Method and apparatus for uniformly debossing and optionally aperturing a moving plastic web

Claim 1

A method of continuously forming a uniformly debossed, and optionally apertured, ribbon of substantially planar plastic film with a fine scale three dimensional pattern, said method comprising the steps of: (a) supporting said plastic film on a moving three-dimensional forming structure exhibiting said fine scale three-dimensional pattern, said three-dimensional pattern including a first predetermined pattern of apertures therein; and (b) transporting said plastic film across a fluid pressure differential zone while supported on said three-dimensional forming structure, said three-dimensional forming structure being prevented from deformation by, and being supported through said fluid pressure differential zone by means of a support member which is stationary with respect to the direction of movement of the forming structure at the point of contact therewith, said support member having a second pattern of apertures therein, said second pattern of apertures in said support member being so sized and spaced relative to said first pattern of apertures in said three-dimensional forming structure that substantially all of said apertures in said three-dimensional forming structure are exposed to the fluid pressure differential existing on the opposite sides of said plastic film in said fluid pressure differential zone at some point during their traverse of said fluid pressure differential zone, whereby said plastic web is uniform}-ý debossed and optionally apertured in the pattern of said three-dimensional forming structure.

Claim 2

A method of continuously forming a uniformly debossed, and optionally apertured, ribbon of substantially planar plastic film with a fine scale three dimensional pattern, said method comprising the steps of: (a) supporting said plastic film on a moving three-dimensional forming structure exhibiting said fine scale three-dimensional pattern, said three-dimensional pattern including a first predetermined pattern of apertures therein; and (b) transporting said plastic film across a fluid pressure differential zone while supported on said three-dimensional forming structure, said three-dimensional forming structure being prevented from deformation by, and being supported through said fluid pressure differential zone by means of a support member which is stationary with respect to the direction of movement of the forming structure at the point of contact therewith, said support member having a second pattern of apertures therein, said second pattern of apertures in said support member being so sized and spaced relative to said first pattern of apertures in said three-dimensional forming structure that substantially all of said apertures in said three-dimensional forming structure are exposed to the fluid pressure differential existing on the opposite sides of said plastic film in said fluid pressure differential zone at some point during their traverse of said fluid pressure differential zone, whereby said plastic web is uniform}-ý debossed and optionally apertured in the pattern of said three-dimensional forming structure.

Claim 5

A method according to either one of claims 2 and 3, wherein said support member is movable in a radial direction, and a constant force is applied to the innermost surface of said cylinder by said support member.

Claim 8

A method according to any one of the preceding claims including the additional, preliminary step of continuously extruding a melt of plastic resin to form the substantially planar plastic film.

Claim 9

An apparatus (640) for the continuous manufacture of a uniformly debossed ribbon of substantially planar plastic (550) film, the debossments exhibiting a fine scale three-dimensional pattern, said apparatus comprising: (a) a three-dimensional forming structure (643, 935) exhibiting said fine scale three-dimensional pattern for supporting said plastic film, said three-dimensional pattern including a first predetermined pattern of apertures (950, 145) therein; (b) a fluid pressure differential zone in the path of said three-dimensional forming structure; (c) means (810, 820, 832, 836, 920, 921) for transporting said three-dimensional forming structure across said fluid pressure differential zone while said plastic film (550) is supported on said three-dimensional forming structure (643, 935); and (d) support means (681, 682, 683, 691, 692, 693, 695, 995) in said pressure differential zone to prevent deformation of said three-dimensional forming structure in said fluid pressure differential zone, said support means being stationary with respect to the direction of transport of said three dimensional forming structures at the point of contact therewith said stationary support means having a second pattern of apertures (700) therein, said second pattern of apertures in said support means being so sized and spaced relative to said first pattern of apertures in said three-dimensional forming structure that substantially all of said apertures in said three-dimensional forming structure are exposed to the fluid pressure differential existing on the opposite sides of said plastic film (550) in said fluid pressure differential zone at some point during their traverse of said fluid pressure differential zone, whereby said plastic web (551) is uniformly debossed in the pattern of said three-dimensional forming structure (643, 935).

Claim 10

An apparatus (640) for the continuous manufacture of a uniformly debossed ribbon of substantially planar plastic (550) film, the debossments exhibiting a fine scale three-dimensional pattern, said apparatus comprising: (a) a three-dimensional forming structure (643, 935) exhibiting said fine scale three-dimensional pattern for supporting said plastic film, said three-dimensional pattern including a first predetermined pattern of apertures (950, 145) therein; (b) a fluid pressure differential zone in the path of said three-dimensional forming structure; (c) means (810, 820, 832, 836, 920, 921) for transporting said three-dimensional forming structure across said fluid pressure differential zone while said plastic film (550) is supported on said three-dimensional forming structure (643, 935); and (d) support means (681, 682, 683, 691, 692, 693, 695, 995) in said pressure differential zone to prevent deformation of said three-dimensional forming structure in said fluid pressure differential zone, said support means being stationary with respect to the direction of transport of said three dimensional forming structures at the point of contact therewith said stationary support means having a second pattern of apertures (700) therein, said second pattern of apertures in said support means being so sized and spaced relative to said first pattern of apertures in said three-dimensional forming structure that substantially all of said apertures in said three-dimensional forming structure are exposed to the fluid pressure differential existing on the opposite sides of said plastic film (550) in said fluid pressure differential zone at some point during their traverse of said fluid pressure differential zone, whereby said plastic web (551) is uniformly debossed in the pattern of said three-dimensional forming structure (643, 935).

Claim 13

An apparatus according to either one of claims 9 & 10 wherein said stationary support means (681, 682, 682, 695) are movable in a radial direction with respect to said cylinder (655), said apparatus further including means for exerting a constant force between said support member (695) and the innermost surface (465) of said cylinder (655).

Claim 17

An apparatus according to any one of claims 8-14, including means (559) for applying a sufficient fluid pressure differential to said plastic perforations (950) in said plastic film in the pattern of said three-dimensional forming structure.

Claim 18

An apparatus according to any one of claims 8-15 wherein said fluid pressure differential zone conprises a stationary vacuum chamber (661, 662, 663, 962) located on one side of said three-dimensional forming structure (643, 935) and fluid appliction means (559) on the opposite side of said three-dimensional forming structure, whereby said fluid application means and said vacuum chamber cooperate with one another to deboss said plastic film in the pattern of said three-dimensional forming structure.

Claim 19

An apparatus according to either one of claims 15 and 16, wherein said fluid application means (559) comprises an air nozzle.

Claim 21

An apparatus according to either one of claims 15 and 16 wherein said fluid application means (559) comprises a liquid nozzle.

Claim 22

An apparatus according to any one of claims 8-19 comprising means (720) for continuously extruding a melt of plastic resin to form the substantially planar plastic film.