SI9210160A - Textile-like apertured plastic films - Google Patents

Description

Textile-like punched plastic wrap

The present invention generally relates to perforated (perforated) foils, more specifically to perforated plastic foils having many small holes formed by a web of fiber-like elements or narrow strips of drawn plastic material. The invention further relates to processes and apparatus for making such hole films as well as products containing such hole films.

Nonwovens have been used for various purposes for at least fifty years. Non-woven fabrics are textile-like materials that are made directly from fibrous tissue to eliminate work operations that take a long time to convert cut viscose fibers into woven or knitted fabrics. In one of the non-woven fabrication processes, for example, by means of carding or by airtight technique, the fibrous tissue) is then reinforced by applying a polymeric binder. According to another non-woven fabric fabrication process, the fibrous tissue is left to force the fluid that traps the fibers to adhere, resulting in the strength of the finished product. Non-woven fabrics are inherently porous structures, i.e., they have openings or pores that allow the passage of fluids such as air and water or aqueous solutions. In addition, the non-woven fabrics are machined so that they are reasonably soft, easily foldable and feel good. Due to their useful properties, nonwovens were used as top (umbrella) material in absorbent products, such as disposable diapers, hygiene pads, accessories for use in incontinence, wound dressings and the like.

Recently, they have tried to produce porous or liquid-permeable roofing materials for absorbent products, using plastic films as a starting material. For example, it is known that a punctured plastic film is made by placing heated thermoplastic material in the form of a sheet on a patterned hole and compressing it with a vacuum. The underpressure pulls the softened material of the sheet through the holes, which results in the tearing of the foil and thus the formation of holes.

U.S. Pat. No. 3,929,135 (Thompson et al.) Disclose punched film covers for absorbent products, such as hygiene pads, incontinence pads, bandages, and the like. These roofing materials are constructed from fluid-tight materials such as low density polyethylene and have a plurality of funnel capillaries, each with a base mouth in the plane of the deck floor and a crown lip that is distant from the plane of the deck sheet. Funnel capillaries, as disclosed by Thompson et al., Are preferably designed in the form of a truncated cone or conical surface with a funnel angle of about 10 ° to 60 °.

US 4324276 (Mullane) discloses perforated molded, sewn-in, less than about 0.075 cm thick, open field of at least 35% and a plurality of holes of at least 75% having an equivalent hydraulic diameter (EHD) of at least 75% 0,064 cm. Punched shaped foil, as disclosed by Mullane et al., Is suitable as an umbrella for single-use absorbent products of the aforementioned type.

US 4839216 (Curro et al.) Discloses bulges and holes designed plastic material, which is made by starting with the initial foil on the perforated molding surface and applying a fluid flow to the upper surface of the initial foil. The force and mass flow rate of the fluid flow are large enough to deform the film against the molding surface, such that the material acquires a substantially three-dimensional structure, and that holes are formed therein.

EP 0304617 (Applicant Kao Corporation) discloses an overhead pole for a sanitary product. The roof pole comprises an opaque hydrophobic film having straight sections and projections, the latter comprising the floor section and the side walls. The side walls have a sloping part that is made with an opening; this is such that the straight part does not cover the inclined part. According to this patent, the opening is always visible when viewed from above.

US 4690679 discloses a punctured film comprising a first layer of a first polymer film and a second layer of a second polymer film. The file states that hole films whose holes have average circle diameters ranging from about 0.0254 cm to about 0.0762 cm are used as cover material for absorbent products.

Puncture films and processes and apparatus for making or executing them are further disclosed in US 3632269 (Doviak et al.) And 4381326 (Kelley).

According to one aspect of the present invention, these are porous films that are porous, have an accessible surface, are soft, strong, tactile, resemble textiles, are touchable, adaptable and can be wrinkled, all of which are typical of many nonwovens goods made from fibrous tissues, except that the foils of the invention do not have the undesirable properties, such as the rigidity, inflexibility and feel of plastic, which you often encounter with holes in the prior art.

The punched plastic films of the present invention comprise a plurality of tiny holes formed by a web of fiber-like elements or tiny strips of drawn plastic material. Bulbs are mostly irregular in shape, i.e. their geometric appearance, whether they are round, square or oval, cannot be clearly defined. Holes may be arranged in a disconnected pattern of recognition groups or swarms. The pattern of identifiable groups or swarms of holes is either random or regular; however, the holes of the individual recognition group or swarm within or within it are distributed randomly. The holes are also unequal in size and have small equivalent hydraulic diameters (EHD).

The individual fiber elements in the fiber element network comprise drawn parts of the starting plastic film. These fiber elements, sometimes referred to as fibers, cooperate with the aforementioned holes to produce a punctured foil of the invention with a appearance resembling non-woven fabric made from air-treated or carded viscose tissue fibers or nonwovens of knitted yarn. The fiber elements also give the hole-like foils of the invention with good softness and the ability to fold. Fibrous elements or fibers have lengths ranging from about 0.013 cm to about 0.127 cm, widths ranging from about 0.003 cm to about 0.089 cm, and thickness ranging from about 0.0006 cm to about 0.005 cm.

The puncture films of the present invention have small accessible surfaces; these range from about 1% to 15%. Such small accessible surfaces are welcome in cases where the perforated foil according to the invention is used as a cover material for the absorption core of products such as sanitary napkins and disposable diapers. In such cases, a small accessible surface significantly reduces the tendency of the fluid (eg, menstrual fluid or urine) absorbed by the absorption core to travel back through the punctured film when it re-moistens its upper surface and touches the user's skin. Punched films according to the invention, if suitably pigmented, e.g. pigmented with titanium dioxide also very effectively erase the stains on the surface of the absorbent core, which are caused by contact with body secretions such as menstrual fluid and urine.

In certain embodiments, the puncture film of the invention further comprises a plurality of secondary openings whose field is substantially larger than that of the small holes mentioned above. It is understood that the proportion of accessible surface area of the punctured film can fluctuate over a very large range by varying the number and / or size of small holes and / or secondary openings.

The punctured foils of the present invention are made by directing controlled forces of the fluid toward one surface of a relatively thin stretchable plastic film, the film being supported on its other side by a support element. Supporting elements suitable for use in the implementation of the present invention include: locally fixed carrier regions for supporting the foil; engraved areas into which the film may deform when fluid forces are applied; and a means of separating the fluid used from the support portion.

In a particular process for the production of punched films according to the present invention, the support portion comprises a plurality of spaced upright pyramids spaced apart from each other, arranged according to a predetermined pattern on one of the surfaces of the support portion. The pyramids have four-sided bases and are oriented so that the sides of the pyramid bases are placed at an angle of about 60 ° with respect to the sides of the supporting part (the latter two sides correspond to the direction of the machine, which determines the direction of the foil when it is laid on said support part, and are parallel to it) ). Multiple pyramids in said particular pattern are arranged in rows running transversely to the supporting portion and in columns extending longitudinally by the supporting portion, with the pyramids in any selected row displaced or displaced relative to the pyramids in each of the two adjacent strings. The side walls of the pyramid group define the first set of valleys, which run at a certain angle with respect to the direction of the machine, which determines the direction of the supporting part. Two sets of valleys intersect each other. The valleys in each set of valleys are arranged parallel to each other. The support section in question further comprises several circular openings to discharge the fluid used. The openings are arranged in the valleys mentioned above between the pyramids.

In a second particular method of manufacturing a punctured film according to the present invention, the support portion for carrying the plastic film comprises a base part and several continuous, upright, spaced apart ribs spaced parallel to one another. The ribs as seen in the floor plan are wavy as a sine curve. The support portion further comprises a plurality of valleys or depressions defined by adjacent pairs of separate ribs. In the recessed areas, several openings are arranged, extending through the support portion from one base surface to the next.

In a further particular method of manufacturing the punched film of the present invention, the support portion comprises a base portion with several openings extending along its thickness. In this embodiment, the supporting part, which can be made either as a flat plate or as a cylinder (also applies to the support parts mentioned above), does not have any projecting elements, such as the pyramids or ribs mentioned above, driven in waves similar to sinusoids.

The present invention will be more clearly understood by the following detailed description and the accompanying drawings, in which FIG. 1 is a schematic, in plan view, of the top surface of a selected embodiment of a punched plastic film according to the present invention; 2 is a photograph of a fragment of the upper surface of a punched film, as schematically shown in FIG. 1, with a magnification of about 20 times, FIG. 3 is a photograph of a fragment of a bottom surface of a punctured film as shown schematically in FIG. 1, with a magnification of about 20 times, FIG. 4 is a photograph of a fragment of the upper surface of a punched sheet, as schematically shown in FIG. 1, with a magnification of about 40 times, FIG. 5 is a photograph of a fragment of a bottom surface of a punctured film as shown schematically in FIG. 1, with a magnification of about 40 times, FIG. 6 is a schematic, in spatial view, of the upper surface of the second embodiment of the punched plastic film according to the present invention; 7 is a photograph of a fragment of the upper surface of a punched film, as schematically shown in FIG. 6, with a magnification of about 20 times, FIG. 8 is a photograph of a fragment of a bottom surface of a punctured film as shown schematically in FIG. 6, with a magnification of about 20 times, FIG. 9 is a photograph of a fragment of the upper surface of a punched film, as schematically shown in FIG. 6, with a magnification of about 40 times, FIG. 10 is a photograph of a fragment of a bottom surface of a punched sheet, as schematically shown in FIG. 6, with a magnification of about 40 times, FIG. 11 is a schematic, in plan view, of the top surface of the third embodiment of a punched plastic film according to the present invention; 12 is a photograph of a fragment of the upper surface of a punched sheet, as schematically shown in FIG. 11, with a magnification of about 20 times, FIG. 13 is a photograph of a fragment of a bottom surface of a punctured film as shown schematically in FIG. 11, with a magnification of about 20 times, FIG. 14 is a photograph of a fragment of the upper surface of a punched sheet, as schematically shown in FIG. 11, with a magnification of about 40 times, FIG. 15 is a photograph of a fragment of a bottom surface of a punctured film as schematically shown in FIG. 11, with a magnification of about 40 times, FIG. 16 is a schematic illustration of a device for making punched films according to the present invention; 17 shows a starting plastic film and a support portion on which the starting film for further processing according to the present invention is laid, in a spatial representation and in a clearly spaced state, FIG. 18 shows the support portion shown in the lower part of FIG. 17, in plan view, FIG. 19 is a cross-sectional view taken along line 19-19 of FIG. 18, FIG. 20 is a block diagram showing the various steps of a process for making a punched film according to the present invention; FIG. 21 is a further device for making punched films according to the present invention, in a schematic illustration; 22 is a schematic illustration of a schematic illustration of an apparatus for making punched films according to the present invention; 23 is a support part used in the manufacture of a punched film from the drawings of FIG. 6 to 10, in plan view, FIG. 24 is a cross-sectional view 24-24 of FIG. 23, FIG. 25 is a support part used in the manufacture of a punched film from the drawings of FIG. 11 to 15, in plan view, FIG. 26 is a sectional view taken along line 26-26 of FIG. 25, FIG. 27 is a hygienic insert comprising a punctured film according to the present invention, in a spatial representation, and FIG. 28 is a cross-section through line 28-28 of FIG. 27.

Sketch of FIG. 1 or photographs of FIG. 2 to 5 show a selected embodiment of a punched plastic film according to the present invention. The punctured plastic film 30 is made of a thin layer with projections of a stretchable thermoplastic polymer material having a thickness prior to treatment that can conveniently vary in the range of about 0.0013 cm to about 0.0127 cm. The punctured plastic film 30 comprises inclined, generally upright sidewalls 31, which meet on the upper surface of the foil to form a series of generally parallel ridges 32. The sloping sidewalls define a series of generally parallel valleys 33. As seen in the floor plan (on photographs), both ridges and valleys have a separate configuration similar to a sine curve. The valleys 33 and the lower regions of the sidewalls 31 along these valleys comprise a plurality of small holes 37 formed by a network of very fine fiber elements 38. The total height or thickness T of the hole foil 30, i.e. the vertical distance from the valley 33 to the ridge 32 is about 0.05 cm.

Sketch of FIG. 6 or photographs of FIG. 7 to 10 show a second embodiment of a punched plastic film of the present invention. The punched plastic film 40 is also made of a protuberant layer of extensible thermoplastic polymer material having a thickness ranging from about 0.0013 cm to about 0.0127 cm before treatment. The punctured plastic film 40 comprises a plurality of generally cone-shaped conical structures 41 whose sloping lateral walls 41a are defined by valleys 43. The valleys 43 and adjacent portions of the lateral conical structures comprise a large number of tiny holes 47 defined by a web of very fine fibers 48. The conical formations 41 comprise secondary openings 42 whose fields are substantially larger than the fields of the fractured holes 47. The total height or thickness T of the punched plastic film, i. the vertical distance from the valley 43 to the top of the conical formation 41 is approximately 0.064 cm.

A third embodiment of a punched plastic film according to the present invention is shown in FIG. 11 and photographs FIG. 12 to 15. The punctured plastic film 50 comprises a thin layer of a stretchable thermoplastic film having a plurality of tiny holes 57 which are arranged or arranged in several groups or swarms of 55 tiny holes arranged in a regular pattern. Each swarm 55 comprises a plurality of arrays of 56 tiny holes, five of which are drawn in FIG. 11. There are a large number of randomly distributed tiny holes 57 in each set 56, with the separation of these tiny holes from each other in a series with very small, fiber-like elements 58. The adjacent sets of 56 tiny holes 57 are in each other 55 the other separated by strips 59 of non-perforated material. As presented, there are essentially no holes 57 in areas 52 around and adjacent swarms 57.

The thickness T of the hole foil of the invention is greater than the thickness t of the original, starting foil from which the hole foil is made. Example: the thickness of the T-hole foil in FIG. 1 to 5 is about 0.05 cm, the thickness T of the perforated foil according to the drawings FIG. 6 to 10 about 0.064 cm.

The depth of the valleys 33 is not uniform across the hole foil. The depth of the valleys 33 may vary slightly from one area of the hole film to the next. Example: the depth of the valley at the lower left part of FIG. 1 may be less than or greater than the depth of that valley at the upper right portion of FIG. 1 or is equal to it.

Sketch of FIG. 16 is a schematic representation of an apparatus for making punched plastic films according to the present invention. The device 60 comprises a movable conveyor belt 62 and a support portion 64 disposed on top of the conveyor belt and a support portion 64 together with the conveyor belt. running through the thickness of the support portion from its upper surface 65a to its lower surface 65b.

A thin continuous and non-punctured film 67 of thermoplastic polymer material is deposited on the upper surface of the support portion. This foil may be permeable or steam-impermeable, may or may not have protrusions, may be coronally discharged on one or both of the base surfaces if desired, or may be corona-free. The stretch film may comprise any thermoplastic polymeric material including, for example, polyolefins such as polyethylene (high, linearly low or low density) and polypropylene, copolymers of olefins and vinyl monomers such as copolymers of ethylene and vinyl acetate or vinyl chloride, polyamino, and polyamines, and acrylate monomers such as ethylene and ethyl acrylate copolymers. A film comprising mixtures of two or more such polymeric materials is also contemplated. The starting foil intended for punching should thus be in the longitudinal direction (LS), i.e. in the direction of the machine as well as in the transverse direction (TS) by at least 100%, determined by ASTM-Test no. The D-882, which runs with the Instron Jaw Test Machine at 127 cm / min. The thickness of the starting foil (foil intended for punching) is preferably uniform and can vary in the range of about 0.0013 cm to about 0.0127 cm. Preferably, the thickness of the foil is between 0.0013 cm and 0.0076 cm. Also contemporaneous are extruded films as well as films that have been modified e.g. by treatment with a surfactant. The starting foil may be made by any known technique such as casting, extrusion or blowing.

Above the starter foil 67 there is a dispensing head 69 for applying fluid 63, preferably water, to the upper surface 67a of the starter foil, while said foil carried by the support portion 64 moves together with the conveyor 62. Water can be applied at variable pressures . Below the conveyor belt is a plurality of inlets comprising a suction device 70 for removing water directed to the upper surface 67a of the starter film 67 as it travels below the distributor head 69.

The starting foil 67 is placed on the support portion 64 during operation, and the foil and the support portion are moved back and forth under the distributor head 69 until the desired punched foil is obtained.

The dispensing head 69 comprises a plurality of holes, the number of which can vary from about 11.8 ^cm-1 to about 39.4 cm ^1st The number of holes of the distribution head preferably ranges from about 13.8 cm &^lt; ^{-1 >} to about 19.7 cm &^lt; ^-1 &^gt;. The holes are preferably round in appearance and vary in diameter from about 0.0076 cm to about 0.0254 cm, preferably from 0.0127 cm to 0.018 cm. When the starter foil and the support portion travel a spot several times under the distributor head 69, the water supply is interrupted, and the suction on the other hand is continued to help remove water from the resulting perforated foil of the invention. The puncture film is removed from the supporting part and dried in any known manner, for example by blowing in warm air or by solvent extraction.

FIG. 17 is a representation of the drawing disassembled particular portions in the spatial representation, in particular the starting foil 67 and the supporting portion 64, described above in connection with FIG.

16. As noted above, the starter foil 67 comprises a thermoplastic polymer material or a mixture of two or more such polymeric materials and is as presented in FIG.

17, may be performed with or without protrusions. Part 75 of the starter foil 67, comprising the projections 76, and the portion 77 of the starter film 67, which has no projections, are presented in the upper part of FIG.

17.

The support portion 64 comprises a base portion 65 having an upper surface 65a and a lower surface 65b. The support portion 64 further comprises a plurality of openings 80 extending along the thickness of the base 65 from the upper surface 65a to the lower surface 65b. As will be seen, the openings 80 are provided for draining water during the manufacture of the perforated foil according to the invention. The support portion 64 also comprises a plurality of upright bearing members 71. These bearing members comprise a base 78 which coincides with the plane of the upper surface 65a of part 65, and a pair of sloping side walls 72, 73 (see FIGS. 18 and 19). The sidewalls 72, 73 extend upwards from the base 78 to meet at the work where the plane field is formed or the ridge 74. The support elements 71 extend parallel to each other and are evenly spaced. They can run parallel to the sides of the support part, at right angles or at any angle to them. As presented in FIG. 17 and 18, the supporting elements 71, when viewed in plan, are generally similar to sinusoids or are wavy in design. It is understood that the supporting elements may also be otherwise guided, e.g. straight, zigzag and the like.

FIG. 20 is a block diagram showing the various steps of the process of manufacturing new hole films according to the present invention. The first step of the process is the positioning of a piece of thin stretch film of thermoplastic polymer material on the supporting part (box 1). The support section with a stretch film on it traveled over the location of the high-pressure fluid injection nozzles (box 2). The preferred fluid is water. Preferably, water is transported away from the support part using a vacuum (box 3). Water is removed from the foil, which is the preferred suction (box 4). The puncture film from which the water has been removed is removed from the support section (box 5). The remaining water is removed from the hole foil, e.g. using an airflow blower (box 6). The puncture film is then wound until it is used, when the film is either used in its available form or as a building block of another product, such as a sanitary napkin, a disposable cloth or a wound dressing (box 7).

FIG. 21 is a schematic representation of a device for continuously making punched films according to the present invention. The apparatus 90 comprises a support portion, which is here in the form of a conveyor 91. The conveyor 91 moves in a continuous manner in a counter-clockwise direction about two spaced cylinders 92, 93. Above the conveyor 91 there is arranged a distribution tube 95 for supplying fluid, which binds a group of pipes or manifolds 96, i devices with multiple mouths. Each head 96 with multiple mouths contains at least one set of very small diameter holes, such that there are 12 or more such holes per cm in length in each set. The manifold 95 is equipped with manometers 97 and valves 98 for regulating fluid pressure in each manifold or manifold. (Not shown) means for supplying the distribution pipe 95 with elevated temperature water. A suction portion 99 is arranged under each mouthpiece or dispensing tube to remove excess water during fabrication and to prevent flooding of the foil area being transformed into a hole. The starting film 67 intended for processing into the hole film 68 according to the invention is introduced onto the conveyor belt, which represents the supporting part. The starter film travels under the distributor head 96, where it is treated by jets of water flowing from the mouth of the distributor head. The pressure of the flowing water jets from the respective distribution head 96 is adjusted by the pressure valves 98 to the desired value. The water pressure in the distribution heads 96 should be at least about 35 bar and can go up to 105 bar or even higher. In the process of making punched films according to the present invention, it is preferred that the individual distributor heads 96 spray water at the same pressure. Referring to FIG. However, the given number is not decisive, since the number of distribution heads depends on the thickness of the starting foil, the speed of the conveyor belt, the set pressure, the number of sets of openings in the respective distribution head 96, etc. When the hole foil 68 travels between the water jets and the suction portion 99, it travels over the additional suction slot 99a to remove excess water from it. The conveyor belt constituting the supporting part may be made of relatively rigid material and may comprise a plurality of laths. Each lath extends over the width of the conveyor and has a groove on one side and a nose on the other, so that the nose of one lath engages with the groove of the adjacent lath, allowing the adjacent laths to move about one another and to allow relatively rigid laths to be used in the design the conveyor of FIG. 21. Alternatively, the support portion may be a woven sieve having raised foil-bearing locations and lowlands into which the foil is immersed when machined.

In FIG. 22 is a preferred device for making punched films according to the present invention. The apparatus 100 comprises a rotating drum 101. The drum has a honeycomb-like structure that allows fluid to pass through, rotates counter-clockwise and carries a support portion in the form of an elongated cylinder or sleeve 103 arranged on its outer surface. A partition tube 105 is arranged around a portion of the exterior of the drum. It binds a group of strip distributor heads 106 for supplying water to a stretchable thermoplastic starter film 107 carried by the outer surface of the sleeve 103. Each strip distributor head comprises a series of very small, uniform circular holes. The diameter of these holes should range from about 0.0127 cm to about 0.0254 cm. These can be up to 50 or 60 or more holes per cm in length, if necessary. We direct the water through the openings under pressure so that there are jets that protrude along the upper surface of the starting foil in the contact or hole field under the distributor heads. Water flowing into the distributor heads is controlled by (unmarked) pressure valves, and the pressure status is indicated by pressure gauges 110. The drum is connected to a sink tank 112, in which a vacuum can be maintained to facilitate removal of water to prevent the hole field from being filled. The starting foil 107 is placed on the support part 103 in front of the distribution heads 106 for water injection during operation. The foil 107 travels under the distributor heads, where it is transformed into a hole foil according to the invention.

EXAMPLE 1

The punched plastic foil as shown in FIGS. 1 to 5, is made with the apparatus 100 of FIG. 22, provided with a support portion as shown in the drawings of FIG. 17 to 19. The starting material was a 0.00254 cm thick film with projections containing 50% by weight of low density polyethylene and 50% by weight of low density polyethylene. The foil was obtained from Εχχοη Corporation under the code EMB-533. This film had a softening point at 80 ° C, a melting point at 120 ° C, a density of 0.91 and 460% elongation at break in the machine direction and 630% in the transverse direction. The foil has a tensile strength of 0.53 daN / cm in LS and 0.45 daN / cm in TS.

The support portion 103 was designed as a cylindrical sleeve that was mounted above the support drum 101, as shown in FIG. 22. The outer surface of the support work has been designed as generally shown in the drawings of FIG. 17 to 19. Base 78 measured 0.076 cm. The height of the supporting elements 71, measured from the base 78 to the ridge 74, measured 0.191 cm. These were 4.7 such supporting elements 71 per cm, measured along the reference line

A-A of FIG. 18. The bearing members 71 were aligned around the periphery of the sleeve around the circumference, i.e. aligned so that the reference line B-B of FIG. 18 parallel to the sides of the sleeve.

As FIG. 19, the spacing X between adjacent bearing portions 71 measured 0.152 cm at the upper surface 65a of the base portion 65. The Y spacing between adjacent bearing sections at their ridges 74 measured 0.229 cm. The openings 80 were round and had a diameter of 0.091 cm. The openings 80a, 80b and 80c of FIG. 18 were spaced 0.112 cm from center to center, and openings 80d were 0.145 cm from center to center adjacent openings 80c and 80e. Such pattern of spacing of openings was uniformly used throughout the support work.

The cylindrical sleeve containing the support part 103 was made of acetone copolymer resin Celcon CE-4 of Hoechst-Celanese hard. If necessary, other materials such as aluminum transformed into said cylindrical sleeve may be used.

In the process of making punched film according to this EXAMPLE 1, only three of the five distributor heads 106 of FIG. 22. Each head 106 has a single set of mouths of 0.0127 cm in diameter, with a series of 19.7 such mouths per cm. Each head 106 was positioned so that the mouths were 2.22 cm above the ridges 74 of the vertical support elements 71. We heatedly dispensed water into the distribution tube 105 and sprayed it from three distribution heads 106. The water was sent to three distribution heads under at about 43 bar and at 71 ° C, the starting foil 107 was guided from the stock roll (not shown in FIG. 22) to the outer surface of the support portion 103, which had sinusoidal ridges just described. It is understood that during the process, the foil on the ridges was 74. The carrier drum 101, which supported the support portion 103, rotated the drive mechanism (not shown in the drawings) at a circumferential speed of 15.24 m / min. The water flowing through the openings 80 in the support part 64 and through the support drum 101 was sucked out via a suction container 112 and returned to the distribution tube 105. After passing the foil under the load of the distribution heads 106, the hole film 108 was then guided into box 113 to remove water. The puncture film 108 was then removed from the support portion by means of a splitting roller 109 and guided through the outer surface of the puncture roller 111 operating under vacuum to remove any residual process water before further treatment.

The punch film made according to the procedure of this EXAMPLE 1 was constructed as described above with reference to the drawings of FIG. 1 to 5.

EXAMPLE 2

Further hole foil was made using the apparatus and procedure described in EXAMPLE 1, except that water was supplied to the three distributor heads 106 at a pressure of about 42 bar. The starting material was a 0.00254 cm thick film with protuberances containing a mixture of low density polyethylene and linear low density polyethylene. The foil was purchased from Edison Plastic, Edison, New Jersey, under the MFST 141. This foil had a tensile strength of 0.59 daN / cm in the machine direction and a 245% extension at the tear, and a tensile strength of 0.39 daN transversely to the machine. / cm and an extension of 650% at the tender. The obtained hole film was tested and found to have the following properties:

Machine tensile strength (LS) 0.34 daN / cm Tensile strength transverse to machine (TS) 0.21 daN / cm Open box 3.0% Mean equivalent hydraulic diameter (EHD) of holes 0,0077 cm Hole size variation coefficient (VK) 162% Thickness 0.0584 cm Duration of beating 27 s

Tensile strength in LS and TS was determined on 2.54 cm (= 1) wide specimens of punctured foil with Instron Testing Machine according to ASTM Test Melhod D-882.

The open field [%] was determined with the Quantimet Q520 Image Analyzer, sold by Cambridge Instruments Ltd.

The open field and EHD of the hole foil were determined by image analysis. Image analysis essentially converts an optical image from a light microscope into an electronic signal that is suitable for processing. The electron beam scans the image line by line (line by line). When each line is scanned, the output signal changes depending on the illumination. White fields create high voltage and black low. An image of the hole film is obtained and in this image the holes in the hole film are white, while the solid fields of thermoplastic material are gray at different levels. The denser the solid fields are, the darker the gray fields are. Each line of the image we measure is divided into sample points. This analysis is performed with the Quanlimet Q520 Image Analyzer, sold by LEICA / Cambridge Instruments Ltd. The device uses Version 4.0 software with Gray Store Option (option to save gray). We used an Olympus SZH Microscope light microscope with a transmitted light base and a 0.5Χ flat lens. The image was taken with a ČOHU camcorder.

The punctured foils are prepared for analysis by spraying (30 s) in a Polaron II HD (spraying) apparatus that makes the transparencies transparent. The samples are mounted on 76.2 mm x 101.6 mm (3x4) glass tiles using double-sided adhesive tape (at the ends of the tiles) to keep the puncture sheets positionally stable.

Place a representative slice of each hole film to be analyzed on a microscope table and sharpen it on a 10x magnification video screen. The open field is determined from the field measurements of representative areas. Qu program output, antimei reports the mean and standard deviation for each sample.

The EHD (equivalent hydraulic diameter) of the openings is measured at 20x magnification. Quantimet calculates the EHD from the measured area and the size of each opening according to the form

EHD = 4 A) P.

where ^ l = aperture area and P = aperture range.

The Quantimet output reports the EHD and standard deviation values for each sample.

EHD values can also be determined by the test procedure as disclosed in US 4324276, which was mentioned initially.

The mean, standard deviation (SZ)) and variation coefficient (VK) are determined using standard statistical procedures. VK is determined by the form

VK = [SD / mean] x 100%.

The variation coefficient of the EHD parameter is an indicator of the variability of the size of the small holes in the hole film, expressed as their equivalent hydraulic diameter. If all the small holes are equal to EHD, there is no change in EHD, the VK of the EHD parameter is therefore 0%. Larger VKs of the EHD parameter mean larger changes in the size of the small holes, expressed by their EHD. As the VK of the EHD parameter of hole films made according to the teachings of the present invention increases, the films are increasingly getting the appearance of fibrous tissues of non-woven fabric made from the prior art.

The breakthrough values for the fluid were determined as follows: In the breakthrough test, we measure the time it takes for a quantity of 5 cm ^{3 of} test water to flow through an elliptical orifice whose main axis measures 3.81 cm and the small axis 1.9 cm. Test fluid is a synthetic menstrual fluid that is comparable to the characteristics, viscosity, color and ionic properties of a woman's menstrual fluid flow. The 1.27 cm thick plexiglass plate with the elliptical opening described above was mounted on an absorbent pad of the type used for hygienic inserts, with said pad being wrapped in the material being tested. Through the elliptical opening in the plexiglass plate, 5 (five) cm ³ of the test fluid mentioned above was then poured. Breakthrough time, measured in seconds, was recorded as the time between fluid intake and disappearance on the surface of the material being tested.

EXAMPLE 3

The punched plastic film of FIG. 6 to 10 were made on apparatus 100 of FIG. 22, provided with a support portion 103. as shown in FIG. 23 and 24. In this case, support part 103 consisted of a plurality of four-sided pyramids 121 arranged in rows 122 and columns 123. The pyramids extended in a general quiz from the upper surface 65a of base part 65 of support 64. The pyramid strings were arranged horizontally, columns and the pyramids are vertical, as shown in FIG. 23. Rows 122 of the pyramids were aligned parallel to the axis of rotation of the drum 101. The columns of the pyramids were aligned perpendicularly to the strings and in a direction parallel to the direction of rotation of the drum 101, so that during operation of the device 100, the columns of the pyramids were aligned parallel to the machine direction of the device and machine direction of the thermoplastic film we worked on it. As can be seen from FIG. 23, the pyramids were displaced in any sequence relative to the pyramids of each of the directly adjacent arrays.

The support element further comprised a plurality of openings 125 extending over the thickness of the base portion 65. The openings 125 were round and 0.081 cm in diameter. As can be seen from FIG. 23, the openings 125 were almost, but not entirely, in contact with each directly adjacent pyramid 121 in a particular column 123; in other words, the diameter of the openings 125 was almost equal to the distance between the base corners 121a, 121 b of any two adjacent pyramids in column 123. As can be seen in both sketches of FIG. 23 and 24, however, openings 125 were slightly offset from each of the directly adjacent pyramids 121 in row 122; in other words, the diameter of the openings 125 was smaller than the distance between the foot corners 121c. 121d of any two adjacent pyramids in a given set 122.

The length of each of the four bases 131,132,133,134 of pyramids 121 was 0.094 cm.

As seen in FIG. 24, the gap 137 between the peaks 135 of two directly adjacent pyramids in row 122 was 0.183 cm. The distance between the vertices 135 of two directly adjacent pyramids in column 123 was 0.105 cm. Pyramids 121 formed, in the supporting element, a plurality of intersecting valleys 139, each of which was 0.089 cm wide, measured perpendicularly from the edge 140 of pyramid 144 to the edge 141 of adjacent pyramid 145.

Starting foil, i.e. Εχχοη EMB-533. which was used in EXAMPLE 1 was also used to produce the punctured foil according to the present EXAMPLE 3. The apparatus 100 (except the support element) used in this EXAMPLE 3 was the same as that of EXAMPLE 1. Water was supplied to three distributor heads under at about 112 bar and at 32 ° C. The carrier drum 101, which bore the support portion as described in connection with the drawings of FIG. 23 and 24, sits at a speed of 15.24 m / min.

The resulting hole film was constructed as described above with reference to the drawings of FIG. 6 to 10. The foil had the following physical characteristics:

Tensile strength in the machine direction (LS) 0.20 daN / cm

Tensile strength transverse to machine (TS) 0.23 daN / cm

Open field 7.2%

Thickness 0.0659 cm

Break time 28 s

According to the sketch of FIG. 6, the mean EHD of the small holes 47 in the hole foil of this EXAMPLE 3 was 0.00859 cm. The variation coefficient of the EHD parameter of small holes 47 was 157%. The punctured film also contained a plurality of larger holes 42, these larger holes 42 being formed when water jets punched the starting foil during the treatment to the tops of the pyramids 121 of the support. The mean EHD of the larger holes 42 in the foil according to EXAMPLE 3 was 0.044 cm. The wide variation in the size of the small holes - 157% of the EHD parameter EK - resulted in a holey foil whose appearance was much more like a non-woven fabric made from fibrous tissue. Undoubtedly, the appearance of larger holes 42 in the hole foil, such as those discussed here, can be avoided by providing pyramids with rounded instead of sharp peaks.

The HOLE foil of EXAMPLE 3 has proven to be particularly useful as a cover layer for hygienic liners.

EXAMPLE 4

The punctured plastic film shown in FIGS. 11 to 15, we have made on device 100 of FIG. 22, provided with a cylindrical support part 103, which was designed according to the drawings of FIG. 25 and 26. The support portion 103 comprised the base portion 65 with a plurality of circular openings 151 arranged in rows 152 and columns 153. The rows 152 were arranged horizontally and the columns 153 vertically, as seen in FIG. 25. The arrays 152 were aligned parallel to the axis of rotation of the support drum 103. Columns 153 were aligned perpendicularly to the strings 152 and parallel to the direction of rotation of the drum 101, so that during operation of the device 100 columns 153 ran parallel to the machine direction (LS) of the device. and the machine direction of the foil we were processing. As can be seen from FIG. 25, the round apertures of any given string were offset horizontally relative to the round apertures in each of the directly adjacent arrays.

The circular openings 151 were about 0.103 cm in diameter. The center spacing between round holes in row 152 was about 0.17 cm, and the center spacing between round holes in column 153 was about 0.104 cm.

Supporting part 103, which has been designed as described above and as shown in the drawings of FIG. 25 and 26, was in the form of a cylindrical sleeve, which was mounted over the carrier drum 101. The starting foil was Εχχοη EMB-533, as in EXAMPLES EXAMPLES 1 to 3. The water temperature supplied to the four distributor heads 106 was 21 °. C. Water flowed into the distribution heads at a pressure of about 56 bar. Water flowed from the mouth in the form of very small jets. The carrier drum 101 rotated at a speed of about 1.5 m / min. We obtained a hole film as described above and presented in the drawings of FIG. 11 to 16.

The punch films of EXAMPLES 2 and 3 were tested for the percentage [%] of the open field, the equivalent hydraulic diameter (EHD), the variation coefficient (VK) of the EHD parameter, the hole size range, the variation coefficient for the hole size parameter, the form factor, the variation factor for the parameter form factor and width of fiber-like elements. The open field [%], the EHD, the VK of the EHD parameter, and the hole size were determined according to the procedures previously described.

The design factor is an indicator of the circumference of the hole or hole in the material being tested. The form factor (FO) is determined by the form

FO = P ² / KA, where P = the circumference of the hole or orifice being measured, A = the surface of the hole or orifice, and K = constant = 4π.

For a hole or aperture that is perfectly circular, the shape factor FO = 1. The higher the shape factor, the more irregular, i.e. far from the circle, in appearance it is a hole or an opening. Materials that have high hole-size variation coefficients (VKs) are much more similar to textiles for the observer, i.e., the materials look much more like everyday non-woven fabrics made from fibrous tissue and look much less like plastic films that they have basically single holes or openings.

In the tests in question, touch materials of the prior art were used as comparative. The first touching material used as a benchmark - sample C in Table I - was the touching material found in Kotex Super-Maxi sanitary napkins sold by Kimberty-Clark Corporation. The other touching material used as the benchmark - sample D in Table I - was the touching material obtained from the Always Maxi-Pads sanitary napkins sold by The Procter & Gamble Company. The third touching material used as a benchmark - sample E in Table I - was the touching material obtained from the Sure & Natural sanitary napkins sold by Personal Products Company. Sample A in Table I corresponds to the hole foil made according to EXAMPLE 2 above, and sample B to the hole foil made according to EXAMPLE 3 above.

The touch material, designated in Table I, as sample C, is a non-woven fabric for non-woven fabric containing fibers of continuous length with substantially uniform diameters of about 0.003 cm, the material being known in the art as spinning non-woven fabric.

The touch material, which is identified in Table I as sample D, is a punctured plastic material such as that described on the outer cover containing hygienic inserts from which it is taken as Dri-Weave Covering. Obviously, this material is made according to the process disclosed in US Patent Nos. 4342314 and 4463045. which are mentioned on said outer cover.

The touching material, designated in Table I as sample E, was made following the teachings of US patent 4690679.

TABLE I

! ί Property SAMPLE A B C D E Open field [%] 3.0 10,0 17 26 28 t ΐ VK design factor [%] 32 29 30 11 17,9 EHD, [%] 95 90 95 75 95 openings [cm] <0,064 <0,064 <0,064 <0,064 med 0.025 in 0.046 VK [%] of the EHD parameter 80 87 92 11 7 Size 95% 95% 95% 80% 95% holes [cm ² ] med med med med med 0.002 in 0.002 in 0.002 in 0.258 in 0.058 in 0.258 0.258 0.258 0,484 th most common 0.258 VK [%] the size of the holes 160 190 200 n 24.5 Width [cm] 80% 80% 100% 100% 100% fiber eligible med med med med elements 0.0025 in 0.0025 in 0, () (). V ' 0.038 m 0.038 in i 1 0,0127 0.0127 j 0,076 # (), () X9 #

* = fiber diameters # = width of plastic material between holes

The results of the tests are shown in Table I. The perforated thermoplastic films of the present invention (Table I, samples A and B) are very similar to non-woven fabrics made from fibrous tissues (here as spunbond nonwoven fabric C), and are completely different from the perforated plastic materials of the prior art, examples D and E here.

The hygienic inserts were made from the liquid permeable puncture films of EXAMPLE 2 herein and the touch materials described above and designated in Table I as specimens C and E. The inserts were tested for breakthrough time, re-wetting properties and color masking properties.

The sanitary napkins we tested contained absorbent cores of the kind found in Sure & Natural sanitary pads sold by Personal Products Company, and were wrapped with touch materials A, C and D. Touch materials were switched and bonded to the lower surface of the test inserts, as known in the art, leaving a single layer of contact material on the upper surface of the insert, i. the surface that the body touches.

The breakthrough time [s] for test hygiene items was determined according to the procedure described above. When the fluid piercing test was behind us, we laid two layers of filter paper 7.62 cm x 10.16 cm (3 x 4) across the box of the sanitary pad soaked in the synthetic menstrual fluid used in the fluid piercing test. . All the upper surface of the cartridge we tested was weighed here and there once with a cylinder of length 12.7 cm, diameter 8.26 cm and mass 1.8 kg. The amount of [g] synthetic menstrual fluid absorbed by the filter papers was considered to be a wetting value.

The masking properties of the stain of various touch materials were determined using the Hunter Color Meter using the following procedure. The hygienic test pads were prepared by wrapping absorbent cores of wood pulp with the touch materials we wanted to test, as previously described. Ready-to-test hygiene cartridges were placed over the portion of the Hunter Color Meter instrument intended to receive the sample and covered with a black calibration glass.

We then read the values for L, a and h on the instrument scales. The procedure was repeated twice on various parts of the cartridge we tested. The opacity, NV, of the sample we tested was determined by the form:

NV = M / N. (100), where M = digital read value from Hunt er Color Meter using a black calibration glass, and

TV = digital color reading from Hunter Color Meter using white calibration glass.

The hygiene test pads are covered with a plexiglass plate used to determine breakthrough times. Through the elliptical opening in the plate, 5 cm ^{3 of the} menstrual fluid described above was poured and allowed to be absorbed by the cartridge, simulating the stain as it would have come into contact with the actual menstrual fluid. The intensity of the stain in the fouled box of the hygiene cartridge was then measured by reading the values of L, a and b on the Hunter Color Meter scales. The intensity of the IM stain was determined by the form:

2η1 / 2

IM = [(L -L Y + (A -AY + (b - h) ² 1

With US ⁷ L with US / VS US / J where indexes = value obtained for the fouled area and index us = value obtained in the nonfattered comparative area.

The VMM stain masking values for each hygienic insert with touch material were then determined using the form:

VMM = NV-IM, where NV = opacity value and IM = stain intensity.

Test results are given in Table II.

TABLE II

Property Touch material used in the sanitary napkin A C f D Breakthrough time [sj 27 16 16 Wetting value [g] 0.18 0.53 0.46 and Stain masking 70 58 46 Open field [%] n 3 17 26

P.s .: Material C is a non-woven fabric that has a curved path for fluid passage. The open field determined by the measurement of the transmitted light may not reflect the common field allowing the passage of fluids.

Materials A, C, and D in Table II correspond to the materials A, C, and D in Table I.

The test results of Table II show that the punctured thermoplastic films of the present invention, such as those obtained by the process of EXAMPLE 2 (touching material A in Table II), are provided with hygienic liners whose masking properties and wetting values are the same or better than those of commercially available hygiene liners which use either spinning nonwovens (ie touching material C in Table II) or plastic punched touching material (ie touching material D in Table H) and whose break times are, albeit slightly higher than those of existing commercially available products, still functionally acceptable. These favorable results are quite surprising when one considers that the punched plastic film of EXAMPLE 2 here has a significantly smaller open field than the prior art C and D materials.

A Fourier Trcmsform Jnfm-Red (FTIR) instrument with a microscope connector was used to determine the differences in the drag ratio between the fiber elements and the parts of the polymeric foil material in addition to these fiber elements in the punctured foil products of the present invention. It should be remembered that in the treatment of the material according to the present invention, the starting foil lies on the tops of the support part and that under the influence of water jet impact, the unsupported parts of the starting material bend down towards the depressed areas or valleys of the support part and partially into them.

This deformation or cracking is continued until the starting film bursts in the range of the small holes and the fiber-like elements typical of the hole films according to the invention. Spreading or pulling is localized so that the bulk of the spreading or pulling falls on those areas of the starting foil that become fiber elements. The purpose of this test is to determine the difference in diffraction occurring in the fiber elements and in the polymeric material adjacent to these fiber element fields.

These measurements were performed on a two-port FTIR spectrometer (FTIR Model 1800, Perkin-Elmer Corp., Norwalk, CT) equipped with a research grade IR microscope (IRPLAN Spectra Tech infrared microscope, Stamford, CT), which worked in the illumination mode. IR spectra were obtained using a 1 mm ² medium mercury-cadmium tellurite (MCT) and a lens (IR) of a 15Χ cassigrain lens. The spectra were scanned at a resolution of 2 cm ' ¹ between 4000 and 600 cm' ¹ . We limited the data interval used to 1 (s / spectrum) for a resolution of 2 cm ' ¹ . The operating mode parameter for the background and for the foil specimens we examined was the same except for the Jacquinot milestone, which was 1 for the background and 4 for the processed specimens. In all cases, we used the normal Hays-Ganzel proof (apodizing) function. All samples were scanned 200 times with the necessary openings in place. One background image collection was used to schedule the following spectra of the test sample. The background spectrum was obtained using a 1 mm large aperture in the capacitor, a 1 mm large hole in the sample tray, and a 1.5 mm large aperture in the upper optical module. The spectra of the samples were obtained by using further openings above and below the sample to identify the specific fields of interest for the samples tested.

The tracer ratio curve was developed by mechanically deforming the starting polymer film material, measuring elongations from 0 to 500% in 100% increments and obtaining FTIR spectra for each specimen.

Spectra were then obtained from the fiber elements in the punched film material and from the areas immediately adjacent to these fiber elements. These spectra were compared with the spectra of the measuring curve, from which the degree of elongation of the fiber elements was obtained. We found. that the fiber elements of the puncture film of the invention were pulled at least 100% in comparison with adjacent areas of the starter film which did not suffer puncture during processing.

The main part of the fiber elements was found to be pulled from about 200% to about 250% compared to the adjacent areas of the starter foil which did not suffer puncture during processing.

As previously noted, the puncture films of the present invention can be used as a touch material for absorbent products such as disposable diapers, sanitary napkins, wound dressings, incontinence accessories and the like.

When used as a touch material in hygienic inserts, it is preferable that the small holes in the holes of the plastic films according to the invention are sufficiently large that there is an open field in the range of about 1 to 15%, thus giving the number of large holes (such as holes 42 in Fig. 6) preferably as little as possible. It is desirable that at least half (50%) of the small holes on the foil have EHDs in the range of 0.00127 to 0.0635 cm. The VK of EHD small holes is preferably at least 50%. It is desirable that the surface area of at least three-fourths (75%) of all small holes is less than 0.258 mm ² and that the variation coefficient of the VK of the small hole surfaces is at least 100%.

We proceed to the sketch of FIG. 27 and 28 showing a hygienic insert 200 comprising a wood pulp absorbent core 202, a thin, fluid-impermeable barrier foil 204 and a covering material 206, which may be any foil of the invention. The roofing material is preferably constructed as described and described above with reference to the drawings of FIG. 1 to 5 and in EXAMPLE 2. Barrier foil 204, which may be e.g. a thin film of polyethylene, touches the lower surface of the absorbent core 202 and extends to some extent up the longitudinal sides of the absorbent core. The roof material 206 is slightly longer than the length of the absorbent core and is wrapped around the absorbent core and the barrier foil, as shown in FIG. 28. The longitudinal edges of the roofing material are covered and joined at the bottom surface of the insert as usual. In the embodiment shown, the cover material is fused to itself at the ends 208, 210 of the sanitary napkin. As FIG. 28, the hygienic insert 200 has a layer of adhesive 212 for attaching the insert to the user's underwear. Adhesive 212 is protected by removable tape 214 before use.

Variations are possible with respect to the structure of the support section described herein. So e.g. are the pyramids shown in FIG. 23, can be three-, five- or multi-sided. The support may also have upright support elements in the form of cones, four-sided projections, etc.

Claims (40)

Patent claims A puncture film, characterized in that it comprises an expandable thermoplastic polymer material containing a plurality of small holes formed by a network of fiber elements. Punched film according to claim 1, characterized in that the thermoplastic polymer material containing said fiber elements has been stretched. Punched film according to claim 1, characterized in that said fibrous elements were stretched by at least 100% compared to the adjacent areas of the starting film which were not subjected to puncture during processing. Punched film according to claim 1, characterized in that the surface of said small holes ranges from about 0.002 mm ² to about 0.258 mm ² . Punched film according to claim 1, characterized in that said small holes are arranged in a pattern with clearly spaced groups. Punched foil according to claim 1, characterized in that the shape of the small holes is irregular and the holes are randomly distributed over the holes of the foil. Punched film according to claim 1, characterized in that the variation coefficient of the shape factor of the small holes is at least about 25%. 8. Punched film according to claim 1, characterized in that the EHD of the small holes lies in the range of from about 0.0013 to about 0.064 mm. 9. Punched film according to claim 1, characterized in that the variation coefficient of the EHD of the small holes is at least about 50%. 10. Punched film according to claim 1, characterized in that it has an open field of from about 1% to about 15%, wherein said open hole is formed by said small holes. Punched film according to claim 1, characterized in that the length of the fiber elements is in the range from about 0.0127 to about 0.127 cm. Punched film according to claim 1, characterized in that the width of the fiber elements is from about 0.00254 to about 0.089 cm. 13. Punched film according to claim 1, characterized in that the thickness of the fiber elements is in the range from 0.000635 cm to about 0.0051 cm. 14. Punched film according to claim 1, further comprising a plurality of secondary openings whose surfaces are substantially larger than those of said small holes. 15. Punctured film, characterized in that it comprises an expandable thermoplastic polymeric material, a series of parallel ridges and a series of valleys between said ridges, each of said ridges being formed by a pair of generally flat-oriented lateral surfaces that contact on the upper surface of said film, said valleys having a plurality of small holes defined by a network of fiber elements. 16. Punched film according to claim 15, characterized in that the lower edges of said sloping lateral side walls comprise a plurality of said small holes. 17. Punched film according to claim 15, characterized in that said ridges, when viewed in plan view, have sinusoids of a similar configuration. 18. Punctured film, characterized in that it contains an expandable thermoplastic polymeric material, a plurality of generically oriented, cone-like structures formed by sloping lateral surfaces, these plots forming a plurality of small holes between conical structures containing a plurality of small holes. defined by the network of fiber elements. 19. Punched film according to claim 18, characterized in that the lower edges of said sloping side walls comprise a plurality of said small holes. 20. Punched film according to claim 18, characterized in that said conical formation contains secondary openings whose surfaces are substantially freer than those of said small holes. 21. Punctured film, characterized in that it contains an expandable thermoplastic polymeric material and a plurality of small holes defined by a network of fiber elements and arranged in a plurality of small hole groups. 22. Punched film according to claim 21, characterized in that each swarm comprises at least one row of said small holes, with a strip of non-punctured material on each side of that row of small holes. 23. Punched film according to claim 21, characterized in that each swarm comprises a plurality of species of said small holes and that these species are separated from each other by bands of non-punctured material. 24. Punched film according to claim 21, characterized in that the areas around the adjacent swellings of the small holes and the areas between the swarms are substantially free of small holes. 25. A method of manufacturing a puncture film comprising an expandable thermoplastic polymeric material containing a plurality of small holes defined by a network of fiber elements, characterized in that it comprises: a) disposing of a starting foil comprising a thermoplastic polymer material which has a top and bottom surface; b) disposing of a support portion comprising positionally defined carrier areas for supporting the foil, indentations into which the foil may be deformed when fluid forces are acting on it, and means for releasing said working fluid from said support portion; c) supporting said starter film on said support portion by contacting the lower surface of said foil with a support surface of said support portion and the upper surface of said foil facing away from said support portion; d) directing the force of the fluid to the upper surface of said starting foil in the field of contact and under pressure sufficient to make said small holes; d) moving said foil from said touching field; and e) removing said now punctured film from said support portion. A method according to claim 25, characterized in that said fluid is directed to the upper surface of said film in the form of jets. Process according to claim 25, characterized in that the fluid under pressure is from about 35 bar to about 112 bar. The method of claim 25, wherein the fluid is water directed to the upper surface of said film at a temperature of at least about 32 ° C. 29. The method of claim 28, wherein the water is pressurized from about 35 bar to about 112 bar. 30. The absorbent product comprising an absorbent core covered with a punctured film, characterized in that said punched film comprises a thermoplastic polymeric material having a plurality of small holes defined by a network of fiber elements. 31. The absorbent article of claim 30, characterized in that it is designed as a wound dressing. 32. The absorbent article of claim 31, wherein said core film is covered with said hole foil. 33. The absorbent article according to claim 30, characterized in that it is designed as a disposable diaper. 34. The absorbent article according to claim 30, characterized in that it is designed as a hygienic insert. 35. The absorbent article of claim 30, further comprising a liquid-impermeable back layer arranged along one of the base surfaces of said absorbent core. 36. A hygienic liner, characterized in that it comprises an absorbent core having an upper base surface and a lower base surface, for a liquid impermeable barrier layer and a covering material, the latter being in contact with at least the upper surface of said absorbent core, and wherein the roofing material comprises a disintegrating tennoplastic polymeric material having a plurality of small holes defined by a web of fiber elements, said barrier layer being disposed at the lower surface of said absorbent core. 37. The sanitary napkin according to claim 36, characterized in that the number of said small holes is sufficient to establish an open field of size from about 1% to about 15%. 38. The sanitary napkin according to claim 36, characterized in that said small holes have equivalent hydraulic diameters ranging from 0.00127 cm to 0.0635 cm. 39. The hygienic pad according to claim 36, characterized in that the variation coefficient of the equivalent hydraulic diameter of the small holes is at least 50%. 40. The sanitary napkin according to claim 36, characterized in that the surface of the at least 75% of the small holes is less than 0.258 mm ² .