FR2565608A1 - Process for obtaining a ribbed fabric from a raw fabric for the production of a velvet - Google Patents

Abstract

Process for obtaining a fabric with ribs or with regular and irregular designs from a raw fabric, semifinished or finished, intended for the production of a velvet using weft, warp or ridge beam or with regular and irregular designs. The process consists in performing a first stage of impregnation with a chemical substance, which is followed by a second stage of heating (carbonising), followed by a third and fourth stage of washing and finishing respectively.

Description

 The subject of the present invention is a process for obtaining a regular or irregular ribbed or drawn fabric from a semi-finished or finished raw fabric intended for the production of a pile by warp, woven, or woven weft. or with regular and irregular designs.

 In the process of obtaining a pile by weft, one of the most expensive operating phases is that of cutting the ribs which is carried out on complex and expensive machines. Once this cut has been made, and after washing and finishing, the fabric takes on the final appearance of a fabric with regular ribs, more or less high and more or less wide depending on the weaving parameters used.

 Velvet would surely have a wider market if its short could be reduced and if it were possible to vary its external appearance. More particularly, a reduction in the cost prices could be achieved by avoiding the rectilinear cutting operation of the ridges by mechanical means, which would also make it possible to modify the external appearance of the product.

 The aim of the present invention is to establish a process for obtaining a fabric which uses a chemical method, rather than a mechanical one, to produce regular or irregular dimensions or patterns thereon.

 This object, as well as others targeted by the invention, are achieved in the manner which emerges from the description below.

 The process according to the invention, for obtaining a ribbed or regular and irregular pattern fabric starting from a semi-fine or finished raw fabric intended for the production of a pile, weft, ribbed or woven or with regular or irregular patterns, is characterized in that a first phase of impregnation with a chemical substance is carried out, which is followed by a second heating phase (carbonization), then a third washing and removal of charred wires, and a fourth finishing.

The process according to the invention will be better understood during the description which follows, given with reference to the appended drawings, in which
Fig. 1 shows the location of a piece of fabric used as raw or semi-finished fabric to make a classic weft velvet.

Fig. 2 shows the location of the piece of fabric in fig. 1 after surface impregnation and carbonization treatments
Fig. 3 is a view of the fabric according to the invention in its final condition, this view showing by way of example various designs or patterns which can thus be produced
Fig. 4 shows the place of a finished piece of velvet, subsequently treated by the method according to the invention.

 To obtain the fabric according to the invention, one starts with a semi-finished or finished raw fabric, intended for the production of a pile by weft (see fig. 1), made on a conventional loom.

 This fabric is obtained in the usual way by means of a warp thread made of pure cotton or mixed according to various percentages with synthetic fibers such as polyester, nylon and others, for example.

 The title of said thread is variable so as to determine a thread density between 24 and 36 threads / linear centimeter.

The weft yarn has, on its side, a variable titer and in this case also it can be made of pure cotton or else blended, according to various percentages, with synthetic fibers such as polyester,
Nylon and others, which gives a thread capable of being woven at the rate of 40 to 54 beating strokes per minute.

2
The semi-finished product thus obtained has a weight varying from 100 to 600 g / m
It is obvious that the above values, relating to warp threads, weft threads, and to the weight of the semi-finished or finished raw fabric which results therefrom, are optimal values capable of ensuring the best results in the implementation of the process which is the subject of the present invention.

 A semi-finished or finished raw fabric having the characteristics just mentioned, can be bleached or not, depending on the aesthetic requirements, by a bleaching or dyeing operation.

This fabric is then subjected to a surface impregnation operation on a rotary flat or vertical press, the rollers of which have been coated with a chemical substance having the following composition per kilogram.
White glycerin 20 to 200 g
Tartaric acid 1 to 50 g
Idrofil M (Sulfosuccinate
non-ionogenic sodium) 1 to 50 g
Thickener 6 to 900 g
Sodium bisulphite 2 to 900 g
Water 1 to 900 g
This substance is spread like ink on the right side of the fabric by the printing rollers in an amount of approximately 100 g / m2 of fabric.

 Amounts above or below this value result in excessive or insufficient effects.

 The press roller, which is a conventional printing roller as already mentioned, can have any protrusions on its face, taking account, however, of the fact that these protrusions, describing the impregnation geometry, condition the orientation of the ribs to get.

 The fabric treated as above is subjected to a charring operation which consists in subjecting it, in a tunnel oven or by means of rollers, to a temperature of 80 to 2200C for a time varying, according to an inverse law, from 5 minutes to 30 seconds.

 At the end of this heating, the fabric takes on a brownish or, in any case, darker color in the regions where the chemical has been deposited.

 The aspect taken by the fabric is that visible in fig. 2.

 The darker areas, designated by A, are those having been impregnated with the chemical compound deposited by the press roller which is of course provided with projections of similar geometry.

 The subsequent heating activates the chemical spread on the fabric which attacks the cellulose thereof at the places where said substance has been deposited.

 The fabric is then subjected to washing in an alkaline solution of water added with hydrogen peroxide and soda, which breaks and detaches the threads which have been chemically attacked and charred, thereby freeing the ribs.

 It is understood that this washing can be carried out on the fabric either deployed or wound (in rope), without this in any way changing the final effect obtained.

 The process is completed by a finishing treatment.

We obtain the finished fabric shown in fig. 3 where the dimensions reproduce in broad lines the irregular orientation of carbonization
Frequent.

 According to a variant also falling within the scope of the present invention, it is possible to obtain the same fabric from a pile fabric in a final form, which is subjected to impregnation, carbonization, washing and finishing according to the same methods as those provided above.

 The fabric thus obtained is illustrated in fig. 4.

 In this variant of the process, use is usually made of a velvet of a different type from the previous one so that one can recycle a product which would otherwise be difficult to sell on the market.

 It should moreover be understood that the above description has been given only by way of example and that it in no way limits the field of the invention from which one would not depart by replacing the execution details described by all other equivalents.

Claims (4)

 1. Process for obtaining a ribbed or regular and irregular pattern fabric from a semi-finished or finished raw fabric for the production of a ribbed or woven weft or regular and irregular pattern velvet , characterized in that a first phase of impregnation with a chemical substance is carried out, followed by a second heating phase (carbonization), then a third washing and removal of carbonized son, and a fourth finishing.  2. Method according to claim 1, characterized in that the first impregnation phase is carried out on a conventional machine for printing fabrics, in that the chemical impregnation substance has the following composition per kilogram White glycerin 20 to 200 g Tartaric acid 1 to 50 g Idrofil M (sulfosuccinate  non-ionogenic sodium) 1 to 50 g Thickener 6 to 900 g Sodium bisulphite 2 to 900 g Water 1 to 900 g  2 and in that the optimal rate of impregnation per m of tissue is approximately 100 g of chemical substance.  3. Method according to claim 1, characterized in that the second heating phase (carbonization) is carried out at a temperature of 80 to 2200C for a time varying from 5 minutes to 30 seconds, in inverse proportion to the temperature.  4. Method according to claim 1, characterized in that the third washing phase is carried out using an alkaline solution of water added with hydrogen peroxide and sodium hydroxide which has the effect of breaking and detaching the chemically attacked wires.