US3503702A - Process and apparatus for fluid treatment of substrate - Google Patents

Description

March 31, 1970 w, T. CARPENTER 3,503,702

PROCESS AND APPARATUS FOR FLUID TREATMENT OF SUBSTRATE Filed Feb. 2. 196'? 2 Sheets-Sheet 1 WILLIAM T. CARPENTER [1i EQJMAM,

tum 13m ATTORNEYS March 31, 1970 w. 'r. CARPENTER 3,503,702

PROCESS AND APPARATUS FOR FLUID TREATMENT OF SUBSTRATE Filed Feb. 2. 1967 2 Sheets-Sheet 2 N NN INVENTOR E. Q; S ATTO R N EY S WILLIAM r. CARPENTER BY Ck United States Patent 3,503,702 PROCESS AND APPARATUS FOR FLUID TREATMENT OF SUBSTRATE William T. Carpenter, Stanley, N.C., assignor to Gaston Country Dyeing Machine Company, Stanley, N.C., a corporation of North Carolina Filed Feb. 2, 1967, Ser. No. 613,651 Int. Cl. D06c 1/04 U.S. Cl. 8-149.2 14 Claims ABSTRACT OF THE DISCLOSURE A process and enabling apparatus for applying a fluid treating medium to substrate, particularly textile materials in either web or strand form. Application is accomplished by sonic generation of a lingering dispersion of the fluid treating medium within a closed chamber while passing the substrate through the chamber for exposure to the dispersion. Results fully comparable to padding are obtained; good control and uniformity of application are provided; and drying rates are much increased, as sonic dispersal allows treating mediums of high solids concentration (i.e., up to about 33%) to be handled effectively.

BACKGROUND OF THE INVENTION The invention is broadly concerned with and intended particularly for the fluid treatment of textile materials.

A sonic device of the sort disclosed by U.S. Patent No. 3,081,946 is employed according to the present invention for generating the treating medium dispersion. An earlier patent disclosure dealing with the principle of sonic generators is found in U.S. Patent No. 2,519,619, while U.S. Patent No. 3,070,313 contains a further relatively recent disclosure of a varied form of device for dispersing liquids sonically.

The only prior art disclosure that has been found which deals in any way with the use of sonic effects for treating textile material is U.S. Patent No. 2,622,961, in which synthetic filament is passed directly through a sonic velocity zone for subjection to wet steam under pressure incident to stretching of the filament.

Otherwise of general interest in illustrating the state of the prior art are U.S. Patents No. 1,683,687 and No. 2,298,906, the first of which proposes an air-brush spray means for forming a dye liquor mist to color silk fabric, while the second shows a cloth-treating chamber in which festooning rolls are arranged for immersing the cloth in a treating liquor and which is provided with means for sealing entrance and exit ports for the cloth so that the treating chamber can be maintained under pressure.

Sonic generation of a treating medium dispersion in accordance with the present invention makes it possible to obtain an aerosol of truly lingering characteristics in which the particles are predominantly of micron range in size (e.g., predominantly in the -10 micron range), and with which a persistent uniformity and exceptional penetrating characteristic are obtained that facilitates fluid treatment of textile materials uniquely with respect to operating control, production rate, and effective use of treating medium.

SUMMARY OF THE INVENTION This invention provides for fluid treatment of substrate, particularly textile substrate, through transient exposure of the substrate to a gaseous dispersion of the fluid treating medium propagated by sonic generation. Transient exposure of the substrate is effected by treating a continuously traveling length thereof through a treating chamber arranged for propagation and application of 3,503,702 Patented Mar. 31, 1970 the treating medium in disperse form. For all usual purposes the gaseous dispersion is an aerosol, and it is produced by a sonic generator located within the treating chamber remotely with respect to the substrate to be treated, while the chamber is otherwise suitably fitted for promoting effective exposure of the traveling substrate to the aerosol atmosphere maintained therein and minimizing condensation of treating medium particles from the atmosphere at the chamber walls.

Effective fluid treatment is obtained according to the present invention with a number of significant advantages. To begin with, the exceptional penetrating characteristic resulting from the micron range particulation obtainable through sonic dispersion provides for thorough interstitial application of the treating medium throughout the substrate. That is, the application effectively reaches each constitutent fiber of a textile web or strand being treated. Moreover, the effectiveness of the application in the foregoing respect is maintained independently of the particular nature of the substrate being treated, for the substrate pickup at a given treating medium feed rate has been found proportional to the weight of substrate exposed to the treating dispersion per unit of time.

Also, the application effectiveness is normally obtainable from only one sonic generator unit in any size of treating chamber, and on any width or weight of sub strate that may be handled in the chamber, for each sonically dispersed particle is truly representative of the treating medium fed to the sonic generator, so that the resulting dispersion creates a homogeneous atmosphere in the treating chamber and it is only necessary to regulate the treating medium feed at a level that will yield a chamber atmosphere from which a desired substrate pickup will be provided at the transient speed of the substrate through the chamber. It should be noted, however, that any consideration making it desirable to use more than one sonic generator may be dealt with as a matter of choice, for the essential homogeneity of the treating atmosphere may also be maintained from plural generators operating in the same chamber. It is further notable that regulation of the treating medium feed for a desired substrate pickup is readily controllable by simply adjusting the rate of feeding to the sonic generator, and that such adjustment may in fact be easily accomplished in the course of processing, if desired, without any necessity for interrupting operations. Likewise, whenever it is desired to change from one treating medium to another, the treating chamber may be cleaned in preparation for the changeover simply by feeding water or other cleaning fluid to the sonic generator for a short intervening period.

A further important practical aspect is the fact that the treating medium consistency remains essentially constant during processing, rather than being subject to solids depletion as is usual in the case of padding applications and the like. Additionally, sonic propagation of the treating medium dispersion allows a much higher solids concentration to be used than is possible with conventional procedures, for as long as the treating medium supply is not too viscous for feeding to the sonic generator it may be handled according to the present invention and solids concentrations up to about 33% are entirely feasible. As a consequence, substantially reduced wetting of the substrate results from the treatment application and drying rates are accordingly much increased (e.g., by as much as 5 to 9 times) those that are usual. Under some circumstances there may be no subsequent drying needed at all.

These and related advantages obtained in accordance with the present invention may be realized throughout the fluid treating field. Representative uses are for sizing,

finishing, resinating, or dyeing. The treating results are fully comparable to those obtainable with conventional procedures, such as padding, and the pickup efficiency is sufiiciently remarkable to reduce to practical insignificance the residual portion of committed treating medium supply that must be dropped at the conclusion of a given processing operation.

DESCRIPTION OF THE DRAWINGS FIG. 1 representatively diagrams the processing arrangement of the present invention and indicates a suitable configuration of apparatus for carrying out the process; and

FIG. 2 diagrams a suitable feeding and recirculating system for handling the treating medium supply in the course of operating the FIG. 1 apparatus.

DESCRIPTION OF THE PREFERRED EMBODIMENT In the apparatus illustrated in the accompanying drawings, a gaseous dispersion of a treating medium is sonically propagated in a treating chamber 10 within a sonically insulated vessel 12 and through which chamber 10 a textile web W is continuously trained for treatment by exposure to the propagated dispersion.

The web W enters and leaves the vessel 12 through rolling seals formed by a set of driven rollers that are disposed across the top of the vessel 12 and form a pair of nips. The roller set includes an input roller 14 that forms one of the nips with a middle roller 16, with the roller surfaces moving downward at the nip for web input. The middle roller 16 forms the other nip with an output roller 1-8 diametrically opposite the input nip, so that the roller surfaces move upward at this output nip for discharge of the textile web W thereat. Preferably, the middle roller 16 is driven, as by any conventional drive means (not shown), and the input roller 14 and output roller 18 are geared with and biased toward the middle roller 16 to maintain identical input and output speeds so that a constant length of the web W is maintained in the treating chamber.

The length of web W within the chamber 10 is trained around parallel upper and lower idler rollers 20 and 22. The upper idler rollers 20 are suitably aligned in a horizontal row, as are the lower idler rollers 22, with a substantial vertical space between rows. The Web W is trained around the upper and lower idler rollers 20 and 22 in staggered alternation such that the web is festooned for effective exposure to the dispersed treating medium within the chamber 10.

Dispersal of the treating medium is accomplished by a sonic generator unit 24 such as that available commercially from Astrosonics, Incorporated, of Syosset, N.Y., under the name Astrospray Series 1600, which incorporates features of the aforementioned U.S. Patent No. 3,081,946. This generator unit 24 is mounted centrally within the chamber 101 on a cross plate 26 below the row of lower idler rollers 22. As described in the aforementioned patent the generator unit 24 discharges air under pressure in a manner that creates a zone or field of sonic influence in which sonic waves emanating radially therefrom act on a treating fluid fed into the zone so as to break down or chop the fluid into particles that may be of micron range in size. The degree of particulation may be controlled with good consistency, and it is preferably regulated for the purposes of the present invention so as to yield particles that fall predominantly within the range of to microns in size. The resulting aerosol dispersion forms a persistent atmosphere in the chamber 10 beyond the sonic zone for treating the exposed length of web W that is festooned therein.

During particulation of the treating medium fluid in the sonic zone, the generated dispersion of treating medium particles spreads initially from the generator unit 24 in a laminar-like pattern under the influence of the active sonic waves, but as the spreading continues to the outer extent of the sonic zone, where the sonic wave energy has been substantially spent in effecting the particulation, a turbulent phase developes from which the dispersion propagates throughout the chamber 10 to form the treating atmosphere therein.

The treating atmosphere thus formed is maintained by continuous operation of the generator unit 24 at a feed rate that will satisfy the pickup desired on the web W. Operation of the generator unit 24 involves feeding the treating medium thereto in a suitable liquid carrier, while creating the sonic field by air discharge thereat as previously mentioned. The air supply needs to be in the order of p.s.i. in the illustrated embodiment. The liquid carrier is used in the proportion needed for fluid feeding of the treating medium, and the feed rate is selected for the solids delivery level that is needed.

As continuous operation of the generator unit 24 proceeds, the turbulent phase of the spreading treating medium dispersion developes in the lower portion of the chamber 10 at which lower portions 28a of the chamber walls 28 are arranged to taper the vessel 12 inwardly to a bottom well 30. These lower wall portions 28a are spaced from the generator unit 24 sufiiciently to allow development of the turbulent treating medium phase without intended impingement of the dispersed treating medium particles thereat. Some impingement does, of course, take place with a resulting condensation and recovery draining of treating medium to the bottom well 30, but such condensation mainly involves particles of larger size that are impelled to a greater extent by the sonic field, and the condensation that does take place on the wall portions 28a consequently serves the good purpose of removing these larger particles from the treating atmosphere so that the persisting disperse particles are more regularly maintained within the desired 5 to 10 micron range.

Above the tapered lower portions 28a, upper vertical wallportions 28b extend to contain the propagating gaseous dispersion, with containment being completed by top wall portions 34 to which resilient wiper blades 36 are fixed for sealing contact with the input and output rollers 14 and 18, which combine with the middle roller 16 to form the aforementioned input and output nips that prevent escape of the gaseous dispersion at the web input and output points.

The chamber space through which the web W is trained for exposure to the treating atmosphere formed by the propagating gaseous dispersion is separated from the space in which the generator unit 24 operates by a flat baffle plate 38 that extends completely across the chamber 10 in the direction viewed in FIG. 1 and has upwardly slanted edge portions 38a terminating laterally at a sufficient spacing from the adjacent vessel walls 28 to admit the gaseous dispersion to the upper chamber space.

This baffle plate 38 forms the bottom of a discharge chamber 40, the top of which is formed by a horizontal series of spaced baffle strips 42 arranged to form slats through which the chamber 10 is relieved to prevent air pressure building up therein from the operation of the generator unit 24. The discharge chamber 40 has an exhaust port 44 leading into a conventional rotary particle condenser 46 that is provided for recovery separation of the relatively small proportion of treating medium particles entrained with the discharging air.

The chamber 10 is also preferably fitted with blowers 48 provided for the purpose of maintaining a thin air plenum chamber 50 over the interior of the upper wall portions 28b and top wall portions 34. The plenum chamber 50 serves as a barrier to repel the gaseous dispersion at the walls and thereby minimize condensation of the treating medium thereat. The plenum chamber 50 is defined interiorly by a fine mesh wire screen 52 that extends at a slight interior spacing over the upper wall portions 28b and top wall portions 34 and is attached thereto by brackets (not shown) or any other suitable means.

In the preferred embodiment, a plenum blower 48 is located generally centrally in each of the upper wall portions 28b and is a low velocity centrifugal device that draws air from the atmosphere and discharges it into the plenum chamber 50 against a diffuser plate 54 that directs the incoming air for circulation through the plenum chamber 50. The air in the plenum chamber 50 is maintained at a pressure suificient to cause a slight air discharge through the screen 52 for the dispersion repelling action mentioned above. Any dispersion particles that do condense at the screen 52 or wall portions 28b flow downwardly to the lower wall portions 28a and into the well 30.

The feeding and recirculating system for operating the above-described apparatus is illustrated diagrammatically in FIG. 2. This system includes an air feed line 56 through which air from a compressed air supply passes sequentially through a globe valve 58, a supply pressure gauge 60, an air filter 62, a ball valve 64, a pressure regulator 66 and a feed pressure gauge 68 to the generator unit 24 to supply air at a regulated constant pressure for the generation of a desired sonic wave zone emanating from the unit 24.

A treating fluid mixture is prepared for feeding to the generator unit 24 in a mixing chamber 70 to which water or other carrier liquid is fed from a supply at a measured rate by a metering pump 72, while a selected treating material is fed from a supply tank 74 by a metering pump 76. If a second treating material is to be employed in the mixture it may be fed from a second supply tank 78 by another metering pump 80, and additional treating material supply means, of course, be provided if desired. The metering pumps 76 and 80 for the two supply tanks 74 and 78 are connected to the mixing chamber 70 through a three-way valve 82 that permits either one or both of the treating materials to be fed to the mixing chamber.

The mixed treating fluid is fed from the mixing chamber 70 through a feed line 84 to a connection with a drain line 86 from the chamber well 30, and a drain line 88 from the particle condenser 46, for delivery through a three-way valve 90 into one of two parallel supply reservoirs 82, from which the fluid supply is released through a three-way valve 94 to a metering pump 96 that delivers through a flow meter 98 and a pressure gauge 100 to the generator unit 24. The parallel arrangement of the supply reservoirs 92 facilitates changeover from one treating mixture to another.

In a typical operation the apparatus is used to apply a finishing medium to a continuous travelling textile web in the form of elastic tape material. The finishing medium comprises a mixture of polyvinyl alcohol, a fluorescent white dye, and water. The polyvinyl alcohol is fed from the first supply tank 74 and the dye is fed from the second supply tank 78 with the metering pumps 76 and 80 controlling the proportionate feeding of these two components to the mixing chamber 70. Water is fed by the water metering pump 72 to the mixing chamber 70 at a controlled feed rate to provide the desired mixture, e.g., two parts water to one part treating material. From the mixing chamber 70 the treating fluid flows to one of the supply reservoirs 92 from which it is pumped by the metering pump 80 to the generator unit 24 at which it is discharged into the sonic zone created thereat by the air feed from line 56.

As soon as the atmosphere within the treating chamber becomes saturated with water vapor, the composition of the dispersed treating medium particles remains constant so that the textile web W picks up the treating medium in the same concentration as that of the fluid being fed to the generator unit 24. The amount of pickup is controlled simply by adjustment of the feed rate of the metering pump 96 in relation to the weight and speed of the travelling web W.

During operation the particle condenser 46 collects treating material from the air being released from the chamber 10 and the well 30 collects material that has condensed within the chamber 10 for draining recovery and recirculation. Typically the quantity of material recirculated amounts to approximately 5% of the material that is fed to the system. In an operation of the type described, the percentage of prepared treating fluid actually applied to the web W may be as much as 98%.

It should be noted that the present invention is applicable to wet processing treatment of various sorts using fluids containing treating material in dispersions, suspen sions, emulsions, solutions, or other fluid carrier systems, and is applicable in finishing, sizing, dyeing, resinating and otherwise treating textile or any other substrate material that is subject to penetration of particles from a treating atmosphere of the sort heretofore described. While use of the invention for treating substrate in continuous web or strand form is its most apparent application, it may also be used to treat separate articles, e.g., finished garments. Additionally, it has particular advantage in treating relatively thick goods, such as for continuous dyeing of carpet which has not heretofore been feasible.

The present invention has been described in detail above in terms of a preferred embodiment for purposes of illustration only and it is to be understood that the scope of the present invention is not intended to be limited thereby or otherwise except as defined in the appended claims.

I claim:

1. A process for fluid treatment of substrate which comprises providing a treating chamber, sonically propagating a gaseous dispersion of a fluid treating medium within said chamber, and exposing said substrate to the propagated dispersion within said chamber.

2. A process as defined in claim 1 and further characterized in that the particles of said gaseous dispersion are predominantly of micron range in size.

3. A process as defined in claim 1 and further characterized in that said gaseous dispersion is formed from a fluid treating medium supply having a relatively high solids concentration up to about 33% but not so high as to render said supply too viscous for practical fluid handling in delivering it for sonic propagation in disperse form.

4. A process as defined in claim 1 and further characterized in that said gaseous dispersion is propagated from a single sonic source within said chamber.

5. A process as defined in claim 1 and further characterized in that said gaseous dispersion is an aerosol.

6. A process as defined in claim 1 and further characterized in that said gaseous dispersion is propagated within said chamber by sonic generation carried out therein remotely with respect to said substrate.

7. A process as defined in claim 6 and further characterized in that a continuous length of said substrate is caused to travel continuously through said treating chamber while said remotely generated gaseous dispersion is caused to form the atmosphere within said chamber.

8. A process as defined in claim 7 and further characterized in that said gaseous dispersion is caused to form the atmosphere within said chamber by maintaining said chamber sealed at entrance and exit of said traveling substrate and permitting gaseous discharge therefrom only incident to the relief of said chamber necessary for controlling the pressure therein.

9. A process as defined in claim 1 and further characterized in that a plenum is maintained at inner wall portions of said chamber for repelling said gaseous dispersion and thereby minimizing contact and consequent condensation of dispersed treating medium particles thereat.

10. Apparatus for fluid treatment of substrate comprising a treating chamber equipped with means for disposing said substrate therein, a sonic generator unit arranged Within said chamber remotely with respect to said substrate disposing means, said sonic generator unit being capable of receiving and generating a gaseous dispersion of predominantly micron range particulation from a fluid treating medium fed thereto, means for feeding. a fluid treating medium to said sonic generator unit for such gaseous dispersion, and means for causing the remotely generated gaseous dispersion to form a substrate treating atmosphere within said chamber.

11. Apparatus for fluid treatment of substrate as defined in claim 10 and further characterized in that said last mentioned means includes chamber sealing structure allowing substrate to be delivered into and removed from said chamber and chamber relief structure permitting gaseous discharge therefrom only incident to the relief of said chamber necessary for controlling pressure therein.

12. Apparatus for fluid treatment of substrate as defined in claim 11 and further characterized in that said substrate disposing means is arranged for festooning a continuous length of substrate within said chamber, and in that said chamber sealing structure incorporates roll elements forming delivery and removal nips for causing said continuous length of substrate to travel through said chamber.

13. Apparatus for fluid treatment of substrate as defined in claim 12 and further characterized in that baflle means is interposed within said chamber for shielding substrate festooned by said disposing means from any direct influence of said sonic generator unit.

14. Apparatus for fluid treatment of substrate as defined in claim 13 and further characterized in that plenum means is arranged at inner wall portions of said treating chamber for repelling a gaseous dispersion generated by said sonic unit and thereby minimizing contact and consequent condensation of dispersed treating medium particles at said wall portions.

References Cited UNITED STATES PATENTS 3,418,969 12/1968 Harris 685 X FOREIGN PATENTS 26,646 12/ 1906 Austria.

1,351,732 12 /1963 France.

WILLIAM I. PRICE, Primary Examiner US. Cl. X.R. 685

Images