US2438328A - Finishing textile materials composed of or containing animal fibres - Google Patents

Description

Patented Mar. 23, 1948 2,438,328 FINISHING TEXTILE MATERIALS COM- POSED OF OR GO FIBRES John Bamber Speakm Leeds, England, assignors NTAINING ANIMAL and Emma. Whewell; to The Fullers Earth Union Limited, Redhill, England, a company of Great Britain No. 556,898. In Great 6 Claims.

This invention relates to a process of treating animal fibres and fabrics composed of or containing the same for the purpose of reducing shrinkage during laundering.

When fabrics composed wholly or partially of wool are wetted out with soap solution and subjected to a rubbing action, in the fulllng stocks and milling machines of th wool textile industry, progressive shrinkage in area, accompanied by an increase in thickness, takes place. Shrinkage of this type is due primarily to the fact that wool fibres possess a surface scale structure, which causes preferential migration in the direction of the root end when fabrics containing wool fibres are subjected to intermittent pressure as under the circumstances outlined above. The fibres migrate in much the same way as a worm crawls i. e. by alternate extension and contraction, andthe soap solution facilitates migration by increasing the ease of extension and contraction of the fibres, as well as by acting as'a lubricant.

Although milling sm' ge of the above type is the basis of several characteristic finishes of the wool textile industry, its occurrence during the laundering of finished fabrics composed whol- 1y or partially of wool is objectionable. Processes have therefore been devised for imparting an unshrinkable finish to wool textile materials. Almost all these processes are based on the principle of treating the material, which may be woven or knitted with a reagent such as chlorine which is capable of attacking the disulphide bonds between the peptide chains of wool. Conditions are' chosen'so as to restrict th attack of chlorine as far as possible to the surface of the fibres, and the surfaceswells and gelatinises when the fibres are treated with soap solution, alkalis and acids in consequence of the breakdown of disulphide bonds during the treatment with chlorine. Such gelatinisation of the surface scale structure makes the fibres incapable of migration when the fabric is laundered or milled in soap solution and shrinkage Of the fabric is prevented.

In contrast to the known processes, the present invention enables the scale structure of animal fibres to be rendered ineffective in producing shrinkage during laundering by mechanical treatment.

Thus, according to the invention, animal fibres or fabrics containing such'flbres are mechanically worked with an abrasive powder in the presence of a non-aqueous medium, such as oil, in which the powder employed is not soluble, in

as in laundering or amount required to No Drawing. Application October 2, 1944, Serial Britain November 11,

water-soluble inorganic substances, for example sodium chloride or sodium sulphate. These materials act as diluents for the abrasive powder and assist in promoting uniform distribution. The powder can be more evenly distributed if it is added to the dry fabric, but if precautions are taken to distribute the powder throughout the oil, for example, by agitation, the oil can be applied before the powder or the oil and powder can be applied together. The last-mentioned method is very convenient in use and is particularly suitable if the powder is practically of colloidal fineness.

In general, the amount of reduction in shrinking increases with increase in the amountof powder applied, other things being equal but the produce the maximum effect is not very great. The finer the grain of powder used, the better is the result obtained. Hard powders such as carborundum and silica produce a greater reduction in shrinking than do soft powders such as kaolin and 'fullers earth but the latter increase the lustre of fabrics containing wool while the lustre may be decreased if desired by the use of coarser powders.

Any oil may be used as the medium for the abrasive but it is desirable, of course, that the oil may be readily removed by an ordinary scouring-process as by the use of a dilute solution of soap and soda. After the scouring, the liquor may be treated with acid so as to recover a mixture of the original oil and the fatty acids of the soap; the liquid may be filtered to separate the abrasive whereupon both the liquor and the abrasive may be employed in further treatment.

The time of treatment depends upon the nature of the abrasive and the reduction in shrinking desired as well as the type of milling machine used.

In order that the invention may be clearly understood and the practical conditions for a desired result be readily determined some examples of the details of the treatment will now be more fully described.

A length of cloth consisting of 1'70 parts by weight of an all-wool flannel is filled with 50 parts by weight of the abrasive powder, then impregnated with 250 parts of olive oil and worked in the machine for one hour. After this treatment. the fabric is freed from oil and powder by a normal scouring process using a dilute solution of soap and, for testing purposes, is milled in per cent soap solution. This treatment may be carried outv with various powders and for the sake of comparison an untreated length of the same flannel may be milled for the same time in 5 per' cent soap solution. The following results have been obtained in this way:

Per cent shrinkage Shrinkage in area of treated fabric as Powder g Untreated Treated of unfabric fabric treated fabric Kaolin 51. B 44. 3 85. Carborundum-lOO mesh 50. 6 41. 8 82. Precipitated Silica 60.0 33.0 66. Fuilers' Earth 48.8 32. 9 67. Carborundum-320 mesh-.-" 50. 3 32. 3 64. Aluminum oxide (electrically fused) 49. 2 31. 8 64. Silical mesh 47. 3 27. 0 57. Carborundum-600 mesh--- 49. 2 26. 8 54. Silica-200 mesh 49. 3 19. 0 38.

These results show that soft powders produce less result than hard powders and that the finer grained the powder, duced as seen from the figures for the carborundum and silica powders.

If lengths of the all-wool flannel are treated as described above except that for 170 parts of the fabric, 25, 50 and 100 parts by weight of fullers earth respectively are used, the following results are obtained:

Per cent Untreated fabric (shrinkage in area) 48.8 parts powder used (shrinkage) 42.3 50 parts powder used (shrinkage) 32.9 100 parts powder used (shrinkage) 32.2

These results show that in practice there is no vantage in using 100 parts by weight of the the greater the result pro-- 4 fullers earth instead of parts with 250 parts of olive oil on parts of the all-wool cloth.

We claim:

1. The process for the treatment of a textile fabric containing animal fibers in order to reduce its shrinkage during subsequent laundering which comprises mechanically working the fabric with an abrasive powder in the presence of a non-aqueous oily chemically inert to the fabric and the abrasive and in which the fabric and the abrasive are insoluble.

2. The process as defined in claim 1 in which the non-aqueous oily liquid medium is olive oil.

3. The process as defined in claim 1 in which after the working the fabric is scoured to remove the abrasive powder and the non-aqueous oily liquid medium.

4. The process for fabric containing animal fibers, duce shrinkage during subsequent laundering which comprises filling the fabric in the dry conabrasive powder, impregnating a non-aqueous 7 subsequently subjecting the filled fabric to mechanical working- 5. The process as defined in claim 4 in which the fabric is a woolen fabric and in which the mechanical working is a milling operation.

6. The process as The foliowingreferences are of record in the file of this patent:

FORHGN PATENTS Country Great Britain Number Date,

liquid medium which is oily medium and defined in claim 4 in which after the mechanical working the fabric is scoured to remove the abrasive powder and the.

Oct. 1, 1934