminate and its top and bottom ends closed along lines generally perpendicular to the direction of the flutes of the laminate. 31. The laminate according to claim 1, wherein the respective plies A and B on opposite sides of each of at least some of the flutes are provided with a row of perforations which on the opposite sides are displaced relative to one another whereby a fluid material passing perpendicularly through the laminate is diverted from a straight path. 32. The laminate according to claim 1, wherein a wavelength of the flutes of the fluted ply A is no more than about 3 mm. 33. The laminate according to claim 1, wherein a wavelength of the flutes of the fluted ply A is no more than about 2.5 mm. 34. The laminate according to claim 1, wherein a wavelength of the flutes of the fluted ply A is no more than about 2.0 mm. 35. The laminate according to claim 1, wherein a wavelength of the flutes of the fluted ply A is no more than about 1.5 mm. 36. The laminate according to claim 1, wherein thickness limits of an attenuated zone is taken to be loci where the ply thickness is an average between its minimum attenuated thickness and its maximum thickness in an adjacent non-attenuated zone. 37. The laminate according to claim 24, wherein the flutes are flattened at intervals and bonded across each ones entire width to make the flute form a row of narrow closed pockets. 38. The laminate according to claim 26, wherein the filling material is adapted to act as a filter material by holding back suspended particles from a liquid passing through the channels or pockets or is an absorbent or ion exchanger capable of absorbing or exchanging matter dissolved in such liquid, the filler optionally beingfibre-formed or yarn-formed, and that each filled flute and matching non-waved film material is supplied with a row of perforations, whereby the perforations or groups of perforations in a flute and the perforations or groups of perforations in the matching non-waved film material are mutually displaced so as to force the liquid with the suspended particles, while passing from one surface of the laminate towards the other surface, to run through the filter material in a direction parallel to the longitudinal directions of the flutes. 39. The laminate according to claim 19, wherein the at least one lamination layer is formed by extrusion during the bonding process. 40. The laminate according to claim 19, wherein the ply A and the ply B include a coextruded lamination layer that bond ply A to ply B during the bonding process. 41. A method for forming a polymeric laminate, which comprises the steps of: passing a ply A formed of monofilm or multifilm comprising a solid-state orientable thermoplastic polymer material, while in a solid state, through a pair of grooved attenuating rollers adapted to subject the ply A to a generally lateral stretching to attenuate the ply A in a set of narrow elongated zones which are laterally spaced apart to form first attenuated zones and non-attenuated zoned in the ply A so that the ply A has a variable thickness, where a thickness of first attenuated zones are less than a thickness of the non-attenuated zone; in concert with the first passing step or subsequent to the first passing step, passing the attenuated ply A between a pair of grooved rollers to produce a fluted ply A with crests of flutes formed thereby on one side of the ply A generally coinciding with the first attenuated zones; and passing the fluted ply A and a flat ply B comprising a thermoplastic polymeric material in sandwiched relation through a pair of laminating rollers of which at least one of the rollers is grooved under sufficient heat and pressure as to adhesively bond a first side of the ply B to crests of a first side of the ply A, where the grooves of the laminating roller are arranged in general registration with the grooves of the attenuating and/or the fluting grooved rollers so that the bonding of the ply A to the ply B takes place mainly within the attenuated zones. 42. The method according to claim 41, including the step of before or after passage of the ply A through the grooved attenuating roller pair for lateral stretching thereof, passing the fluted ply A through an additional pair of attenuating grooved rollers adapted to subject the ply A to lateral stretching to attenuate the same in a second set of narrow elongated attenuated zones which are parallel to the flute direction and laterally spaced apart in alternating relation to the first set of attenuated zones, the lateral dimension of the second set of attenuated zones being less than that of the first set of attenuated zones. 43. The method according to claim 41, wherein a lateral spacing of the grooves of the laminating grooved roller measured parallel to the roller axis is not greater than 3.0 mm. 44. The method according to claim 41, wherein the ply A before the formation of the flutes is subjected to orientation so that the ply A has a main direction of orientation which corresponds with the direction to be taken by the flutes. 45. The method according to claim 41, further comprising the step of, simultaneously with or subsequent to the bonding of the ply B to the ply A, bonding a second non-waved monofilm or multifilm formed ply C comprising a thermoplastic polymer material to the crests of the ply A on a second side thereof. 46. The method according to claim 41, wherein the plies A and B comprise mainly a polyolefin and are formed by an extrusion process. 47. The method according to claim 41, wherein at least one of the plies includes a surface layer adapted to facilitate lamination of the ply while a body of the ply remains in its solid state. 48. The method according to claim 41, wherein after the lamination at least some of the resultant flutes are subjected along transverse loci at selected intervals along their length to heat and pressure that are sufficient to bond together the plies along such loci to thereby deform the flutes into rows of discrete pockets. 49. The method according to claim 48, wherein the heat and pressure to deform the flutes is applied by means of at least one laterally extending bar or cog which extends over at least a plurality of the flutes and is adapted to be brought into pressure contact with the flutes at the selected intervals. 50. The method according to claim 41, wherein the first attenuated zones are given a distinctive stripe character either by heating the crests of the grooved roller of the attenuating roller pair which correspond to the first attenuated zones to a higher temperature than the crests of its mating grooved roller or by selecting a lesser radius of curvature for the corresponding crests than for the crests of the mating roller. 51. The method according to claim 41, comprising the further step not later than during the lamination of the plies, of introducing a particulate, liquid, or elongated thread material into at least some of the flutes which are created to form filled channels by the lamination. 52. The method according to claim 51, comprising the further step after the lamination of applying to discrete loci across at least some of the filled channels at spaced intervals along the length thereof heat and pressure sufficient to close the filled channels at the loci with the material therein and thereby form filled pockets. 53. The method according to claim 51, comprising the further step of forming in the respective plies on opposite sides of at least some of the filled pocktes at least one row of perforations which on the opposite sides are displaced out of alignment relative to one another whereby a fluid material passing perpendicularly through the laminate is diverted from a straight path. 54. The method according to claim 41, wherein prior to the lamination, the ply B is given an orientation generally transverse to the direction of the ultimately formed flutes, and comprising the further step of subjecting the ply B after the lamination to shrinkage in the generally transverse direction. 55. The method according to claim 41, wherein the ply A is supplied with attenuated zones and flutes with the flutes extending in a direction essentially parallel to the length of ply A by passing ply A through at least one set of driven mutually intermeshing grooved rollers to transversely stretch the same, the grooves of the rollers being either circular or helical along an angle of at least 60째 to the roller axis. 56. The method according to claim 55, comprising the further step of delivering the ply A after the same exits from one of the intermeshing grooved rollers directly to the grooved lamination roller, the two grooved rollers being in close proximity to one another and having the same pitch when measured at the operational temperatures thereof. 57. The method according to claim 55, comprising the further step of after the ply A exits from one of the intermeshing grooved stretching rollers, passing the same over at least one grooved transfer roller before delivery to the grooved lamination roller, all of the rollers in the sequence having the same pitch when measured at their respective operating temperatures. 58. The method according to claim 41, wherein each grooved roller used to form the flutes in ply A and to laminate ply A to ply B and each arooved roller used to form the attenuated zones and the at least one grooved roller used in the lamination step are grooved rollers where the grooves of each grooved roller are essentially parallel to its axis. 59. The method according to claim 58, further comprising the step of directing a flow of air to direct the ply A into the grooves of one of the grooved flute-forming rollers. 60. The method according to claim 41, wherein at least one of the plies A and B is provided with a laminating layer on a surface facing the other ply to facilitate in the lamination. 61. A method according to claim 41, further comprising the step of applying printed matter on a surface of the ply A and/or B in registration with the the flute-forming and lamination processes so that the printing is on an inside of the laminate in non-bonded zones while the bonded zones are generally free of printed matter. 62. The method according to claim 41, wherein the lateral spacing of the grooves of the laminating grooved roller measured parallel to the roller axis is not greater than 2.5 mm. 63. The method according to claim 41, wherein the lateral spacing of the grooves of the laminating grooved roller measured parallel to the roller axis is not greater than 2.0 mm. 64. The method according to claim 41, wherein the lateral spacing of the grooves of the laminating grooved roller measured parallel to the roller axis is not greater than 1.5 mm. 65. The method according to claim 41, wherein a groove configuration of the attenuating rollers is different from a groove configuration of the grooved laminating rollers. 66. The method according to claim 41, further comprising the step of producing, in that in a manner similar to the forming and application of A, a second monofilm formed or multifilm forms ply (D) having waved flute configuration with a wavelength preferably of no more than 3 mm, and the crests on one side of D are laminated to the second side of B simultaneously with or following the lamination of B with A. 67. The method according to claim 51, further comprising the step of perforating, prior to, simultaneously with or following the filling step, the laminate at least on one side to help the filling material or part thereof dissipate into the surroundings or to allow air or liquid to pass through the pack of filling material. 68. An apparatus for producing a laminate comprising a ply A and a ply B all formed of at least one monofilm or multifilm and comprising mainly a thermoplastic polymer material, which apparatus comprises: a first attenuation station for stretching the ply A in its solid state in a direction laterally of the flutes along laterally spaced lines to form laterally spaced apart first attenuated zones of reduced thickness in the ply A; combined with or downstream of the first attenuation station, a fluting station including a pair of grooved fluting rollers for imparting to the ply A passed therebetween a wavy fluted configuration with crests of formed flutes on one side of the ply A generally coinciding with the first attenuated zones; means for feeding a continuous web of the ply A to the attenuating stations; and downstream of the fluting station, at least one laminating station including a pair of laminating rollers of which at least one of the rollers is grooved for laminating a first side of the ply B to the crests of some of the flutes of a first side of the ply A to form a laminate; means for applying heat and pressure to the grooved laminating roller of the laminating station and/or a counter-roller to the latter to form bonding zone between the ply A and the ply B, where the first attenuation zones have a width and alignment such that each of the bonding zones lies mainly within a first attenuation zone; and means for feeding a continuous web of the ply B to the laminating station to form the bonding zones between the ply A and the ply B. 69. The apparatus according to claim 68, wherein the intermeshing pair of grooved rollers in the fluting station also serve to stretch the ply A in its solid state in a direction laterally of the ultimately formed flutes along laterally spaced lines to form the laterally spaced apart first attenuated zones of reduced thickness in the ply A, the grooves of the grooved roller pair and the grooved laminating roller being so aligned that each of the bonding zones lies mainly within a first attenuated zone. 70. The apparatus according to claim 68, wherein the attenuation station comprises upstream of the pair of fluting rollers, at least one pair of intermeshing grooved stretching rollers for stretching the ply A in its solid state in the lateral direction, the grooves of the stretching rollers and the grooved laminating roller being so aligned that each of the bonding zones lie mainly within the first attenuated zones and the feeding means for ply A first feeds the ply A to the pair of intermeshing grooved stretching rollers. 71. The apparatus according to claim 68, further comprising heating means for heating the ply A in discrete zones corresponding to the ultimately formed first attenuated zones and thereby facilitate the attenuation. 72. The apparatus according to claim 71, wherein the heating means comprises upstream of the lateral stretching grooved rollers for making the first attenuated zones a heated grooved roller having heated tips of the grooves thereof in contact with one side of the ply A in line with the grooves of the attenuation rollers. 73. The apparatus according to claim 72, wherein the radius of curvature of the tips of at least one of the stretching rollers, the radius of curvature of the tips of the heated grooved roller and the temperature of the latter, the speed of travel of the ply A through the stretching rollers, and the degree of intermeshing of the grooved attenuation rollers are selected to achieve an attenuation of the ply A in the first attenuate zones reducing the thickness thereof by more than 25%. 74. The apparatus according to claim 68, wherein the crests of the grooved laminating roller are flat and have a dimension measured along the roller axis in the range of 0.15-0.90 times a division between crests of the grooved laminating roller. 75. The apparatus according to claim 68, wherein the laminating station comprises a flat roller having rubbery surfaces and the grooved roller of the laminating station is adapted to apply heat and pressure to the plies fed between the rollers. 76. The apparatus according to claim 68, further comprising at least one grooved transfer roller arranged between the grooved rollers of the fluting station and the grooved roller of the laminating station such that the ply A is maintained generally in contact with the surface of at least one grooved roller from its entrance into the grooved rollers of the fluting station to it exit form the grooved roller of the laminating station. 77. The apparatus according to claim 68, wherein the grooves of all the grooved rollers are circular. 78. The apparatus according to claim 68, wherein the grooves of all the grooved rollers extend parallel to the axes of the rollers. 79. The apparatus according to claim 68, further comprising: a printing station at least prior to the lamination station for applying to a surfaces of the ply A and/or ply B printed matter, where the printed matter is applied in registration with the non-bonded zones of the ultimate laminate leaving the bonded zones generally free of such matter. 80. The apparatus according to claim 68, further comprising: downstream of the lamination station a flute flattening station for applying pressure across at least some of the flutes of the laminate of the plies at localized loci spaced intermittently along the length of the flutes and means for delivering the laminate from the lamination station to the flute flattening station. 81. The apparatus according to claim 68, further comprising: downstream of the lamination station perforating means for perforating the plies of the resultant laminate in the non-bonded zones thereof. 82. The apparatus according to claim 68, further comprising intermediate the fluting station and the lamination station a filling station for introducing filling material into the interior of the flutes for incorporation into the laminate produced by the lamination station. 83. The apparatus according to claim 68, wherein a division between crests of the grooved laminating roller is not greater than about 3 mm. 84. The apparatus according to claim 68, wherein a division between crests of the grooved laminating roller is not greater than about 2.5 mm. 85. The apparatus according to claim 68, wherein a division between crests of the grooved laminating roller is not greater than about 2.0mm. 86. The apparatus according to claim 68, wherein wherein a division between crests of the grooved laminating roller is not greater than about 1.5 mm. 87. The apparatus according to claim 68, further comprising second attenuating station including a second pair of intermeshing grooved stretching rollers for solid-state stretching of the ply A in a direction substantially perpendicular to the flutes upstream of the laminating roller, to form second attenuated zones mutually separated in the perpendicular direction, the grooves of the second stretching rollers being adapted and aligned relative to the grooves of the laminating roller so that the second attenuated zones are located between the first attenuated zones whereby a second attenuated zone is located between each adjacent pair of first attenuated zones. 88. The apparatus according to 68, further comprising: means for supplying the laminate from the laminating station to a downstream C ply laminating station; means for supplying a continuous web of substantially smooth ply C formed of a thermoplastic material from a supply to a second laminating station so as to be in face to face relationship with the A/B laminate and in contact with the second side of the ply A, where the second laminating station comprises rollers for applying mild pressure between the ply C and the A/B laminate to bond some of the crests of the second side of the ply A to a first side of the ply C without flattening the flutes of the ply A. 89. The apparatus according to 88, further comprising: means for heating the surface of the second side of the ply A of the A/B laminate and/or the face the first side of the ply C brought into contact with the A/B laminate prior to or simultaneously with application of mild pressure in the second laminating station. 90. The apparatus according to 68, further comprising: a second fluting station including a grooved ply D fluting roller for imposing a waved fluted structure on a ply D comprising a thermoplastic material; feeding means for feeding a continuous web of the ply D formed of the thermoplastic material from a supply to the second fluting station; a second laminating station comprising a grooved ply D laminating roller for applying heat and pressure between one side of the ply D and the second side of the ply B of the A/B laminate to form bonding zones between some of the crests of this side of the ply D and the second side of ply B in the A/B laminate; and means for supplying ply A/B laminate or the plies A and B to the second laminating station.