US2568499A - Method and apparatus for applying liquids to textile fibers - Google Patents

Description

Sept. 18, 1951 Filed Feb. 28, 1950 R. S. HOOD METHOD AND APPARATUS FOR APPLYING LIQUIDS TO TEXTILE FIBERS 2 Sheets-Sheet 1 Sept. 18, 1951 R. s. HOOD METHOD AND'APPARATUS FOR APPLYING LIQUIDS TO TEXTILE FIBERS Filed Feb. 28, 1950 Patented Sept. 18, 1951 METHOD AND APPARATUS FOR APPLYING LIQUIDS TO TEXTILE FIBERS Ralph S. Hood, Marblehead, Mass., asslgnor to Monsanto Chemical Company, St. Louis, Mo., a corporation of Delaware Application February 28, 1950, Serial No. 146,666

11 Claims.

The present invention relates to improved methods of applying liquids to textile fibers at some stage of their processing prior to their formation into a lap and also relates to improved apparatus for applying liquids to textile fibers which at some stage of their processing are con veyed in an air stream.

It has been proposed heretofore to treat cotton fibers to increase their moisture content. In one of the methods proposed the cotton fibers are continually progressed through a predetermined path, and during such progression they are continually agitated and repeatedly dropped through a moving column of gas containing sufficient water vapor or moisture to impart a certain amount of the moisture to the cotton being treated. The apparatus used to carry out such method includes a rotatable horizontally positioned drum, the inner walls of which are provided with vanes which serve the purpose of conveying the cotton fibers to the top of the drum so that they will drop through the column of moisture-containing gas moving through the drum. The above described method while it is satisfactory in those instances where relatively small amounts of moisture are introduced into the fiber is not suitable where relatively large amounts of moisture or liquid are present in the moving gas stream. In such instances the fibers become sufiiciently wet to adhere to the walls of the drum with the result that the walls of the drum must be cleaned out periodically. The apparatus used in accordance with this method is relatively costly and must be furnished as an additional piece of equipment since such apparatus is not employed in normal textile mill operations.

It has also been proposed heretofore to treat salvaged cotton with slightly moistened ozone. In this method the cotton is conveyed in a moving air stream through a pipe which is provided with a fan which serves to break up the cotton, the slightly moistened ozone being blown into the moving air stream before the cotton reaches the fan. This method is satisfactory in those instances where the amount of water introduced into the air stream is not sufiicient to wet the fibers. However, when relatively large amounts of liquids, that is, amounts suflicient to penetrate into the fiber are introduced into the moving air stream, the distribution of liquid on the fibers is not sufficiently uniform with the result that some fibers become sufiiciently wet to adhere to the walls of the pipe or to other objects and must be removed periodically to prevent operating, difli-' culties.

Various other methods and apparatus have been proposed, heretofore, for applying liquids to loose fibers while they are being processed in various types of apparatus such as heaters, pickers,etc. or while they are being conveyed mechanically, that is, by conveyor belts, wheels, rolls, etc., but none of the methods or devices proposed have been commercially satisfactory for obtaining uniform distribution of the treating liquid through the fibers without the formation of an undesirably large number of neps, that is,

lumps of fibers, which appear as such in the finished yarn.

The present invention has for one object, therefore, the provision of an improved method and apparatus for applying liquids to textile fibers at some stage prior to the formation of the fibers into a lap for the purpose of eliminating or minimizing the difficulties heretofore experienced with the methods and devices which were known in the prior art.

A further object of this invention is to provide an improved method of applying liquids which contain solid or substantially non-volatile materials therein to tufts of textile fibers to secure, a substantially uniform distribution of liquid and non-volatile material throughout the fibers and at the same time open or fluff the tufts of fibers so that they become more amenable to further processing operations.

A further object of this invention is to provide a simple, inexpensive and efficient apparatus for applying liquids to textile fibers, which apparatus is easily installed in commercial textile processing equipment and which can be used without interfering with the normal operation of such equipment.

Still further objects and advantages of this invention will appear in the following description when considered with the accompanying drawings and the appended claims.

The methods of this invention are carried out, in general, by first bringing textile fibers, preferably fibers which have been at least partially opened, into contact with a gas stream, for example, an air stream, which is moving at a sufficient velocity to pick up and convey the fibers and to maintain the fibers in a suspended state. The gas stream containing the fibers suspended therein is next directed through a passageway provided with at least one narrow portion which converges to form an opening of substantially smaller cross sectional area than the normal cross-sectional area of the passageway. A jet of air is continuously discharged into the moving gas stream in the same direction that the gas stream is moving and at such point in the line of travel of the gas stream and at sufficient velocity to accelerate the fibers in their passage through the narrow portion of the passageway. The term-accelerate is intended to cover only those instances in which the fibers are increased in velocity by the added velocity imparted to the gas stream by the jet of air or gas, and not the normal increase in velocity imparted by the passage of the air stream per se through the narrow portion of the passageway. As the fibers emerge from the narrow portion of the passageway and move into the downstream end of the passageway, they decelerate. At some point between the time the fibers are accelerated by the jet of air and the time they decelerate because of the loss in velocity of the gas stream emerging from the narrow 'portion of the passageway, the fibers are subjected to a spray consisting of fine droplets or a mist of the liquid which it is desired to apply to the fibers. The fibers are preferably sprayed with the liquid however at some point in their passage between the point where they are accelerated by the jet of air and the point where they emerge from the narrow portion of the passageway. By carrying out the above process it is possible to intimately mix the fibers and the treating liquid and secure substantially uniform distribution of the liquid through the fibers without appreciably overwetting the fibers.

The apparatus of the present invention comprises, ingeneral, a conduit or pipe through which textile fibers are conveyed, means for supplying fibers to one end of the conduit, means for generating a gas stream in the conduit for conveying fibers therethrough, means for discharging a jet of air into the conduit and longitudinally thereof, and means for spraying liquid onto the fibers as they pass through the conduit.

vThe conduit is provided with at least one narrow portion which converges in the direction of fiow of the fibers and which may suitably be a converging duct or nozzle inserted within the conduit. When a converging duct or nozzle is used, it is positioned in the conduit with its large end closest to the fiber supply means, its other end being spaced from the inner walls of the conduit and terminating in an opening which is substantially smaller in cross-sectional area than the cross-sectional area of the conduit. The air jet means referred to above is located near the large end of the nozzle, while the spraying means is I located in the immediate vicinity of the nozzle, that is, either just in front of or within the nozzle or just beyond the small end of the nozzle.

One specific embodiment of such apparatus is illustrated in the accompanying drawings which form a part of this application. In the drawings Fi ure 1 illustrates, semi-diagrammatically, a number of devices employed in a mill which processes textile fibers according to the cotton system, and also illustrates partly in section and semi-diagrammatically the liquid-applying apparatus with which the present invention is primarily concerned. and

Figure 2 illustrates an enlarged vertical section of a part of the liquid-applying apparatus shown in Figure l, and

Figure 3 illustrates an enlarged partial vertical section of a modification of the liquid applying apparatus illustrated in Figure: 1.

In the drawings in which like numerals refer to like parts, In refers to a vertical opener for opening cotton fibers. This opener communicates '4 through pipe II with a fiber condenser l2 which is provided with a fan for sucking the fibers from the vertical opener through pipe I I into the condenser. Adjacent to condenser I2 is a feed chamber l3 which communicates with a cleaning and opening section l4. The latter communicates through pipe IS with a. second condenser it which is provided with a fan for sucking filbers from the cleaning section l4 through pipe i5 into the condenser. The fibers in condenser l6 are discharged mechanically on a feed table II. Positioned immediately above the feed table and the fibers thereon is a conduit l8 which is arranged vertically and provided with an opening, the open end of the conduit being in a horizontal plane substantially parallel to the surface of the feed table'to which the fibers are supplied. The apparatus described up to this point is conventional and forms no part of the present invention, except to provide a setting in relation to which the present invention may be more readily understood.

The conduit I8 is provided with a horizontally positioned section, shown partially broken away in Figure 1, in which is positioned a tapered nozzle I9 and means for supplying a jet of gas or air and a liquid spray, which means is designated generally by the numeral 20. Both the nozzle l9 and means 20 will be described in greater detail hereinafter. The conduit l8 terminates at a conventional fiber condenser 2| which is provided with a. suction fan. The fan sucks'air from conduit l8 thus inducing a fiow of air into the upstream end of conduit i8 (positioned above feed table II) at sumcient velocity to pick up the fibers from feed table I! and convey them through the conduit. The condenser 2| communicates with a conventional feed chamber 22 from which the fibers are fed at a predetermined rate into a conventional picker 23 in which the fibers are further cleaned and opened and eventually formed into a lap.

Referring specifically to the air and liquidapplying means 20, which is illustrated diagrammatically in Figure 1 and is partly shown in greater detail in Figures 2 and 3, numeral 24 represents a cylindrical pipe, one'end portion of which is provided with a valve 25, a pressure gauge 26 and an'air pump 21. The other end of pipe 24 is internally threaded and is provided with a nozzle 28 which is screwed into the pipe. This pipe is supported in any satisfactory manner, for example, in the conduit by suitable spider-type braces (not shown) or it maybe supported externally oi the conduitbyany suitable support lot shown). Joining pipe 24 near the nozzle end thereof and atright angles thereto is a vertically positioned cylindrical pipe 29 which is provided with a curved portion and a horizontal portion, the longitudinal axis of the horizontal portion being coincident with the longitudinal axis of pipe 24. The horizontal portion of pipe 29 terminates inside of conduit i8 in an internally threaded end portion which is provided with a nozzle 30 which is screwed to the pipe.

Pipe 29 passes through thenipple 3| in the wall of pipe 24, which nipple is provided with a bushing 32, and also passes through the nipple 93 in the wall of conduit l8, which nipple is provided with a bushing 34. This arrangement provides some support for pipe 29 and also prevents air from leaking from pipe 24 and conduit l8. The lower end of pipe 29 is externally threaded and screwed into the top ortion of reducing T 35. Positioned inside of pipe 26 is a second cylindrical pipe 36, the center axis of which is coincident with the center axis of pipe 29. Pipe 36 is supported by bushing 31 which is screwed into the lower portion of T 35. The bushing also serves to seal the lower portion of T 35 and prevent leakage of air. The horizontal portion of pipe 36 terminates flush with the end of nozzle 30, The vertical portion of this pipe is provided with a valve 38 (see Figure 1) and a liquid gear pump 39 and terminates near the bottom of container 40 in which the liquid to be supplied to the fibers is stored.

Extending horizontally from T 35 and screwed therein is cylindrical pipe 4| which is provided with a valve 42 and an air pump 43. Pipes 23, 36 and 4| and container 40 are all supported externally of the conduit l8 by suitable means (not shown).

The nozzle H! which was referred to above consists of a shell or horn which tapers gradually toward its exit or downstream end and is circular in cross section. The longitudinal axis of the nozzle is coincident with the longitudinal axis of the conduit l8. The end of nozzle l9 closest to the feed table II, that is, the large or upstream end of the nozzle, abuts against the inner walls of the conduit l8 and is welded thereto. The other end of the nozzle, that is, the small or downstream end, is also annular in form and is spaced equidistantly from the inner walls of conduit l8. The opening in this end of the nozzle is substantially smaller in cross-sectional area than the cross-sectional area of the conduit. In general, the ratio of the cross-sectional area of this opening to the crosssectional area of the conduit is from about 1:2 to 1: 12. These ratios are dependent upon the diameter of the conduit l8 which is generally from 6 to 14 inches but which may be larger or smaller, the velocity of the gas stream flowing through the conduit l8 and the velocity of the air injected into the gas stream through pipe 24. It is preferable, however, to employ a ratio of 1:5 to 1:10 for most satisfactory results.

The apparatus described in the present invention is not limited to the use of one nozzle I9 as illustrated in Figuresl and 2. In Figure 3 is illustrated a specific embodiment of an apparatus constructed for use in accordance with this invention in which more than one nozzle is em ployed. In Figure 3, numeral 44 represents a cylindrical conduit which is constructed of several cylindrical pipes of different diameters. The upstream portion of conduit 44 is provided with tapered nozzle IS, the downstream end of which opens into a cylindrical chamber 45. The downstream end of chamber 45 is in the form of a second tapered nozzle 46. Welded to the outer wall of nozzle 46 is conduit 41 which serves as a continuation of conduit 44 to conduct the fibers to the fiber condenser, such as shown at 2| in Figure l.

The operation of the liquid-applying apparatus is as follows:

Textile fibers such as cotton fibers or other natural cellulose fibers, synthetic staple fibers, animal fibers and the like are first partially opened as in the vertical opener l0 and the cleaning and opening section I4 and are then supplied to a feeding device such as feed table II. In the apparatus illustrated in the drawing a moving air stream is created in conduit l8 by sucking air therefrom by means of a fan located in condenser II a y dis r in a jet of air from pipe 24 into nozzle l3. This induces a current of air to flow into the lower end of conduit l8 which is positioned immediately above feed table H. The air stream thus generated has suflicient velocity to pick up the tufts of fibers from the feed table and to maintain the fibers in a suspended state as the air stream moves in the direction of condenser 2|. The air stream containing the suspended fibers passes through the tapered nozzle 9. As the fibers enter nozzle l9 they are subjected to a jet of air from pipe 24, which air is supplied to pipe 24 by pump 21 at a velocity exceeding the velocity of the air stream in conduit I8. As a result the fibers suspended in the air stream are accelerated in their passage through nozzle l9. That is, they are accelerated to a greater extent than would be possible by the mere velocity of the air stream in conduit H3. The jet of air from pipe 24 also produces a turbulent air flow in the nozzle l9 and this in combination with the acceleration of the fibers through nozzle' I9 causes a distortion of the tufts of fiber. The fibers emerging from the downstream end of the nozzle l3 lose some of their velocity, that is, they decelerate, and again are distorted by this deceleration.

While the fibers are being conveyed through nozzle |9 and are being accelerated by the jet of air from pipe 24, they are sprayed with a fine mist or fine droplets of the liquid which it is desired to apply to the fibers. This is accomplished by the air and liquid-applying means 20 as follows: liquid is pumped from contaainer 40 at a metered rate through pipe 36 by means of gear pump 39 after opening valve 38. Atthe same time air is pumped through pipe 4| into pipe 29 thence through nozzle 30 at a velocity sufficient to atomize the liquid emerging from pipe 36. The rate at which the liquid is supplied through pipe 36 is so adjusted in relation to the weight of fibers being conveyed that the desired amount of liquid is applied to the fibers. A slight excess of liquid may be used in those instances where the liquid is volatile in view of the fact that some of the liquid may be vaporized before it penetrates into the fibers. The fibers are next conveyed to the condenser 2| where they are separated from the air stream in the usual manner.

By using the apparatus illustrated in the drawings and described above, it is possible to apply liquids to textile fibers in a uniform manner without wetting the fibers to the extent that they stick to the side walls of the conduit or to other surfaces with which the fibers may come into contact in subsequent processing operations.

The applicant has observed that when tufts of cotton fibers, for example, are processed according to the method described herein and using the apparatus described in the drawings such tufts are opened up and expanded, and hence occupy a large volume. Thus, the volume occupied by the original fibers is increased from 1% to 3 times by using the methods and apparatus of this invention. The exact explanation for this is not known, but it is believed that the tufts of fibers in their passage through nozzle l9 are subjected to shear by the differential in velocity between the gas stream in conduit l8 and the jet of air from pipe 24 and a resulting differential in pressure existing in nozzle l9. Best results are obtained by supplying a jet of air which has a velocity of from 10 to times the velocity of the as stream. This shear is believed to distort the tufts of fibers sufficiently to cause the tufts to open up, that is, occupy a, larger volume, become more porous and thus present a larger area. It is also believed that since the tufts of fibers emerging from nozzle I9 are subjected to decreasingly less shear, they are again distorted in an opposite sense by deceleration of the tufts of fibers and are further opened. It is thus seen that when the tufts of fibers are subjected to a fine mist or fine droplets of liquid while they are being accelerated and declerated in the manner described the fibers are not only intimately mixed with such liquid but also become more porous and present a larger surface area for penetration of the. liquid through the tufts of fibers, At the same time the liquid is worked into the center of the tufts of fibers by the distorting forces to which the tufts cf fibers are subjected while being accelerated and decelerated. Although the above explanation is believed to account for the uniform distribution of liquid on the tufts of fibers treated in accordance with the present invention, it is not intended to limit the invention to any theory presented herein.

It has presently been found that satisfactory results are obtained by subjecting the fibers in the gas stream to a fine mist or fine droplets of nozzle l9, or equivalent narrow portion of the conduit l8, during their passage through nozzle l9, or after they have emerged from nozzle l9 but are not fully decelerated. It is preferred, however, to subject the fibers to the mist or fine droplets of liquid at some point in their passage through nozzle l9.

Various changes and modifications may be made in the apparatus illustrated in the drawings in view of the above discussion. In the first place the nozzle end of pipe 24 may be positioned further inside of the nozzle l9 to obtain a maximum acceleration of the fibers for any given velocity of air pumped through pipe-24, or it may be positioned upstream of and away from the upstream end of nozzle l9. However, the nozzle end 28 of pipe 24 should not be located at such a distance from the flaring or upstream end of nozzle 19 that no appreciable acceleration of the fibers is obtained. The position of the nozzle end of pipe 24 is therefore largely dependent on the extent to which the fibers are to be accelerated and the extent to which it is desired to open the tufts of fibers and on the velocity of the air from pipe 24, and is also dependent on the size of pipe 24 in relation to conduit l8 and the amount of liquid which is applied to the fibers. It is preferable however to position pipe 24 so that the jet of air therefrom is directed along the longitudinal axis of conduit I8 and the nozzle end 28 terminates near the upstream end of nozzle l9, or inside of nozzle l9.

The position of the nozzle end of pipe 29 may be varied to a considerable extent provided that the following conditions be observed. The nozzle end of pipe 29 should not be positioned upstream of the nozzle end of pipe 24 or downstream of nozzle l9 beyond the point at which the fibers are fully decelerated after emerging from the downstream end of nozzle IS. The pipe 29 need not be positioned in or inserted through the pipe 24, but may be positioned between the pipe 24 and the nozzle I9 and at an angle to the longitudinal axis of conduit l8 or even transverse to such axis. Thus, the liquid may be sprayed longitudinally, transversely or at an angle to the direction of flow of the gas stream in conduit I8. It is preferred, however, to position the nozzle end 30 of pipe 2! so that it terminates at some point between the nozzle end 28 of pipe 24 and the downstream end of nozzle l9 and is coincident with the longitudinal axis of conduit l8.

Thus, the fibers in the gas stream are preferably" subjected to a fine mist of liquid which is projected longitudinally of conduit l8 and at some point in their passage between the point at which they are first accelerated by the jet of air from pipe 24 and the point at which they begin to. emerge from nozzle l9.

A separate air stream such as is provided by pipe 28 is not essential for the successful operation of the apparatus. The jet of air from pipe 24 may be utilized to atomize the liquid flowing from pipe 36 and, accordingly, pipes 29 and 4|, reducing T 35, valve 42 and air pump 43 may be dispensed with. It is preferred, however, to use a separate air pipe such as pipe 29 for atomizing the liquid from pipe 36 since such an arrangement provides for greater flexibility of operation and better control over the size of the atomized liquid particles.

It is not essential that the nozzle I9 and the air and liquid-applying means 20 be located in the horizontal portion of conduit l8 since satisfactory results are obtained if they are located in a vertical or inclined portion of the conduit. In most textile mills conveying conduits such as conduit iii are usually positioned horizontally v and only contain short sections which are inclined from the ,horizontal or positioned vertically. Therefore, in most instances the apparatus described herein will be utilized m a horizontal section of the conduit. Moreover, the liquid-applyin apparatus can be used in conveying conduits other than the conduit which is employed to convey fibers from feed table I! to condenser 2|. Thus, the apparatus may be employed, for example, in the conduit or pipe H through which fibers from the opener ID are conveyed by air to condenser l2, or in the conduit or pipe l5 through which fibers from the cleaning and opening section l4 are conveyed by air to condenser It, or in any other conduit through which the fibers are conveyed by an air stream prior to their formation into a lap.

The nozzle 19 need not be a flared nozzle such as shown in the drawings for satisfactory operation of the apparatus. Thus, it is possible to use a nozzle which is in the form of a frustrated cone, the sides of which form an angle of less than 30 with the longitudinal axis of the cone. It is also possible to employ a standard Venturi nozzle. Moreover, since the conduit may be rectangular, polygonal, elliptical, square or circular in cross-section, it is possible to employ nozzles which have the same cross-sectional shape as'that of the conduit in which they are used. Furthermore, it is possible to dispense with a nozzle as such and provide a conduit, a portion of the walls of which are in the form of a. nozzle of the type described. It is preferred to use a nozzle having smooth inner surfaces.

The liquid may be supplied through pipe 36 by means other than a gear pump. Thus, it is possible to use a rotameter for this purpose in those instances where the liquid is stored above the conduit, or the liquid may be supplied by gravity feed.

A wide variety of liquids may be supplied to textile fibers by the liquid-applying apparatus of this invention; As examples of such liquids may be mentioned textile lubricating or conditioning oils, either alone or in admixture with aeoacoo water in the form of emulsions; liquid hygrosoopic agents or water solutions of hydroscopic agents; water solutions of inorganic salts; water solutions of dyes or tinting agents; colloidal solutions of silica or other inorganic oxides and the like. The method and apparatus of this invention are particularly suitable for the application of liquids which contain a volatile liquid such as water and a non-volatile substance or substantially non-volatile substance such as colloidal silica or textile oils. The amount of liquid applied to the fibers in accordance with the present invention may be varied considerably depending upon the particular liquid applied and the particular fiber which is being processed. For

example, wool fibers or other animal fibers absorb considerable amounts of liquid and particularly water without becoming excessively wet.

- Since such fibers may contain some water or liquid prior to treatment the weight of liquid applied by the processes described herein together with the liquid present in the fibers should not exceed about 40% by weight based on the bone dry fibers. In the case of natural cellulose fibers such a cotton or linen fibers or regenerated cellulose staple fibers, such as viscose staple fibers, the amount of liquid applied together with the water or liquid originally present in the fibers should not normally exceed about 10 to 12% by weight based on the bone dry weight ofthe fibers. Synthetic staple fibers such as cellulose acetate staple fibers, linear polyamide staple fibers and the like normally do not tolerate more liquid than cotton fibers.

The methods of this invention are particularly directed to the application of aqueous solutions of colloidal silica to fibers which are processed in machinery employed in the cotton system, for example, cotton fibers, linen fibers, ramie fibers and jute fibers, and synthetic staple fibers including regenerated cellulose staple fibers. In such instances aqueous solutions of colloidal silica containing from about 1 to 35% by weight of colloidal silica are applied to the fibers in the form of a fine mist or fine droplets in amounts suificient to deposit from about 0.1 to 5% of colloidal silica based on the weight of the fibers.

A further understandingof the present invention will be obtained from the following specific example, which is intended to further illustrate this invention, but not to limit the scope thereof.

Example Cotton fibers in the form of individual tufts of 1 inch size were conveyed through a 6 inch conduit l8 at the rate of 1 to 2 pounds/minute suspended in an air stream moving at a velocity of 1500 feet per minute. In the nozzle l9 which was provided with a two inch opening or throat the cotton fibers were subjected to a jet of air from pipe 24 which was provided with a inch nozzle. The velocity of this jet of air was 21,000 feet per minute. At the same time the fibers were sprayed with an atomized aqueous solution of colloidal silica. This solution which contained into the conduit. The tufts of cotton had a dry feel and were uniformly tinted with the dye, which had been added to the solution, which indicated that the hquid was applied uniformly throughout the fibers. The walls of the conduit were found to be substantially free of tufts of fibers.

Modifications and changes in the method and apparatus of the present invention other than those described herein may be made as will be apparent to those skilled in the art to which it appertains without departing from the spirit and intent of this invention. It is to be understood therefore that the scope of the present invention i not intended to be limited in any manner except by the scope of the appended claims.

What is claimed is:

1. A method of applying liquids to textile fibers which comprises bringing textile fibers prior to their formation into a lap into contact with a gas stream which is moving at suificient velocity to pick up the fibers and convey them in a suspended state, directing the gas stream containing the suspended fibers through a passageway provided with at least one narrow portion which defines an opening of substantially smaller crosssectional area than the cross-sectional area of said passageway, continuously discharging a jet of air into the moving gas stream in the same direction that the gas stream is moving and at such a point in the line of travel of the gas stream and at sufiicient velocity to accelerate the fibers in their passage through the narrow portion of said passageway, and subjecting the fibers in said gas stream to a spray consisting of fine droplets of liquid between the point in their travel through said passageway where they are first accelerated and the point at which they decelerate after their passage through the narrow portion of said passageway.

2. A continuous method of applying liquids to textile fibers which comprises continuously bringing textile fibers prior to their formation into a lap into contact with an air stream which is moving at sufficient velocity to pick up the fibers and convey them in a suspended state, directing the air stream containing the suspended fibers through a passageway provided with at least one narrow portion which terminates in an opening of substantially smaller cross-sectional area than the cross-sectional area of said passageway, continuously discharging a jet of air into the moving air stream in the same direction that the air stream is moving and at such a point in the line of travel of the air stream and at sufficient 'velocity to accelerate the fibers in their passage through the narrow portion of said passageway, and subjecting the fibers in said air stream to a spray consisting of fine droplets of liquid while the fibers are being accelerated by the jet of air and before they emerge from the narrow portion of said passageway.

3. A continuous method of applying liquids to textile fibers which comprises continuously bringing textile fibers prior to their formation into a lap into contact with an air stream which is moving at sufficient velocity to pick up the fibers and convey them in a suspended state, directing the air stream containing the suspended fibers through a passageway provided with at least one narrow portion which converges to form an opening of substantially smaller cross-sectional area than the cross-sectional area of said passageway, eontinuously discharging a jet of air into e moving air stream near the beginning of the ammo ll narrow portion of said passageway and in the same direction that the air stream is moving and at sufiicient velocity to accelerate the fibers as they move through the narrow portion of said passageway, and subjecting the fibers in said air stream to a spray consisting of fine droplets of liqui while the fibers are being accelerated by the ct of air and before they emerge from the narrow portion of said passageway.

4. A process substantially according to claim 3, but further characterized in that the velocity of the jet of air is from to 100 times greater than the velocity of the air stream.

5. A process substantially according to claim 3, but further characterized in that the liquid used is an aqueous solution of colloidal silica.

6. A continuous method of applying liquids to cotton fibers which comprises directing a mov-' ing air stream in which cotton fibers are suspended through a passageway provided with at least one narrow portion which converges to form an opening of substantially smaller crosssectional area than the cross-sectional area of said passageway; continuously discharging a jet of air into the moving gas stream near the beginning of the narrow portion of said passageway and in the direction of movement of the air stream, the velocity of the jet of air being from 10 to 100 times greater than the velocity of the air stream, whereby the cotton fibers are accelerated as they move through the narrow portion of said passageway, and subjecting the fibers in said air stream to a spray consisting of fine droplets of an aqueous solution of colloidal silica while the fibers are being accelerated by the jet 1 air and beiore they emerge from the narrow gortion of said passageway, said solution containing from 1 to 35% by weight of colloidal tilica and being supplied in an amount sufiicient provide from 0.1 to 5% by weight of silica on the weight of the fibers.

.7. An apparatus for applying liquids to textile ,fibers comprising a conduit through which xtile fibers are conveyed ,by an air stream; means for supplying textile fibers to the upstream end of said conduit; means for generating a gas stream in the conduit; at least one nozzle positioned in said conduit, the large end of the nozzle being closest to the upstream end of the conduit and abutting against the inner wall of the conduit and the small end of the nozzle terminating in an opening which is substantially smaller in cross-sectional area than the crosssectional area of the conduit; means for dis- 12 charging a jet of air into the conduit and longitudinally thereof near the large end of the nozzle, and means for spraying liquid on said fibers in the immediate vicinity of the nozzle.

8. An apparatus for applying liquids to textile fibers'comprising a conduit through which textile fibers are conveyed by an air stream; means for supplying textile fibers to the upstream end of said conduit; means for generating a gas stream in said conduit; at least .one nozzle positioned inside of the conduit, the large end of the nozzle being closest to the upstream end of the conduit and abutting against the inner wall or the conduit and the small end of the nozzle being spaced from the inner walls of the conduit and terminating in an opening which is substantially smaller in cross-sectional area than the cross sectional area of the conduit; means for discharging a jet of air into the conduit and longitudinally thereof near the large end of the nozzle, and

means for spraying liquid into said nozzle.

9. An apparatus for applying liquids to textile fibers comprising a conduit through which textile fibers are conveyed by an air stream; means for supplying textile fibers to the upstream end of said conduit; means for generating an air stream in said conduit; -'a nozzle positioned inside of the conduit, said nozzle being provided with a large end portion which is positioned closest to the upstream end 01' the conduit and abuts against the inner wall of the conduit, and a small end portion whichis spaced from the inner walls of the conduit and terminates in an opening which is substantially smaller in cross-sectional area than the cross-sectional area of the conduit; a

pipe positioned inside the conduit coincident with the longitudinal axis thereof and terminating nearthe large end of the nozzle; means for supplying air to said pipe; a tube positioned inside of said pipe and terminating between the end of said pipe closest to the nozzle and the small end 01' said nozzle, and means for supplying liquid to said tube.

10. An apparatus substantially according to claim 9, but further characterized in that the ratio of the cross-sectional area of the opening in the small end of the nozzle to the cross-sectional area 01' the conduit is between about 1:2 and 1:12. llfiAn apparatus substantially according to claim 9, but further characterized in that the conduit is provided with at least two nozzles.

. RALPH S. HOOD.

No references cited.

Claims (1)

1. 2. A CONTINUOUS METHOD OF APPLYING LIQUIDS TO TEXTILE FIBERS WHICH COMPRISES CONTINUOUSLY BRINGING TEXTILE FIBERS PRIOR TO THEIR FORMATION INTO A LAP INTO CON TACT WITH AN AIR STREAM WHICH IS MOVING AT SUFFICIENT VELOCITY TO PICK UP THE FIBERS AND CONVEY THEM IN A SUSPENDED STATE, DIRECTING THE AIR STREAM CONTAINING THE SUSPENDED FIBER THROUGH A PASSAGEWAY PROVIDED WITH AT LEAST ONE NARROW PORTION WHICH TERMINATES IN AN OPENING OF SUBSTANTIALLY SMALLER CROSS-SECTIONAL ARE THAN THE CROSS-SECTIONAL AREA OF SAID PASSAGEWAY, CONTINOUSLY DISCHARGING A JET OF AIR INTO THE MOVING AIR STREAM IN THE SAME DIRECTION THAT THE AIR STREAM IS MOVING AND AT SUCH A POINT IN THE LINE OF TRAVEL OF THE AIR STREAM AND AT SUFFICIENT VELOCITY TO ACCELERATE THE FIBERS IN THEIR PASSAGE THROUGH THE NARROW PORTION OF SAID PASSAGEWAY, AND SUBJECTING THE FIBERS IN SAID AIR STREAM TO A SPRAY CONSISTING OF FINE DROPLETS OF LIQUID WHILE THE FIBERS ARE BEING ACCELERATED BY THE JET OF AIR AND BEFORE THEY EMERGE FROM THE NARROW PORTION OF SAID PASSAGEWAY.

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