Classifications

• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61F—FILTERS IMPLANTABLE INTO BLOOD VESSELS; PROSTHESES; DEVICES PROVIDING PATENCY TO, OR PREVENTING COLLAPSING OF, TUBULAR STRUCTURES OF THE BODY, e.g. STENTS; ORTHOPAEDIC, NURSING OR CONTRACEPTIVE DEVICES; FOMENTATION; TREATMENT OR PROTECTION OF EYES OR EARS; BANDAGES, DRESSINGS OR ABSORBENT PADS; FIRST-AID KITS
  • A61F13/00—Bandages or dressings; Absorbent pads
  • A61F13/15—Absorbent pads, e.g. sanitary towels, swabs or tampons for external or internal application to the body; Supporting or fastening means therefor; Tampon applicators
  • A61F13/51—Absorbent pads, e.g. sanitary towels, swabs or tampons for external or internal application to the body; Supporting or fastening means therefor; Tampon applicators characterised by the outer layers
  • A61F13/511—Topsheet, i.e. the permeable cover or layer facing the skin
  • A61F13/512—Topsheet, i.e. the permeable cover or layer facing the skin characterised by its apertures, e.g. perforations
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61F—FILTERS IMPLANTABLE INTO BLOOD VESSELS; PROSTHESES; DEVICES PROVIDING PATENCY TO, OR PREVENTING COLLAPSING OF, TUBULAR STRUCTURES OF THE BODY, e.g. STENTS; ORTHOPAEDIC, NURSING OR CONTRACEPTIVE DEVICES; FOMENTATION; TREATMENT OR PROTECTION OF EYES OR EARS; BANDAGES, DRESSINGS OR ABSORBENT PADS; FIRST-AID KITS
  • A61F13/00—Bandages or dressings; Absorbent pads
  • A61F13/15—Absorbent pads, e.g. sanitary towels, swabs or tampons for external or internal application to the body; Supporting or fastening means therefor; Tampon applicators
  • A61F13/15577—Apparatus or processes for manufacturing
  • A61F13/15707—Mechanical treatment, e.g. notching, twisting, compressing, shaping
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61F—FILTERS IMPLANTABLE INTO BLOOD VESSELS; PROSTHESES; DEVICES PROVIDING PATENCY TO, OR PREVENTING COLLAPSING OF, TUBULAR STRUCTURES OF THE BODY, e.g. STENTS; ORTHOPAEDIC, NURSING OR CONTRACEPTIVE DEVICES; FOMENTATION; TREATMENT OR PROTECTION OF EYES OR EARS; BANDAGES, DRESSINGS OR ABSORBENT PADS; FIRST-AID KITS
  • A61F13/00—Bandages or dressings; Absorbent pads
  • A61F13/15—Absorbent pads, e.g. sanitary towels, swabs or tampons for external or internal application to the body; Supporting or fastening means therefor; Tampon applicators
  • A61F13/53—Absorbent pads, e.g. sanitary towels, swabs or tampons for external or internal application to the body; Supporting or fastening means therefor; Tampon applicators characterised by the absorbing medium
  • A61F13/539—Absorbent pads, e.g. sanitary towels, swabs or tampons for external or internal application to the body; Supporting or fastening means therefor; Tampon applicators characterised by the absorbing medium characterised by the connection of the absorbent layers with each other or with the outer layers
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
  • B23K—SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
  • B23K26/00—Working by laser beam, e.g. welding, cutting or boring
  • B23K26/36—Removing material
  • B23K26/38—Removing material by boring or cutting
  • B23K26/382—Removing material by boring or cutting by boring
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
  • B23K—SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
  • B23K26/00—Working by laser beam, e.g. welding, cutting or boring
  • B23K26/36—Removing material
  • B23K26/38—Removing material by boring or cutting
  • B23K26/382—Removing material by boring or cutting by boring
  • B23K26/389—Removing material by boring or cutting by boring of fluid openings, e.g. nozzles, jets
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
  • B23K—SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
  • B23K26/00—Working by laser beam, e.g. welding, cutting or boring
  • B23K26/36—Removing material
  • B23K26/40—Removing material taking account of the properties of the material involved
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
  • B23K—SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
  • B23K2103/00—Materials to be soldered, welded or cut
  • B23K2103/16—Composite materials, e.g. fibre reinforced
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
  • B23K—SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
  • B23K2103/00—Materials to be soldered, welded or cut
  • B23K2103/16—Composite materials, e.g. fibre reinforced
  • B23K2103/166—Multilayered materials
  • B23K2103/172—Multilayered materials wherein at least one of the layers is non-metallic
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
  • B23K—SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
  • B23K2103/00—Materials to be soldered, welded or cut
  • B23K2103/30—Organic material
  • B23K2103/38—Fabrics, fibrous materials
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
  • B23K—SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
  • B23K2103/00—Materials to be soldered, welded or cut
  • B23K2103/30—Organic material
  • B23K2103/42—Plastics
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
  • B23K—SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
  • B23K2103/00—Materials to be soldered, welded or cut
  • B23K2103/50—Inorganic material, e.g. metals, not provided for in B23K2103/02 – B23K2103/26

Definitions

• the present invention relates to a method for producing through appertures in the form of holes and/or slots or slits in a web, preferably a web having a weight per unit area of about 5-100 g/m 2 , more preferably 10-50 g/m 2 , said web including polymeric and/or cellulosic material and being intended for use in absorbent articles.
• the present invention also relates to a method of making appertures in such a web while, at the same time, joining the web to another web of similar material.
• cellulosic is meant here that the material can include larger or smaller amounts of cellulose fibres.
• Absorbent articles which term includes diapers, sanitary napkins, incontinence guards, panty protectors, etc., are known to the art in many different designs. These articles always include at least one absorbent body and at least one top sheet or layer which is intended to lie proximal to the wearer.
• Appertures are also often provided for the purpose of for ⁇ ming so-called tear lines, i.e. perforations arranged sequ ⁇ entially in rows along lines or curves along which the material is intended to be torn apart when sufficiently large, counteracting forces are applied on respective sides of the material.
• tear lines i.e. perforations arranged sequ ⁇ entially in rows along lines or curves along which the material is intended to be torn apart when sufficiently large, counteracting forces are applied on respective sides of the material.
• a known technique for forming appertures in material webs of the aforesaid kind comprises subjecting the material to conventional treatment with the aid, for instance, of pin rolls or drums while supplying heat, or with the aid of different types of punches or dies.
• the aid for instance, of pin rolls or drums while supplying heat, or with the aid of different types of punches or dies.
• the more modern methods of providing such appertures are those which are based on the use of ultrasound and powerful water jets (so- called water jet technique) .
• water jet technique One particular method of for ⁇ ming holes in plastic film with the aid of perforated rolls and applied vacuum conditions is described in US-A
• the known technique is also encumbered generally with a further drawback.
• the material located around the appertures is compressed, for instance by an RDC drum or by the pattern drum or roll of an ultra ⁇ sonic device. This compression will, of course, often have a significant negative effect on the properties of the material, such as softness, flexibility and so on.
• the main object of the present invention is to provide a method of the kind defined in the introduction which is essentially free or totally free of the drawbacks associa ⁇ ted with known techniques.
• Another object is to provide such a method which will af ⁇ ford the advantage of enabling the web in which the holes are formed to be joined, laminated, with another material of a similar kind.
• the use of focused electromagnetic beams or particle beams for hole-forming purposes affords a number of advantages.
• the point of attack or impingement of such a beam i.e. the point at which the beam impinges on the substrate
• Mirrors and prisms have a relatively small mass and thus present only a small degree of inertia against movement, therewith enabling the beam impingement point to be moved rapidly and with very small energy consumption.
• the focused beam used in the inventive process will trans ⁇ mit energy at much higher power per unit area than in the case of the known techniques, in other words the energy supply per time and unit area is considerably greater.
• This enables the speed of the web, and therewith the production rate, to be increased to roughly twice the speed, or hig ⁇ her, than that which can be achieved with the known tech ⁇ niques. Since the energy supply is highly concentrated at those locations at which appertures are to be formed, very well- defined appertures are obtained in the absence of undesi ⁇ rable compression of surrounding material.
• the focused beam may be a beam of charged or neutral parti ⁇ cles, or may be a light beam, such as a coherent or non ⁇ coherent, or onochromic or polychro ic light beam respec ⁇ tively.
• a beam of coherent electromagnetic radiation preferably a laser beam, and more preferably a beam generated by a C0 2 laser, since the wavelength range of beams emanating from a C0 2 laser is such that the efficiency is very high for converting radiant energy to heat in the material concerned (different polymers and cellulose), i.e. the applied energy is utilized very effectively to form holes in the material.
• a fluid preferably a gas
• the flow of fluid functions to remove molten/burned/- vapourized material from holes made in the web, and also to cool the edges of the holes so as to reduce the heat-affec ⁇ ted zone around the holes, and also functions to cool oc ⁇ current focusing means, such as lenses and the like.
• a fluid commonly used in this regard is air.
• an inert gas such as nitrogen or argon
• an inert gas when the web contains a high proportion of cellulose.
• the through appertures may be permeable to both liquid and vapour, although they are preferably intended to allow liquid to pass through.
• the web material is plastic film or plastic foil, while in another embodiment the web material is a bonded-fibre fabric or a sheet of nonwoven material.
• the appertures may be holes having a diameter of up to 4 mm, preferably from 0.3-3 mm, more preferably from 0.5-1.5 mm, or slots having a length of up to 10 mm, preferably up to 5 mm.
• the slots may be straight or more or less curved and may also intersect or break one another.
• the web when irradiating the web the web is in contact with another web which includes material of a kind similar to the first web and which is located on that side of the first web that lies opposite to the irradiation source, and the properties of the beam and the duration of the irradiation period are chosen so that the material in the first web and/or in the further web will be supplied with sufficient energy to join the webs together in the immediate vicinity of the appertures.
• holes are formed in one web while laminating the webs together at the same time.
• this is a technical advance of very great significance.
• it is unnecessary to perform a separate laminating stage, which naturally implies a considerable economic advantage.
• there is also obtained improved contact between the webs which is favourable to absorption and also to the transportation of liquid through the laminate.
• Fig. 1 illustrates schematically an embodiment of an inven ⁇ tive method for forming appertures in a web of material in ⁇ tended for the production of absorbent articles
• Fig. 2 illustrates schematically an embodiment of the in- vention, wherein appertures are formed in a web while at the same time joining the web to another web;
• Fig. 3 is an enlarged view of the encircled region in Fig. 2.
• Fig. 1 is a sectioned view of part of a laser 10 which generates a laser beam 20, which is focused with the aid of a focusing lens 30.
• the beam 20 diffracted by the lens 30 passes through a nozzle 50 and leaves the nozzle through an apperture 60.
• a shielding gas delivered through a conduit 40 flows through the space defined by the lens 30 and the walls 50 of the nozzle.
• the beam impinges on a web of mate ⁇ rial 70, so as to make an apperture 80 in the web.
• the laser device 10 of the Fig. 2 illustration is of the same kind as that shown in Fig. 1, although in this case, the laser is used to form holes or appertures in an upper web 70 while simultaneously joining the web to a lower web 90.
• the laser beam Prior to being focused, the laser beam had a diameter of about 7 mm, a beam divergence of about 1.5 mrad, and an approximate gaussic power distribution across the beam cross-section; in focus the beam diameter is about 60 ⁇ m.
• the focusing lens had a focal length of about 38 mm.
• the shielding gas used was air at a gauge pressure of 0.1- 0.5 bars.
• the exit opening of the gas nozzle had a diameter of about 1.5 mm and when working the web was located at a point about 1.5 mm above the focal plane, which in turn was located at a point about 3 mm above the surface of the material to be worked.
• Table I presents the results obtained with a number of tests in which holes were formed in different sheet or surface materials with the aid of the aforesaid equipment.
• the materials used were
• B7W Spunbonded polypropylene with wetting agent, weight per unit area 15 g/m 2 .
• N9W Spunbonded polypropylene without wetting agent, weight per unit area 23 g/m 2 .
• ESC Carded and thermobonded bicomponent material of polyethylene/polypropylene, weight per unit area
• V180 Carded and thermobonded polypropylene material, weight per unit area 22 g/m 2 .
• Pulse rep. time Time between each laser pulse.
• Mean power Time mean value of the power of the transmitted laser beam.
• Focus distance Distance from the focal plane of the diffracted laser beam, to the surface of the irradiated material.
• Table II presents the results obtained from a number of tests carried out with combined holes forming in surface material while simultaneously joining the material to anot ⁇ her similar material with the aid of the aforesaid equip ⁇ ment.
• B9W Spunbonded polypropylene with wetting agent, weight per unit area 20 g/m 2 (surface material in the tests) .
• L4-601 Carded and thermobonded bicomponent material con ⁇ sisting of polyethylene/polyester, weight per unit area 50 g/m 2 (spacing material in the tests) .
• the speed given in Table II relates to the speed of the movable table in the X-direction.

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• Engineering & Computer Science (AREA)
• Health & Medical Sciences (AREA)
• Optics & Photonics (AREA)
• Physics & Mathematics (AREA)
• Mechanical Engineering (AREA)
• Heart & Thoracic Surgery (AREA)
• Epidemiology (AREA)
• Biomedical Technology (AREA)
• Plasma & Fusion (AREA)
• Vascular Medicine (AREA)
• Life Sciences & Earth Sciences (AREA)
• Animal Behavior & Ethology (AREA)
• General Health & Medical Sciences (AREA)
• Public Health (AREA)
• Veterinary Medicine (AREA)
• Manufacturing & Machinery (AREA)
• Absorbent Articles And Supports Therefor (AREA)
• Laminated Bodies (AREA)

Priority Applications (1)

Applications Claiming Priority (2)

Publications (1)

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Family Applications (1)

Country Status (3)

Cited By (13)

Citations (4)

• 1994
  • 1994-12-22 SE SE9404478A patent/SE513841C2/sv not_active IP Right Cessation
• 1995
  • 1995-12-15 AU AU43207/96A patent/AU4320796A/en not_active Abandoned
  • 1995-12-15 WO PCT/SE1995/001522 patent/WO1996019313A1/en active Application Filing

Patent Citations (4)

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