| JP08325869 | SPECIAL HETEROGENEOUSLY SHRINKABLE BLENDED POLYESTER YARN |
| JP2002088663 | HETEROCOLOR CARPET |
| JP04091237 | PRODUCTION OF SILK WOOL-LIKE COMBINED FILAMENT YARN |
FRIGNANI, Alberto (Strada Cantone Ramella Gall, 82Fraz. Vandorno, Biella, I-13900, IT)
G.T.I.S.P.A. - GRUPPO TESSILE INDUSTRIALE (Strada Trossi 57, Verrone, I-13871, IT)
GHERARDI, Claudio (Via Cuzzi Giuseppe 12, Milano, I-20155, IT)
FRIGNANI, Alberto (Strada Cantone Ramella Gall, 82Fraz. Vandorno, Biella, I-13900, IT)
CLAIMS
1. Process for making a fabric by a first thread comprising natural and/or artificial and/or synthetic and/or mineral fibres, either pure or mixed with each other, consisting in making a third thread by twisting the first thread with the second thread made of fibres soluble in an environment wherein the first thread is not soluble, weaving the third thread making a fabric and then, immersing the fabric in a bath for dissolving the second fibres and obtaining the fabric composed of the first fibres only, after that acetic acid is added for imparting an acid PH to the bath and then the bath is heated, characterised in that the acetic acid is added to obtain a bath with a PH equal to about PH 5.5, and in that the bath is warmed to a temperature of 50 0 C ± 10%.
2. Process according to claim 1 or 2, characterised in that the soluble fibres consist of water soluble fibres such as alginate or polyvinyl alcohol or PVA fibres that are soluble in aqueous solution.
3. Process according to one or more of the previous claims, characterised in that the ratio between fabric weight and bath weight is less than 1:25 and preferably equal to about 1 :30.
4. Process according to one or more of the previous claims, characterised in that the fabric is then left to spin in the bath for a period of about 30 minutes ±10%.
5. Process according to one or more of the previous claims, characterised in that at the end of the dissolution of the second fibres in the bath, the bath is cooled with the input of cold water and drained.
6. Process according to one or more of the previous claims, characterised in that after the bath, the fabric is subject to a first wash with purified water having a temperature of about 40 0 C ± 10%, preferably for a period of about 10 minutes ± 10%.
7. Process according to one or more of the previous claims, characterised in that once the first wash has been carried put, more washes are carried out with cold purified water.
8. Process according to one or more of the previous claims, characterised in that said first thread is a coloured thread.
9. Process according to one or more of the previous claims, characterised in that said first thread is a thread of a natural colour.
10. Fabric made by threads of natural and/or artificial and/or synthetic and/or mineral fibres, either pure or mixed with each other, characterised in that it is made by a process according to one or more of claims 1-9. |
"PROCESS FOR MAKING A FABRIC AND FABRIC THUS MADE"
Description of a patent for invention in the name of:
1) GHERTEX S.R.L- 20020 Cesate (Mi) 2) G.T.I. SPA - GRUPPO TESSILE INDUSTRIALE - 13871 Verrone (BI)
The present invention relates to a process for making a fabric and to a fabric thus made.
In particular, the present finding relates to fabrics made of vicuna, cashmere, alpaca, silk, wool, cotton, hemp and fibres in general, natural and/or artificial and/or synthetic and/or mineral, either pure or mixed with each other, which due to the limited sizes thereof (i.e., they are very thin fibres that have a very high metric number, that is, ratio between thread length and weight) cannot be woven or during the weaving, tend to break up.
By fabric it is meant both the fabric made with a shuttle machine and the fabric made with a knitting machine, either circular or rectilinear.
As is known, when fabrics are to be made using very thin fibres (for example one of the indicated fibres), the fibres are alternately woven alone, or together with soluble fibres.
In the first case, very thin fabrics are made; however, such processes have very high costs since the fibres have a poor resistance and are difficult to weave.
In the second case, a thread consisting of the desired fibre twisted with a soluble thread is used.
The twisted thread is woven making a fabric that is immersed in a solution suitable for dissolving the soluble fibres so as to obtain the fabric made of the desired fine fibre only.
Traditionally, after having woven the thread, the fabric is immersed in a cold water bath with a bath ratio (that is, ratio between fabric weight and water weight) equal to about 1 :50.
Afterwards, acetic acid is added to bring the solution to a PH equal to about PH 4-4.5 and then the bath is warmed and brought to the process temperature of about 85-90 0 C, for a period of about 30 minutes.
However, traditional process methods exhibit some drawbacks.
In the case of a fabric of a natural colour, when very thin threads are processed that are composed of many very thin fibres (that have a very low micron rating) the bath temperature negatively affects both the fibres and the fabric, since it considerably modifies the fabric fibre quality and the intrinsic qualities of fibre and fabric.
In other words, we will have:
a hairy fabric that has a poor resistance to friction with the consequent pilling problem. Te fabric worn and used, that is, that rubs on itself or another one, generates nap and/or lint. This is a big problem also because the companies buy these fabrics and request, or run laboratory tests themselves, to assess whether they can use the fabric for predetermined items. This problem affects the possibility of sale;
a felted fabric that has lost all its lightness and softness quality; the fabric is not light anymore since threads and wefts have compacted; the resulting fabric therefore is heavy. The felting/compacting generates a fabric with a larger weight per square metre than the non-felted one since the fabric decreases both as height and as length. This is a big problem since the fabric becomes unusable and not sellable.
Moreover, when fabrics made of coloured threads are processed, the previous problems add up to the fact that they tend to discolour or change colour; in other
words, coloured fabrics lose a part of their colour that lays on the fabric immersed in the bath and stains it. This is possible even if "colour catching" products have been added.
From the practical point of view carrying out these treatments for coloured fabrics is very risky.
The technical task of the present invention therefore is to provide a process for making a fabric and a fabric thus made which should allow eliminating the aforementioned technical drawbacks of the prior art.
Within the scope of this technical task, an object of the invention is to provide a process that during the second fibre dissolving step should not alter the intrinsic properties of the fibres, should not felt and discolour the fabric.
The technical task, as well as these and other objects, according to the present invention are achieved by providing a process for making a fabric and a fabric thus made according to the annexed claims. In a particular embodiment of the process according to the invention, the first thread may be obtained through a spinning cycle among the following ones:
carded spinning, combed spinning, "compact", "open end", where "compact" spinning indicates the process with fibre compacting during the spinning through pneumatic depression as described for example in document US6134872.
Further features and advantages of the invention will appear more clearly from the description of a preferred but non-exclusive embodiment of the process for making a fabric and of the fabric thus obtained according to the finding.
The process allows making a fabric by a first thread of a natural colour (raw) or coloured, comprising natural and/or artificial and/or synthetic and/or mineral fibres, either pure or mixed with each other.
The process consists in using a first thread made of natural and/or artificial
and/or synthetic and/or mineral fibres, either pure or mixed with each other, of a natural colour and/or coloured preferably by reagent dyes (that better withstand the temperature) so as to obtain a thread having the desired colour.
Such first thread is then twisted with a second thread made of fibres soluble in an environment wherein the first thread is not soluble, so as to make a third thread.
The third thread is then woven and a fabric is made.
The fabric is then immersed in a cold bath for dissolving the second fibres and obtaining the fabric composed of the first fibres only.
Once the fabric has been immersed in the cold bath, acetic acid is added for imparting an acid PH to the bath, in particular the acetic acid is added to obtain a bath with a PH equal to about PH 5.5, then the bath is heated to a temperature of 50 0 C ± 10%.
The fabric is then left to spin in the bath for a period of about 30 minutes ±10%.
After the indicated time interval, when the second fibres have been dissolved, the bath is cooled with the input of cold water and drained.
After this bath, the fabric is subject to a first wash with purified water having a temperature of about 40 0 C ± 10%, preferably for a period of about 10 minutes ± 10%.
Once the first wash has been carried out, other washes are carried out with cold purified water; a second and a third wash are preferably carried out with cold water.
Advantageously, the ratio between the fabric weight and the bath weight is less than 1:25 and preferably equal to about 1 :30 and the soluble fibres consist of water soluble fibres such as alginate or polyvinyl alcohol or PVA fibres that are
soluble in aqueous solution; for example, the thread composed of the second fibres corresponds to product WN4 by the company Kuraray.
The present finding also relates to a fabric made by threads of a natural colour and/or coloured of natural and/or artificial and/or synthetic and/or mineral fibres, either pure or mixed with each other, made according to this process.
In the practice, the materials used as well as the sizes, can be whatever, according to the technical requirements and to the prior art.