DK146291B - Moisture-absorbing material consisting of multiple layers - Google Patents

Description

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(19) DENMARK

φ (12) PUBLICATION MANUAL od 146291 B

DIRECTORATE OF THE PATENT AND TRADEMARKET SYSTEM

(21) Patent Application No .: 0232/76 (51) Int.CI.3: A 61 F 13/00 (22) Filing Date: Jan 21, 1976 (41) Aim.Available: Jul 25, 1976 (44) Submitted: Aug 29, 1983 ( 86) International application no .: - (30) Priority: 24 Jan 1975 NL 7500874 (71) Applicant: TEVIC INTERNATIONAL BV; Neede, NL.

(72) Inventor: Wilhelmus Franclacus Johannes' Verbeeten; NL

(74) Plenipotentiary: International Patent Office (54) Multilayer moisture-absorbing material

The invention relates to a moisture-absorbing material comprising at least one moisture-resistant, moisture-permeable surface layer and below it a layer of moisture-absorbing material.

Such materials are known in advance in the form of bedding OQ patients to absorb body moisture, in the form of diapers, sanitary napkins and Γ · dressings such as tampons and wound patches.

O) ^ These materials serve to absorb body moisture, but lead, after (O ...

^ that they have absorbed a certain amount of moisture, to irritate the skin. Further, if used as a dressing, they may get stuck in the wounds. G As an example of such material it may be mentioned from French Patent Application no.

1,365,163 known menstrual bindings comprising a separate moisture-resistant, moisture-permeable surface layer containing synthetic fibers, e.g.

Polypropylene fibers, bonded to an adhesive such as starch, polyvinyl alcohol or a meltable resin, including a layer of moisture-absorbing material. Opposite to said surface layer is a moisture-impermeable layer which, when used, must be away from the wearer's body.

A further example is the menstrual pad known from French Patent 2,000,595 consisting of an absorbent pad, a layer of polypropylene fibers and a casing which is proposed to be made of cotton which may be made hydrophobic.

These known menstrual bandages are both afflicted with the aforementioned disadvantage that, after absorbing a certain amount of moisture, they cause skin irritation.

The present invention aims to solve this problem.

It has been found according to the invention that what is essential for avoiding said skin irritation and for a moisture-absorbing material not getting stuck in wounds is that the surface of the material consists of a material which exhibits a "retention" of less than 0.5%. This "retention", which is a well defined physical property, is the natural increase of the water content of a material, expressed as a percentage by weight, after total drying. To determine this material-dependent property, a standard test method is used.

The present invention, based on the foregoing disclosure, relates to a moisture-absorbing material consisting of several layers having at least one separate, moisture-resistant, moisture-permeable surface layer containing polypropylene fibers, and a layer of moisture-absorbing material and optionally having a moisture-impervious layer disposed thereon. from the moisture-permeable layer, especially for use as mattress covers, diapers, sanitary napkins and dressings, and the characteristic of the invention is that the moisture-permeable surface layer is a non-woven or woven fiber fabric. material consisting solely of polypropylene fibers and containing no binder, which material exhibits a retention of less than 0.5%, the layer being most closely associated with the other layer (s) in the edge region. Using such a surface layer in contact with the skin or wound, it is surprisingly found that there is no skin irritation and that this layer does not get stuck in the wound. However, although such woven or nonwoven fiber material sheds moisture, it does appear that under varying pressure or motion, moisture readily allows moisture to pass through to the moisture absorbent material to which traditional material such as cellulose in fiber or woven form and / or cotton wool can be used.

Said surface layer also exhibits high curl strength, thereby also minimizing mechanical irritation. As mentioned, the surface layer does not contain any binder; a binder will usually increase retention and may further adversely affect moisture permeability.

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A material which has obtained particularly favorable results is a nonwoven fibrous material or felt whose fibers have been felt by ultrasound.

The invention is described in greater detail below with reference to a drawing of a partially cut mattress cover to which the material according to the invention is used, for example.

In this drawing, on a moisture impervious substrate 1, e.g. of polyethylene film, applied several layers of nonwoven cellulose 2 and a further layer 3 ultrasonic treated nonwoven polypropylene nonwoven material; The latter layer 3 is slightly longer and wider than the layers of nonwoven cellulose material 2 and with the protruding edges is adhered to the substrate 1 all the way around by a suitable moisture-resistant adhesive. The adhesive seam 4 runs over the entire length and width of the mattress cover. The mattress cover is e.g. of the dimensions 0.90 x 2 m, while e.g. the base on both the long sides can be 30 cm longer, to form patches 5, which serve to hold the mattress cover on the mattress by securing it with safety pins or tucking it under the mattress. The moisture-permeable layer for this purpose usually has a weight of 25-45 g / m, which provides a sufficient strength and at the same time a sufficient moisture permeability.

Similarly, dressing material can be composed, in many cases then no moisture impermeable layer must be present. For the manufacture of patches, a similar structure can be used, as shown in the drawing, in that the patches of the substrate must then be provided with an adhesive on the side facing upwards. such bonding material, the moisture-permeable surface layer is preferably of a weight of 5-15 g / m.

For use as diapers and sanitary napkins, the moisture-permeable 2 surface layers are preferably of a weight of 15-25 g / m for the greater mechanical load relative to dressings, but less than for mattress covers.

Further, when used for obstetrical dressings or compressive dressings for wounds to be kept under pressure, a surface layer 2 2 having a weight of 30-80 g / m and especially from 40-60 g / m is preferably used. This layer is applied in application tightly over the wound while the absorbent portion of the material does not need to be kept under pressure so that its moisture absorption remains high and air can pass through almost unobstructed.

The moisture-absorbing layers can, of course, be connected locally to one another in a manner known per se and to the possible substrate. Further, instead of a certain number of layers of nonwoven cellulose material, another moisture-absorbent filling such as cotton wool or a single thick layer of cellulose fibers can be used.