US3172780A

US3172780A - Apparatus for treating textile filaments

Info

Publication number: US3172780A
Authority: US
Publication date: 1965-03-09
Anticipated expiration: 1982-03-09

Description

United States Patent 3,172,780 APPARATUS FOR TREATING TEXTILE FILAMENTS Tibor Csok, Camden, S.C., and Thurman V. Williams, Jr., Wilmington, Del., and Thomas D. Williamson, Lugolf, S.C., assignors to El. du Pont de Nemours and Company, Wilmington, Del., a corporation of Delaware Filed Apr. 10, 1961, Ser. No. 101,747

2 Claims. (Cl. 11850) This invention relates to a new process and apparatus for applying liquid finish to a continuously moving filamentary tow. More particularly, the invention relates to a process and apparatus for uniformly applying liquid finish to a very large number of continuous filaments comprising a tow.

To effectively process textile fibers into yarns and other more finished products, it is necessary to apply a surface lubricant or other liquid conditioning agent to the fibers. Moreover, it is essential that the conditioning agent be present in an essentially uniform amount on substantially all the fibers undergoing textile processing. The most economically feasible way to apply such finish to the fibers is while they are in the form of a very large tow of many tens of thousands of continuous filaments as collected from the spinning machine. When the finish ingredients are applied to a washed and drawn tow of, for example, acrylonitrile polymer filaments while still wet, there is substantial finish migration during drying and many filaments acquire a great excess of finish while many others retain very little, if any, finish at all. Obviously, application of finish to the dried filaments obviates this migration problem; but to apply the conditioning agent to the very large number of dry filaments in a single bundle or tow with any semblance of uniformity of application to all the filaments has proved to be a serious problem.

It is, therefore, an object of the present invention to provide an apparatus for applying a liquid finish to a dense, filamentary tow. Another object of the invention is to provide an apparatus for applying a liquid finish to a moving tow in a predetermined amount uniformly to each of the filaments comprising the tow. It is another object of the invention to provide a process for applying a uniform liquid finish to the filaments of a dense, filamentary tow. These and other objects will become apparent from the following detailed description and accompanying drawings, in which:

FIGURE 1 is a cross-sectional view of the apparatus of the invention taken along a line parallel to the direction of travel of the filamentary tow;

FIGURE 2 is an offset cross-sectional view of the apparatus taken along line 22 of FIGURE 1; and

FIGURE 3 is a perspective view of a portion of the finish applicator nozzle shown in FIGURE 1.

Referring now to FIG. 1, the apparatus of this invention comprises a rigid, essentially airtight, compartmented housing 10, having two

finish application chambers

12 and 14 with

nozzles

16 and 18 mounted therein, and two

exhaust chambers

20 and 22 positioned

opposite chambers

12 and 14, respectively, on either side of the path of travel of a filamentary tow 11.

The filamentary tow 11 is fed into the housing through an inlet 24 located between tow supporting members 26 and 28 and is guided through the housing by

sup porting members

30, 32, 34, and 36. The tow is discharged from the housing through outlet 38 between

tow supporting members

40 and 42.

Support members

26 and 42 are secured to chamber access covers 44 and 46, respectively, which are in turn hingeably mounted on supports 45 and 47. Accordingly support member 26 may be moved toward and away from support member 28 to substantially seal inlet 24 and to accommodate different 3,172,780 Patented Mar. 9, 1965 thicknesses of tow passing through housing 10. Likewise support member 42 may be moved toward and away from support member 40.

In the course of travel of the tow 11 through the housing, a sheet of fluid, which is discharged from orifice 48 of nozzle 16, is directed onto one of the major surfaces of the tow at a position between support members 28 and 30. As illustrated in FIG. 2, nozzle 16 is elongated and extends across the tow 11 at right angles to its direction of travel, thus providing a sheet of fluid which extends across the full width of the major surface of the tow. Referring again to FIG. 1, simultaneously with the application of the fluid, a negative pressure from exhaust chamber 20 is exerted on the opposite side of the tow in a zone between support members 28 and 32.

As the tow 11 continues to travel through housing 10, a sheet of fluid discharged from nozzle 18 is applied to the opposite surface of the tow at a position between supporting

members

36 and 40. Simultaneously, a negative pressure is exerted on the other side of the tow by exhaust chamber 22 in the zone between supporting

members

34 and 40.

Referring now to FIGS. 1 and 2, duct 50 is positioned to withdraw air from exhaust chamber 20 which extends across the width of tow 11. A similar duct 52 withdraws air from exhaust chamber 22. The ducts may be connected to separate or a common exhaust system.

The nozzles will now be described in more detail. Referring again to FIGS. 1 and 3, nozzle 16 is provided with an air supply reservoir 54 which is in communication through channel 56 with

lips

58 and 59 which form orifice 48. A gaseous medium, under pressure, is supplied to the air reservoir 54 through conduit 64. Liquid finish supplied to a liquid reservoir 62 through conduit 66 intermingles with the gaseous medium at the juncture of channel 56 and

lips

58 and 59 and is discharged through orifice 48 in the form of a sheet of atomized fluid.

Nozzle 18 is also provided with an air supply reservoir 68, a liquid supply reservoir 70, and

conduits

72 and 74 for supplying air and liquid to the respective reservoirs. The fluid mixture provided by intermingling of air supplied through channel 76 is discharged from orifice 78 and directed onto tow 11 at a position intermediate supporting

members

36 and 40.

In the fabrication of the

nozzles

16 and 18, a number of parts may be utilized for ease of assembly and disassembly for cleaning. These parts may be joined together by conventional means, with sealing

gaskets

80 and 82, as illustrated in FIG. 3, being utilized to provide a seal and define the Width of channel 56 and orifice 48.

In the fabrication of the apparatus of the present inve 1* tion, all parts coming in contact with the moving tow should be of material which resists abrasion but, at the same time, does not damage the filaments of the tow. For example, the supporting

members

26, 28, 30, 32, 34, 36, 40, and 42 may be coated with a synthetic resin such as polytetrafluoroethylene which resists abrasion and coincidentally provides lubricity.

In carrying out the process of this invention, a dense tow, in the form of a web of substantially uniform thicl ness, comprising from about 50,000 to 250,000 filaments or more of textile denier, is passed through the liquid finish apparatus at a predetermined rate. As the tow is passed into the essentially airtight housing, a sheet of fluid under pressure is directed onto the surface of the tow at a right angle to its direction of travel at a localized position. Simultaneously, a negative pressure is applied to the other surface of the tow in a zone adjacent to the localized position. Thereafter, at a position displaced from the first localized position, a second sheet of fluid, under pressure, is directed onto the other surface of the tow while a negative pressure is applied to the opposite surface of the tow.

Upon examination of the tow, it is found that each of the filaments is coated with a substantially uniform quantity of the liquid material.

The amount of liquid applied to the tow and the pressure used will, of course, depend on the particular liquid finish being used as well as the density of thetow. Gen erally, by the described process, relatively high speeds, e.g., 75 to 1000 feet per minute, may be utilized with outstanding uniformity of finish application being attained. The amount of negative pressure or vacuum must, of course, be adjusted, depending on such factors as Viscosity of the material being utilized, the pressure and temperature at which it is applied, and the speed of travel and density of the tow. The pressure may be only slightly subatrnospheric, e.g., one-half to two inches of water, negative gage pressure, or lower.

The principal advantage provided by the present invention resides in the application of uniform quantity of finish to the filaments throughout a dense filamentary tow. In addition, this uniformity is achieved by speeds somewhat in excess of those possible utilizing known apparatus which has proved to be unsatisfactory in obtaining uniformity of application. The apparatus of this invention is likewise essentially maintenance-free since it is free of moving parts. In addition, the apparatus is exceptionally reliable without encountering difiiculties due to plugging and consequent non-uniformity of finish application provided the finish contains no insoluble particles. i

As many widely diiferent embodiments of this invention may be made without departing from the spirit and scope thereof, it is to be understood that this invention is not to be limited to the specific embodiments thereof except as defined in the appended claims.

We claim:

1. Apparatus for applying a liquid finish to a moving dense filamentary tow of substantially uniform thickness and having two essentially smooth opposed major surfaces, said apparatus comprising in combination a rigid essentially airtight housing having an elongated inlet for receiving said tow and an elongated outlet for discharging said tow from said housing, a plurality of supporting members mounted in said housing for guiding said tow therethrough, said inlet and said outlet -each being formed by two supporting members; 'the first of said two'members being fixedly attached to said housing andthe other being hingeably mounted for movement toward and away from said first member to substantially seal said housingass'aid tow movestherebetween, two nozzles each having a pair of lips defining an elongated discharge orifice for directing a sheet of fluid onto said tow at a localized position mounted in said housing on opposite sides of said tow, each nozzle being spaced "from one of said major surfaces of said tow with said discharge orifice extending across said tow at a right angle to its direction of travel, and exhaust means opposite each nozzle for applying a negative pressure to said tow in a zone opposite said localized position.

2. The apparatus of claim 1 wherein the lips of said nozzles are in communication with a liquid reservoir and a compressed air reservoir to provide a sheet of atomized fluid.

References Cited in the file of this patent UNITED STATES PATENTS 1,667,408 Allen Apr. 24', 1928 2,963,002 Glaus Dec. 6, 1 960 FOREIGN PATENTS 556,207 Belgium Apr. 15, 1957

Claims

1. APPARATUS FOR APPLYING A LIQUID FINISH TO A MOVING DENSE FILAMENTARY TOW OF SUBSTANTIALLY UNIFORM THICKNESS AND HAVING TWO ESSENTIALLY SMOOTH OPPOSED MAJOR SURFACES, SAID APPARATUS IN COMBINATION A RIGID ESSENTIALLY AIRTIGHT HOUSING HAVING AN ELONGATED INLET FOR RECEIVING SAID TWO AND AN ELONGATED OUTLET FOR DISCHARGING SAID TOW FROM SAID HOUSING, A PLURALITY OF SUPPORTING MEMBERS MOUNTED IN SAID HOUSING FOR GUIDING SAID TOW THERETHROUGH, SAID INLET AND SAID OUTLET EACH BEING FORMED BY TWO SUPPORTING MEMBERS, THE FIRST OF SAID TWO MEMBERS BEING FIXEDLY ATTACHED TO SAID HOUSING AND THE OTHER BEING HINGEABLY MOUNTED FOR MOVEMENT TOWARD AND AWAY FROM SAID FIRST MEMBER TO SUBSTANTIALLY SEAL SAID HOUSING AS SAID TOW MOVES THEREBETWEEN, TWO NOZZLES EACH HAVING A PAIR OF LIPS DEFINING AN ELONGATED DISCHARGE ORIFICE FOR DIRECTING A SHEET OF FLUID ONTO SAID TOW AT A LOCALIZED POSITION MOUNTED IN SAID HOUSING ON OPPOSITE SIDES OF SAID TOW, EACH NOZZLE BEING SPACED FROM ONE OF SAID MAJOR SURFACES OF SAID TOW WITH SAID DISCHARGE ORIFICE EXTENDING ACROSS SAID TOW AT A RIGHT ANGLE TO ITS DIRECTION OF TRAVEL, AND EXHAUST MEANS OPPOSITE EACH NOZZLE FOR APPLYING A NEGATIVE PRESSURE TO SAID TOW IN A ZONE OPPOSITE SAID LOCALIZED POSITION.