US3396527A - Ring travelers - Google Patents

Description

Aug. 13, 1968 c. w. JOSEPH, JR.. ETAL 3,396,527

RING TRAVELERS Filed Oct. 22, 1965 IIVVENTORS:

CHARLES w. JOSEPH, JR.

' KARL H. BACKHAUS BYM United States Patent 3,396,527 RING TRAVELERS Charles W. Joseph, Jr., Rock Hill, S.C., and Karl H.

Backhaus, Charlotte, N.C., assignors to Celanese Corporation, New York, N.Y., a corporation of Delaware Filed Oct. 22, 1965, Ser. No. 501,330 Claims. (Cl. 57-125) ABSTRACT OF THE DISCLOSURE Travelers for use in ring spinning and twisting operations are made from a composition comprlsing a polyacetal resin containing a minor proportion of fluorocarbon resin.

This invention relates to travelers for use in the textile industry. More specifically, it relates to improved plastic travelers of acetal resin polymer.

Travelers for use in ring spinning and twising operations are most commonly made of metal. Metal travelers require varying amounts of lubrication depending upon the particular application. In twisting operations where drag is heaviest, proper lubrication is essential for good operation. Even with good lubrication, however, both the traveler and ring are subject to considerable wear because of the metal-to-metal contact. Metal particles worn off the traveler on ring, or both, become embedded in the lubricant and are subsequently oxidized. Thus visible stains are formed on the yarn coming in contact with the lubricant which are very diflicult to remove in the ordinary processes of kier-boiling and bleaching.

The prior art has long recognized the need to provide a suitable traveler from materials other than metal in order to eliminate or at least reduce the staining problem caused by the necessity of having to lubricate metal travelers. Travelers have been manufactured from various plastic materials as is disclosed in the following United States patents which are deemed exemplary of the state of the art: Nos. 2,326,834; 2,918,780 and 3,134,219.

None of the plastic travelers in use over the years have proved to be totally satisfactory in operation. Even with nylon travelers, widely in use today, some lubrication is still required. The problem of yarn stainage from lubricants, therefore, still exists. Moreover, none of the plastic travelers posses the desired combination of flexural properties that permit easy insertion onto the traveler ring, yet do not have too much flexibly that permits the traveler to fly off the ring during operation. In summary, no plastic traveler available today possesses the total combination of physical properties desired in a traveler, i.e., good frictional properties so that the traveler is selflubricating, a combination of good frictional properties and hardness so that the traveler wears Well, and good flexural properties so that the traveler possesses the desired degree of flexibility and rigidity.

It is, therefore, a primary object of this invention to provide improved plastic travelers not possessing the aforementioned objectionable defects.

It is another object to provide improved plastic travelers having desirable physical properties such as dimensional stability, heat resistance, high tensile and impact strength, good frictional properties and long wear life,

3,396,527 Patented Aug. 13, 1968 "ice It is also an object of this invention to provide selflubricating travelers thereby eliminating the problem of yarn stainage from lubricants.

It is a further object to provide improved plastic travelers which can be easily and economically produced.

It is additionally an object to provide travelers which can operate at higher traveler speeds with less yarn ten sion and better control and which cause less ring wear.

Other objects of this invention will become more apparent from the following detailed description and appended drawings wherein:

FIGURE 1 illustrates a traveler according to the invention;

FIGURE 2 is a view, partly in section, showing a portion of a metal textile spinning and twisting ring having the improved polyacetal resin traveler shown in FIG- URE l movably mounted thereon;

FIGURE 3 is a view, partly in section, showing a portion of another type of metal textile spinning and twisting ring having an improved polyacetal resin traveler of a slightly different configuration movably mounted thereon;

FIGURE 4 illustrates a traveler according to the invention having a metal wearing surface;

FIGURE 5 illustrates another embodiment of a traveler according to the invention having a metal wearing surface; and

FIGURE 6 illustrates a further embodiment of a traveler according to the invention having a metal reinforce.

In accordance with the general aspects of our invention, an improved self-lubricating plastic traveler is provided comprising acetate resin polymer.

Referring now to FIGURE 1 of the drawing, traveler 20 in accordance with the invention comprising polyacetal resin is shown in one particular embodiment. Travelers may be fabricated into any desired size or configuration depending upon the ultimate use of the traveler; i.e., the size yarn to be twisted and the ring with which the traveler is to be used.

Travelers manufactured from polyacetal resin resemble metals in their springiness. Traveler 20 is characterized by just the right degree of flexibility and is easily snapped into position on a conventional metal spinning ring 22 (as shown in FIGURE 2) provided with a vertical web portion 21 and with opositely projecting flanges 24 and 25 integral with the upper portion of web 21. Traveler 20 is held into sliding engagement with the lower surfaces of flanges 24, 25 at points or horns 23 located at opposite ends of traveler 20 by yarn 26 passing underneath the traveler.

The polyacetal resins are essentially self lubricating and have a coefiicient of friction which permits higher traveler speeds than are possible with metal, e.g., bronze or case hardened steel travelers, or even with nylon travelers currently widely used. Because of these self-lubricating properties, travelers according to our invention require no external lubrication. The elimination of external lubrication results in better housekeeping but of greatest importance is the elimination of lubricant stains on the yarn. Moreover, because the dynamic and static coeflicients of friction are in a ratio of approximately about 1:1 stick-slip friction does not occur and the noise level in the spinning and twisting areas is reduced. Due to the combination of hardness and good frictional properties of polyacetal resin, the wear-life of travelers made from such resin is good.

In FIGURE 3 of the drawing, traveler 27 of slightly diflerent configuration is shown in use on another type of conventional metal spinning ring 29 provided with annular supporting web 30 and flange 31. Traveler 27 is held in sliding engagement with the surfaces of flange 31 at points or horns 28 located at opposite ends of the traveler by yarn 26 passing underneath the traveler as shown in the drawing.

Because of the abrasiveness of certain yarns such as woolens and various types of man-made fibers, e.g., nylon, it is sometimes desirable to provide a more wear resistant surface on the traveler portion which is directly in contact with the yarn. A metal insert 33, for example, as shown in traveler 32, may be provided in the traveler during its manufacture. Another type of wearing surface 35 is shown in traveler 34 in FIGURE 5 of the drawing. Wearing surface 35 may serve additionally as a reinforcement to increase the rigidity of the traveler. The ends of wearing surface 35 may extend the full length of the traveler or merely protrude a short distance into the plastic portion of the traveler.

In some circumstances, e.g., when higher traveler speeds and greater tension are required, it may be desirable to provide a traveler having greater rigidity and less likelihood of flying off the ring during the spinning or twisting operation. A metal reinforcement 37 may be provided such as is shown in traveler 36 (FIGURE 6) which extends the full length of the traveler and is entirely surrounded by polyacetal resin 38.

Our invention is further explained, but is not intended to be limited by the following examples.

Example 1 Ring travelers are formed from oxymethylene copolymer by conventional acetal polymer injection molding techniques. Such an acetal copolymer is disclosed in United States Patent No. 3,027,352, the disclosure of which is hereby incorporated by reference. The traveler weighs 3.2 grains and fits a A inch x 6 inch traveler ring.

It is, of course, understood that any size or shape traveler can be molded in the same conventional manner. Metal wearing surfaces such as inserts 33, 35 and metal reinforcements, such as is indicated in the drawing by reference numeral 37, may be positioned in the mold and incorporated into the traveler body during the molding operations, according to conventional molding techniques.

Alternatively, although less desirable, travelers of polyacetal resin may be manufactured by methods other than molding. They can, for example, be die-punched or stamped from sheet stock which may be prepared by conventional pressing or calendering techniques and then polished so as to remove the rough edges by suitable means such as tumbling on abrasive materials. It is also possible to provide reinforced ring travelers according to the invention by dip-coating a metal reinforcement in a molten polyacetal resin bath to provide an acetal layer on the reinforcement, such as is disclosed, e.g., in copending United States application Ser. No. 90,212, filed Feb. 20, 1961, by Thomas J. Dolce and Frank M. Berardinelli, now abandoned. The dip-coating can also be performed in a polyacetal resin solution. Suitable s01- vents for polyacetal resin include dimethyl formamide and benzol alcohol.

Although the preferred polyacetal resin is oxymethylene copolymer, ring travelers according to the invention are also easily manufactured by the above described techniques from the oxymethylene homopolymer such as is disclosed in United States Patent No. 2,768,994.

The preferred polyacetal resin can be prepared as follows:

25.0 g. of trioxane is placed into a test tube, 23 cm. in length, equipped with a ground glass joint, 25.0 g.

of cyclohexane is added and the tube is placed into a Dry Ice-acetone bath at a temperature of 60 to C. until solidification occurs. 0.03 ml. of ethylene oxide is addedfollowed by 0.1 ml. of boron fluoride etherate. The tube is sealed and placed upon a rotor which is immersed in a water bath. The tube is left in the bath for a period of four hours at a temperature ranging between 66-68 C. The tube is opened and the polymer is removed. It is then washed successively with hot 5% sodium carbonate, hot water and finally ether. It is dried overnight in an air circulated oven.

The self-lubricating properties of polyacetal resin travelers may be further increased by incorporating fluorocarbon resin in the traveler in the form of particulate material such as fibers, powder, floc, particles and the like. The particulate fluorocarbon resin may comprise from as little as about one percent by weight of the traveler to as much as about 99 percent by weight of the traveler. Preferably, however, the traveler comprises a major proportion by weight of polyacetal resin and even more preferably from about 75 to percent by weight polyacetal resin.

The particulate fluorocarbon resin may range from about 5 microns to about 25 microns in size and more preferably from about 8 to 12 microns.

More desirably, the particulate fluorocarbon resin is uniformly dispersed throughout the polyacetal resin; however, it may be of higher concentration on the surface layer of the traveler which is in contact with the traveler ring. In fact, the surface layer of the traveler directly in contact with the traveler ring may comprise only fluorocarbon resin if such is desired.

Such traveler may be provided by molding a substrate of polyacetal resin in the desired traveler configuration and then coating the substrate with a fluorocarbon resin according to known methods.

Travelers comprising polyacetal resin and fluorocarbon resin are desirably provided with metal wearing surfaces and reinforcements such as heretofore described, as is understood by those skilled in the art.

Fluorocarbon resins which may be used in the practice of the invention include polytetrafluoroethylene, polyperfluoroethylenepropylene and polychlorotrifluoroethylene. More preferably polytetrafluoroethylene resin is used.

Example 11 Travelers are molded from a commercially available fluorocarbon-acetal polymer resin alloy using conventional injection molding techniques for acetal polymers. Such thermoplastic alloy comprises approximately 72 percent by Weight oxymethylene homopolymer and the remainder polytetrafluoroethylene. The thermoplastic alloy consists of finely divided (5-l0 micron) polytetrafluoroethylene uniformly dispersed in the acetal polymer resin. The alloy is in the form of a 60-80 mesh molding powder.

Such fluorocarbon-acetal polymer alloy provides a traveler with unusually good physical and frictional properties, having combined the excellent physical characteristics of acetal polymer resins and the frictional properties of the fluorocarbon resins. Travelers molded from such composition possess low-wear and long-life qualities which no other plastic travelers can match.

1 It is to be understood that the foregoing detailed description is given merely by Way of illustration, and that many variations may be made therein without departing from the spirit of our invention.

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:

1. Ring traveler for spinning or twisting operations comprising in combination polyacetal resin and particulate fluorocarbon resin dispersed therein, said combination having a dynamic and static coefiicient of friction in the ratio of approximately 1:1, and said particulate fluorocarbon being from about five microns to about 25 microns in size and comprising from about 5 to 25% by weight of the traveler.

2. Traveler according to claim 1 having a metal reinforce extending the full length whereby a greater degree of rigidity is provided in the traveler.

3. Traveler according to claim 1 wherein the particulate fluorocarbon is uniformly dispersed in the polyacetal resin.

4. Traveler according to claim 3 wherein the fluorocarbon resin is polytetrafluoroethylene and the polyacetal resin is oxymethylene copolymer.

5. Traveler according to claim 4 wherein a metal reinforce extending the full length of the traveler is provided whereby a greater degree of rigidity is provided in the traveler.

References Cited UNITED STATES PATENTS 3,134,219 5/1964 Carter et a1. 57-125 3,141,914 7/1964 Morin 57125 3,148,496 9/1964 Kight 57-125 E. I. du Pont de Nernours and Co., Teflon, 1955, p. 16.

FRANK I COHEN, Primary Examiner.

WERNER H. SCHROEDER, Assistant Examiner.

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