DK148380B - INFLATABLE ITEMS MADE OF RUBBERED MATERIALS MATERIALS AND PROCEDURES FOR PRODUCING THEREOF - Google Patents

Description

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The invention relates to an inflatable article formed from rubberized material webs, in particular of rubberized textile or plastic material, such as an air mattress, pillow, hose boat or the like, and a method of making it.

The invention thus relates to a method for establishing a site-lasting, durable connection between rubberized material webs, of the kind used in the manufacture of inflatable articles, for example air mattresses, seat cushions, hose 2.

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boats, timber rafts, etc. or to fluid containers of the most diverse species. All such articles are usually made of webs of woven or resin fabric which, on the one hand, are provided with a layer of adhesive, rubber or the like, which with its rubberized sides are adhered to each other and which are only at the so-called seam places, ie. . at the periphery and at certain intermediate strips, are permanently interconnected using pressure and heat. Between the seams, there are no sticky surfaces that produce chambers to be filled with air or liquid. To prevent diffusion of the air or liquid outwardly, the rubber ring must necessarily extend over the entire surface of the material webs used. This creates considerable difficulties in fabrication, because it must be prevented that the material webs, which are on top of each other with their rubberization and which have not yet been vulcanized, also connect with each other outside the existing seams. For this purpose, the surface areas in question had to be heavily covered with powders such as, for example, talc. For this purpose, suitable templates and coverings were needed, which had to be imposed and again removed. In addition, great care had to be taken so that the powder layer was not damaged. Despite this, the fraction of bridges in the manufacturing was relatively large. Another known method, described in Austrian Patent No. 125,784, consisted of attaching pieces on the substrate, corresponding to the course of the seams, which in turn produced the connection between the two material webs. Also, it was necessary to firmly powder the surfaces of the material web between the connectors to prevent the two adjacent material webs within the connectors from adhering to each other. The disadvantages of this fabrication method include increased material e and labor supply for fabrication and placement of the connectors.

Also known from German Patent No. 821.715 is a process for the production of hollow bodies of elastic fabrics, in which, as separating layers, sheets of plastic or paper which are already precisely cut and which are punched in the areas where a connection must be made between the material webs. This is a very time consuming process and shows the disadvantage that the relatively rigid foils remain enclosed in the finished product and inhibit its use.

SUMMARY OF THE INVENTION It is an object of the invention to provide an inflatable article formed from rubberized material webs, of the kind set forth in the preamble of claim 1, which is cheaper than the prior art articles of this kind, and to a process for producing these articles which can be carried out more simply and cheaper than the known methods of this kind.

The inflatable article formed from rubberized material webs according to the invention is characterized by the characterizing part of claim 1. Surprisingly, it has been found that the arrangement of the specified nonwoven fabric causes the bridging portion to fall significantly during fabrication, thereby lowering the object.

Although the nonwoven material remains in the finished article, it has been found that it does not bother using the article.

The process according to the invention is characterized by the method of claim 2. This ensures that the rubberized material webs can be permanently connected to each other in certain places under the influence of pressure and heat without having to take into account the cumbersome dusting and labor-intensive attachment of connectors.

A particularly preferred embodiment of the method according to the invention is characterized by the characterizing part of claim 3. In practice, it has been found that this combination of surface weight of the nonwoven material, pressing temperature and pressing pressure gives rise to inflatable articles with excellent properties.

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According to the invention, a flexible, porous, flat material of textile fibers, which may, after prior reinforcement, be joined by mechanical means (for example, by sewing), by bonding by means of a binder, by starting solution, by welding, or by a combination of these methods. Such nonwoven fabrics consist of randomly interposed, thin, single fibers, and more specifically natural fibers (wool, cotton, etc.), semi-synthetic fibers (cellulose acetate fibers) or fully synthetic fibers (polyamide, polyester, polyacrylonitrile, polyethylene, PVC and polypropylene fibers).

Preferably, a very small thickness cellulose viscose web of the type commercially referred to as "Viledon" is used in the method of the invention. Its thickness corresponds to a weight of from approx. 25 to approx. 30 g per m. Conveniently, the fibrous web is applied to one of the two rubberized material webs to be joined together, and this, together with the nonwoven fabric, is applied immediately to the rubberized layer of the second material web, upon which the hot pressing of the seams is already done. The interlayer has two functions. First, it forms an effective separating agent between the loosely superposed, rubberized material surfaces, which prevents the undesirable, interstitial adhesion therebetween. Secondly, it is completely penetrated in the area corresponding to the hot pressing, that is, in the area of the seams and edges, completely of adhesive or rubbery material, thereby at the same time providing a considerable reinforcement of the seams and edges, whose tear strength is increased. Finally, due to the small thickness, the permeability and the random fiber structure of the nonwoven fabric, the density of the seams and edges is not affected.

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With particular advantage, a cellulose viscose web 50/50 (viscose and cellulose proportion) having a unit weight of about 50 is used. from approx. 2 to approx. 30 g / m, whereby the hot pressing in a manner known per se is carried out under a pressure of approx. 10 atm. overpressure and at 180 ° C.

A further, particularly advantageous method of making the inflatable articles is that the hot pressing of the material webs to be joined together continues for so long that the adhesive or rubber ring is pushed laterally from the area of the pressing tool to form a bead lying between the material webs and bridging the gap.

Thus, air-inflatable or other medium-filled articles according to the invention, such as air mattresses, pillows, hose boats or the like, or collapsible liquid containers, water beds, etc., may exhibit a bead formed by the adhesive or rubberization of the webs of material extending along the the seam or rim, which bridges the gap between the webs of material and is thereby tightly sealed.

The idea of the invention, which manifests itself in various embodiments, is illustrated in the drawing.

FIG. 1 shows a schematic drawing of an air mattress as a floor drawing.

FIG. 2 shows a perspective view of the material webs superimposed.

FIG. 3 shows a schematic representation of the pressing tool.

FIG. 4 shows a section through two rubberized and hot pressed material webs connected to each other.

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In the practice of the method according to the invention, material webs are used, for example textile webs 1, which on one side are provided with a rubber ring 2. These material webs, as can be seen in FIG. 2 - in a position where they are facing each other with their rubberization, laid on one another on a work table 3. A thin fibrous nonwoven fabric 4 of random, natural or artificial fibers or the like is introduced between the two material webs. This web 4 is, for example, a cellulose-viscose web sold under the designation "Viledon" and exhibiting a unit weight of from approx. 23 to approx.

30 g / m. This web extends over the full surface of the web and first forms a sub-layer which prevents the adhesion between the material which is not yet vulcanized.

Finally, in a heat press, the connection between the material webs 1, 2 passes through the nonwoven fabric 4 and also only in certain areas, as can be seen, for example, in the diagram of FIG.

1. This is achieved by using a heating press plate which corresponds to the image of FIG. 1, and showing protruding edge surfaces 5 as well as seam surfaces 6 or 7 and 8. The edges 5 and the seams 6 to 8 are arranged so that between these within the edges 5 are surface parts 9 within which there is no connection between the adjacent material webs.

When inflating the air mattress parts, the usual air chambers appear between the seams 6, 7 and 8 within the edges 5.

At the hot pressing that occurs at a pressure of approx. 10 atm. overpressure and a temperature of approx. 180 ° C, the rubberized material 2 penetrates the nonwoven fabric 4 in the region corresponding to the edges 3 and the seams 6, 7 and 8, thus establishing a close and intimate connection between the material webs.

On the other hand, the hot pressing is suitably continued between a metallic press plate 10 and a suitably of plywood consisting of plywood 11 to such an extent that the rubber ring 2 extends in a known manner in a lateral direction to a certain extent according to FIG. . 3 and 4, forming a bead 12 along the pressing surfaces, which bead bridges the gap between the material webs along the seams 6 or the edges 5. The rubberized material 2 adhering to the textile webs 1 exhibits a smooth transition with respect to the bead 12. This bead forms a fuse. against tearing the seams and replacing the commonly used folding strips for this purpose.

In FIG. 4, a section through a seam is shown, and one can easily see the bead 12 of adhesive material and rubber ring 2 and nonwoven material 4 which readily adhere to the rubber ring 2 of a material web.

It is sufficient when only one web of material is covered with nonwoven fabric 4 during processing. But of course, for simplifying reasons, both webs of material can exhibit a broad nonwoven fabric. It is clear from FIG. 4, that the rubber ring 2 in the area corresponding to the pressing tool is pressed through the nonwoven fabric 4 and that it is to some extent compressed or that part of the rubber ring is laterally pressed out to form the bead 12.

After the hot pressing, the manufactured article is vulcanized as usual, and the vulcanization is by air mattresses or the like. 20 minutes, the temperature is 140 ° C and the pressure is approx. 3 atm. overpressure.

Of course, press times, pressures temperatures, and vulcanization data must be adapted to the individual item to be manufactured.