US1979399A - Dry cleaning process - Google Patents

Description

gas

Patented Nov. 6, 1934 DRY CLEANINGPBOOESS 7 Ralph A. Morgen, Kansas City, Mo.

No Drawing. Application June 8, 1933, Serial No. 674,898

4 Claims. (01. 63-38) My invention relatesto a process of dry cleaning, and more particularly to a process of that character wherein clothing or other articles to be cleaned are subjected to a bath of non- 5 aqueous liquid, such as gasoline, naphtha, carbon tetrachloride, tri-chlorethylene, ethylene dichloride or the like, commonly referred to as solvent or cleaners solvent, capable of removing impurities from the clothing or other articles to be cleaned, hereinafter referred to as clothing, and in which the dirty solvent is clarified for reuse.

With some such processes, wherein only the solvent has been employed, loose dirt has been removed from the solvent by settling or centrifuging, and grease or fats by reaction with caustic soda or sulphuric acid, but with such processes some of the clarifying agent is usually'taken up by the solvent and hasa detrimental eflecton the clothing to be cleaned with the reused solvent.

Detergents have been employed for aiding the solvents in removal of fatty acids, fats and other impurities, such as those held to the clothing by the fatty acid and fats, from the clothing, but these have usually been soaps containing excess fatty acids, and which, with those removed from the clothing, remain in solution in the solvent and cannot beremoved by filtration, centrifuging or settling, and may soil garments sub- :lected tothe reused solvent.

Weak alkaline clarifiers have been employed,

but unless properly proportioned to known quantitles of fatty acids, fats. and alkali transferred to the solvent from clothing in the washer and present in the detergent employed, an excess of the fatty acids and fats will remain in the solvent to streak or soil the clothing when the solvent is reused, and accumulate therein, so that the solvent must'be treated with a strong alkali, such as caustic soda, and/or a strong acid, such as sulphuric acid, after a comparatively few reuses to recondition the solvent for further use. h

I have discovered that by using analkaline detergent formulated both qualitatively and quantitatively according toknown acidic and alkaline content of the impurities removed from clothing with any of the solvents commonly employed for dry cleaning, and then treating the solvent with a clarlfler capable of adsorbing the fatty acids and fats transferred to the solvent from the clothing and detergent, I am able to effect substantially complete removal of the acidic, fatty and other impurities and avoid is loading of the solvent with components of either the detergent or clarifler, and to reduce the quantity of clarifier that'would otherwise be required in the proportion that fatty acids introduced into the solvent from the clothes are neutralized by alkalinity of the detergent.

Due to the fact that, although the quantity of fatty acid and alkaline content of the impurities removed from clothing may vary slightly in different localities, the soil content, including free dirt as well as fatty acid and fats, remains substantially constant, and the mass of impurities substantially uniform at 5% by weight to the weight of the clothing regardless of location, a detergent and a clarifler of substantially uniform compositions respectively may be sup- 7 plied for dry cleaning according to my improved process, as presently more particularly described.

It is, therefore, the object of my invention to provide a balanced unit process of dry cleaning with non-aqueous solution including addition of an alkaline detergent to the solvent during the cleaning operation and purification of the solvent with an adsorbing agent, preferably supplied in dry form, with or without filtration of loose dirt as a separate st p, the invention contemplating reversal of order of supply of detergent and clarifler to the solvent if so desired. I

As my process may be employed with any of several well known bath or continuous types of dry cleaning apparatus, 1 have not illustrzted its use with any particular form of appara us.

The term alkaline detergent as here employed may be defined as any mixture of detergent value which disperses or dissolves in the particular dry cleaning solvent to be used, and v which when shaken with twice its volume of distilled water gives a pH value to the water of greater than 7 and less than 12. The composi-' tion of the alkaline detergent should, be such that all materials which would cause odor or streaks in the cleaned garments are removed by the action of the dry clarifier defined herein.

The term dry clarifler as here employed may,

be defined as any powder or mixture of a natural silicious base, known commercially as bleaching or adsorbing earth, including the potentially active earth of the Creede formation near Creede, Colorado, when crushed and roasted at approximately 500 F. until the total moisture content is approximately 10%, and to which there is added approximately 1.25% of an alkali, such assodium carbonate.

'One example of alkaline detergent for employment with my process'may comprise a thin consisting of 78% liquid vehicle, preferably such as alcohol and/or other volatile solvents capable of dissolving a'weak alkali having cleaning characteristics, completely saponifled material, such as corn oil saponifled with caustic potash,

solu- 4% excess potassium carbonate, or other weak alkali;

Creede formation in Colorado,

An example of dry clarifier adapted for use with the detergent above stated may consist of:-

A clay product such as obtained from the activated by treatment with heat and, if necessary, alkali, to obtain a total moisture content of approximately 10% and a pH when shaken with distilled water of greater than 9 and less than 12.

1 Another example of alkaline detergent may consist of approximately:-

- 65 to 70% liquid vehicle, preferably such as alcohol and/or other volatile solvents capable of dissolving a weak alkali having cleaning characteristics, 20 to 24% completely saponified ma- .terial, such as corn oil saponified with caustic potash, is to 12% excesspotassium carbonate,

or other week alkali.

With the second example-of alkaline detergent should be used a dry clarifier consisting of A clay product such as obtained from the Creede formation in Colorado, activated by treatment with heat and, if necessary, alkali, to obtain a total moisture content of 6% and a pH when shaken with distilled water of greater than 'i' and less than 10.

With either of the above examples the alkali and fats in the detergent is completely balanced with the fatty acids and fats in the detergent plus those transferred to the solvent from the clothes so that a substantially balanced product results from the treatmentto leave no appreciable amount of fatty acids and fats added with the detergent to be removed by the clarifies,

\ for approximately ten minutes to remove loose dirt from the clothing, and the solvent then preferably removed, filtered and returned to the washer or replaced with a clean batch of solvent, the loose dirt being removed at this stage to avoid loading the detergent and clarifying agent with the loose soil. Any ordinary filter aid may be employed and centrifuging or settling substituted for nitration if desired.

4 to 6 ounces of either of the above stated examples of alkaline detergent solution is then added to the filtered cleaning solvent and the garments agitated in the bath for approximately thirty minutes.

,7 During this operation the soap and any vola- V tile solvents in the detergent loosens the fatty acids and fats so that they may be removed from the clothing, and the alkaline component neutralizes a portion of the fatty acids and fats 4 to 6 ounces of either of the above stated examples of dry clarlfier is then added to the mixture of cleaning solvent and detergent and the garments agitated in the solution of cleaning solvent, detergent and clarifler for from five to ten minutes.

During this operation any fatty acids and fats remaining in the solvent are adsorbed on the particles of clarifying agent, the clarifying agent acting as acoupling for transfer of the fats from the solvent to the excess alkali supplied by the detergent and which may be present in the clariiier as disclosed in Letters Patent No. 1,926,- 813, issued to me under date of September 12, 1933 the particles of clarifying agent with the impurities adsorbed thereon remaining in suspension in the solvent while the agitation continues.

The dirty solvent containing the clarifying agent and its adsorbed impurities, together with the spent detergent which is no longer soluble V in the solvent, is then removed from the machine and the impurities and detergent removed from the solvent mechanically as by filtration, centrifuging or settling. The clean solvent may then be returned to the washer or stored for reuse. v

- The process as above stated maybe varied by transfer of the clothing to another washer for T 9 treatment by a stronger detergent solution after preliminary cleaning with the solvent, and, when it is desired to leave a portion of the detergent in the clothing, the dry clarifier may be supplied ahead of the detergent for removal of impurities introduced by the clothing and left in the solvent by the detergent employed in a previous operation; the-detergent, in such cases, being then added to remove stains which cannot be removed by solvent alone. The propertions and control of theicleaning material is, however, the same for either order of operation.

What I claim and desire to secure by Letters Patent is:

i. In the process of dry cleaning including application to the articles to be cleaned of a nonaqueous solvent and a detergent having alkalinity sumcient for substantially neutralizing the fats and the fatty acids in the detergent and those transferred to the solvent from the articles being cleaned, purifying the solvent with a clarifying agent having an alkaline content balanced with alkalinity of the detergent to effect substantially complete removal of fatty acids and fats in the solvent by adsorption thereof by the clarifler.

2. In the process of dry cleaning including application to the articles to be cleaned of a non-aqueous solvent'and'an alkaline detergent, purifying the solvent with an adsorbing clarifier having an alkaline content which, together with that of the detergent, balances the acidity imparted to the solvent from the cleaned articles and the fats present in the detergent, to neuralize such acidity and'permit substantially complete removal of the. fats and fatty acids from the solvent by adsorption by the clariner.

3. In the process of dry cleaning including application to the articles to be cleaned of a non-aqueous solvent and an alkaline detergent composed of approximately 76% liquid vehicle, 20% completely saponifled material and 4% weak alkali, and removal of the solvent and detergent from the articles to be cleaned, purifymg the removed mixture with-a clarifler having 1,979,809 an alkaline content balanced with that of the detergent to Substantially neutralize fatty acid transferred to the solvent from the articles being cleaned and from thedetergent.

4. In the process of dry cleaning including application to the articles to be cleaned of a non-aqueous solvent and an alkaline detergent composed of approximately 76% liquid vehicle, weak alkali, and removal of the solyentand decompletely saponifled material and 4%.

whereby combined alkalinity of the detergent and clarifler substantially balances combined acidity imparted to the'solvent from the articles to be cleaned and from the detergent.

' RALPH A. mm