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Publication numberUS3397033 A
Publication typeGrant
Publication dateAug 13, 1968
Filing dateApr 5, 1965
Priority dateApr 9, 1964
Also published asDE1301996B
Publication numberUS 3397033 A, US 3397033A, US-A-3397033, US3397033 A, US3397033A
InventorsPeter Ney, Walter Kuhnmunch
Original AssigneeDegussa
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Textile bleaching process
US 3397033 A
Abstract  available in
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Claims  available in
Description  (OCR text may contain errors)

FIP8309 3,397,033 TEXTILE BLEACHING PROCESS Peter Ney, Frankfurt am Main, and Walter Kuhnmiincll, Frankfurtlam Main-Heddernheim, Germany, assignors to Deutsc'he Goldund Silber-Scheideanstalt vormals Roessler, Frankfurt am Main, Germany No Drawing. Filed Apr. 5, 1965, Ser. No. 445,696 Claims priority, application Germany, Apr. 9, 1964,

,1 3 Claims. (Cl. 8-111) ABSTRACT OF THE DISCLOSURE The present invention relates to an improved process for bleachingfibers, especially, cellulosic fibers, either as such or in the form of yarns, woven fabrics or knit goods, in which the goods to be bleached are impregnated with an aqueous bleaching solution, the excess bleaching solution is removed by squeezing or centrifug" ing and the goods are then subjected to a heat treatment followed by washing which simplifies and reduces the time required for the bleaching.

In the bleaching of textile goods, processes are known in which the goods are first impregnated with the bleach ing solution at room temperature or raised temperatures, the excess bleaching solution then squeezed out or spun out, and then heated, for example, by a steam jet and then held at an elevated temperature for a longer period of time. This procedure in general provides good bleaching results. However, it requires a considerable period of time and considerable energy in order to provide the necessary elevated temperature over the longer periods of time required.

In the further development of this process, it Was found to be expedient in some instances to store the goods which had been impregnated with the bleaching solution for several hours, for example, 3 to 10 hours, at room or moderately Warm temperature and then to heat such goods for a short period of time, preferably, 10 to 12 minutes, to about 100 C. with, for instance, a steam jet. Expediently the storage is effected in a tightly packed condition. This procedure is effective for bleach ing fibers, yarns, woven fabrics, knitted goods or other textile goods of all types and especially those which are of cellulosic nature. The usual textile bleaching agents, such as hydrogen peroxide, sodium peroxide, sodium perborate, sodium chlorite, peracetic acid and the like can be used in such procedure.

The object of the present invention is to provide a process in which the time the bleaching agent acts on the goods could be shortened substantially while at the same time attaining a higher degree of whiteness.

According to the invention it was unexpectedly found that the results of a bleaching treatment with regard to the degree of whiteness, as well as wettability could be substantially improved while effecting a saving in steam Patented Aug. 13, 1968 and heat energy if, according to the invention, the goods to be bleached are impregnated with the aqueous bleaching solution, such impregnated goods are stored at room or moderately raised temperatures, for instance up to about 40 C. for several hours, for example, 3 to 10 hours, in a tightly packed state, and after such storage are treated in a pressure steamer at temperatures between and 200 C. for 15 to 120 seconds. Preferably, suchpressure steaming treatment is effected at temperatures between and 150 C. at corresponding pressures for 30 to 60 seconds.

Peroxidic textile bleaching solutions, such as, for example, those of hydrogen peroxide, sodium peroxide or sodium perborate, are especially suited for the process according to the invention. The process, for instance,

can be carried out by impregnating the textile goods to be bleached with, for example, an alkaline hydrogen peroxide containing bleaching solution, removing the excess solution to provideabout a 100% to 150% take up by the goods. Thereupon the goods are folded up or rolled up and left to be acted on by the bleaching solution contained therein for several hours at room temperature. Thereafter, the goods are introduced into a pressure steamer without repeating the impregnation or an intervening Wash and treated in such pressure steamer at the temperatures indicated for a short time and then given the usual rinse.

While it is known that fabrics can be impregnated with an alkaline peroxide solution and then immediately treated at elevated temperatures of at least C. for a short time with steam at corresponding pressures, such process only leads to a satisfactory white content if the goods have been given an alkaline pretreatment.

With the process according to the invention the total time required for the treatment of the goods to be bleached can be shortened substantially while at the same time a higher degree of whiteness and a better removal of seed shells in theicase of cotton fabrics can be attained. Furthermore, the wettability of the goods bleached according to the invention is considerably improved.

The results obtainable with the process according to the invention are illustrated in the following example in which it is compared with known processes which do not include a pressure steam treatment.

Example The tests were carried out on desized Reutlinger nettle cloth which still contained seed shells. The steaming apparatus employed was an Obermaier HT apparatus. The nettle cloth was impregnated with an aqueous bleaching solution which per liter contained Water glass 38/40 B. "ml-.. 30 NaOH g 10 H 0 (35% by weight) ml 40 Lamepon A (condensation product of oleic acid chloride and sodium lysalbinate) g 2 Wetting agent (lauryl sulfate) g 2 In all instances the cloth after impregnation was squeezed out to a 100% bleaching solution content and then subjected to the action of the retained bleaching solution at room temperature for the periods indicated in the following table. The steam Was at a temperature of 130 C. which corresponds to a gauge pressure between 2.8 to 3.2. After completion of the bleach the cloth samples were each rinsed successively with hot, warm and cold tap water. The degree of whiteness, the time required for submerging when placed on water and the degree of seed shell removal was determined for each bleached sample. The results are given in the following table:

impregnating such fibrous textile material with the aqueous peroxidic bleaching solution, removing the excess TABLE Room Pressure Degree of Test- No. Temp. Steaming whiteness Submerging Time Seed Shell Removal Bleach (see) (percent) (hours) 18 77 Over 2 min. r Shell free.

3 60 80 o. 3 72 Still contained shells. 6 60 81. 9 2sec Shell free. fi 73 90 sec Still contained shells. Starting material desized Over 10 min..

As can be seen from such table, tests 2 and 3, which were according to the invention, resulted in goods which were seed shell free, and had good wettability and a higher degree of whiteness than were obtained in tests 1, 2a and 3a.

Analogous improved results were obtained when the above bleaching solution was replaced by aqueous bleach- .ing solutions which per liter contained the ingredients given below.

Bleaching solution :1:

1. The process of bleaching fibrous textile materials with an aqueous peroxidic bleaching solution, the steps of bleaching solution, storing the thus impregnated fibrous textile material for a period of about 3 to 10 hours at a temperature between room temperature and moderately raised temperature, then subjecting the fibrous textile material to steam under pressure at a temperature between and 200 C. for a period of 15 to 120 seconds.

2. The process of claim 1 in which the fibrous textile material contains cellulosic fibers.

3. The process of claim 2 in which the steam treatment is carried out at a temperature between and C. for a period of 30 to 60 seconds.

References Cited FOREIGN PATENTS 539,280 4/1957 Canada. 577,546 6/1959 Canada. 589,916 12/1959 Canada. 844,699 8/ 1960 Great Britain. 1,276,635 10/1961 France.

LEON D. ROSDOL, Primary Examiner.

MAYER. WEINBLATT, Assistant Examiner.

Patent Citations
Cited PatentFiling datePublication dateApplicantTitle
CA539280A *Apr 9, 1957Chicopee Mfg CorpBleaching process
CA577546A *Jun 9, 1959Du PontTextile bleaching process
CA589916A *Dec 29, 1959Du PontBleaching cotton
FR1276635A * Title not available
GB844699A * Title not available
Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US4139697 *Apr 6, 1977Feb 13, 1979Tenneco Chemicals, Inc.Color stabilization of vinyl chloride resins
US4220754 *May 25, 1976Sep 2, 1980Tenneco Chemicals, Inc.Process for the purification of polyvinyl chloride with oxidizing agents
US4734098 *Nov 22, 1985Mar 29, 1988Crucible Chemical CompanyMethod for bleaching cotton
Classifications
U.S. Classification8/111, 8/107
International ClassificationD06L3/00, D06L3/02
Cooperative ClassificationD06L3/02
European ClassificationD06L3/02