NL8901653A - Moisture-absorbent material - comprises two low density fibre layers compressed together and joined to each other - Google Patents

Abstract

Moisture-absorbent material such as sticking-plaster, incontinence pads etc., comprises an absorbent layer and one permeable to moisture joined to it. The first and absorbent layer is formed of fibres barely adhering together or not at all, and has a low density, while the second and permeable one is similarly constituted. These are placed together one above the other, compressed, and joined together over their entire surfaces.

Description

Method for manufacturing a moisture-absorbing product and product obtained therewith

The invention relates to a method for manufacturing a moisture-absorbing product, such as a wound plaster, an incontinence pad, upholstery for car seats and the like, comprising: - a moisture-absorbing layer, and - a moisture-permeable layer connected thereto.

Such a method is known.

A known method of this type is carried out in such a way that the moisture-absorbing layer and the moisture-permeable layer are each manufactured as a cloth in a separate production step, i.e. bringing the fibers together in such a way that they are joined together and have a certain mechanical strength. to own.

A drawback of a product obtained with this method is that it is composed of separate cloths, so that shrinkage differences can occur during washing treatments.

The object of the invention is to provide a method which makes it possible to save a production step, as a result of which the moisture-absorbing product can be manufactured more simply and therefore cheaper.

Another object of the invention is to provide a method by which a product can be obtained which does not exhibit the aforementioned shrinkage differences.

In this connection, the invention provides a method, characterized by the following steps: (1) providing a first layer of little or non-cohesive fibers of a material suitable for forming the moisture-absorbing layer, which first layer has a low density (2) providing a second layer of little or non-cohesive fibers of a material suitable for forming the moisture-permeable layer, the second layer having a low density, (3) superimposing the first and second layers, (4) compacting the two superimposed layers, and (5) joining the two layers together over substantially their entire surface.

A product obtained therewith can for instance be used as an incontinence pad in hospitals or nursing homes. When using such a product, the moisture-absorbing underlayer can be deposited on a moisture-proof and urine-resistant layer, which is placed on the mattress.

If desired, the method can be extended with the following step: (6) applying a moisture-proof coating on the outer surface of the first layer.

A product thus obtained, used as an incontinence pad, can be used without an additional waterproof backing.

The first and second layers can be so-called "webs", each composed of a number of even thinner layers, referred to as "webs." It is not necessary to discuss the method of manufacture thereof; it is known per se.

The necessary compaction and joining of both very few dense and loose layers 1 and 2 together can be performed by a mechanical operation, such as stitch bonding or needling. In the stitch bonding, both layers are sewn together by a yarn pattern spread over the entire surface. The spacing of the stitches should be chosen in view of the average (statistical) length of the fibers used, in order to obtain the desired fabric structure. In the needling, no yarn is used which provides the necessary cohesion and compaction, but fine barbed sharp needles are inserted through the layers, so that at the treated places the desired compaction and connection are obtained. The degree of compaction, and thus the density and thickness of the final product, can be within wide limits in both mechanical operations by suitable choice of densities, tensile strength in the yarns, the density of the needles, the number of stitches per centimeter, etc. etc. be chosen.

In addition to mechanical processing, a heat treatment can also serve to compact and bond both layers.

The product obtained by the method according to the invention can be washed and reused. To this end it is required that it can withstand a washing treatment with chemical agents and elevated temperature without wrinkling, warping and the like. Due to the cloth-like cohesion obtained with the method according to the invention, little can be feared for the aforementioned warping. Because the constituent layers are ultimately united into one cohesive cloth, uniform shrinkage occurs during washing. Nevertheless, depending on the application and the materials used, it may be advisable to subject the finished product to an anti-shrinkage treatment without, however, the moisture-proof coating on the outer surface of the first layer. For example, sanforization is eligible for this.

The first and second layers can be supplied intermittently in the form of custom-made webs. It is also possible to supply the first and the second layer continuously, for example from a manufacturing device or a supply roll, and to connect and compact the superimposed layers in a continuous process. Optionally after storage on a supply roll, or also in the same production run, if desired, the moisture-proof coating can be applied to the outer surface of the first layer.

In addition to the method for manufacturing a moisture-absorbing product, the invention is also directed to this product itself.

For a particular application, this product may be characterized by a moisture-proof foam layer applied to the outer surface of the first layer. In addition to incontinence pads, this application can also serve, for example, for the manufacture of insoles in shoes. As further applications, consider car seat covers, nursing home chairs where the washability of the removable covers is required, sleeping bags, incontinence briefs, and further applications of moisture absorbing products.

A waterproof coating can consist of a polyurethane film or film. The watertight foam layer can consist mainly of polyethylene. Polyurethane has the advantage of good temperature resistance, good washability and good urine resistance. Polyethylene also has the advantage of having a closed cell structure, which ensures good resilient compressibility and good thermal insulation properties.

The moisture-permeable cover layer can for instance consist of polypropylene, polyester or other suitable fiber material. For applications in which the products come into contact with the skin, it may be important that the moisture-permeable layer is skin-friendly and has a very low reprise, i.e. has a low moisture-retaining capacity. This achieves for medical applications that symptoms such as pressure ulcers (bedsores) can be largely prevented. Generally, a synthetic material such as polyester or polyamide will be chosen for the coating. For general applications some suitable material can also be used.

The moisture-absorbing layer can consist of another suitable material, for example a natural fiber material, such as cellulose fiber, such as viscose, cotton or also wool. Polyester yarns can be used for bonding the two layers together.

The invention will now be elucidated with reference to the annexed drawings. Herein the figures 5 show schematic cross-sections through products of different type.

Fig. 1 shows a product 1 comprising a top layer 2 and a moisture absorbing layer 3. The layers 2 and 3 are joined together by schematically indicated yarn 4. The layer 2 consists of polypropylene or polyester with a density of about 180 grams per m2. The layer 3 consists of viscose with a density of approximately 270 grams per m2, while the yarns 4 consist of polyester.

Fig. 2 shows a product 5 which differs from the product 1 according to fig. 1 in that the outer surface of the moisture-absorbing layer 3 is provided with a moisture-proof covering layer 6.

Fig. 3 shows a product 7 in which the outer surface of the moisture-absorbing layer 3 is provided with a moisture-proof foam-plastic layer 8. The layers 2 and 3 are in this case not connected by yarns 4, but thermally connected and compacted.

Fig. 4 shows a product 9, in which the outer surface of the absorbent layer 3 is covered by a polypropylene or polyester protective layer 12, which can serve, for example, for moisture removal.

Fig. 5 shows a product 10, the outer surface of the moisture-absorbing layer 3 of which is provided with a moisture-proof covering layer 6, while the outer surface of the moisture-permeable layer 2 is provided with a coating layer 11. This coating layer can serve, for example, an aesthetic purpose, as a result of which the product 10 is suitable for use as a cover for car seats or the like.

It will be clear that the exemplary embodiments 1, 5, 7, 9, 10 according to the above-described figures 1-5 are only examples and that many variants and combinations are possible within the scope of the invention. It is also pointed out that the joining together and the compacting of the two layers of moisture-absorbing and moisture-permeable material can not only take place by stitch bonding, needling or by thermal means, but that combinations of these techniques are also possible.

The choice of materials depends on the intended use of the finished product. For example, the coating layer 11 of the product 10 should be resistant to long-term use and have high wear resistance. For medical applications, for example, it is required that the moisture-permeable layer itself remains as dry as possible, while at the same time demands are made on the flexibility.

The industrial washability of the product according to the invention is of great importance.

If desired, an antibacterial agent can be applied to the fiber material. This layer must remain unaffected during wash treatment.

Claims (10)

A method for manufacturing a moisture absorbent product, such as a wound plaster, an incontinence pad, car seat upholstery and the like, comprising: a moisture absorbing layer, and an associated moisture permeable layer, characterized by the following steps: (1) providing a first layer of few or non-cohesive fibers of a material suitable for forming the moisture-absorbing layer, which first layer has a low density, (2) providing a second layer of few or non-cohesive fibers of a for forming of the moisture-permeable layer of suitable material, which second layer has a low density, (3) superimposing the first and second layers, (4) compacting the two superimposed layers, and (5) joining the two layers together over substantially their entire surface. Method according to claim 1, characterized by the following step: (6) applying a moisture-proof coating on the outer surface of the first layer. Process according to either of Claims 1 and 2, characterized in that step (4) and / or step (5) is performed by a mechanical operation. Method according to claim 3, characterized in that the mechanical processing is stitch bonding. Method according to claim 3, characterized in that the mechanical processing is needle-punched. Process according to either of Claims 1 and 2, characterized in that step (4) and / or step (5) is carried out by a heat treatment. A method according to claim 2, characterized by the following step, prior to step (6): subjecting the product to an anti-shrinking treatment, such as sanforization. A method according to any one of the preceding claims, characterized in that step (1) and step (2) are carried out by continuously supplying the first and second layers respectively, for example from a manufacturing device or a supply roll. Moisture-absorbing product obtained by a method according to any one of the preceding claims. Moisture-absorbing product according to claim 9, obtained by the method according to claim 2, characterized by a layer of foam applied to the outer surface of the first layer.