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
  • A61F13/56—Supporting or fastening means
  • A61F13/58—Adhesive tab fastener elements
• • C—CHEMISTRY; METALLURGY
  • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
  • C09J—ADHESIVES; NON-MECHANICAL ASPECTS OF ADHESIVE PROCESSES IN GENERAL; ADHESIVE PROCESSES NOT PROVIDED FOR ELSEWHERE; USE OF MATERIALS AS ADHESIVES
  • C09J7/00—Adhesives in the form of films or foils
  • C09J7/20—Adhesives in the form of films or foils characterised by their carriers
  • C09J7/22—Plastics; Metallised plastics
  • C09J7/24—Plastics; Metallised plastics based on macromolecular compounds obtained by reactions involving only carbon-to-carbon unsaturated bonds
  • C09J7/241—Polyolefin, e.g.rubber
  • C09J7/243—Ethylene or propylene polymers
• • C—CHEMISTRY; METALLURGY
  • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
  • C09J—ADHESIVES; NON-MECHANICAL ASPECTS OF ADHESIVE PROCESSES IN GENERAL; ADHESIVE PROCESSES NOT PROVIDED FOR ELSEWHERE; USE OF MATERIALS AS ADHESIVES
  • C09J2423/00—Presence of polyolefin
  • C09J2423/006—Presence of polyolefin in the substrate

Definitions

• This invention relates to flexible plastics tapes, and to sanitary articles provided with such tapes.
• the invention relates to diapers provided with such tapes.
• solid tapes In order to provide adequate strength for the tapes, it is normal to use a strong, relatively stiff plastics material, such as polypropylene, in the form of solid tapes produced, for example, by extrusion.
• solid here is used to mean that the material of the tape is present throughout its cross-section, as opposed, for example, to tapes formed of matted fibres.
• the tapes are cut with a blade from a roll of material. Normally what is done is to start with a roll whose width is equal to the desired length of the tapes, and cut it into lengths equal to the desired tape width.
• the tapes are quite thin. They might be as much as 500 ⁇ m in thickness, but would normally be less than 200 ⁇ m, and typically about 100 ⁇ m or 150 m.
• a flexible plastics tape formed using a plastics material, wherein at least one edge of the tape is rounded as viewed in cross-section and wherein the tape has a thickness not greater than that at which the said edge would be sharp if it were not rounded.
• the edges of the tape which have been cut are rounded.
• the tape typically has a thickness of less than 500 m, more typically less than 200//m, still more typically less than 150 m, and most typically of the order of 100//m.
• the invention further provides a sanitary article, for example a diaper, which comprises a fluid-absorbing body portion and at least one tape as just defined.
• a sanitary article for example a diaper
• closure tapes are cut from a roll by a cutting device, and conveyed to a point at which they are fixed in place on the diaper.
• at least one edge, and preferably both edges of the tapes have their sharpness reduced.
• One way of doing this is to arrange for the tapes to contact hot metallic surfaces during the above mentioned conveying process, so that they are softened or partially melted and thereby assume a curved shape as viewed in cross-section. Altematively, and this is preferred, the hot metallic surfaces are formed by the cutting device itself, which is kept at the desired elevated temperature.
• the plastics material of the tape must have a sufficiently low elongational viscosity to avoid the occurrence of lagging, a phenomenon in which the hot surface pulls filaments of material outwardly thereof and gives rise to an irregular surface.
• a low viscosity, and/or the maintenance of the material at a sufficiently high temperature for a sufficient length of time, also assists in ensuring that surface tension effects are able to produce the desired rounding of the edge.
• the rounding of the edges is achieved by directing hot air at the edges of the tape.
• air at 350 °C will produce the desired effect on a conventional polypropylene tape of a type normally used on diapers.
• the temperature of the hot surface with which the tape is contacted can be different depending on the polymer nature and structure, on the crystallinity fraction and on the process speed and so on the time of contact. Similar considerations apply where hot air is used to achieve rounding.
• the tape material is a polypropylene copolymer containing up to 10% of ethylene. This makes the material intrinsically softer, which itself helps in partially reducing the sharpness of the edges. Moreover this lowers the softening point and makes easier the application of the present invention.
• this copolymer is a random copolymer. These materials have a limited heat-shrinkability which helps the curving of edges without giving macroscopic distortion to the tape, helping the formation of rounded edges also in the zones which do not reach a level of temperature sufficient for softening or melting.
• MOPLEN EP2 C3OF is a random polypropylene copolymer containing 2% by weight of ethylene, and is available from HIMONT. At 100 °C it shrinks about 3%. Depending on the tape structure and process conditions, this level of shrinkage can be useful in the present invention.
• the degree of heat-shrinkage can be tailored to the desired level by properly formulating the polymer.
• the polypropylene with the compatible hydrogenated hydrocarbon resin ARKON P-125 available from ARAKAWA CO., it is possible to modify the behaviour as follows: % of resin in PP % of heat-shrinkage at 100 °C 0% 3%
• the invention can also be applied even where the plastics material has not significant heat shrinkability. In that case, however, the temperature at which the edges are treated needs to be sufficient to cause melting of the material, thus permitting surface tension to cause the necessary rounding.
• Figures 1 and 2 of the accompanying drawings are photomicrographs showing the edge of a polypropylene plastics film, of a type conventionally used for diapers, respectively before and after treatment with hot air at 350 °C.
• the film on which the treatment was carried out was coated on the side facing away from view with a Iayer of adhesive.
• Figure 2 the Iayer can be seen quite clearly.
• Figure 1 a broken line has been added to mark the boundary between the adhesive and the plastics material. Comparison of the two Figures clearly shows the rounding which is achieved. It is also noteworthy that it is found that the process does not adversely affect the adhesive.

Landscapes

• Health & Medical Sciences (AREA)
• Epidemiology (AREA)
• Engineering & Computer Science (AREA)
• Biomedical Technology (AREA)
• Heart & Thoracic Surgery (AREA)
• Vascular Medicine (AREA)
• Life Sciences & Earth Sciences (AREA)
• Animal Behavior & Ethology (AREA)
• General Health & Medical Sciences (AREA)
• Public Health (AREA)
• Veterinary Medicine (AREA)
• Chemical & Material Sciences (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Organic Chemistry (AREA)
• Absorbent Articles And Supports Therefor (AREA)
• Orthopedics, Nursing, And Contraception (AREA)
• Adhesive Tapes (AREA)

Priority Applications (1)

Applications Claiming Priority (4)

Publications (2)

Family

ID=8222005

Family Applications (1)

Country Status (7)

Families Citing this family (2)

Citations (1)

Family Cites Families (4)

• 1996
  • 1996-08-13 AU AU67241/96A patent/AU6724196A/en not_active Abandoned
  • 1996-08-13 MX MX9801206A patent/MX9801206A/es not_active IP Right Cessation
  • 1996-08-13 CA CA002228455A patent/CA2228455C/en not_active Expired - Fee Related
  • 1996-08-13 WO PCT/US1996/013144 patent/WO1997006764A1/en not_active Ceased
  • 1996-08-13 EP EP96927413A patent/EP0844860A4/de not_active Withdrawn
  • 1996-08-13 JP JP9509434A patent/JPH11511197A/ja active Pending
  • 1996-08-13 KR KR1019980701101A patent/KR19990036431A/ko not_active Ceased

Patent Citations (1)

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