US3330015A

US3330015A - Methods for the controlled shrinkage of textile fabrics

Info

Publication number: US3330015A
Application number: US278955A
Authority: US
Inventors: Sieber Johannes Helmut
Original assignee: Bohler & Weber KG Fa
Current assignee: Bohler & Weber KG Fa; Bohler & Weber Kg Firma
Priority date: 1960-12-23
Filing date: 1963-05-08
Publication date: 1967-07-11
Anticipated expiration: 1984-07-11
Also published as: GB968399A; BE611618A; US3370330A; DE1179537B; US3473175A; CH395015A; CH1381161A4

Description

July 11, 1967 J. H. SlEBER 3,330,015

METHODS FOR THE CONTROLLLED SHRINKAGE OF TEXTILE FABRICS Filed May 8, 1963 2 Sheets-Sheet 1 Fig: 1.

DISTILLING UNIT FILTER F RESERVORR 24 PROGRAMMER INVENTOR.

JOHANNES H. SIEBER Jfissiem, jam (5 Jdaalzm July 11, 1967 J. H. SIEBER 3,330,015

METHODS FOR THE CONTROLLLED SHRINKAGE OF TEXTILE FABRICS Filed May 8, 1965 2 Sheets-Sheet 2 V OP V6 INVENTOR. JOHANNES H. SIEBER BY Jlulem; 3L

United States Patent 3,330,015 METHODS FOR THE CONTROLLED SHRINKAGE 0F TEXTILE FABRICS Johannes Helmut Sieber, Neusass, near Augsburg, Germany, assignor to Firma Biihler & Weber KG., Augsburg, Germany, a corporation of Germany Filed May 8, 1963, Ser. No. 278,955 Claims priority, application Germany, Dec. 23, 1960, B 60,633 3 Claims. (CI. 2619) My present invention relates to a method of controlledly treating a fabric with water and is a continuation-inpart of my copending application Ser. No. 160,640 filed December 19, 1961, and now abandoned.

In this copending application I disclose a process for the milling and after-treatment of fabrics with water wherein the water is transferred onto the fabric from a liquid vehicle, containing a dry-cleaning solvent, in which the water formed a dispersion. This technique has been found to have general applicability in the shrinkage of nonwool fabrics as well as those containing wool, for the impregnation of fabrics with various treating agents and other fabric-finishing steps in addition to the milling or fulling mentioned above.

Generally speaking, treatment of fabrics with water has been carried out heretofore by immersing and agitating the fabric in a water bath. This method, by virtue of the fact that an excess of water is always present in contact with the fabric, is complicated by a number of variables, all of which must be controlled for effective milling. In the direct water treatment of fabric, for example, temperature is of prime importance since wool, cotton, viscose rayon and like fabrics swell more rapidly with increasing temperatures. The shrinkage effect is also more significant in hot water than in cold water. When wool fabrics are involved, felting occurs very rapidly in the presence of pure water so that extremely close control over the treatment time is essential. Additionally, in a pure aqueous medium, control over pH must be observed if reproducibility is to be insured. As a consequence of the aforementioned complications arising from the aqueous milling of fabrics, the industry has long sought to control the several variables in a convenient manner and to eliminate as variables as many factors as possible. Efforts to eliminate controllable and uncontrollable variables in the treatment of fabrics in general have led to only limited success heretofore. It may, for example, be noticed that the impregnation of fabrics with water-soluble material in the presence of a purely aqueous medium has shown that considerable care must be taken with respect to the same variables which governed milling action.

It is an object of the present invention to provide an improved method of milling wool-containing fabrics.

Another object of this invention is to extend the principle advanced in my above-identified copending application to the controlled treating of fabrics in general.

Still another object of this invention is to provide an improved method of treating fabrics with water-soluble treatment agents.

A further object of my invention is to provide a process for controlledly shrinking fabrics.

Yet another object of this invention is to provide an improved apparatus for treating fabrics and milling woolcontaining textiles.

These objects and others, which :will become more readily apparent hereinafter, are attained, in accordance with the present invention, by a method of treating fabrics wherein water is dispersed in a liquid vehicle in which it is only slightly soluble but in the presence of a quantity of a surface-active agent sufiicient to stabilize the water dispersion but less than that required to solubilize the water. The fabric is then immersed in the liquid vehicle and absorbs water therefrom while being agitated therein, e.g. by tumbling.

I have discovered that, under these circumstances, water completely saturates the liquid vehicle or solvent so that the latter can always be considered to possess a humidity of 100% at the operating temperature. Since the amount of water which will saturate the solvent is well defined, no difiiculties arise from excess moisture or insuflicient moisture. The liquid vehicle is preferably composed entirely of a dry-cleaning solvent of conventional type since such solvents are readily removed from the fabric and have a water-saturation point wherein the water content is not insignificant but yet below the level at which undesirable efi'ects will result. As the fabric absorbs moisture from the solvent, additional water in a dispersed state, but not yet in solution, dissolves to maintain saturation of the solvent. As previously pointed out, the surface-active agent is present in sufiicient quantity to stabilize the water dispersion but not in a quantity capable of solubilizing it within micelles of the surfactant.

I am aware that earlier efforts in the dry-cleaning industry have involved the used of surface-active agents to stabilize and increase the quantity of water dispersed within a dry-cleaning solvent. It must be noted, however, that these efliorts were based upon an entirely different principle of operation from that involved in the present invention. It is an essential aspect of such dry-cleaning processes that water be provided in the solvent to remove water-soluble soils, the water being provided in a substantial proportion of the dry-cleaning solvent. To insure that the soils dissolved by the water were removed and prevented from again depositing upon the fabrics, sufficient quantities of a surface-active agent were provided to solubilize the water in micelles. In such methods the quantity of surface-active agent was invariably greater than the quantity of water to insure total solubilization and, in fact, was often ten to twenty times greater than the quantity of water it was desired to solubilize. In contradistinction, the present invention derives from the discovery that water can be dispersed in a dry-cleaning solvent in the presence of a quantity of surface-active agent less than that of water and sufiicient only to stabilize the dispersion but incapable of solubilizing the water so that dispersed water is free to go into solution in the solvent without dissolving in the surface-active agent. In dry-cleaning systems operating with the aid of water, moisture solubilized in surfactant micelles is prevented from freely dissolving in the organic solvent as required.

According to a further feature of the present invention, the liquid vehicle, consisting predominantly of the drycleaning solvent, is circulated through the fabric and the water dispersed therein replenished during this circulation. I have discovered that excellent results are obtained when the dry-cleaning machine or immersion receptacle in which the treatment of the fabric is carried out is provided with a solvent-circulating system including pump means capable of effecting a fine dispersion of the water in the solvent and supply means for the water and/ or the surface-active agent is disposed rearwardly of the pump in the direction of circulation of the liquid. Advantageously,

the system can be provided with means for extracting the liquid vehicle from the fabric at the conclusion of the treatment process, control means being provided to direct a portion of the solvent removed from the treatment vessel to a distilling means for purification. Preferably, the free liquid within the receptacle is first drained into a storage tank or reservoir with only the tailings, removed by extraction, being fed to the distilling device.

As previously indicated, the quantity of surface activation may be equal to a small fraction of that of the dispersed water (between 0.1 and 10% by weight of the fabric to be treated), the water being present in an a-mount ranging between substantially and 50% by weight of the fabric. Best results are obtained when the liquor ratio, i.e. the ratio of fabric in kilograms to total liquid vehicle in liters, ranges between 1:2 to 1:50 and preferably .is about 1:10. The relative quantities of water dispersed in the dry-cleaning solvent and surface-active agent are more dramatically demonstrated by noting that the preferred range of surfactant quantities lies between 0.5 and 3% by weight of the fabric while the water quantity is between 5 and 20% by weight of the fabric.

7 Almost any dry cleaning solvent is suitable for carrying out the process of the present invention, it being noted that solvents in which water is only slightly soluble are the most satisfactory. The most practical solvents for use in treating fabrics in the manner described above are the chlorinated hydrocarbons and solvent mixtures containing aliphatic, aromatic and alicyclic hydrocarbons of the Stoddard type. Solvents having particular suitability are those described in ASTM Standards D484-52 and hereafter designated as Stoddard solvents. Of the chlorinated hydrocarbons, perchlorethylene and trichlorethylene are.

most suitable since they are readily removed from the fabric at the conclusion of treatment by conventional means.

According to another aspect of the present invention, the water dissolved in the dry-cleaning solvent'serves as a carrier for water-soluble adjuvants for treating the fabric. In this case the adjuvant, which can be a syntheticresin stiffening agent, a softening medium or any other water-soluble substance with which it is desired to treat the fabric, is added to the solvent subsequently to the dispersion of the water and surfactant therein or concurrently with such dispersion. The adjuvant is found to dissolve in the dispersed Water and to be carried with it onto the fabric as the dispersed water itself dissolves in the solvent upon withdrawal of water therefrom by the hydrophilic fabric.

Still another feature of the present invention resides in the treatment of both Wool and other fabrics by this technique for controlledly shrinking them to the desired dimensions. Whereas the present technique is particularly suitable for milling and felting wool-containing fabrics, it should be noted that treatment of fabrics with water is more generally applicable. Thus, cotton fabrics may be treated, according to the invention, with water in a solvent vehicle as described above to shrink the fabric in a controlled manner with time and temperature being the sole, variables determining the quantity of water absorbed by the cotton fabric. In this connection it may be pointed out that direct immersion of cotton fabrics in water often results in an uncontrolled shrinkage since many other factors enter into the determination of the quantity of water absorbed by the fabric and affecting shrinkage thereof. Again adjuvants may be carried by the water to the cotton fabric in order to treat the latter.

The surface-active agents employed in the present method include anionic, cationic and noniouic types as well as conventional soaps. It is desirable, for the most part, to operate at about room temperature when milling and fabric shrinkage are. to be carried out, but at higher temperatures (say 30-40 C.) when felting is required.

a It may be noted that the organic solvents to be used have a water-saturation level on the order of 0.04% by weight at 25 C., a preferred temperature for milling Wool-containing fabrics. I

The above and otherobjects, features and advantages of the present-invention will become more readily apparent from the following description and examples, reference being made to the appended drawing in which:

FIG. 1 is an axial cross-sectional view through a drycleaning machine of the rotating-basket type, schematically showing a system embodying the present invention;

FIG. 2 is a graphof the sequence of operation of the FIG. 3 is a diagram illustrating another apparatus for carrying out the present method.

In FIG. 1, 'I show a dry-cleaning machine '10, of a generally conventional type, wherein a receptacle 11 encloses a rotating fabric-receiving basket 12 into which the fabric 13 can be introduced via an opening 14 in the receptacle which can be closed by a door 15. The perforated basket 12 is provided with vanes 16 for agitating the fabric in the liquid 17 contained by the receptacle. The basket 12 is provided with a driven pulley 18 connected via a belt 19 with the drive wheel 20 of a motor M whose two-speed transmission 22 is normally in its low-speed state. An electromagnetically operable clutch C is provided on the transmission for shifting it to its high speed. The motor M also carries a pump for'draining solvent from the receptacle 11.

another pipe 26 whereby regenerated solvent can be drained into the reservoir'24 by gravity. A conduit 27 leads from the outlet of the pump and supplies a first duct means 28 via an electrically operable valve V to convey the liquid vehicle to the distilling unit D. A second duct means 29, having an electrically operable valve V is also provided to convey the liquid directly to the reservoir 24. A conduit means 30 with its valve V forms with line 27 and pipe 25 a closed system for circulating the solvent, as will be described hereinafter.

The intake end of pump 23 is fed by a drain pipe 31 from the receptacle 11 and serves as the termination for a supply line 32 whose gravity-fed dispenser 33 adds water and surfactant to the solvent. The amount of water added can be determined by a manually adjustable valve 34, although sensing means 35, responsive to the water content of the solvent, may be provided in line 27 for automatic control of this valve. A two-position cntofi valve V is provided in supply line 32 for initiating and halting flow of water into the solvent. a A filter F, whose inlet 36 is connected to line 27 'via an electromagnetically operable valve V can also be provided to remove solid and certain liquid impurities from the solvent stream as desired. The outlet pipe 37 of filter F contains a check valve 38 toprevent backflow of the liquid. An air-inlet duct 39, supplied by a blower not shown, is fitted with an electrically controlled valve V for supplying a blast of drying air to the receptacle 11. An outlet duct 40 is designed to carry air saturated with the solvent to the distilling unit D for recovery of the solvent. A timer and programming means 41, which can be of the card-control type, is provided for sequentially operating the valves. Such programmers are well known per se and need not be described in detail.

The operation of the apparatus of FIG. 1 will now be described with reference to a five-minute milling opera tion. The programming sequence may, of course, be altered as desired to suit any particularrequirements. The

fabric, e.g. wool-containing garments to be milled, is introduced into the basket 12 via opening 14 and the door, 15 then closed. The programmer is then turned on to and not shown herein. After approximately three-quarters of a minute (FIG. 2), a period sufiicient to permit intro-. duction of the desired quantity of solvent, valve V isclosed and valve V opened. Valve V has meanwhile been energized so that the pump 23 circulates the drycleanrng solvent from and back to the receptacle 11. This pump is preferably of the centrifugal type to ensure thorough agitation of the solvent. Concurrently with or shortly after the actuation of valve V valve V is opened to admit water and surfactant from the supply means 33 into the solvent stream rearwardly of the pump 23 in the direction of circulation of the liquid. The pump thus constitutes a dispersing means which forms a fine dispersion of water in the solvent. The water, carried by the solvent, is thus brought into contact with the fabric 13 as the drum rotates at low speed for the duration of the milling operation shown to be approximately 4 minutes.

At the five-minute point, valves V and V; are closed while valve V remains open and either valve V or V is opened. The pump then displaces the free solvent of receptacle 11 into reservoir 24 directly or into the latter via the filter F. Solvent trapped in the fabric 13 is not, however, drained from the receptacle 11 at this time. After approximately one minute of draining, valve V or V is closed and valve V 'opened concurrently with energization of clutch C and the distilling unit D. This energization of clutch C shifts the transmission 22 into its high speed whereupon the basket 12 is rotated rapidly to force liquid out of the fabric 13 by centrifugal force. This liquid constitutes the tailings and is conveyed by pump 23 to the distilling unit D via line 28 whose valve V, has been opened as previously noted. When the extraction stage has been completed, clutch C is de-energized and valve V closed and the basket 12 rotated again at low speed to tumble the fabric 13. The valve V is then operated to admit a stream of drying air, heated is desired, to the receptacle 11. As the fabric dries, the solvent-containing gas is carried to the distilling unit D wherein the solvent is recovered. At the conclusion of the operating cycle, motor M is cut off and the fabric removed.

In FIG. 3 I show an arrangement wherein a fabric 42 can be continuously treated. The fabric can be drawn from a supply roll 43 or from earlier processing apparatus and passes into a receptacle 44 containing the solvent 45 in which water and a surface-active agent are dispersed. An outlet tube 46 conveys a solvent to a pump 47 which circulates it back to the receptacle 44. A dispenser 48 is provided to feed water and surfactant to the conduit means 36 etc. rearwardly of pump 47 but forwardly of the receptacle 44. A wheel 49, with radially extending arms 50, serves to agitate and maintain the fabric 42 below the level of the liquid 45 for a period sufiicient to carry out the desired treatment. From the receptacle 44 the fabric can pass into a drying zone 51 wherein blowers 52, diagrammatically shown, remove the solvent which can be recovered and returned to the tank. A distilling unit or reservoir may be provided as shown in FIG. 1.

EXAMPLE I In a dry-cleaning machine of the aforedescribed type (FIG. 1), I dispose 4 kg. of a wool-containing knitwear, consisting substantially of 70% wool and 30% viscose rayon. The knitwear is in a damp state and contains 11.5%, by weight, of water. The drycleaning machine is charged with a perchlorethylene cleaning solvent at a liquor ratio of 1:10 (for one kilogram of goods ten liters of solvent). A quantity of a surface-active agent equal to 1% of the weight of the fabric is distributed in the solvent. It should be noted that the water/surfactant weight ratio is approximately 11521. An anionic emulsifier (sodium dodecylbenzinesulfonate) serves as the stabilizer for the dispersion. The milling time is approximately 15 minutes. The dried knitwear is found to have been milled to the desired extent without undue felting.

EXAMPLE II A woven fabric containing approximately 70% wool is treated in the dry-cleaning machine with Stoddard solvent (ASTM 13484-52) at a liquor ratio of 1:5 (for one kilogram of fabric five liters of solvent). Approximately 14 kg. of fabric are treated. A paste soap (560 cc.) containing 75 g. of water is then added. In this case it is desirable that a total water content of 17%, based upon the weight of the fabric, be employed. Approximately 2.3 kg. of water must then be added to the dry-cleaning solvent together with or subsequent to the addition of the soap at the supply means whereupon the water is dispersed thoroughly in the solvent by the pump. The fabric is milled for 15 minutes whereupon the solvent is drained to the reservoir, and is then extracted for 3 minutes, the liquid tailings being conducted to the distilling unit. Again the dried fabric shows the desired milling effect.

EXAMPLE HI 18 kg. of woolen blankets, consisting of 30% by weight cotton and 70% by Weight wool, just olf the loom and still containing size and natural oils, are treated for 5 minutes in 360 liters of trichlorethylene dry-cleaning solvent (liquor ratio 1:20). The blankets are then extracted, with the solvent distilled and returned to the receptacle by way of the pump which disperses 360 g. of a nonionic emulsifier (a nonylphenylethyleneoxide condensate such as the one marketed under the trademark Tergitol NPX) together with 2.2 liters of water (approximately 12% calculated on the weight of the blankets) in the recirculating solvent stream. After milling of the fabric in this solution for 5 minutes, the spent liquor is returned to the reservoir with the tailings being passed through the distilling unit. After drying for 20 minutes at 80 C., the blankets are found to be not only clean but also free of size and provided with the desired milling effect so that only a final napping treatment is necessary to finish the fabric.

EXAMPLE IV A wool cardigan is milled in a perchlorethylene solvent (liquor ratio 1:10) in the presence of 12% water based upon the weight of the fabric. About 1% by weight of the fabric of a quaternary ammonium compound (as a cationic surface-active agent) stabilizes the water-insolvent emulsion. The quaternary ammonium compound is a commercially available substance such as that marketed by Armour & Co. under the trade name Arquad HT and containing long-chain alkyl groups. A milling time of approximately 12 minutes in used. If it is desired to apply a filler or softener to the fabric, this adjuvant can be dissolved in the vehicle for transfer to the fabric by the Water dispersed therein. For example, approximately 0.8% by weight of the fabric of dextrin can be dissolved in the system just described for the treatment of a woven fabric consisting of 30% viscose rayon and 70% wool. Substantially all of the dextrin dissolved in the vehicle is deposited in the fabric and adsorbed thereby.

EXAMPLE V A l00%-wool material is felted in the dry-cleaning machine or receptacle of FIGS. 1 or 3 with a perchlorethylene liquor ratio of 8:1. The solvent contains 40% Water, based upon the weight of the fabric, and the aforedescribed nonionic emulsifier is used. The treatment temperature is 40 C. A stiffening adjuvant (10% by weight of the fabric of polyvinyl alcohol) is added to the vehicle for transfer to the felt by the dispersed Water. After at least partial drying the felt can be blocked and set.

EXAMPLE VI A cotton-knit fabric is agitated for 5 minutes in perchlorethylene (liquor ratio 1:10) in the presence of a softening-type surface-active agent. Approximately 1% of the weight of the fabric of the sulfated diisobutylamide of oleic acid marketed under the trademark Humectol is used as the surfactant and serves to stabilize an emulsion of 35% water, by weight of the fabric, in the solvent. The fabric shrinks by about 6% to the desired dimensions.

I claim:

1. A method of treating, with controlled shrinkage, a water-absorbent fabric, comprising the steps of dispersing Water in an organic vehicle containing a dry-cleaning solvent, in which said water is only slightly soluble, in the presence of a quantity of a surface-active agent suf ficient to-sta'bilize the Water dispersion but lessthan that required to solubilize said water, whereby dispersed insolubilized water enters into solution in said solvent to maintain said solvent saturated with water, the quantity of water ranging between substantially and 50% by weight of the fabric, the liquor ratio ranging between substantially 1:2 and 1:50, and the quantity of surfaceactive agent ranging between substantially 0.1 and of the weight of the fabric;

immersing and agitating said fabric in said vehicle with the water dispersed therein under controlled conditions of time and temperature compatible with the fabric treated;

adding to said vehicle further quantities of water and said agent sufiicient to replace water absorbed from said vehicle by said fabric;

separating the fabric from said vehicle; and thereafter drying said fabric.

2. A method of treating, with controlled shrinkage, a water-absorbent fabric, comprising the steps of dispersing water in an organic vehicle containing a dry-cleaning solvent, in which said water is only slightly soluble, in the presence of a quantity of a surface-active agent sufficient to stabilize the waterdispersion but less than that required to solubilize said water, whereby dispersed insolubilized water enters into solution in said solvent to maintain said solvent saturated with water, the quantity of water ranging between substantially 5 and 50% by Weight of the fabric, the liquor ratio ranging between substantially 1:2 and 1:50, and the quantity of surfaceactive agent ranging between substantially 0.1 and 10% of the weight of the fabric;

, dissolving in said vehicle an adjuvant soluble in the water dispersed in said vehicle for transfer by the dispersed water to said fabric;

separating the fabric from said vehicle; and thereafter drying said fabric.

, 3. A method of treating, with controlled shrinkage, a

water-absorbent fabric, comprising the steps of dispersing water in an organic vehicle containing a dry-cleaning solvent, in which said water is only slightly soluble, in

the presence of a quantity of a surface-active agent equal to a small fraction of that of the dispersed water and sufiicient to stabilizethe water dispersion but less than that required to solubilize said water, whereby dispersed insolubilized water enters into solution in said solvent to maintain said solvent saturated'with water, the quantity of water ranging between substantially 5 and by weight of the fabric, the liquor ratio ranging between substantially 1:2 and 1:50, and the quantity of surfaceactive agent ranging between substantially 0.1 and 10% of the weight of the fabric;

immersing and agitating said fabric in said vehicle with the water dispersed therein under controlled conditions of time and temperature compatible with the fabric treated; V dissolving in said vehicle an adjuvant soluble in the water dispersed in said vehicle for transfer by the dispersed water to said fabric; separating the fabric from said vehicle; and thereafter drying said fabric.

References Cited 5 ROBERT R. MACKEY, Primary Examiner.

DONALD W. PARKER, MERVIN STEIN,

Examiners.

Claims

1. A METHOD OF TREATING, WITH CONTROLLED SHRINKAGE, A WATER-ABSORBENT FABRIC, COMPRISING THE STEPS OF DISPERSING WATER IN AN ORGANIC VEHICLE CONTAINING A DRY-CLEANING SOLVENT, IN WHICH SAID WATER IS ONLY SLIGHTLY SOLUBLE, IN THE PRESENCE OF A QUANTITY OF A SURFACE-ACTIVE AGENT SUFFICIENT TO STABILIZE THE WATER DISPERSION BUT LESS THAN THAT REQUIRED TO SOLUBILIZE SAID WATER, WHEREBY DISPERSED INSOLUBILIZED WATER ENTERS INTO SOLUTION IN SAID SOLVENT TO MAINTAIN SAID SOLVENT SATURATED WITH WATER, THE QUANTITY OF WATER RANGING BETWEEN SUBSTANTIALLY 5 AND 50% BY WEIGHT OF THE FABRIC, THE LIQUOR RATIO RANGING BETWEEN SUBSTANTIALLY 1:2 AND 1:50, AND THE QUANTITY OF SURFACEACTIVE AGENT RANGING BETWEEN SUBSTANTIALLY 0.1 AND 10% OF THE WEIGHT OF THE FABRIC; IMMERSING AND AGITATING SAID FABRIC IN SAID VEHICLE WITH THE WATER DISPERSED THEREIN UNDER CONTROLLED CONDITIONS OF TIME AND TEMPERATURE COMPATIBLE WITH THE FABRIC TREATED; ADDING TO SAID VEHICLE FURTHER QUANTITIES OF WATER AND SAID AGENT SUFFICIENT TO REPLACE WATER ABSORBED FROM SAID VEHICLE BY SAID FABRIC; SEPARATING THE FABRIC FROM SAID VEHICLE; AND THEREAFTER DRYING SAID FABRIC.