US2276681A - Process for dry cleaning - Google Patents

Description

March 17, 1942. I D. P. ALLIS ON 2,275,631

PROCESS FOR DRY CLEANING I Filed Jan. 3, 1940 .FfiO/f FILTER WAS/I'm I DENNIS RALLESON [NVENTUR flag-Kg @W%A Patented Mar. 17, 1942 UNITED STATES PAT FF and apparatus for dry cleaning.

At present the usual procedure of dry cleaning by completely dry process consists of entering fabrics in a washer by weight according to the size of the washer and the amount of solvent therein. These fabrics are given a preliminary run of from five to fifteen minutes with a circulating pump operating. This removes loose or easily soluble soil of solvent solubility. The circulating pump is then stopped and a detergent, or cleaning aid, for the solvent is then applied to the fabrics for the purpose of aiding in removing imbedded or stubborn soil. This procedure is continued for from ten to thirty minutes according to the amount of soil to be sus pended from the fabrics. The circulating pump is then started again for clearing this suspended soil and detergent from the washer and depositing the same on the screens of a filter in closed circuit circulation with the washer. This step usually requires from ten to thirty minutes dely'completely destroys the surface tension of water and'for its more remarkable quality of being a very effective detergent, not being greatly changed for this purpose by even concentrated acids. I Sulphated. fatty alcohol plays an important part in my process as it serves at least three different purposes. First, it reduces the surface tension of water to which it is applied, causing it to be a practical carrier for itself in combination with dry cleaning fluids of volatile hydrocarbons.- Second, when small quantities of water,

'treatedwith this product, are administered to termined by color .or clarity of the filtered solvent in a sight glass in the circulation circuit.

The above procedure removes to a great degree soil of solvent'solubillty from the fabric, but leaves the water soluble stains such as, perspiration, fruit juices, and theother stains of like nature.

with the above in mind my invention provides 7 a process adapted to remove water soluble stains while using. the same procedure above explained without changing washers, or solvents, and without the addition of water proofing agents or solvent soluble moisture carriersto the solvent.

My process includes the usual procedure above outlined, which employs a detergent for the purpose of a cleaning aid to the solvent, and then clears the detergentand soil from the circulation by the use of a filter. Then, and this is the new step, I humidify the solvent in the washer with a detergent solution of fatty alcohol sulphate in water form, for the purpose of removing stains of watersoluble nature. This solution has all the practical advantages of soap and water without the disadvantages of soap as it does not hy-' drolyze to form an alkaline solution which is damaging to both fabrics and colors.

Sulphated fatty alcohol is manufactured and sold by difierent chemical manufacturers under several trade names such as Arysol, Hyrholol Salt (Orvus W. A. Paste), or Musolite, and other trade names. The product has been used for various purposes, especially for its penetrating qualities dry cleaning solvent according to my process, the solution due to retarded surface tension, breaks into small bubbles underagitation of the solvent ln circulation, and causes it to stay suspended in this form for a long enough period of time for its entrance into the washer and whom absorption by the fabrics. Third, sulphated fatty alcohol possesses remarkable penetrating qualities, and since it is suspended in the solvent in a very fine state, it is absorbed faster and more uniformly than plain water, giving the desired results, where needed, without using water repellents to assure even penetration.

The penetrating quality of my sulphated fatty alcohol solution assures practically all of the solution being absorbed by the fabric, consequently reducing the colloidal moisture content of the. .solvent in use, to a very fine point. This is of great importance dueto the fact that my process calls for cleaning by the completely dry process first, and then performing a semi-dry process, so that I am able to run succeeding loads of fabrics without changing machines or solvents.

. This penetrating. quality is also of advantage since it keeps moisture of any amount from leaving the washer and being deposited on the screens of the filter by the pump circulation.

My sulphated fatty alcohol solution, besides reducing surface tension and possessing great penetrating qualities, has another advantage, that of possessing and carrying useful detergent action to fabrics in moisture form. This action accomplished in dry cleaning due to the fact that this solution is not aflected by acid or alkali that may be present in the area of absorption, or free in the solvent. Also this solution does not affect fabrics or colors that are not affected by plainwater. In other words"! am able to get i soap and water results on water soluble stains in due to the fact that a very small percentage neardry cleaning without the hazards of water, am

able to hasten the dry cleaning operation, and am able to use minimum moisture.

- exceed six percent of The preferred percent is v fThesesmall amounts administered to the dry cleaning machine have, by test, proved to have soil removing qualities of twice the amount of filtered during the dry vent under slight pressure downwardly into the The humidifying detergent solution according to my invention is a small percentage, about two i percent,'of sulphated fatty alcohol detergent, and

about 98 percent water. The percentage of water finay vary according tothe type of trade sulphated fatty alcohol product used, but the usual 3 amount with standards products, such as Arysol or HymololSalt issubstantially as follows:

Arysol or Hymolol Salt ;ounces 2 Y The resulting solution is a detergent that will .not break down in acids and that will have greatly reduced surface tension. The amount of solution to be applied by my method to the dry cleaning solvent will vary according to the controls entrance ofthe culation in the pipe amount of soil of water soluble nature to be re-. 1

moved from fabrics, but the amount need never the wefiht of the fabrics.

four percent by weight.

plain water when exposed for the same periodbf time.

My invention also relates to an apparatus for applying 'the'sulphated fatty alcohol solution to the dry cleaning-solvent. I

In the circuit of the solvent being used and cleaning process, all soldegrees and with this in mind is immediately before entrance to the washer. This point of installation of the apparatus is when the solvent is circulated and the apparatus is adapted to offset this pressure by vacuum to allow the solution to flow into the circuit by gravity.

In the accompanying drawing of this specification:

Figure 1 is a side elevation of the apparatus, with parts in section, constructed in accordance forming a part with the invention.

Figure 2 is a plan view of the fan-shaped nozzle.

Referring now to thenr wm m which usecharacters of referencedesignate similar parts in the various views, I designates a funnel for re is connected to one of the alined branches of a T 3. A valve 4 is connected to the other alined branch of the T by a pipe 18 for regulating flow of-the solution to the solvent circulating line. The valve 4 is equipped outside of the washer itself is under pres- 'sureof varying my apparatus is adapted to inject the solution in the circuit at a point of least pressure which tion of the solvent by the fan-shaped nozzle. at

the end of the injector nipple lg, located in the solvent flow line and discharging toward the washer, which la'tteristhe destination of the sol- .vent being circulated. The nozzle serves two purposes, one being to cause a vacuum to form at this point by the solvent rushing past the nozzle, and the other is that by virtue of the nozzle having a narrow opening it releases the solution in a thin fan-shaped sheet which is broken into fine particles by agitation of the solvent in circulation. to enter the washerin suspended form while the circulation is in progress.

It will be understood that the solution must enter the solvent circulation slowly, therefore, the control valve 4 must be set according to the velocity of flow which varies according to the size of filter or pump used. The valve cannot beset to gravity flow before installation, but must be set at the beginning of its first use, and according to the speed of solvent flowing past the outlet of the nozzle. When once set to the size of the P p, not in use, because the solvent does not back up in the apparatus.

- ceiving the sulphated fatty alcohol solution. The funnel is equipped at the tom with a pipe 2 which lowest pointin the bot at the bottom with a pipe 5 which is screwed into i a plug 6 which closes the lateral branch of a. T I.

' The circulating pipe 8 from the filter (not shown) enters one alined branch of the T 'I while the circulating pipe l3 to the' washer (not shown) enters the other alined branch of the T I.

A pipe I! is screwed into the plug 6 and connected with the pipe 5. The .pipe I 1 extends the T 3 and is equipped'with a valve it which T l toiabout the center of the washer In practice the period of time required to inject a given amount of the sulphated fatty alcohol solution to the solvent and assure suspension may vary slightly. Preferably the control valve 4 may be regulated to release the solution to the solvent circulating line at the rate of one-half pint for every twenty-five gallons of solvent flowing past the nozzle H. For pump circulation of 1200 gallons an hour, it will require approximately five minutes to inject, in suspended form, one quart of solution. The same percentage of injection may be followed as to faster flow of circulation based on this method of simplified calculation.

It will be pointed out that my sulphated fatty alcohol solution having moisture detergent qualities, can be applied to, and suspended in, solvent of less than one-quarter of one percent free fatty acid content. Above this figure solvent has a definite tendency to carry the-selvent residue through the filter and back to the fabrics in the washer. Therefore, solvent. kept below onefourth of. one percent of free fatty acid content proves in practice to be better suited for efiicient cleaning.

In'actual practice, the process is as follows: Thefabrics are placed in the washer according to weight as is the usual practice. The circulation of the solvent from the washer to the filter and back to the washer is-started and continued for a short period oftime to remove loose or surface soil of solvent solubility and the circulation is then stopped. Rotation of the cylinder is continuedwhile the solvent detergent-or cleaning aidis added. The rotation of the washer cylinder in the detergent charged solvent may be continued for from ten to thirty minutes according to the type of fabric being cleaned and amount of soil to be suspended from the same. Absorbent powder is then added to the solvent at the washer or'other provided place to be circulated to the filter to remove the detergent or cleaning aid and the soil suspended I! which rises from the it needs no further attention, even when solution in the funnel l.

vent shows optical clarity in the sight glass provided for this purpose. At this point my step oi administering the sulphated fatty alcohol detergent to the solvent at file washer inlet is to be started by placing the required amount of This solution due. to its rapid penetration is instantly absorbed by fabrics as it slowly enters the washer, releasing from the fabrics water soluble stains that have not been removed by the'preceding' treatment. The treatment of the fabrics in this manner is allowed to continue for approximately two or three minutes after the solution has all entered the solvent. This short period of 'time has proved suflicient in practice for complete uniform absorptionof the solution by the fabrics and the release of stains affected, but can be continued for any length of time without detrimental effect to most fabrics. The load of fabrics is then r ready for extraction and de-odorizing to be done preferably at minimum temperature since by having used solvent in its most volatile state it is unnecessary to use high temperatures, and in so doing to remove thepossibility of wrinkles 2,276,681 by'them, on the filter-screens. Circulation is then started again and continued until the solwill beiully understood without further explain tion.

what is claimed is: v

In a dry cleaning process. subjecting fabrics in a washer to the action of a solvent solution containing a detergent, removing the detergent from a the solution by filtration, circulating the filtered fatty alcohol detergent to the circulating solvent I solvent solution, introducing sulphated fatty alcohol detergent into the circulating solvent solution in a thin fan-shaped sheet at the washer inlet, controlling the release of the sulphated solution to a ratio of one-half pint to every twenty iive gallons of solvent solution flowing past the point of admission of the sulphated alcohol detergent, such controlled admission and v thin fan-shaped sheet form of the admission eifecting the breaking up of the sulphated fatty alcohol detergentinto fine particles by agitation of the solvent solution in circulation so that the detergent enters the washer in suspended form while the circulation is in progress, maintaining vfrom extraction and exposure to sudden high temperatures.

From the abovedescription it is thought that the construction and operation of the invention the solvent at'less than one quarter of one. per cent free fatty acid content while the sulphated fatty alcohol detergent is being applied to and suspended in the solvent solution, and returning the solvent solution with the sulphated fatty alcohol detergent suspended therein to the washer for further treatment of the fabrics.

' DENNIS P.-ALLISON.--..

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