DE946881C - Process for pre-cleaning raw cotton - Google Patents

Description

ISSUED AUGUST 9, 1956

B 22489 IVcJ8i

The best-known process for pre-cleaning cotton materials in textile finishing consists in subjecting the said material to a so-called buckling. The material will soaked in alkali solutions after desizing, for example soda or caustic soda solution and heated to over 100 ° for a long time under low pressure. This method has the disadvantage that the material receives a dry, brittle handle and becomes inelastic, because in this way except Apparently undesirable accompanying substances also include the cotton wax contained in the natural fiber is removed quite completely. These disadvantages are particularly evident in the high-quality, long-staple ones Cotton varieties.

Attempts have already been made to make this process more gentle, for example by worked without pressure and with more dilute alkali solutions or a treatment with bleach, especially with chlorine and then hydrogen peroxide. These Processes have become common especially in the jersey finishing, where it is to a large extent it is important to achieve an elastic and full grip of the material. On the other hand, they have Processes in general have not found any major entry into technology where woven goods do It has to be pre-cleaned far enough so that it can also be used in lighter tones and also for later colors becomes suitable for printing.

It has now been found that you can properly pre-clean the material without the aforementioned Disadvantages of the pressure dent if one pre-treats the cotton material with pectin-degrading bacteria or enzymes. Such treatment is gentle, does not require any complicated apparatus, in particular no application of pressure, and has High profitability.

ίο The main bacteria are roasted bacteria can be used for flax processing; as enzymes the well-known pectin-degrading pectase, pectinase and the like containing preparations as they are in the trade (cf. Maas, "Die Pektine", p. 124 and 146). When working with enzymes, this is also the case. to emphasize the great security of the new procedure, where even if the treatment is extended to several days, no undesirable whatsoever Attack of the fiber can take place.

After the treatment with the bacteria or enzymes, the cotton material becomes more usual Washed out and appropriately bleached, all known bleaching processes can be used, for example with Chlorine, sodium hypochlorite, calcium hypochlorite, hydrogen peroxide and other peroxides, Sodium chlorite, etc. can be used.

That after the applied procedure bacterial or enzymatically pretreated and then bleached cotton material has to a large extent Preservation of the natural fiber properties, d. H. with high elasticity, pleasant, soft handle and good gloss, excellent whiteness and very good absorbency, so that it is suitable for all purposes of dyeing and printing can be used.

Raw cotton has already been pretreated with pancreatic enzymes in order to reduce the to replace the alkaline beech process. Apart from the fact that in this process the Fat and waxy substances are broken down, which is undesirable, shows the method of the present invention Invention a much better effect. The cotton fabric treated with it shows extensive destruction and elimination of the pectin substance, is lighter in color and has an increased Dyeability.

example 1

500 m of raw tricot material made of Egyptian maco cotton are placed in a liquor which has been produced by diluting a customary used roasting liquor from the flax processing with water 20: 1000. The goods are treated with the liquor circulating at about 35 ^° until the sample with ruthenium red on pectin is negative and the fibers are only slightly pink when viewed under the microscope. The time required for this can be Depending on the activity of the bacteria present, it is normally between 24 and 48 hours. Then it is rinsed in between, bleached and finished in the usual way with 2 g of active chlorine per liter in the form of sodium hypochlorite. The treated fabric has a pleasant, soft feel Handle and shows good elasticity.

Example 2

. 1000 m of nettle made of American Louisiana cotton are after the usual desizing with an iVoigen suspension of a technical commercial pectinase preparation impregnated on the reel vat and 3 hours at 35 up to 40 ° and a pjj value of about 5. After winding, 1.2% sodium chlorite, calculated on the weight of the goods, is added in the usual way acid bleached and finished. The goods have a soft handle and good absorbency.

Example 3

'200 kg of a blend fabric of 60% cotton and 40 "/ o Viskosezellwolle be desized, and then treated in an aqueous bath containing 0.75% of a commercial pectinase preparation. The treatment is carried out during 2V2 hours at 35 ° and at _pH 6 The goods are then rinsed and alkaline-bleached in a further bath with hydrogen peroxide.The goods are finished in a known manner and then show a pure white shade as well as good elasticity and suppleness.

Example 4

In an aqueous liquor containing per liter 20 g of a commercial pectinase preparation, 4 g of dipotassium phosphate and 2 cc of phosphoric acid and the _pH value has 4.7, is allowed on the winch cotton piece goods for 3 hours at 37 ° run.

After rinsing, the piece of cotton wool is treated in an aqueous bleach bath which contains 3 ecm hydrogen peroxide (40 ⁰ AUg), 2 ecm water glass (38 ⁰ Be) and 1 g soda per liter. The bath temperature is initially kept at 35 ° and then increased to 85 ° over the course of 1 hour. The bleaching time is 2.5 to 5 hours.

The piece of cotton fabric treated in this way has a white hue and is pleasant soft grip and excellent absorbency.

Example 5 " ⁵

150 kg of cotton poplin are singed, desized, rinsed and treated for 8 hours at 35 ° in an aqueous bath containing 1 g of techn. Mushroom pectinase and 0.5 g addition product 'from ι moles of dodecyl alcohol and about 10 moles of ethylene oxide contains. It is then rinsed briefly with 3 g of ^a kt. Chlorine bleached in the form of sodium hypochlorite. After the usual finishing, a full-grip, pliable and absorbent material with a good whiteness is obtained.

Claims (1)

Claim: Process for pre-cleaning raw cotton, characterized in that the Subjecting raw cotton to a pectin-degrading bacterial or enzymatic treatment, rinses and then bleaches in the usual way if necessary. Documents considered: German Patent Nos. 316098, 316995; Austrian Patent Specification No. yy 905, 138257; British Patent No. 475,880; French patent specification No. 318070, 47S43I; French patent specification No. 19 944. © 509 658/29 2.56 (609 575 8.56)