US3295180A

US3295180A - Apparatus for crimping tow

Info

Publication number: US3295180A
Application number: US350412A
Authority: US
Inventors: Mylo John
Original assignee: Monsanto Co
Current assignee: Monsanto Co
Priority date: 1964-03-09
Filing date: 1964-03-09
Publication date: 1967-01-03
Anticipated expiration: 1984-01-03

Description

Jan. 3, 1967 J. MYLO APPARATUS FOR CRIMPING TOW Filed March 9, 1964 FIG. 2.

FIG.3.

INVENTOR. JOHN M YLO B; i & ATTORN Y United States Patent 3,295,180 APPARATUS FOR CRIMPING TOW John Mylo, Athens, Ala., assignor to Monsanto Company, a corporation of Delaware Filed Mar. 9, 1964, Ser. No. 350,412 1 Claim. (Cl. 281) This invention relates to an apparatus for crimping textile fibers, and more particularly to an apparatus for continuously imparting a crimp in a thermoplastic tow without heating the same.

A quality which thermoplastic filaments initially lack is that of interfilament cohesion. After they have been formed and washed, the surface thereof is very smooth, thereby preventing the yarn from immediately being used by the textile industry. In order to make the thermoplastic yarn more useful, the tow is crimped or textured. The crimping is generally done in the presence of heat so that when a tow is subjected to a deforming force, it will retain that shape after such force has been removed. Most crimping devices currently in use employ a conventional stuffing box in working association with nip rolls, wear discs, clapper bars and the like. The crimp is produced mechanically by feeding the fibers by feed rolls into a crimping chamber which is generally stuffed with fibers and maintained under a predetermined back pressure. Since the fibers still retain the heat supplied thereto while in the stuifer box, the crimp which has been previously imparted by the crimping gears is partially removed by the withdrawing rollers. Accordingly, to alleviate these and other problems, a primary object of this invention is to provide a yarn crimping apparatus which operates efficiently in the absence of heat, crimping gears, stuffer boxes and the like.

Another object of the present invention is to provide a yarn crimping apparatus which is exceedingly simple and rugged so that it will have long life and which also is very reliable in operation.

A further object of this invention is to provide a yarn crimping apparatus which uses an adhesive-coated roller to crimp the yarn.

Still another object of this invention is to provide a yarn crimping apparatus which imparts a crimp by sharply bending the tow back upon itself.

Other objects and advantages of this invention will become apparent when the following detailed description is read in conjunction with the appended drawings.

FIGURE 1 is a front pictorial view of the apparatus illustrating the principles of the invention and showing a pair of take-up rollers ripping the tow from an adhesive roller; and

FIGURE 2 is a fragmentary side view of the apparatus of FIGURE 1 illustrating the adhesive roller, the guide bar and showing the tow being sharply bent back upon itself and the convolutions produced thereby.

FIGURE 3 is a blown-up view of a filament which is being crimped by continuously elongating the outer portion thereof in relation to the inner portion.

One embodiment of the present invention contemplates using an adhesive roller to hold and position a tow for crimping. The crimp is permanently imparted to the filaments comprising the tow thereby aiding in the interfilament resistance to slippage.

This crimping apparatus uses a roller having an adhesive cured thereon to provide a tacky surface. A press roll which is parallel to and contiguous with the adhesive roller firmly presses a tow of filamentary material against the adhesive roller so that each filament is adhesively held thereon as the tow is rolled therebetween. The tow is carried by the adhesive roller through an arc and is then pulled off the adhesive roller by a pair of take-up rolls at a sharp angle. The take-up rolls then move the crimped tow out of the crimping area.

As in most compositions, thermoplastic filaments have an inherent tensile strength. If a filament is bent, stretched or compressed below the yield point, the filament will behave as an elastic body and when the distorting force is removed it will return to its origin-a1 shape. If the filament is bent or stretched beyond its yield point, it retains that shape and is permanently deformed. This phenomenon is produced by having re-oriented the molecular arrangement of the filament. When forced beyond its yield point, the molecules remain in their re-oriented position. In view of the above, a crimp may be imparted to the filaments by bending them beyond their yield point thereby causing a permanent deformation in the molecular structure of the tow.

The tow is held on the adhesive roller by an adhesive such as that found on cellophane tape. Alternatively, an adhesive applicator may be used to apply a veneer of glue to the adhesive roller immediately before the tow tangentially contacts the adhesive roller. The take-up rolls then pull the tow off the adhesive roller at a sharp angle. Best results are obtained when the tow is pulled oif the adhesive roller at an angle of about The invention is illustrated in connection with the accompanying drawings in which the figures are illustrative of the preferred embodiment of the invention.

As shown, a tow 10, which is comprised of a plurality of filaments, is received and advanced by an adhesive roller 11 which has an adhesive thereon. A press roll 12, which is parallel to and in contiguous rolling arrangement with the adhesive roller 11, impinges the tow 10 against the adhesive roller 11 with a force sufiicient to securely cohere the tow 10 to the adhesive roller 11. After the adhesive roller 11 rotates the tow 10 beyond its acme, take-

up rolls

13 and 14 which are parallel to each other and perpendicular to the path of the tow 10 rip it from the adhesive roller 11 and remove it from the apparatus. The tow is then passed over a guide bar 22 which can also be used as a static electricity eliminator for removing any charges which may build up during the process.

FIGURE 3 shows the manner in which the filaments in the tow are pulled off the roller 11. Forces represented by arrows 20 pull the filament off the roller 11 while forces represented by arrows 21 tend to retain the filament in contact with the roller 11. There forces co-operate to stretch the outer edge of the filament. It can be seen that the amount of stretch X applied to one side of the filament is considerly less than the stretch X applied to the other side of the filament. The portion of the filament along the line X has been stretched beyond its yield point and is there-by permanently deformed. Since one side of the filament is longer than the other, the filament convolutes into a helical or wavy configuration.

The amplitude of the crimp or waviness of the tow 10 can be increased by more acuately pulling the tow 10 back over itself. The acute angle 15 which is formed in tow 10 illustrates the desired inclination of the path of the tow 10 from an imaginary tangent at that point with the adhesive roller 11.

To lay a veneer of glue on the surface of the adhesive roller 11, an adhesive collector roller 23 is partially submerged in a trough 16 in which the glue is stored. The adhesive collector roller 23 is in a rolling arrangement with a planetary roller 17 and transfers the glue thereto. The planetary is also in a rolling arrangement with the adhesive applicator 18 which'in turn applies the glue to the adhesive roller 11. Although some of these rollers may be eliminated by enlarging one roll or repositioning the adhesive applicator 18, the previously discussed arrangement appears to be most satisfactory. Instead of using the adhesive applying arrangement shown, the roller 11 may be provided with a layer of adhesive which is cured thereon to provide a tacky surface of some permanence.

While the preferred embodiment of this invention has been disclosed, it is to be understood that changes and variations may be made without departing from the spirit and scope of the invention as defined by the appended claim.

I claim:

Apparatus for crimping a tow of filamentary material comprising:

(a) a cylindrical roll mounted for rotational movement about an axis;

(b) an adhesive supply;

(c) means for transferring said adhesive in a thin layer to the lateral surface of said cylindrical roll;

(d) a press roll mounted in juxtaposition to said cylindrical roll on an axis parallel to said axis of said cylindrical roll whereby a filamentary tow fed between said cylindrical and press rolls will contact and adhere to the adhesive on the lateral surface of said cylindrical roll;

(e) a pair of take-up rolls mounted adjacent said cylindrical roll with their axes parallel to said axis of said cylindrical roll and with the nip between said take-up rolls disposed such that a line therethrough will be parallel to a tangent to said lateral surface; and

(f) said cylindrical roll, press roll, and take-up rolls being relate-d in such a manner that a flow of tow therebetween will :be along the lateral surface of said cylindrical roll to a point at which, under the influence of said take-up rolls, it is pulled back on itself at a sharp angle to thereby stretch the filaments on one side of the tow beyond their yield point so that said filamentary tow becomes crimped.

References Cited by the Examiner UNITED STATES PATENTS 1,664,319 3/1928 Pellerin 264-168 1,914,869 6/1933 Rowe 264-283 X 2,030,156 2/1936 Rowe 264--283 X 2,279,366 4/1942 Childs 264283 X 2,556,954 6/1951 Zeigler et a1. 264-283 X 3,177,556 4/1965 Van Blerk 2872 FOREIGN PATENTS 1,224,861 2/ 1960 France.

ROBERT R. MACKEY, Primary Examiner.