US2631385A - Apparatus for treatment of strands - Google Patents

Description

March 17, 1953 w. T. R. KINRAIDE APPARATUS FOR TREATMENT OF STRANDS Filed June 30, 1949 ATTORNEY Patented Mar. 17, 1953 UNITED STATES ATENT OFFICE APPARATUS FOR TREATMENT OF STRANDS ware Application June 30, 1949, Serial No. 102,216

Claims.

This invention relates to the treatment of traveling strands such as films or filamentary material. More particularly, it relates to a chamber provided with a specially constructed orifice and to the use of this chamber in the treatment of continuous strands traveling through the chamber.

The utilization of fluids such as steam in the manufacture of filamentary materials has been handicapped by the diificulties involved in handling the fluid which is generally used at elevated temperatures and under pressure. For example, steam is induced into a chamber through which a yarn is passing and it escapes out into the atmosphere through the inlet and outlet holes through which the yarn passes. Special methods hitherto known for preventing the escape or for handling the escaping fluid have been for the most part unsatisfactory and costly. Further, thees precautionary measures have not satisfactorily brought about an immediate separation of the escaping fluid from the traveling strand. Adherent disadvantages are yarn damage, difflcult operation, undesirable humidity build-up and atmospheric contamination. Still further, such currents prevent a rapid cooling or hardening of the materials after leaving the treating chamber.

Accordingly, it is an object of this invention to provide a simple apparatus for the treatment of a continuous strand such as a film, a yarn, a continuous filament or the like which avoids the above mentioned difficulties. It is a further object of this invention to provide a simple means for separating the treating fluid from the strand immediately and completely at the desired points. A further object of this invention is the provision of a simple chamber through which many strands may be passed simultaneously and uniformly treated. Further objects and advantages of this invention will be apparent hereinafter.

The above-mentioned objectives are accomplished by the herein described apparatus for treating a continuous strand with a fluid which apparatus comprises a substantially closed chamber for the treating fluid and inlet and outlet orifices through which the strands pass and out of which the fluid emerges, the said orifices being formed by two round edges preferably having different radii. The distance of one round edge from the other edge is for most purposes not more than 0.05 inch. The fluid as it leaves the chamber follows the curved surface of the rounded edge having the larger radius whereas the strand continues in a direct path generally perpendicular to the orifice. An immediate and complete separation of the strand and the fluid is made through the use of this novel orifice. The treating fluid is made to turn and flow in a rapidly diverging path away from the yarn.

The invention will be more clearly understood by reference to the discussion below and to the figures which are given for illustrative purposes and of which:

Figure 1 is a longitudinal cross section showing the relationship of the strand, the path of the strand and that of the fluid;

Figure 2 is an end view showing a plurality of the strands;

Figure 3, taken on line 3-3 of Figure 4 illustrates one embodiment of this invention in which cylinders or rods of diiferent diameters are used in the formation of the orifice;

Figure 4 shows the grooved cylinder of Figure 3 from an end view;

Figure 5 illustrates another embodiment of this invention and Figure 6 illustrates still another embodiment of the invention.

Referring to the figures, the chamber I is formed by a top 2, top end walls 3, a bottom 4 and bottom end walls 5 and side walls (not shown). In the top 2 is any appropriate inlet valve i. In the bottom 4 there is a drain or trap It for removal of condensate from the cell body. Top end walls 3 and the bottom end walls 5 lie very closely together forming slot II and allowing the chamber to be substantially closed. The slot II so formed may be made by cutting out the desired section of the end plate or the top and bottom sections may be bolted together at E. The edge or lip 8 of the top walls 3 and the edge or lip 9 of the bottom walls 5 are rounded in such a manner that the radius of one of the rounded edges is larger than the radius of the other rounded edge. As shown in Figure 1, the lip 8 has a radius, designated by r, smaller than that of lip i? which radius is designated by R. The distance separating these two rounded edges is designated by the letter T, as shown in Figure 1. The continuous strand Ill passes through the orifice or slot II formed by the rounded edges 8 and 9. The fluid inserted under pressure through the valve i strikes the strand Ill as it passes through the chamber I. The fluid flows out through the orifice I I and follows the surface of the rounded edge having the larger diameter as shown by the dotted lines I2. The fluid and the strand are immediately separated. An appropriate collecting means, such as a funnel 13 or any other similar device is used to carry away the fluid for recovery or recycling. As shown in Figure 2, which is an end view, a plurality of yarns may be passed through the chamber to receive uniform treatment. Each strand is drawn through the chamber at a uniform rate and is wound up by any appropriate winding mechanism (not shown). The separation of the treating vapors from the strands is simple, automatic and complete and the apparatus is inexpensive to build and basically simple to operate.

As shown in Figure 5, the bottom wall need not be of uniform diameter for all that is necessary is a curved surface extending far enough to carry the fluid sufficiently far from the yarn to effect the separation. In such a device as that shown in Figure 5 the ratio of the radii may be, for example,

and the distance T may be 0.015 inch. A chamber equipped with such orifices may be operated efficiently at pressures within the chamber of from 5 lbs. to 50 lbs. gauge with atmospheric pressures prevailing outside of the chamber.

In another embodiment, shown in Figure 3, two rods or cylinders, l4 and ii of different diameters are mounted on suitable plates. an apparatus the ratio of the radii may be, for example,

and the distance T may be 0.010 inch. As shown in Figure 4, one of the cylinders preferably the one having the smaller radius may be grooved. This grooved cylinder serves the dual purpose of the upper lip and of a comb guide. The grooves l9 in the upper cylinder may have a radius of 0.010 inch. A notched efiect added to the lip facing provides sufiicient clearance to permit the yarn to be crossed under running ends. This allows for ease of string-up at the start of operation and if breakage occurs. Grooves are not essential, for with smooth lips an external guide may be located close to the lips. However, it is preferred for simplicity and for economy in space to use grooved lips. Only one is needed and it has been found that best results are obtained by running the yarn in grooves in the upper lip. Effective control and prevention of sidewise fluttering is obtained using a grooved upper lip.

In still another embodiment shown in Figure 6, for example 1' is inch and R is d; to inch; the lower wall 5 is provided with an escape slot I7 and a lateral passage 13. This slot is set so that 80% to 90% of the fluid, such as steam is carried off through the lateral passage for recycling or recovery. The remaining 10% to goes around the outside to an exhaust duct such as duct I3. This device has the advantage of reducing entrainment of air and disturbance of the yarn or article being processed. Further, the upper lip is so designed to facilitate further the separation of the fluid from the yarn.

The apparatus of this invention may be used for various purposes, as, for example, in subjecting films, yarns, and continuous moncfilaments or multifllaments to steam or other vapors under pressure above atmospheric. The apparatus may be employed with particular advantage in the treatment of continuous artificial filamentary structures, such as those of cellulose In such 4 esters and ethers, regenerated cellulose, polyamide and polyester materials, and of other synthetic materials such as polyvinylidene chloride, polyvinyl chloride, copolymers of vinyl chloride and vinyl acetate, after-chlorinated polyvinyl chloride, polyacrylonitriles, as well as those of proteins such as casein or soya bean protein.

In a specific example, a plurality of polyacrylonitrile yarns were passed through the chamber. Each of the yarns forming the warp left the chamber and were then passed around a series of positively driven rolls, the peripheral speed of which was 8 times that of the feed rolls which metered the yarns off a pirn or package. The steam in the treating chamber was kept at 20 lbs. gauge pressure. The polyacrylonitrile yarn in passing through this chamber under these conditions was drawn 8 times its original length. The treated yarn had a uniform denier along its length and possessed a uniform tenacity of 4.9 grams per denier and a uniform elongation of 19%. The undrawn, untreated yarn had a low tenacity of about 0.5 gram to 1.0 gram per denier and a low elongation of about 5 to 10%. In this particular example and in every instance using other continuous traveling strands, the steam or treating fluid issuing from the slots followed the curvature of the larger lower lip and separation of the fluid and the strand was immediate and complete.

Pressures used within the fluid may vary over a large range as for example between 5 and 50 lbs. gauge pressure, depending upon the material being treated and the substance being used as the treating material. For olyacrylonitrile yarns, steam is usually preferred in the drawing step and pressures ranging from 30 to 45 lbs. gauge are preferred. The fiow of the fluid depends also on the difference between the pressure within the vessel and that without. This difference need not be great but should be about 5 The various values for the ratio r/R and for the distance T are not limited to those shown but may be varied considerably depending upon the size and shape of the material being treated and to some extent upon the treating material being used. Both lips need not be curved. The upper lip may be at a sharp angle and r may be zero. With the upper lip at a sharp angle, very effective control of the steam flow was obtained. The use of sharp edges, however, leads to more mechanical wear on the articles and. for that reason, rounded edges are preferred. Such an upper lip, as shown in Figure 6 in which 1' is 4 inch, has the advantages of a rounded lip and a sharp angle. The radius of the upper lip may also be equal to that of the lower lip in which event the steam is deflected either up or down but not outwards. For convenience it is preferred to have the fluid deflected downwards and for control 1' should be slightly less than R and preferably should be no greater than 095R. R may be very large, as, for example, infinity or the radius of a flat plate extendin beyond the upper lip. The ratio r/R may then vary from 0 to about 0.95. Upper lips inch in diameter and lower lips inch in diameter are generally satisfactory. For most purposes, the distance T should be no more than 0.05 inch. The apparatus may be modified so that either or both of the rounded edges are moveable to provide for adjusting the distance T. Such adjustment is an advantage in that fluid loss may be reduced during operation and yet provisions may be made for large openings to facilitate string-up or the cleaning out of fluff, dirt or plugs. Simultaneously such rolls or cylinders as shown in Figure 3 may be positively driven in the direction of the flow to enhance the separation of the fluid, such as a liquid, from the yarn.

The apparatus of this invention may be applied to the treatment of traveling strands as for example continuous filaments for fabrics, yarns, wires, rods, tubing and in general of any continuous filamentary structure whether natural or synthetic in nature. When films are being processed it is preferred to draw them up around the upper lip forming or approaching a radius 1. Similarly, in practice with yarn, the yarn is usually drawn upwards at an an le of about 5 to above the horizontal.

The simplicity and economy of construction and operation of apparatus in this invention constitutes a decided advantage. The traveling strand being treated passes freely through the chanber and receives uniform treatment. The treating fluid being employed is readily and completely separated from the traveling strand as the traveling strand enters and leaves the chamber. The escaping fluid is easily conducted away and recycled, with the prevention of undesirable atmospheric contamination and with the elimination of safety hazards and without the use of bulky equipment such as hoods and ducts.

Any departure from the procedure described herein which conforms to the principles of the invention is intended to be included within the scope of the claims below.

I claim:

1. Apparatus for the treatment of a traveling strand with a fluid which comprises a substantially closed chamber having an inlet for the said fluid and an inlet orifice and outlet orifice for the traveling strand, these said orifices being also outlets for the said fluid and being formed .by two rounded edges extending outwardly from said chamber, said edges being situated one above the other, the lower rounded edge extending beyond the upper rounded edge.

2. Apparatus for the treatment of a traveling strand with a fluid which comprises a substantially closed chamber having an inlet for the said fluid and an inlet orifice and outlet orifice for the said traveling strand, these said orifices being also outlets for the said fluid and being formed by two rounded edges of different radii located close to each other and extending outwardly from said chamber, said edges being one above the other, the lower rounded edge extending beyond the upper rounded edge.

3. Apparatus in accordance with claim 2 in which the distance of one rounded edge to the other roundedv edge is no more then 0.05 inch.

4. Apparatus in accordance with claim 2 in which the ratio of the smaller radius to the larger radius varies from 0 to about 0.95.

5. Apparatus for the treatment of a traveling strand with a fluid which comprises a substantially closed chamber having an inlet for the said fluid and an inlet orifice and an outlet orifice for the said traveling strand, these orifices being also outlets for the said fluid and being formed by an upper, rounded edge and a lower, rounded edge located close to the said upper, rounded edge, the radius of the lower, rounded edge being larger than that of the upper, rounded edge and the lower rounded edge extending beyond the upper rounded edge, both of said edges extending outwardly from said chamber.

6. Apparatus in accordance with claim 5 in which the radius of the said upper edge is no more than 0.95 of that of said lower edge.

7. Apparatus in accordance with claim 5 in which the distance between said upper and said lower edges is no more than 0.05 inch.

8. Apparatus in accordance with claim 5 in which the said upper edge contains grooves.

9. Apparatus in accordance with claim 5 in which the said upper edge is rounded on a circle having a diameter of 1% of an inch and the said lower edge is rounded on a circle having a diameter of /8 of an inch.

10. Apparatus in accordance with claim 5 in which the said lower edge contains an escape slot and a lateral passage for removal of escaping fluid.

WILLIAM THOMAS REED KINRAIDE.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 879,867 Gray Feb. 25, 1908 1,170,228 Elliott Feb. 1, 1916 1,633,5a8 Jones June 21, 1927 2,119,261 Andrews May 31, 1938 2,144,919 Gautreau Jan. 24, 1939 2,376,839 Wansker May '22, 1945

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