ITMI930939A1 - COMPOSITE FABRIC FORMED FROM SIMPLE YARN OR TWISTED YARN OF CONVENTIONAL FIBER TEXTILE INTERCALATED AS A CROSSBAR FROM SIMPLE YARN OR TWISTED YARN AT LEAST PARTIALLY MIXED WITH A CARBON FILAMENT, HAVING PROPERTIES CONTACT - Google Patents

Description

"Composite fabric consisting of single yarns or twisted yarns of conventional textile fibers interspersed in a lattice-like manner from single yarns or twisted yarns at least partially mixed with a carbon filament, having shielding properties against electromagnetic waves",

DESCRIPTION

The present invention relates to a composite fabric formed by simple yarns or by twisted yarns of conventional textile fibers of any type and count, in the warp and weft of which, according to predetermined alternation ratios and with an orthogonal reticular arrangement, simple yarns or twisted yarns are at least partially mixed with a carbon filament. In the context of this description the term "carbon filament"? used to designate a carbon filament consisting of one or more? leaders.

Purpose of the invention? was that of creating a fabric that, while maintaining the best possible qualities of appearance and moldability, presented properties? shielding from the fields of electromagnetic waves originating from the presence of alternating currents.

According to the invention, the proposed purpose? achieved by inserting, in a predetermined way, with an orthogonal lattice arrangement and according to determined ratios not necessarily equal in the warp and weft, one or more? single yarns or twisted yarns mixed, at least in part, with a carbon filament, said single or twisted yarns being interleaved with the single yarns or twisted yarns of the basic fiber or fibers of the fabric.

A fabric of only carbon filaments arranged in warp and weft and therefore with an alternation ratio of 1: 1,? was subjected to screening tests of an electromagnetic field at the frequency of 60 Hz of the United States power distribution network.

The measurements, carried out in a laboratory of the National Bureau of Standards (NBS) in Gaithersburg (USA), in an electromagnetic field generated between two parallel planes, showed an average shielding factor of 30 dB using a single layer of this fabric as a shield. and a further decrease of 45% with two layers of said fabric.

Similar measurements were carried out in Italy, on a layer of the same fabric made up entirely of carbon filaments, at a public laboratory using a TEM (Transverse Electromagnetic Mode) cell which allows to create a plane wave electromagnetic field, perpendicular to the affected surface. With said cell, placed inside an anechoic chamber to cancel reflective effects that can affect the accuracy of the measurements,? A shielding of the electric field with a factor of 32 dB at a frequency of 50 Hz was highlighted, perfectly in line with the NBS measurements. This shielding factor drops to 2.5 at the frequency of 105 Hz and to 1.4 at the frequency of 10 ^ Hz, while at very high frequencies of 103 or 10-LA Hz the shield almost completely disappears, the latter frequencies being presented for example from microwave ovens.

A fabric of this type, bench? the carbon filaments are endowed with lightness and flexibility? comparable to yarns or plies of ordinary natural or synthetic textile fibers with a finer count? end, it might be suitable for the packaging of traditional clothing at the expense of? of appearance, of workability? and cost.

By thinning out the insertion of carbon filaments within certain proportions, coupled with simple yarns or twisted yarns of the prevailing fiber or fibers of the base fabric, and then intercalating these mixed elements according to suitable alternation ratios included in a range of proportionality? from 1: 2 to 1: 100 in order to form an orthogonal lattice in fabrics with any type of weave, fabrics have been obtained with an appearance and softness to the touch unchanged compared to the original one. No problem ? emerged in the workability? to the loom during weaving, n? in tailoring, while the increase in cost? very small result.

A sample of such fabrics according to the invention? was subjected to screening measurements of the electromagnetic field, at the same Italian public laboratory, previously mentioned.

The results of the measurements carried out at a frequency of 50 Hz, on a layer of fabric having a "batavia" weave, that is to say with the weft passing alternately twice over and twice under the warp, are reported below. In this case, a single wool yarn mixed with a carbon filament was inserted into the fabric with a 1: 9 ratio, both in the warp and in the weft, every eight simple wool yarns of the base fabric. The yarn mixed with the carbon filament therefore formed, in this case, an orthogonal lattice symmetrical in both directions, with the appearance of a square mesh net.

The attenuation of an electric field artificially reproduced in the laboratory? highlighted by the following values:

- Electric field in the absence of the sample

E1 - 463 V / m

- Electric field in the presence of a sample layer

E2 = 2.8 V / m.

- E1 / E2 ratio = 165.3

corresponding to an attenuation factor of 44.3 dB.

The attenuation of the electric field? was then evaluated outdoors in the vicinity? of a high voltage line, always at a frequency of 50 Hz, by arranging the same fabric according to the invention on a dielectric support allowing the insertion of the measurement probe inside it, thus realizing a complete shielding of the probe with respect to the external electric field. The electric field values E'1 and E'2 detected respectively without the tissue and in the presence of the same were:

It is 1 = 6000 V / m

It is 2 = 32 V / m

E11 / E12 ratio = 187.5

corresponding to an attenuation factor of 45.4 dB.

The attenuation in the open field confirms the validity? of the shield found in the laboratory in the TEM cell.

The results of the fabric according to the invention, equal to or better than samples of totally carbon fiber fabric seem to be due to the orthogonal lattice arrangement of the carbon filaments, which thus constitute a kind of cage or net fixed in the body. of the fabric itself.

The meshes of the net do not necessarily have to have equal sides, that is to say they can have a rectangular shape, instead of having the same shape. square, with the longer side extended in the direction of the warp or weft.

The alternation ratio of simple yarns or mixed twisted yarns to one or more? carbon fibers? variable based on the weight / square meter of the fabric and therefore? dependent on the count of the basic yarns, simple or twisted, from which the fabric itself? format, and? included in the range of values, already? mentioned, from 1: 2 to 1: 100.

Just by way of example, the preferential range of variability? of the alternation ratio in a fabric made up of two-ply twisted yarn of wool base fiber with a count of 2/80 equal to a total of 250 dTex? ranging from 1: 3 to 1:16; for a title 2/150 equal to 133 dTex overall, lower than the previous one, can? preferably vary from 1:16 to 1:25; for a 1/14 titer equal to 715 dTex preferably from 1: 2 to 1: 8; for a 2/200 titer equal to a total of 100 dTex, preferably from 1:20 to 1:40; for a 2/300 titer equal to 66 dTex overall, preferably from 1:35 to 1:70.

Further details of the present invention will become evident from the following description which refers to some embodiments of composite fabrics, given by way of non-limiting example, illustrated in the attached drawings, in which

Figure 1 schematically represents a fabric consisting of simple yarns or twisted yarns of wool or any other fiber, arranged with a plain weave, in which they are interleaved, with an orthogonal warp / weft reticular scheme and with a symmetrical alternation ratio of 1:10, elements formed from a single or twisted yarn of wool or any other fiber mixed with a carbon filament, any nine single or twisted yarns of wool or any other fiber;

figure 2 schematically represents a fabric consisting of simple yarns or twisted yarns of wool or any other fiber, in a "twill" weave in which they are interleaved, with an orthogonal warp / weft reticular scheme and with a symmetrical 1:12 alternation ratio according to the the warp and the weft themselves, elements formed by a single yarn or twisted yarn of wool or any other fiber mixed with a carbon filament for every eleven single or twisted yarns of wool or any other fiber;

Figure 3 schematically represents a fabric having as a base simple or twisted yarns of wool or any other fiber with "batavia" weave, in which they are interspersed, with an orthogonal symmetrical reticular pattern, with an alternation ratio 1: 9 according to the warp and the weft, elements consisting of a single or twisted wool yarn mixed with one carbon filament for every eight single or twisted yarns of wool or any other fiber; And

Figure 4 schematically represents a fabric consisting of simple yarns or twisted yarns also formed by fibers of a different nature, arranged with a "batavia" weave, in which they are interspersed with an asymmetrical orthogonal reticular pattern, i.e. a different alternation ratio according to the warp and the weft, elements formed by a simple yarn or a twisted yarn, also comprising fibers of different nature, mixed with a carbon filament.

With reference to the figures, the elements constituting the weave of any type of fabric are indicated respectively with the symbol of a warp stitch and with a circle in the weft when they are formed by the prevailing fiber or fibers constituting the base of the fabric itself, while the same symbols with a superimposed cross indicate the same elements mixed, at least in part, with one or more? carbon filaments.

The figures represent one of the surfaces of the fabric, i.e. the warp or weft elements visible, for example, on the obverse of the fabric itself.

In fabrics, the type of base fiber can? vary in the whole field of natural, artificial or synthetic fibers known, such as wool, cotton, linen, hemp, rayon, Terilene, Nylon and so on? away, even mixed together; the weave, that is the crossing arrangement of the weft with respect to the warp, can? be any, from the pi? simple or "plain weave", to other pi? complex such as those called in the weaving technique as "batavia weave", "twill weave", "satin weave" and so on? Street.

In the most? general, the simple yarns or the twisted yarns, two or more? garments, of the various basic fibers can be of any title, while the title of the carbon filament, generally very thin, varies at most in a range between 20 and 70 dTex.

In the various figures, so? as they appear in the accompanying drawings, 1 1 warp? arranged vertically and the plot horizontally.

Figure 1 illustrates in this case, by way of example, a fabric according to the invention consisting of simple wool yarns both in the warp and in the weft, arranged with a plain weave, in which each warp and weft element passes repetitively alternately above and below the respective warp and weft element.

In this fabric? inserted, both in the warp and in the weft, a mixed yarn consisting of a simple wool yarn twisted with a carbon filament, with a recurring alternation ratio of 1:10, i.e. a yarn with a carbon filament as above specified every nine single pure wool yarns. In this case, each simple wool yarn has a count of 250 dTex, the carbon filament a count of 27 dTex.

Another example among the many that can be imagined by varying the nature and the count of the basic yarn, simple or twisted, of the fabric, the type of weave, the alternation ratio of the mixed elements with carbon filament? shown in Figure 2.

In this figure? indicated a woolen fabric formed by a two-ply yarn or twisted 2/80 (altogether 250 dTex) in the warp and a simple weft yarn of the same overall count, alternation ratio 1:12, symmetrical according to the warp and the weft, "twill" weave in which the weft passes repeatedly under two warp elements and above only one. The mixed element? consisting of a simple wool yarn twisted with a carbon filament of count 30 dTex per weft and a two-ply wool yarn twisted in turn with a carbon filament of 30 dTex for the Ordito.

In Figure 3? indicated, by way of example, a fabric according to the invention having as base fiber the wool and "batavia" weave in which each warp and weft element passes alternately twice above and twice below the respective weft element and warp.

In the fabric of the same armor, the subject of the shielding tests of the magnetic field in the laboratory and outdoors already? do you mention,? "inserted with a symmetrical orthogonal reticular pattern and with the same 1: 9 alternation ratio in the warp and weft, a mixed element consisting of two simple wool yarns twisted with a carbon filament in the warp and a mixed element consisting of a yarn simple wool twisted with a carbon filament, in the weft.

In Figure 4? indicated in this case, by way of example, a fabric consisting of twisted yarns of two fibers of different nature arranged with a "batavia" weave already? defined in the example of figure 3, in which mixed elements with carbon filament are interspersed with an orthogonal reticular scheme, precisely with an alternation ratio of 1:12 in the warp and 1:16 in the weft, i.e. one every 11 twisted yarns of two different fibers in the warp and one every 15 twisted as above, in the sense of the weft.

The basic elements of the fabric are two-ply twisted yarns, one being a simple wool yarn and one being Terylene. The mixed elements contain a carbon filament with a title of 27 dTex, twisted to the simple filament of wool, in turn twisted to the simple filament of Terylene.

The orthogonal pattern of the lattice formed by the said yarns twisted to a carbon filament forms, in this case, rectangular meshes with the longer side according to the warp direction, instead of? square-shaped meshes as in the previous figures.

In the fabrics mentioned in the figures, any simple yarn of the basic fiber, in the case of wool, can vary from a count of 60 dTex to 250 dTex as a simple yarn and, as a yarn twisted to two or more? garments, from 150 to 700 dTex while the carbon filament joined to a simple yarn or to a twisted yarn of the basic fiber or fibers of the fabric, preferably varies between 20 and 40 dTex.

How already? mentioned, the alternation ratio of simple yarns or twisted yarns mixed with a carbon filament can? vary between the values from 1: 2 to 1: 100 preferably in the range from 1: 3 to 1:70.

What has been said in general also applies to fabrics in which the basic fiber is different from wool, in the field of all natural, artificial or synthetic fibers and also to fabrics formed not by a single homogeneous fiber of any type but also to fabrics with basic fibers mixed in the many possible combinations of two or more different types, in the most? various types of armor.

For the properties? surprisingly demonstrated with regard to shielding from electromagnetic fields, induced by any source in the frequency range particularly between 50 and 1000 Hz, the fabric according to the invention acquires real qualities. ecological type.

Bench? the invention has been particularly illustrated and described with reference to preferred embodiments, those skilled in the art will understand that various changes in shapes and details can be made without departing from the scope of the invention as defined by the appended claims.

Claims (7)

RESELL CATIONS 1. Composite fabric for the preparation of packaged products, in particular garments, consisting of warp and weft threads, however intersecting in the weave pattern, said threads being formed by simple yarns or by yarns twisted in two or more. single yarn garments of any type of natural, artificial or synthetic fiber, characterized by the fact that in the warp and weft of the base fabric, simple yarns or twisted yarns at least partially mixed with a filament of carbon so that said carbon filament forms in the fabric an orthogonal lattice similar to a network constituting a shield against electromagnetic fields induced by alternating currents, particularly in the range of frequencies from 50 to 1000 Hz. 2. Fabric according to claim 1 characterized in that said simple yarns or twisted yarns at least partially mixed with a carbon filament are interleaved in the alternation ratio from 1: 2 to 1: 100 in the warp and weft of the fabric, preferably in the ratio from 1: 3 to 1:70, i.e. a simple yarn or a twisted yarn coupled with a carbon filament from one every one to one every ninety-nine, preferably one every two to one every sixty? nine single yarns or twisted yarns of the basic fiber constituting the fabric. 3. Fabric according to claims 1 and 2, characterized in that the carbon filament has a titer in the range from 20 to 70 dTex, preferably from 20 to 40 dTex. 4. Fabric according to claims 1 to 3, characterized in that said simple yarns or twisted yarns at least partially coupled with a carbon filament are interleaved according to equal alternation ratios in the warp and weft of the base fabric. 5. Fabric according to claims 1 to 3, characterized in that said simple yarns or twisted yarns at least partially coupled with a carbon filament are interleaved according to different alternation ratios in the warp and weft of the base fabric. 6. Fabric according to one or more? of claims 1 to 5, characterized in that the base fabric? consisting of simple yarns or homogeneous twisted yarns included in the field of traditional natural, artificial or synthetic fibers, or even two or more? of such fibers of different types, in the warp and in the weft, to which simple yarns or twisted yarns are interleaved with said simple yarns or twisted yarns coupled to a carbon filament. 7. Fabric according to one or more? of claims 1 to 5, characterized in that in the case of a wool base fabric, the simple wool yarns have a count between 60 and 250 dTex, while the twisted wool yarns have a count between 150 and 700 dTex .