Electrically heated textile sheet - of chemically metallised fibres

(74)

Holder: Same (71)

Agent: Cabinet J. Bonnet-Thirion, L. Robida & G. Foldès.

(54) Textile or fibrous product in the form of a sheet that can be heated electrically.

72) Invention of (33) (32) (3j) Conventional priority:

Sale of booklets at the IMPRIMERIE NATIONALE, 27, rue de la Convention - PARIS (15^e)

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The present invention relates to a flat or sheet-shaped textile or fibrous product which can be electrically heated and is intended for furnishing living and living rooms, bungalows, living tents, inflatable tents, ship cabins, vehicles , for example carpets, floor coverings, wall and ceiling coverings, mattresses, mats, etc., as well as electrically heatable lining fabrics, for example for protective clothing against the cold, shoes, gloves etc., felt shoes, boots etc., for airplane pilots, fishermen and other outdoor professions, as well as for therapeutic articles useful in medicine, for example for combating circulatory disorders and rheumatic pains and for shock treatments, etc.

Electrically heated floor coverings are known in which the heating takes place according to the principle of heating pads by means of conductive electric cable s. These articles usually form several covering layers. It is known for example to cover the heating wires of such products on both sides with plastic sheets and at the top with a fabric, and, above, with a fabric covered with a layer of polyvinyl chloride while below a covering layer of card sail under which is placed a fabric covered with a layer of polyvinyl chloride.

In addition, electrically conductive fabrics are known which, instead of electrically conductive cables, are equipped with small carbon (graphite) threads.

There are also known men's socks which contain a heating mini-pad at the end of the foot. There are also, for example, in this type of article, electrically heated ladies' stockings in which heat-conducting wires start from the edge of the stocking and end at the toe of the stocking reinforced by a metal trim.

In addition, it has already been proposed to extend to the field of clothing, for example by measures taken in the confection, arrangements which have already existed for a long time such as heating pads, heating blankets, etc.

The disadvantage of these electrically-operated heating articles is that they must be supplemented with heating metal wires, heating cords, heating strips, heating pads, or else with graphite wires used ex69 45048 exclusively to conduct the current. From the technical point of view of the process, these conductors cannot be incorporated in the manufacturing process of the web of textile material due to their foreign nature, but they require additional measures to manufacture or to complete these products, Compared to the products made up by non-conductive textile materials, they are distinguished by an entirely different appearance which manifests itself in a disadvantageous way, for example by a larger cross-section and a smaller surface, and/or by a lower flexibility and softness and/or by a greater hardness resulting in a smaller volume. This appearance of the above-mentioned conductive products, which differs greatly from that of textile products and their fibrous material elements, also leads to an increase in labor and production expenditure and in the cost price, because of the particular nature necessary for manufacture, including the need to isolate each of the elements separately, also because of the additional measures necessary for the insertion and for the juxtaposition as well as for the assembly not susceptible to displacement in and on the heating products with electrical heating whose essential elements are textile fibers which do not conduct electrical current.

These extremely different state forms between, on the one hand, the spatially non-distributable conductors mentioned above and, on the other hand, the voluminous sheet textile also necessarily have the disadvantage that these non-conductive textile fibers distributed along three dimensions on much larger surface areas receive only after a fairly long heating time and after a relatively strong rise in the temperature of the heating wires the surplus of heat necessary to be able to transmit it to the colder external environment and to come into action in an effective way. In addition, the inflexible and relatively brittle metal heating wires which cannot be distributed in all directions over the material panels have yet another serious disadvantage: due to their extremely different dimensions and hardness, they cannot, for example, yield by sinking into the interior of the floor trim when subjected to pressure stress and, due to violent local friction, they contribute to accelerating the wear of the textiles which cover them and

45048 to increase sensitivity to operating incidents, for example in the event of breakage by bending, by interruption of current, destruction of the insulating layer, etc.

The present invention eliminates the above defects by improving the quality and increasing the technical-economic efficiency of such electrically heated heating products by means of an entirely new construction.

The invention makes it possible to produce heated textile or fibrous products with electric heating in the field of upholstery and clothing textiles as well as for medical uses, the manufacture of which does not require a large expense, which can be used with little of energy, and which ensure high operating safety"

This result is obtained by the invention thanks to the fact that fibers or threads made of natural or synthetic polymers or cotton, metallized by a chemical process, are used as current-conducting elements, the fineness of the fiber or thread and the thickness of the applied metal layer which may vary depending on the intended purpose of use. It has been found that the ratio between the metal and the mass of yarn or fiber must be between 3/1000 and 400/1000 to obtain the values ​​of substance and structure of fiber or yarn that guarantee the processability on the known textile machines while allowing these conductors to be used as construction elements for manufacturing textile products in the form of a sheet. The above ratio is a function of the fineness of the fiber or yarn, the proportion of metallized fiber or yarn in the mixture of non-conductive textile products and the thickness of the metallic layer.

The invention makes it possible to distribute these conductors technologically in a largely independent manner over the surface and cross-section of the product and, thanks to this largely homogeneous conductor system, it allows a uniform and immediate distribution of heat in all dimensions. . In addition, the invention offers the advantage that, thanks to the uniform distribution in all directions of the fine conductors, there is no current interruption even in the event of partial destruction, which greatly reduces the sensitivity to incidents. operation and increases safety against the danger of short circuits.

In addition, thanks to the use of fibers or son metallized by chemical process, the invention fully retains the character

45048 textiles for heating products.

The characteristics and advantages of the present invention will become apparent from the description which will follow by way of example and from the tables 1 to 3 which are appended thereto.

According to the example chosen, the fine conductors or heating elements are obtained by chemical metallization of fibers, or plied or untwisted yarns, obtained from these fibers made of natural or synthetic polymers or of cotton. They are used either alone or, depending on the purpose of use, in a mixture with fibers and/or non-metallized, that is to say non-conductive, yarns.

These conductors or heating elements can be worked as constituent elements in the same way as non-metallized or non-conductive fibers and/or threads on known textile machines and can therefore be used for the manufacture of card webs, twisted threads, knits, fabrics. The different stages of work listed above of known textile manufacture clearly show that products having a characterized textile nature are obtained because there is no need to use materials of a foreign nature such as metal heating wires, etc. .

By varying the proportion of metallized fibers and/or threads, the fineness of the fiber or thread as well as the thickness of the applied metal layer, it is possible, for example, by treating sails and by varying the structure of veil, obtaining different layers of veil having a different electrical conductivity which can be insulated from each other, for example by interposing non-woven or other textile layers made of fibers or non-metallized threads, and therefore non-conductive. It is possible in this way, depending on the coupling, to mount different circuits which, when the heating voltage is applied, give rise to different thermal equilibrium temperatures in the areas concerned. The correlations in question are reproduced in Tables 1 to 3 by way of example.

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Table 1

Thermal equilibrium temperatures in *G, depending on the proportion of metallized fibers and the fiber fineness, under heating voltage of 42 v.

Percentage of fibers Fineness of metallized fibers 920 mtex (Nm 1100) 1700 mtex (Nm 600)

<td> 20</td><td> 51,7</td><td> 52,7</td>

<td> 50</td><td> 54,8</td><td> 57,8</td>

<td> 40</td><td> 44,4</td><td> 49,2</td>

<td> 50</td><td> 58,0</td><td> 72,1</td>

Table 2

Thermal equilibrium temperature in °C, depending on heating voltage, surface to mass ratio and metal layer

<td>Heating voltage (v) Mass/area ratio,</td><td> 42</td><td> 42</td><td> 65</td><td> 65</td>

<td>(gsm) Temperature d¹ thermal equilibrium for:</td><td> 145</td><td> 86</td><td> 145</td><td> 86</td>

<td>x % metallic layer</td><td> 58</td><td> 54</td><td> 58,1</td><td> 51,7</td>

<td>2x % metallic layer</td><td> 108,7</td><td> 57,7</td><td> 222,5</td><td> 94,0</td>

Table 5

<td colspan="4">Relationship between thermal equilibrium temperature and voltage</td>

<td colspan="3">of heating</td><td rowspan="2"> 65</td>

<td>Heating voltage in (v) 12</td><td> 24</td><td> 42</td>

<td>Thermal equilibrium temperature in °C 54</td><td> 58,5</td><td> 108,7</td><td> 222,5</td>

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