US3229347A

US3229347A - Method and apparatus for roughening the outer surfaces of filaments made of high molecular plastic material

Info

Publication number: US3229347A
Application number: US311289A
Authority: US
Inventors: Libuse A Tlamicha
Original assignee: Individual
Current assignee: Individual
Priority date: 1963-09-23
Filing date: 1963-09-23
Publication date: 1966-01-18
Anticipated expiration: 1983-01-18

Description

Jan. 18, 1966 TLAMICHA 3,229,347

METHOD AND APPARATUS FOR ROUGHENING THE OUTER SURFACES OF FILAMEN'TS MADE! OF HIGH MOLECULAR PLASTIC MATERIAL Filed Sept. 25, 1965 //VVN7'0R A'DC'L? JABOSJSAV TLAMICHAJECEASIED, LIEUSE TLAMICHA mczcm my 6:. 940a) FhToRnEys United States Patent 3,229,347 METHOD AND APPARATUS FOR ROUGHENING THE OUTER SURFACES OF FILAMENTS MADE OF HIGH MOLECULAR PLASTIC MATERIAL Adolf J. Tlamicha, deceased, late of Goeppingen, Germany, by Libuse A. Tlarnicha, sole heir and executrix, Gellertstrasse 3, Goeppingen, Germany Filed Sept. 23, 1963, Ser. No. 311,289 28 Claims. (Cl. 28-67) The present invention relates to a method and apparatus for roughening or abrading and delustering monofilaments or multifilaments made of high molecular plastics, such as, for example, poly-amide.

It is known in the prior art to guide multifilarnent yarns over abrading bodies in order to tear individual filaments of the multi-twisted yarn and to abrade or roughen up in this manner the yarn for various purposes. For example, to make it appear dull. The US. Patent 2,244,333 to W. C. Hanse, issued June 3, 1941, is representative of such prior art apparatus and process. However, with such prior art apparatus and process, the yarn is weakened non-uniformly and its mechanical properties are significantly reduced.

Known further in the prior art is a process for roughening or abrading monofilament or multifilament threads of high molecular plastics, especially of polyamides as are needed in large quantities, for example, in the manufacture of ladies hose, in which the filament is tangentially guided over a rotary abradingor roughening-body and is, as a result thereof, roughened and abraded as disclosed in my co-pending application Serial No. 96,418, filed March 17, 1961, now US. Patent 3,140,526, the contents of which are incorporated herein insofar as necessary.

The present invention relates to a process of the type described in my aforementioned co-pending application inclusive the apparatus appertaining thereto, in which, however, the filament is emplaced within an axial plane upon conical surfaces provided on the abrading or roughening body at least once each at mutually opposite places and is thereby roughened or abraded in different, mutually crossing directions.

This may be, for example, :achieved by guiding the filament obliquely through a hollow cylindrical abrading or roughening body. The abrading or roughening body is, accordingly, for example, a cylindrical hollow body with conically shaped end surfaces increasing in the outward direction or with hollow conical annular end surfaces that are inclined in the inward direction and rounded off, or again the abrading or roughening body is an abrading disk with conically shaped, inclined circumferential surfaces or with cylindrical, circumferential surfaces rounded off on both sides or also with semicircularly shaped circumferential surfaces.

By reason of the circumferential speed of the roughening or abrading body rotating .at relatively high rotational speeds, the filament is slightly deviated or deflected from its feed direction whereby the filament rotates about its own axis numerous times while maintaining its circular cross section. As a result of the roughening or abrad ing action, obliquely or diagonally extending, microscopically fine grooves are produced on the surfaces of the very thin filament which are produced during the first abut- "ice ment against or engagement of the filament with the abrading body in the one diagonal direction and during the second abutment against or engagement of the filament at the opposite place of the abrading body in an approximately perpendicular direction with respect thereto.

Thus, a double transverse grooving of which the two sets of grooves intersect crosswise is obtained by the process in accordance with the present invention which is considerably better and more satisfactory than a roughening or abrading in a single longitudinal direction. The dulling of the surface of the filament produced by the abrading or toughening action according to the present invention is additionally much more pronounced and more intense as well as also still more uniform over the entire length of the filament having many kilometers, and light impinging thereon is equally good reflected with diffusion in all directions. Furthenrnore, the cross section of the filament is neither weakened nor, with multifilament threads consisting of several individual filaments, are parts thereof torn so that the mechanical properties thereof are far-reachingly maintained.

Accordingly, it is an object of the present invention to provide a process and apparatus for 'abrading or roughening the surfaces of filaments of high molecular plastic material which further significantly improves the prior art processes and apparatus of the type described hereinabove.

It is another object of the present invention to provide an apparatus for abrading filaments made of high molecular plastic materials which, notwithstanding its highly satisfactory results and extreme reliability in operation, is relatively simple in structure, inexpensive in manufacture and without difiiculties in operation.

A further object of the present invention resides in the provision of a process and apparatus for roughening and abrading filaments made of high molecular plastic materials which produce a highly uniform surface roughening without impairing the mechanical properties of the filaments.

Still a further object of the present invention resides in the provision of a process and apparatus for abrading filaments made of high molecular plastic materials which lend themselves readily to mass-production techniques, can be continuously operated, and may be readily incorporated into existing manufacturing installations for the production of such filaments.

Another object of the present invention resides in the provision of a process and apparatus for abrading filaments of high molecular plastic materials which produce, by simple means, an abrading action in mutually intersecting directions to enhance the intensity of the surface dullness as well as the light diffusing and reflecting prop erties of the filaments.

A further object of the present invention resides in the provision of a process and apparatus for abrading filaments of high molecular plastic materials which eliminate tearing of the filaments during the abrading action by limiting the grooves to microscopic depths and at the same time enable continuous wetting of the filaments in minute, predetermined metered quantities.

These and further objects, features and advantages of the present invention will become more obvious from the following description when taken in connection with the accompanying drawings which show, for purposes of illustration only, several embodiments in accordance with the present invention, and wherein:

FIGURE 1 is a longitudinal cross-sectional view through a first embodiment of an abrading or roughening body constructed as cylindrical hollow body;

FIGURE 2 is an end elevational view of the abrading body of FIGURE 1;

FIGURE 3 is a partial elevational view, on a highly enlarged scale, of a filament produced in accordance with the present invention;

FIGURE 4 is an elevational view of a modified embodiment of an abrading or roughening body in accordance with the present invention constructed as abrading disk;

FIGURE 5 is anend elevational view of the abrading body of FIGURE 4;

FIGURE 6 is a longitudinal cross-sectional view through a still furthermodified embodiment of an abrading or roughening body in accordance with the present invention constructed as abrading disk; and

FIGURE 7 is an end elevational view of the abrading body of FIGURE 6.

Referring now to the drawing wherein like reference numerals are used throughout the various views to designate like parts, and more particularly to FIGURES 1 and 2, the abrading or roughing body of this embodiment is constructed as cylindrical hollow body 11 provided either with hollow, conically shaped, annular surfaces 12 inclined inwardly and rounded off or with conically shaped, annular end surfaces 12 increasing outwardly. The filament 1 is guided obliquely through the hollow body 11 within an axial plane and thereby sequentially rests on or engages with the opposite end surfaces 12. The filament 1, if necessary, is thereby guided through guide eyelets 13 of any suitable construction and arranged on both sides of the abrading body 11. The hollow body 11 is, for. example, surrounded by a roller bearing 14 and is suitably driven by means of a belt drive including pulley 15 from any suitable driving means, for example, an electric motor with speed-adjusting and/0r speed-reversing means. The rotational speed of the hollow body 11 which is a fine-grain grinding body either throughout its entire structure or at the end surfaces 12 only, amounts up to 15,000 r.p.m. or more. A fine-grain silicon abra s'ive may be used with the grinding body of any one of the embodiments described herein.

I The filament 1, while being guided through the rotating hollow body 11, is slightly deflected from its normal feed direction by the end surfaces 12 as shown in FIGURE 2. As a result of this deflection which depends on the rotational speed of the hollow body 11 and on the mechanical tension in the filament 1 as well as also on the exit speed thereof, all of which may be adjusted by suitable conventional means, the filament 1 rotates itself about its own longitudinal axis. Consequently, the filament 1 is abraded or roughened on all sides during its abutment against and engagement with the end surfaces 12 without, however, impairing or adversely affecting the original circular cross-section thereof in any manner whatsoever. .The guide eyelets or loops 13 and the inclined angle of the hollow, conically extending end surfaces 12 are further so arranged and dimensioned that the filament 1 passing therethrough rests flush on the surfaces 12. The abutment or engagement of the filament 1 may be adjusted, if necessary, by suitably changing the position of the guide eyelets 13.

' As a result of the first abutment against or engagement with the. end surfaces 12, there are imparted to the filament 1 grooves extending obliquely or diagonally to the longitudinal direction thereof which grooves, however, are only microscopically deep (FIGURE 3). As a. result of the subsequent abutment against or engagement with the end surfaces 12 at the opposite place, there are also produced diagonal grooves 17 which, however, are disposed transversely to the grooves 16. In this manner,

the surface of the filamentl receives a double-transverse, mutually crossing groove configuration which remains uniform over the entire length thereof, and reflects the impinging light completely diflused so that a very intense and deep surface dullness results therefrom. With a 20 denier filament having a diameter of approximately 48 microns the depth of the grooving 16, 17 amounts to only approximately 0.5 micron so that the rigidity properties and strength characteristics of the filament are in no way impaired.

With the embodiment according to FIGURES 4 and 5, the abrading or roughening body is constructed as flat abrading or roughening disk 19 mounted on the drive shaft 18. The filament 1 is guided over the circumferential surfaces 20 of the disk 19 which are inclined inwardly conically shaped and are rounded off within an axial longitudinal plane at two mutually opposite places, that is, above and below the axis of the drive shaft 18 whereby the filament 1 is guided through correspondingly arranged guide eyelets 13. However, it is also understood that the circumferential surfaces 20 may also be of cylindrical configuration with adjoining oblique surfaces or rounded off surfaces.

The filament 1 is taken along in the circumferential direction by the circumferential velocity of the rotating, abrading disk 19 but is not lifted off because this is prevented by guide eyelets 13 provided closely adjacent to the abrading disk 19, for example, also staggered obliquely in the axial direction. Consequently, only a deflecting or bulging, that is, an inclined guiding of the filament 1 over the abutment places of the abrading disk 19 takes place so that the filament I is twisted in itself and is thereby abraded or roughened uniformly and simultaneously by the resulting mutually crossing transverse grooves (FIG- URE 3).

The embodiment according to FIGURES 6 and 7 also shows an abrading or roughening disk 21 mounted on a drive shaft 18 and provided with double, conically shaped inclined circumferential surfaces 22 or with cylindrical circumferential surfaces 22 rounded off on both sides thereof, over which the filament 1 is guided at opposite places on both sides of the axis of the drive shaft 18, that is, altogether four times. In order to achieve this completely satisfactorily, the abrading or roughening disk 21 is provided in the center thereof with a circumferential trough or recess 23. Additionally, the filament is so guided through guide eyelets 13 in the axial longitudinal plane that it abuts sequentially flush against the various places of the circumferential surfaces 22 either bulged or diagonally. The circumferential recess 23 is only provided for the accommodation of the centrally arranged guide eyelets -13. The operation of the embodiment of FIGURES 6 and 7 is the same as that of the embodiment of FIGURES 4 and 5. V

In the embodiment of FIGURES 6 and 7, a nozzle 24 is additionally provided which extends into a dish-shaped or ring-shaped bore or recess 26 at one of the two end faces of the abrading disk 21 and through which a liquid 25, for example, water may be dripped onto the abrading disk. It is possible in this manner to wet the rotating abrading disk 21 continuously from the inside thereof. By reason of the centrifugal force, the liquid 25 leaves through the circumferential surfaces 22 in minute drops so that the pores of the abrading disk 21 are continuously cleansed by flushing of the abrasion or dust produced by the abrading or roughening of the filament 1. It is, of course, also within the .purview of the present invention to supply the liquid 25 on both sides of the abrading disk 22 or to provide a similar wetting system in the embodiment of FIGURES 4 and 5 and 1 and 2.

v The threads to which the present invention apply are, as mentioned above, monofilament or multifilament threads of highly molecular plastics, especially polyamides. Hence, the term filaments as used herein and in the appended claims is to be considered directed to such monoand multifilament threads.

While there has been shown and described several embodiments in accordance with the present invention, it is understood that the same is not limited thereto but is susceptible of numerous changes and modifications within the spirit and scope thereof; and the applicant, therefore, does not wish to be limited to the details shown and described herein but intend to cover all such changes and modifications as are encompassed by the scope of the appended claims.

What is claimed is:

1. A method of roughening the surfaces of filaments of highly molecular plastics on a rotating element having an axis of rotation and providing with abrading surfaces, comprising the steps of passing said filament over said surfaces at least once on each side of said axis whereby the surfaces of said filament are roughened in intersecting directions.

2. A method of abrading the surfaces of filaments of highly molecular plastics on a rotating element having an axis of rotation and provided with abrading surfaces on opposite sides of said axis, comprising the steps of positively rotating said element and continuously passing said filament over said surfaces at least once on each side of said axis, whereby said filament is abraded in mutually crossing directions while turning about its own axis so that the entire surface of the filament will be abraded substantially uniformly on all sides and throughout its length and the initial cross section of the filament and its mechanical properties will remain substantially unchanged.

3. A method of roughening the surfaces of filaments of highly molecular plastics on a rotating element having an axis of rotation and provided with abrading surfaces, comprising the steps of passing said filament approximately within an axial plane over said surfaces at least once on each side of said axis, whereby the surfaces of said filament are roughened in intersecting directions.

4. A method of abrading the surfaces of filaments of highly molecular plastics on a rotating element having an axis of rotation and provided with abrading surfaces on opposite sides of said axis, the diameter of said surfaces varying in the direction of said axis, comprising the steps of positively rotating said element and continuously passing said filament approximately within an axial plane over said surfaces at least once on each side of said axis, whereby said filament is abraded in mutually crossing directions while turning about its own axis so that the entire surface of the filament will be abraded substantially uniformly on all sides and throughout its length and the initial cross section of the filament and its mechanical properties will remain substantially unchanged.

5. A method of roughening the surfaces of filaments of highly molecular plastics on a hollow rotating element having an axis of rotation and provided with approximately conically shaped roughening end surfaces increasing in the radially outward direction and located on opposite sides of said axis, comprising the steps of passing said filament through said hollow element over said end surfaces at least once on each side whereby the surfaces of the filament are sequentially roughened two times in intersecting directions.

6. A method of roughening the surfaces of filaments of highly molecular plastics on a hollow rotating element having an axis of rotation and provided with approximately conically shaped roughening end surfaces increasing in the radially outward direction and located on opposite sides of said axis, comprising the steps of passing said filament through said hollow element approximately within an axial plane over said end surfaces at least once on each side whereby the surfaces of the filament are sequentially roughened two times in intersecting directions.

7. A method of roughening the surfaces of filaments of highly molecular plastics on a rotating element having an 6 axis of rotation and provided with roughening surfaces of approximately conical circumferential surfaces, comprising the steps of passing said filament in approximately opposite directions over each of said surfaces at least once whereby the surfaces of said filament are roughened in intersecting directions.

8. A method of roughening the surfaces of filaments of highly molecular plastics on a rotating element having an axis of rotation and provided with roughening surfaces of approximately conical circumferential surfaces, comprising the steps of passing said filament in approximately opposite directions substantially within an axial plane over each of said surfaces at least once whereby the surfaces of said filament are roughened in intersecting directions.

9. A method of roughening the surfaces of filaments of highly molecular plastics on a rotating element having an axis of rotation and provided with at least two roughening surfaces nonparallel to said axis and disposed, as seen in cross section, in different quadrants which are defined by said axis and a line perpendicular thereto within an axial plane comprising the steps of passing said filament over each of said surfaces at least once in such a manner that the surfaces of said filament are roughened at least in two mutually crossing directions.

10. A method of roughening the surfaces of filaments of highly molecular plastics on a rotating element having an axis of rotation and provided with at least two roughening surfaces nonparallel to said axis and disposed, as seen in cross section, in ditferent quadrants which are defined by said axis and a line perpendicular thereto within an axial plane comprising the steps of passing said filament approximately within said axial plane over each of said surfaces at least once in such a manner that the surfaces of said filament are roughened at least in two mutually crossing directions.

11. A method of roughening the surfaces of filaments of highly molecular plastics on a rotating element having an axis of rotation and provided with at least two roughening surfaces nonparallel to said axis and disposed, as seen in cross section, in different quadrants which are defined by said axis and a line perpendicular thereto within an axial plane comprising the steps of passing said filament over each of said surfaces at least once in such a manner that the surfaces of said filament are roughened at least in two mutually crossing directions, and supplying fluid to said rotating element at a point radially inwardly thereof so that said roughening surfaces are continuously cleansed during rotation thereof from the ground-off material of the filament by the centrifugal discharge of the liquid through said roughening surfaces.

12. A method of roughening the surfaces of filaments of highly molecular plastics on a hollow rotating element having an axis of rotation and provided with approximately conically shaped roughening end surfaces increasing in the radially outwardly direction and located on opposite sides of said axis, comprising the steps of passing said filament through said hollow element approximately within an axial plane over said end surfaces at least once on each side whereby the surfaces of the filament are sequentially roughened two times in intersecting directions, and cleansing the surfaces of said rotating element by supplying thereto liquid radially inwardly thereof which is discharged through said surfaces by centrifugal forces.

13. A method of roughening the surfaces of filaments of highly molecular plastics on a rotating element having an axis of rotation and provided with roughening surfaces of approximately conical circumferential surfaces, comprising the steps of passing said filament in approximately opposite directions substantially within an axial plane over each of said surfaces at least once whereby the surfaces of said filament are roughened in intersecting directions, and cleansing the surfaces of said rotating ele- 7 ment by supplying thereto liquid radially inwardly thereof which is discharged through said surfaces by centrifugal forces.

14. A method of abrading the surfaces of filaments of highly molecular plastics on a rotating element having an axis of rotation and provided with abrading surfaces on opposite sides of said axis, the diameter of said surfaces varying in the direction of said axis, comprising the steps of positively rotating said element, supplying to said rotating element a cleansing liquid radially inwardly thereof to be discharged through the surfaces by the centrifugal forces. and continuously passing said filament approximately within an axial plane over said surfaces at least once on each side of said axis, whereby said filament is abraded in mutually crossing directions While turning about its own axis so that the entire surface of the filament will be abraded substantially uniformly on all sides and throughout its length and the initial cross section of the filament and its mechanical properties will remain substantially unchanged.

15. An apparatus for roughening the surfaces of a filament of highly molecular plastic material, comprising a rotary roughening element having an axis of rotation, said element being provided with roughening surfaces on mutually opposite sides, :and means for feeding the filament at least once over each of said surfaces in such a manner as to roughen the surfaces of the filament by engagement with said roughening surfaces in mutually crossing directions.

16. An apparatus for roughening the surfaces of a filament of highly molecular plastic material substantially uniformly on all sides thereof and throughout its entire length without substantially changing the original cross section of the filament and its mechanical properties, comprising a rotary roughening element having an axis of rotation, means for driving said element so as to positively rotate the same about its axis, said element being provided with roughening surfaces on mutually opposite sides, and means for feeding the filament approximately within an axial plane at least once over each of said surfaces in such a manner as to roughen the surfaces of the filament by engagement with said roughening surfaces in mutually crossing directions, the speed at which said roughening element is driven being different from the feeding speed of said filament.

17. An apparatus for abrading the surfaces of a filament of highly molecular plastic material, comprising a rotary abrading element constructed as a hollow body and having an axis of rotation, said abrading element being provided with abrading end surfaces which are formed by inwardly inclined and rounded-off annular end faces forming engagement surfaces for the filament on opposite sides of said axis, and means for feeding the filament through said hollow body at least once in engagement with each of said end surfaces to thereby abrade the surfaces of the filament by engagement with said end surfaces in mutually crossing directions.

18. An apparatus for abrading the surfaces of a filament of highly molecular plastic material, comprising a rotary abrading element constructed as a hollow body and having an axis of rotation, said abrading element being provided with abrading end surfaces which are formed by inwardly inclined and rounded-off annular end faces forming engagement surfaces for the filament on opposite sides of said axis, and means for feeding the filament through said hollow body approximately Within an axial plane at least once in engagement with each of said end surfaces to thereby abrade the surfaces of the filament by engagement with said end surfaces in mutually crossing directions.

19. An apparatus for roughening the surfaces of a filament of highly molecular plastic material, comprising a rotary roughening element having an axis of rotation, said element being provided with roughening surfaces on mutually opposite sides, means for supplying liquid to said i element radially inwardly thereof to thereby cleanse the surfaces thereof by the discharge of said liquid as a result of centrifugal forces, and means for feeding the filament at least once over each of said surfaces in such a manner as to roughen the surfaces of the filament by engagement with said roughening surfaces in mutually crossing directions.

20. An apparatus for abrading the surfaces of a filament of highly molecular plastic material, comprising a rotary abrading element constructed as a body of revolution having an axis of rotation, said abrading element being provided with abrading surfaces that vary in diameter along the axial direction, as seen in an axial longitudinal cross section thereof, and means for feeding the filament approximately within an axial plane over said surfaces in such a manner as to abrade the surfaces of the filament by engagement with said abrading surfaces in mutually crossing directions.

21. An apparatus as defined in claim 20, wherein said body is provided with conical circumferential surfaces.

22. An apparatus as defined in claim 20, wherein said body is provided with rounded-off cylindrical surfaces.

23. An apparatus according to claim 20, wherein said body is provided with approximately semi-circularly shaped circumferential surfaces.

24. An apparatus for abrading the surfaces of a filament of highly molecular plastic material, comprising a rotary abrading disk-like element having an axis of rotation, said element being provided with external doubleconically shaped end surfaces, and means for feeding the filament substantially within an axial plane at least once over each of the end surfaces in such a manner as to abrade the surfaces of the filament by engagement with said end surfaces in mutually crossing directions.

25. An apparatus for abrading the surfaces of a filament of highly molecular plastic material, comprising a rotary abrading disk-like element having an axis of rotation, said element being provided with external doubleconically shaped and rounded-off end surfaces and with an annular recess therebetwen, and means for feeding the filament substantially within an axial plane at least once over each of the end surfaces in such a manner as to abrade the surfaces of the filament by engagement with said end surfaces in mutually crossing directions including filament guide means within said annular recess.

26. An apparatus for abrading the surfaces of a filament of highly molecular plastic material, comprising a rotary abrading element constructed as -a body of revolution having an axis of rotation, said abrading element being provided with abrading surfaces that vary in diameter along the axial direction, as seen in an axial longitudinal cross section thereof, and means for feeding the filament approximately Within an axial plane over said surfaces in such a manner as to abrade the surfaces of the filament by engagement with said abrading surfaces in mutually crossing directions, said element being provided with an axial bore, and means for supplying liquid to said element within the area of said axial bore to cleanse the surfaces of said element by the discharge of said liquid as a result of centrifugal forces.

27. An apparatus for roughening the surfaces of a filament of highly molecular plastic material substantially uniformly on all sides thereof and throughout its entire length without substantially changing the original cross section of the filament and its mechanical properties, comprising a rotary roughening element having an axis of rotation, means for driving said element so as to positively rotate the same about its axis, said element being provided with roughening surfaces on mutually opposite sides, means for supplying liquid to said element radially inwardly thereof to thereby cleanse the surfaces thereof by the discharge of said liquid as a result of centrifugal forces, the diameter of said surfaces varying in the direction of said axis, and means for feeding the filament approximately within an axial plane at least once over each of said surfaces in such a manner as to roughen the surfaces of the filament by engagement with said toughening surfaces in mutually crossing directions, the speed at which said roughening element is driven being different from the feeding speed of said filament.

28. An apparatus for roughening the surfaces of a filament of highly molecular plastic material, comprising a rotary toughening element having an axis of rotation, said element being yrovided with roughening surfaces on mutually opposite sides, the diameter of said surfaces varying in the direction of said axis, and means for feeding the filament at least once over each of said surfaces in such a manner as to toughen the surfaces of the filament by engagement with said roughening surfaces in mutually crossing directions.

References Cited by the Examiner UNITED STATES PATENTS Clark 2867 X Koster 2867 X Hanse 2867 X Saether 161-180 Stanton et a1 161-180 MacHenry 2867 X Formen 51281 Crankshaw et al 51-281 DONALD W. PARKER, Primary Examiner.

15 EARL M. BERGERT, Examiner.

Claims

15. AN APPARATUS FOR ROUGHENING THE SURFACES OF A FILAMENT OF HIGHLY MOLECULAR PLASTIC MATERIAL, COMPRISING A ROTARY ROUGHENING ELEMENT HAVING AN AXIS OF ROTATION, SAID ELEMENT BEING PROVIDED WITH ROUGHENING SURFACES ON MUTUALLY OPPOSITE SIDES, AND MEANS FOR FEEDING THE FILAMENT AT LEAST ONCE OVER EACH OF SAID SURFACES IN SUCH A MANNER AS TO ROUGHEN THE SURFACES OF THE FILAMENT BY ENGAGEMENT WITH SAID ROUGHENING SURFACES IN MUTUALLY CROSSING DIRECTIONS.