US3154835A - Apparatus and method for yarn texturizing - Google Patents

Description

Nov. 3, 1964 o. J. PALMA ETAL 3,154,835

' APPARATUS AND METHOD FOR YARN TEXTURIZING Filed April 10, 1962 INVENTORS O. J. PALMA J-H. ABBOTT,Jr.

Mam",

ATTORNEY United States Patent 3,154,835 APPARATUS AND METHOD FOR YARN TEXTURIZING Oscar J. Palma, Chapel Hill, and James H. Abbott, In,

Cary, N.C., assignors, by mesne assignments, to Monsanto Company, a corporation of Delaware Filed Apr. 10, 1962, Ser. No. 186,379

5 Claims. (Cl. 281) This invention relates generally to method and apparatus for processing yarns and more particularly to improved method and apparatus for treating continuous filament thermoplastic yarns to impart a textured efiect thereto.

There are commercially available any number of socalled texturized or elasticized yarns which are employed in the knitting of stockings, sweaters, blouses and other similar type articles and for the knitting of fabrics employed in the manufacture of such articles. In most instances the primary reason for employing an elasticized or texturized yarn in the manufacture of such fabrics and articles is to obtain a fabric having a resilient or elastic nature, but in some instances the primary reason for employing an elasticized yarn is to obtain a fabric of increased bulkiness or coverability, and in still other instances both of these characteristics are equally desirable. Products having one or both of these characteristics as a result of being fabricated from elasticized yarns have been widely accepted and are presently sold in large volumes.

A textured or elastic nature can be imparted to a continuous filament thermoplastic yarn by any of several well-known processes. One such process comprises highly twisting the yarn, heat-setting the twist therein and thereafter untwisting the yarn so that the filaments thereof are highly stressed. Such a process can be accomplished with conventional ymn twisting and heatsetting apparatus or it can be accomplished with the falsetwisting apparatus especially designed for the purpose, but in this specification no distinction is made between yarns produced with the difierent types of twisting apparatus and all such yarns are referred to as torque elasticized yarns.

A second procedure for imparting an elastic nature to an end of yarn comprises passing it, while at an elevated temperature, about the sharpened edge of a blade member to thereby stress the yarn such that the filaments thereof tend to assume a highly convoluted configuration. This method of texturizing continuous filament, thermoplastic yarns is highly desirable for the reason that yarns elasticized by this method normally have little or no tendency to twist and can therefore readily be employed as single ply. It also differs from most other methods of elasticizing or texturizing thermoplastic yarns in that the elastic nature of a yarn processed in this manner is only partially apparent following passage of the yarn about the blade edge, and a heat treatment is necessary to develop its full textured nature. Yarns elasticized by this procedure will be herein referred to as edge elas ticized yarns.

Still other methods for imparting an elastic nature to continuous filament, thermoplastic yarns comprise the steps of mechanically crimping the yarn and heat-setting the resulting crimp therein. The mechanical crimping necessary in such processes can be accomplished by any ice one of several dififerent procedures such as passing the yarn through a pair of matching corrugated rolls, forcing the yarn into a crimping chamber, or by knitting the yarn into a closely knit fabric from which it is subsequently unraveled. Yarns produced by all such methods are referred to in this specification as mechanically crimped yarns.

Of the above outlined procedures, this disclosure is particularly concerned with improvement in the procedure of edge elastic zing or texturizing yarns, both with regard to the method and the apparatus for practicing such mode of texturizing. This procedure has undergone considerable investigation in determin ng the significant parameters which may be varied with respect to one another to obtain optimum results. One such variable that has been subjected to intensive study is the radius of curvature or sharpness of the working edge of the blade members. Other such variables which have also been considered in detail are the temperature of the yarn before, during and after it is drawn across the sharpened blade edge, the tension at which the yarn is introduced to and withdrawn from the blade edge, the angle of approach and departure of the yarn with respect to the blade edge, and the diameter and physical characteristics of the particular yarn that is being treated. These and other conditions may be varied over a wide range to obtain the desired results and there has been constant effort in determining various optimum conditions to obtain the maximum degree of texturizing or elasticizing. It has now been discovered that there exist three other important variables that may be manipulated in conjunction with the variation of the above mentioned conditions to result in heretofore unobtainable degrees of texturizing. One of these variables has been found to be the angle at which the blade edge is caused to intersect the yarn path, another the sequence and mode in which the yarn is drawn or elongated and texturized with respect to the teXturizing operation and, lastly, the number and sense of abrupt changes in direction to which the yarn path may be subjected. It has been found that a predetermined controlled variation of these parameters, as will be more fully disclosed hereinbelow, results in a textured yarn of significantly greater bulkiness than was heretofore obtainable by similar procedures.

It is, therefore, an object of the present invention to provide an improved apparatus for treating yarns.

It is another object of this invention to provide an improved apparatus for texturiziug continuous filament thermoplastic yarns.

Still another object of the instant invention is to provide an apparatus for simultaneously drawing and texturizing a continuous filament thermoplastic yarn in one continuous operation.

A further object of this invention is to provide an improved apparatus for texturizing continuous filament thermoplastic yarns, which apparatus may be easily incorpo rated into a conventional drawtwister with a minimum of modification.

Still another object of this invention is to provide an improved yarn texturizing apparatus of the edge elasticizing type which allows at least two degrees of freedom of variation of the direction of engagement of the working edge of the apparatus with the yarn path.

A further object of this invention is to provide an improved yarn texturizing apparatus having a plurality of yarn engaging blade edges, which blade edges have at least two degrees of orientation.

Yet another object of this invention is to provide a novel mounting bracket for maintaining the plurality of blade edges in the desired configuration for obtaining optimum results.

It is a further object of this invention to provide an improved method for texturizing continuous filament thermoplastic yarns.

A still further object of this invention is to provide a method of simultaneously and continuously drawing and texturizing a thermoplastic yarn.

A still further object of this invention is to provide an improved method of drawing and texturizing a thermoplastic yarn, which method comprehends the drawing, blading and changes of direction in the yarn path to obtain significantly improved results.

Still another object of this invention is to provide a texturized continuous filament thermoplastic yarn having improved characteristics imparted by the use of the presently disclosed method and apparatus.

According to the present invention, the foregoing and other objects are attained by modifying a conventional drawtwister to include an improved yarn texturizing device, which'device manifests a novel and beneficial interrelationship with other components of such a drawtwister and which can be oriented to co-act upon the yarn being worked to effect a significantly greater degree of texturizing. Inpractice, this is accomplished by providing a novel blade bracket structure which enables the operator to selectively orient the texturizing tool to effect the most beneficial results. In accordance with another aspect of this invention, there is comprehended'an improved method for working continuous filament thermoplastic yarn by simultaneously drawing and texturizing same in such fashion as to result in a textured yarn having properties heretofore unattainable by similar methods and apparatus.

Reference will now be made to the accompanying drawings in which:

. FIG. 1 is a schematic perspective of one version of a modified drawtwister which incorporates an improved means for yarn for texturizing and shows the path of a yarn end through such a modified drawtwister;

FIG. 2 is a side elevation, partially in perspective, showing the blade assembly with the blade members oriented within the range of novel configuration to efiect improved texturizing; and FIG. 3 is a front elevation, partially in perspective, showing the blade assembly of FIG. 2. 7

Referring now to the drawings wherein like reference numerals designate identical or corresponding parts throughout the several views, and more particularly to FIG. 1, there is shown the yarn path through a conventional drawtwister which has been modified to incorporate thenovel features embodying one version of the instant invention. Following the yarn path through such a modified drawtwister, there is first encountered a conventional yarn supply means 10 mounted on a suitable frame or support member, not illustrated. The yarn end,

indicated by reference numeral 12, is led from supply package. 10 through guide 14, thence to a conventional feed roll 16, about which yarn end 12 is passed a plurahty of times suflicient to insure against slippage thereon. trained about'a conventional heated draw pin 18 which pm may be accurately maintained at a desired temperature by any of several well known heating means, such as an electrlcal resistance heater 20 provided with a manually operated control 22. It may be noted at this juncture that drawpln 18, or its equivalent, is not considered essential to the practice of the instant invention and any suitable means for generating a drag upon the yarn end 12 as it' proceeds thiough the drawtwister may be employed; Fur- Departing the feed roll 16, yarn end 12 is then ther, the drawpin 18, or any of its equivalents, may be entirely eliminated, whereby drawing action, if desired, will be localized at the edges of texturizing blades 24, 24', later to be described. Also, as another possible alternative, the functions of heating the yarn and generating a drag thereupon, as performed by the heated drawpin 18, may be desirably separated by providing an independently heated plate upstream of a non-heated drawpin.

Continuing, now, along the yarn path, after yarn end 12 departs drawpin 18 or, in the absence of such drawpin, feed roll 15, it encounters the first of a plurality of blades 24, 24', there being two illustrated, which blades are provided with sharpened edge portions 26, 26'. The details of the blade configuration, mounting and orientation, both with respect to one another and to the yarn path, will be subsequently more fully described. On departing from the downstream-most blade 24', it may be desired to subject the yarn to a cooling agent, here schematically indicated as an air jet 28, which effects a sudden cooling of yarn end 12 immediately after its departure from blade 24, thereby maximizing the texturizing action of blades 24, 24'. The yarn end next encounters a draw roll 30, is wrapped thereabout a suflicient number of times to insure against slippage, departs therefrom and through a series of suitably arranged guides 32, thence to a conventional yarn take up means 34, here illustrated as comprising a ring and spindle array. The yarn is then collected by the take up means 34 in the form of a conventional yarn package.

As previously mentioned, it is generally well known that a textured effect can be imparted to continuous filament yarns by passing same over an arcuate edge when accompanied by a change of direction in the yarn path. Known refinements in this area involve variations in certain conditions to bring about an increased textured effect, which conditions may include the angles of approach and departure of the yarn end from the blade edge, which angle is measured in a plane perpendicular to the blade edge, heating the yarn at varying degrees prior to its encounter with the blade edge and cooling the yarn as it engages or departs from the blade edge. None of these 'possible variations constitute an essential part of the ing of the yarn prior to its engagement with the blade edge has been found to have notably beneficial results and the temperature to which the yarn is heated just prior to engagement will most desirably vary between the point at which the yarn will plasticize and the melting point of the yarn. Again, the angle of approach and departure of the yarn with respect to the blade edge is also a matter of trial and error in which the limiting factors have been found to include the matters of blade sharpness, yarn temperature, size and linear speed, and the inherent properties of the. yarn itself. As an indication of the range of choice available, it has been found that highly beneficial results may be obtained by abruptly changing the direction of the yarn path as it passes the blade edge to an angle ranging anywhere from as low as 45 to as high as It is to be understood that applicants attach no criticality to the factors of preheating the yarn, cooling it upon departure from the blade edge, or the precise angle of,ap proach and departure of the yarn with respect to the blade edge, nor to the radius of curvature of the blade edge, or the draw ratio between rolls 16 and 30, any or all of which factors may be widely varied or even eliminated, subject only to the above indicated ranges.

Turning now to another important feature of applicants invention, it has been discovered that by providing one or more additional blades arranged in a particular manner with respect to the conventional single blade embodiment significantly improved results have been obtained with regard to the degree of texturizin Though it is contemplated that more than one additional blade may be employed, the following discussion shall relate to the use of only one additional blade in the two blade arrangement illustrated in the drawings, it being understood, however, that any number of additional blades might beneficially be employed, the number depending upon the particular yarn being worked and the details of a particular installation in which it may be found desirable to practice this invention. In the two blade arrangement, it has been found that, if the yarn path is caused to experience a change in direction over the second, or downstream-most, blade, as shown in FIG. 1, of an opposite sense to the change of direction occurring about the upstream-most blade, a higher degree of what is commonly termed yarn bulkiness is obtained. One possible arrangement for accomplishing this is shown in FIG. 1, where the yarn, on approaching the upstream-most blade 24 experiences a counterclockwise change of direction of the magnitude indicated by angle A which, as previously pointed out, may range between 45 and 120. On departing the first blade 24 and encountering the second blade 24', the yarn path is subjected to a clockwise change in direction of the magnitude indicated by angle B in FIG. 1, which angle may likewise be varied between similar limits. Both angles A and B may be varied merely by displacing one or both blades vertically with respect to one another and may therefore be arranged on any suitable common or independent bracketing to allow for ready adjustment as indicated by the needs of the job at hand. This arrangement and procedure of subjecting the yarn path to two or more changes of direction of opposite hand may be supplemented by yet another aspect of applicants invention, namely that of arranging the blades so that their sharpened edge portions 26 will lie in intersecting vertical planes, the angle of such intersection being indicated by angle C in FIG. 1. It has been found that the angle defined by such intersecting vertical planes may, with good effect, be varied from 30 to 85, the angle depending upon the degree of texturizing desired. It is to be understood that the canting of the blade edges may be accomplished by varying the orientation of one or both blades. For example, one of the blade edges may be maintained at right angels to the yarn path and the other of said blade edges would be canted at an angle within the above disclosed range. The mechanism which accounts for the significantly improved results attained from such an arrangement has not been definitely established, but is thought to be due to the fact that the yarn as it travels between the two blade edges, is momentarily subjected to a slight degree of false twist by virtue of the canted arrangement or" the blade edges. This slight degree of false twist is believed to maximize the texturizing effect of the yarn being worked as it departs the upstream-most blade 24 and engages the downstream-most blade 24'. In any event, that yarn bulkiness, which is a measure of the volume occupied by a given length of yarn, obtained by this means and procedure of texturizing can be increased by as much as 30 percent over that obtained from conventional practices, as exemplified by the use of a single blade positioned with its sharpened edge portion extending perpendicular to the yarn path. For purposes of clarity, it should be noted that the use of the term vertical in referring to the planes of intersection that measure the degree of cant of the blade edges has meaning only with reference to the particular arrangement shown in FIG. 1. In general, the pertinent angle described by the canted edges of any given pair of blades is that angle formed between two planes, each of which contains one of the pair of blade edges and both of which are perpendicular to a common plane.

There will now be described an adjustable blade bracket assembly which may be employed in the practice of the instant invention, but it is to be understood that the applicants do not desire to limit themselves to the details of a particular bracket configuration, any multi-blade bracket or series of single blade brackets allowing the two requisite degrees of freedom being adequate. One such bracket is illustrated in FIGS. 2 and 3 and includes a base plate 40 having planar forward and rearward surfaces and a threaded recess formed centrally of said rearward surface to receive mounting bolt 42. Each end of base plate 40 is provided with a circular aperture which receives shanks 44, 44' of rotatable bosses 46, 46. At the ends of bosses 46, 46 remote from base plate 40 there are formed transverse circular apertures which rotatably mount the blade holder shafts 48, 48', which shafts mount integrally formed blade holders 50. Blades 24, 24' are rotatably mounted on blade holders 50, 50' by means of flat head machine screws 52. Conventional set screws 54 may be provided to allow each blade holder 50, 50' to be releasably locked to its respective boss 46, 46 and, in turn, by the same means, each boss 46, 46 may be releasably locked into engagement with base plate 40. An alternative arrangement for allowing the bosses 46, 46' to be selectively engaged with base plate 40 is illustrated at the lower boss 46', as shown in FIG. 3. In this arrangement the shank 44 is elongated to accommodate a compression spring 55 which is maintained in position at one end by means of collar 56 and lock ring 58 and, at the other end, by a circular recess 60. The forward surface of base plate 40 is provided with a series of radially spaced notches 62 which are selectively engaged by a pin 64 formed integrally on boss 46'. By this means, boss 46 may be rotated and locked into any desired position with respect to base plate 4% simply by pulling the boss to the left, as viewed in FIG. 3, to compress spring 54 and thereby disengage lug 64 from notch 62, whence boss 46' is rotated to the next desired position and released to allow lug 64 to re-engage another of the notches 62 by virtue of the action of compression spring 54.

It is seen, therefore, that applicants have provided a convenient bracket which allows the blades the two independent degrees of freedom of rotation necessary to orient the blades to have the proper cant angle C and to effect the desired degree of change of direction in the yarn path, as measured by angles A and B.

Obviously, numerous modifications and variations of the present invention are possible in the light of the above teachings. It is, therefore, to be understood that within the scope of the appended claims the invention may be practiced otherwise and as specifically described herein.

We claim:

1. An apparatus for texturizing a running length of continuous filament thermoplastic yarn comprising a blade assembly having at least one pair of opposed blades having sharpened edge portions, one of said blades being positioned to effect a sudden clockwise change of direction in said yarn path, the other of said blades being positioned to effect a sudden counter-clockwise change in direction of said yarn path, each of said blade portions being disposed at the apex of the angle described by the changes in direction of the yarn path, said edge portions of said pair of blades lying in intersecting planes having a common perpendicular, whereby a yarn passing under tension between said blade edges is subjected to a false-twist to provide a high-bulk yarn.

2. The apparatus as recited in claim 1 wherein the angle between said intersecting planes is 30 to 3. The apparatus as recited in claim 1 wherein the angle formed between each blade edge and said yarn path is 30 to 85.

4. In a method of texturizing a running length of thermoplastic yarn characterized by the steps of continuous- 1y passing said yarn about a first blade edge through a References Cited in the file of-this patent a sudden change in direction, thence passing said yarn UNITED STATES PATENTS abouta second blade edge through a sudden change in 2,022,854 Greenwood D 3, 1935 directlon of opposite sense to that change In directlon 2,913,800 Ammerall N0v.241959" about said first blade edge; the improvement'comprising, 3 ,'017,634 Pitt J n,- 23, 1962 imparting a false-twist to said yarn intermediate said first FOREIGN PAT NT and second blade edges to thereby improvethe bulking E S action of said blade edgeson said yarn. 564382 Canada 5. The improved method as recited in claim 4 wherein 10 OTHER REFERENCES the step of imparting a false-twist to the yarn is charac- Pratt: This Simple Assembly Puts Bulk Back In Packterized by positioning said blade edges to lie in intersectage Dyed Orion, August 1961, 'ljextile World, pages ing planes h i a common perp'qndiculal; V V 52 and 53; published by McGraw-Hlll, New York.

Claims (2)

1. AN APPARATUS FOR TEXTURIZING A RUNNING LENGTH OF CONTINUOUS FILAMENT THERMOPLASTIC YARN COMPRISING A BLADE ASSEMBLY HAVING AT LEAST ONE PAIR OF OPPOSED BLADES HAVING SHARPENED EDGE PORTIONS, ONE OF SAID BLADES BEING POSITIONED TO EFFECT A SUDDEN CLOCKWISE CHANGE OF DIRECTION IN SAID YARN PATH, THE OTHER OF SAID BLADES BEING POSITIONED TO EFFECT A SUDDEN COUNTER-CLOCKWISE CHANGE IN DIRECTION OF SAID YARN PATH, EACH OF SAID BLADE PORTIONS BEING DISPOSED AT THE APEX OF THE ANGLE DESCRIBED BY THE CHANGES IN DIRECTION OF THE YARN PATH, SAID EDGE PORTIONS OF SAID PAIR OF BLADES LYING IN INTERSECTING PLANES HAVING A COMMON PERPENDICULAR, WHEREBY A YARN PASSING UNDER TENSION BETWEEN SAID BLADES EDGES IS SUBJECTED TO A FALSE-TWIST TO PROVIDE A HIGH-BULK YARN.

4. IN A METHOD OF TEXTURIZING A RUNNING LENGTH OF THERMOPLASTIC YARN CHARACTERIZED BY THE STEPS OF CONTINUOUSLY PASSING SAID YARN ABOUT A FIRST BLADE EDGE THROUGH A SUDDEN CHANGE IN DIRECTION, THENCE PASSING SAID YARN ABOUT A SECOND BLADE EDGE THROUGH A SUDDEN CHANGE IN DIRECTION OF OPPOSITE SENSE TO THAT CHANGE IN DIRECTION ABOUT SAID FIRST BLADE EDGE; THE IMPROVEMENT COMPRISING, IMPARTING A FALSE-TWIST TO SAID YARN INTERMEDIATE SAID FIRST AND SECOND BLADE EDGES TO THEREBY IMPROVE THE BULKING ACTION OF SAID BLADE EDGES ON SAID YARN.

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