US2922694A - Process for cleaning spots on fabric by applying a solvent and sub-atmospheric pressure to boil off the solvent - Google Patents

Description

Jan. 26, 1960 2,922,694

F. L. AVERA PROCESS FOR CLEANING SPOTS ON FABRIC BY APPLYING A SOLVENT AND SUB-ATMOSPHERIC PRESSURE TO BOIL OFF THE SOLVENT Filed June 8. 1953 INVENTOR. F/TZHUGH L. AVE/7A ATTORNEY States- Fitzhugh L. Avera, Alameda, Calif.

Application June 8, 1953, Serial No. 360,155

1 Claim. (Cl. 8-137) The invention, in general, relates to the garment cleaning art. More particularly, the invention relates to an improved method and improved equipment for eflecting the complete and rapid removal of spots, such as paint and ink spots, or food stains and the like, from a fabric.

Heretofore in the art of removing spots from garments, it has been the practice to apply a soil solvent on the upper surface of the material at the location or area of the spot to be removed and then rub the solvent over the spotted area with a brush or cloth in order that the solvent will take up the solids of the spot or stain., This is a tedious method of spot removal. In recent years, spot cleaning equipment has been introduced in the art, and such equipment includes the application of a vacuum to the underside of the garment material at the location or area of the spot to be removed and upon which the soil solvent has been applied. The equipment above mentioned is used in conjunction with a spray of steam which is intended to forcethe solvent and soil throughthe material into the low pressure or so-called vacuum area. This force of steam, when applied to the surface of material more often results in driving the solvent and soil, into the material rather than through the material resulting in a serious residual cleaning problem. With this equip ment, rubbing of the solvent over the soiled area of the garment is dispensed with since the vacuum drawn from underneath effects a quick drying of the garment and sol vent. desirably effective in removing the stain or the spot from the garment since the solvent and soil may be driven into the material and the solvents employed are incapable, in one application thereof, of taking the solids of the stain into solution, through the material and into the low pressure area. It has frequently required multiple applications of a given solvent in order to remove the'undesired spot, with deleterious results to the garment being cleaned because of the chemical action of the solvent drawn into the garment material which not only may discolor the material but may weaken the weave. The present invention is directed to obviating disadvantages inherent in prior spot removal methods and technique and to the provision of improved equipment and methods which afford instant spot removal with no deleterious action to the material being cleaned.

A primary object of my present invention is to provide means affording substantially instant and increased solubility of soil solids in aliquid solvent applied to garment material for removal of spots therefrom.

Another object of the invention is to provide an improved method and improved equipment of the indicated nature which effects the removal of spots from material with one application of a given solvent and which reduces the likelihood of damage to the material to a minimum.

A still further object of the present invention is to provide means of the aforementioned character which is relatively inexpensive to manufacture, install, maintain and This recent equipment, however, has not been as improved equipment which is illustrated in the accompanying drawings. It is to be understood, however, that I am not to be limited to the precise order of steps of the process nor to the precise embodiment of the equipment shown, as my invention, as defined in the appended claims, can be carried out in a plurality and variety of ways and can be embodied in a plurality and variety of forms.

Referring to the drawings:

Fig. 1 is a diagrammatic showing of the preferred embodiment of the invention, as applied to the removal of a spot or spots from a garment disposed on a planar surface.

Fig. 2 is a detail looking into the orifice of the tube forming a part of the invention.

In its preferred mode, the improved method of the present invention for effecting rapid removal from material of spots, such as paint spots, ink spots, or food stains or the like, preferably comprises applying a liquid spot cleaning solvent at room temperature to a spot on a material, and then effecting the boiling of the solvent at room temperature to quickly dissolve the soil solids in the solvent and to remove the solvent from the material along with the soil solids. In its preferred form, the improved equipment of my present invention comprises a vacuum pump vented to the atmosphere and capable of producing a vacuum approaching 30 inches of mercury, a flexible tube connected to said pump, a manually controlled valve in said tube controlling fluid flow therethrough, and an inlet orifice on said tube for overlying a spot area on material to which a liquid spot cleaning solvent has been applied; actuation of said pump to produce a vacuum of 29 to 30 inches of mercury effecting the boiling of the solvent to quickly dissolve soil solids therein.

The improved process can effectively be practiced with such standard spot cleaning solvents as perchloroethylene, tri'chloroethylene, or water, which boil at 20 C. (68 F.) when under vacuums greater than 29.33, 27.4 and 29.31 inches of mercury, respectively. Any other suitable spot cleaning solvent which boils at 20 C. (68 F.) when under vacuum exceeding 15 inches of mercury could also be employed.

In accordance with the present invention, I provide a smooth, glass-like surface 11 upon which a garment 12 may. be laid. I also provide a vacuum pump 13, which may be a mechanical pump, or a venturi type, or a steam or air evacuator and vented, as at 14, to the atmosphere and capable of producing a vacuum exceeding 15 inches of mercury and preferably close to 30 inches of mercury. Connected to the pump 13 is a flexible tube 16 which may be fabricated of rubber, or a synthetic rubber-such as neoprene, or of a plastic material, and in which is connected a manually operable valve 17 for controlling fluid flow through the tube; the valve being provided with a lever 18 for actuating the same. The pump 13, if mechanical, can be driven by a motor, not shown, or other prime mover as desired. On the inlet end of tube 16 I provide an orifice 19 which preferably has a cross-sectional area comparable to a circle of approximately /4 inch in diameter, it being understood that the shape of the orifice is not critical although its restricted size or cross-sectional area is critical to effect the application of the appreciably high vacuum desirable for effective operation.

In accordance with the invention, a garment 21 from which a spot is to be removed is placed upon a planar surface 22 with the garment so disposed as to place uppermost the area of the garment containing the spot. A

liquid spot cleaning solvent is then poured upon the said area and the tube 16 brought into position to place the orifice 19 thereof over the said area and in engagement with the garment. The vacuum pump 13 is then started and with valve 17 closed, the pump will build up a vacuum to the capacity of the pump which preferably approaches 30 inches of mercury. Thereafter, valve 17 is opened to effect a drawing of the appreciably high vacuum through orifice 19 which causes the boiling, at room temperature, of any one of the selected above named spot cleaning fluids. It requires only an instant application of the stated vacuum to the cleaning solvent over the area of the garment having the spot to be removed to effect the rapid dissolving of the soil solids in the solvent.

Should the spot area be relatively large and greater than the cross-sectional area of the orifice 19, it has been found practicable to rub the orifice over this larger area while holding the orifice sufficiently in tight engagement with the material not to lose effective vacuum, for example below 15 inches of mercury. In the event the vacuum inadvertently falls below such value, then the operator merely turns lever 18 to close valve 17 and permits the valve to remain closed a sufficient interval with the pump operating for the vacuum again to rise to the effective value.

For convenience, a suitable vacuum gauge 31 is connected into the vacuum line, or flexible tube 16, and supported adjacent to the work table, to enable the operator to have ready vision of the operating vacuum at all times.

Since the orifice 19 has a tendency to become clogged after a period of use, because of the almost instant removal of the soil from the material which can lodge in the orifice, any one of a multiple of means for cleaning the orifice may be provided; which among others may include couplings, not shown, for detachably connecting the orifice to the tube 16 so that the orifice can be removed readily for cleaning, or reversed air or steam flowed through the orifice under pressure,'or a solvent flush can be employed or some similar means of which there are numerous could be used.

The enhanced spot cleaning effected by my improved process and equipment, utilizing extreme vacuums which are applied to restricted material areas, is partially due, it is believed, to the kinetic action and physical agitation produced in the boiling away of the spot cleaning solvent. This theory is advanced only as a possible explanation of the spot cleaning benefits resulting from the process, and is not intended to be an accurate analysis of the chemical and physical reactions which occur. Accordingly if the analysis be faulty, the explanation hereinabove advanced is not to be construed in limitation of the advance made in the art, as recited in the appended claims.

By restriction of the area of applied vacuum to the size stated hereinabove; namely, an area equivalent to a circle of inch diameter, I have been able to hold vacuums in excess of 15 inches of mercury and to the extent of 29 to 30 inches of mercury for the few moments of solvent removal by boiling under such reduced pressures, all at atmospheric or room temperatures where the process is carried out. No damage to the material can result from the operation, and no discoloration of the material by reason of the application of excess amounts of solvent or undue extension of the solvent to larger areas of the garment can occur.

It may be mentioned that the prior art devices, using so-termed vacuum underneath the material being cleaned,

- are found inescapably to exert on the material only a moderate low pressure or vacuum on the order of the equivalent of a few inches of mercury at the maximum. Even the most restricted areas of applied vacuum from underneath the material, as taught and contemplated by the prior art, are such that the vacuum room temperature boiling away of solvents, achieved by the unique invention herein disclosed, has never been approached or contemplated heretofore.

his to be understood that the appended claims are to be accorded a range of equivalents commensurate in scope with the advance made over the prior art.

I claim:

A' material spot cleaning process consisting of placing a fabric having a spot containing area on an impervious surface, applying to said fabric at the spot containing area thereof a liquid spot cleaning solvent capable of boiling at a sub-atmospheric pressure applied thereto, and then eifecting the simultaneous boiling of said solvent and the removal of the spot from said fabric by subjecting the applied solvent at said area to sub-atmospheric pressure of a sufficient value to cause the solvent to boil at room temperature and maintaining. said sub-atmospheric pressure on the applied solvent to obtain boiling thereof and removal of'the spot through the kinetic action and physical agitation produced in the boiling away of the spot cleaning solvent.

References Cited in the file of this patent UNITED STATES PATENTS 1,106,231 Marshall Aug. 4, 1914 1,531,501 Popkin 4 Mar. 31, 1925 1,669,077 Brewer May 8, 1929 2,009,365 Wait July 23, 1935 2,058,632 Riebel et al Oct. 27,1936 2,193,804 Dahlberg Mar. 19, 1940 2,297,726 Stephanoif .m Oct. 6,, 1942

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