US3613161A

US3613161A - Apparatus for continuously extruding net-like structures composed of twisted multifilament yarns

Info

Publication number: US3613161A
Application number: US825213A
Authority: US
Inventors: Theodore H Fairbanks
Original assignee: FMC Corp
Current assignee: FMC Corp
Priority date: 1969-05-16
Filing date: 1969-05-16
Publication date: 1971-10-19
Anticipated expiration: 1988-10-19

Abstract

APPARATUS FOR MAKING NET-LIKE STRUCTURES IN WHICH EXTRUDED GROUPS OF STREAMS OF STRAND-FORMING MATERIAL ARE SET INTO GROUPS OF FILAMENTS, WITH THE INDIVIDUAL GROUPS OF FILAMENTS BEING TWISTED INTO YARNS AND INTERLACED AND/ OR TWISTED WITH EACH OTHER CONCOMITANTLY WITH THEIR FORMATION.

Description

Oct. 19, 1971 T. H. FAIRBANKS 3,613,161

APPARATUS FOR CONTINUOUSLY EXTRUDING NET-LIKE STRUCTURES COMPOSED OF TWISTED MULTIFILAMENT YARNS Filed May 16, 1969 2 SheetsSheet 1 Oct. 19, 1971 T. H. FAIRBANKS 3,513,161

APPARATUS FOR CONTINUOUSLY EXTRUDING NET*LIKE STRUCTURES COMPOSED OF TWISTED MULTIFILAMENT YARNS UnitedStates Patent O1 ice 3,613,161 Patented Oct. 19, 1971 3,613,161 APPARATUS FOR CONTINUOUSLY EXTRUDING NET-LIKE STRUCTURES COMPOSED OF TWIST- ED MULTIFILAMENT YARNS Theodore H. Fairbanks, West Chester, Pa., assignor to FMC Corporation, Philadelphia, Pa. Filed May 16, 1969, Ser. No. 825,213 Int. Cl. B29t 3/ 06' U.S. Cl. 18--12 N Claims ABSTRACT OF THE DISCLOSURE Apparatus for making net-like structures in which extruded groups of streams of strand-forming material are set into groups of filaments, with the individual groups of filaments being twisted into yarns and interlaced and/ or twisted with each other concomitantly with their formation.

The present invention is directed to an apparatus for making, by extrusion, net-like structures of twisted multifilament yarns.

In U.S. Pat. No. 3,331,903, there is disclosed a method and apparatus for making a net from plastic material by extruding a plurality of pairs of monofilaments of plastic material in such a manner that the filaments in each pair are spaced from each other in a first direction and the pairs of filaments are spaced from each other a given distance in a second direction. The monofilaments of each pair of filaments are revolved, at the moment of their extrusion and before being solidified, about an axis extending between the filaments of each pair of filaments so as to twist the filaments of each pair together and to thus integrally connect the filaments. One of the filaments of each pair of filaments is then moved in a second direction a distance equal to the spacing between pairs of filaments while continuing the extrusion of the filaments, afterwhich pairs of filaments are again revolved as heretofore described. By continuously repeating the above steps and setting of the extruded filaments of plastic material, a netlike structure is provided.

In my United States patent application entitled Method for Continuously Extruding Net-Like Structures, Ser. No. 825,210, filed May 16, 1969 there is disclosed a method of making net-like structures of woven or braided monofilaments using an apparatus similar to that described in U.S. Pat. No. 3,331,903.

Using conventional knitting, weaving or knotting processes, the strength and flexibility characteristics of net-like structures can be brought into a desired balance using preformed twisted multifilament yarn. On the other hand, extruded net-like structures formed of monofilaments, as produced by methods disclosed in U.S. Pat. No. 3,331,903 and my above-noted pending application, as well as other methods known in the art, generally exhibit either good strength and poor flexibility or poor strength and good flexibility. Accordingly, a primary object of this invention is the provision of an improved and more satisfactory apparatus for making net-like structures by extrusion.

Another object of this invention is to provide an apparatus for making extruded net-like structures which possess good strength and flexibility characteristics.

Still another object is the provision of an apparatus for making, by extrusion, continuous net-like structures of twisted multifilament yarns.

A further object is the provision of an apparatus for making, by extrusion, net-like structures having twisted multifilament yarns which are interlaced with each other and/ or twisted together at their crossing points.

These and other objects are accomplished in accordance with the present invention by an apparatus in which a plurality of separate groups of closely spaced streams of flowable strand-forming material are continuously extruded, with the groups arranged in pairs. The groups of streams of each such pair of groups are spaced from each other in a first direction and the pairs of groups of streams are spaced from each other a given distance in a second direction. At least the surfaces of the extruded streams are set to provide groups of filaments, after which the filaments of each individual group are twisted to provide yarns. The groups of streams of each such pair of groups are revolved about an axis extending between the groups of each respective pair of groups to at least exchange the positions thereof. Relative movement is then imparted to the groups of streams in each such pair of groups in the second direction to arrange at least certain of the groups of each such pair of groups into different pairs. By continuously repeating the above sequence of movements concomitantly with the continuous extrusion of the groups of streams of strand-forming material, setting of such streams into groups of filaments and twisting of the individual groups of filaments into yarns, a net-like structure of interlaced or twisted yarns is provided.

Preferably, the streams in each group of streams are alike in number, size and spacing, the groups of streams in each of the pairs of such groups are spaced like distances in the first direction and the pairs of groups are spaced like distances in the second direction.

During the revolving of the groups of streams of each such pair of groups, they are moved through an angle equal to a multiple of More specifically, the groups of streams of each such pair of groups may be revolved through an angle of only 180, providing that the direction of relative movement of the groups of streams in the second direction and the direction of revolution of the groups of each pair of groups is each reversed after the respective alternative movement has been completed, That is, relative movement of the groups of streams in each pair of such groups in a second direction is eifected alternately with revolving of the groups of each pair of groups. Thus, if the direction of relative movement of the groups is reversed after each revolution of the groups of each such pair of groups, and the direction of revolution of the groups of each pair of groups is reversed after each relative movement of the groups, then each revolution of the groups may be limited to only 180. With this procedure the twisted multifilament yarns are interlaced with each other so that the resulting net-like structure is of woven or braided construction.

Revolving the groups of streams of each such pair of groups through an angle of 360 or further multiple of 180 will cause the individual twisted multifilament yarns formed from the respective groups of streams to be twisted with each other at their points or locations of crossing. The resulting net-like structure will exhibit good strength, yet will be flexible in view of the absence of bonding between the filaments in the individual yarns and between the yarns which are twisted to each other.

Obviously, the groups of streams of each such pair of groups may be revolved only 180 in certain instances and 360 or further multiples of 180 in other instances so that the resulting net-like structure will exhibit interlaced and twisted junctions between the multifilament yarns.

If it is intended to revolve the groups of streams of each such pair of groups through an angle of 360 or further multiple of 360, the pairs of groups of streams, and the filaments and yarns formed therefrom, may be arranged in a circular array.

Relatively moving the groups of streams of each such pair of groups in the second direction may be achieved by moving only one group of streams of each pair of groups or by moving both groups of each pair of groups oppositely of each other or in the same direction but at different rates of speed. Further, when in a circular array, the groups of streams of each such pair of groups may be moved relative to each other by oscillating or rotating the one or both of such groups about an axis common to all the pairs of groups,

More particularly, the apparatus of the present invention includes cylindrical extrusion nozzles which are arranged as a plurality of spaced pairs to which fiowable strand-forming material is continuously delivered under pressure. Each of the nozzles has a multiplicity of extrusion orifices whereby the flowable strand-forming material delivered to each nozzle is extruded therefrom as a group of separate streams. The extruded streams of each individual group are rapidly set into filaments and the nozzles are continuously rotated to twist each group of filaments into a yarn.

Periodically, each pair of nozzles is revolved through an angle equal to a multiple of 180 about an axis located between the respective nozzles of each such pair of nozzles whereby the groups of streams issuing from such pair of nozzles at least exchange positions. Operative alternately with the nozzle revolving means are means for relatively moving nozzles of each pair of nozzles into positions as to be arranged in different pairs.

The revolving means of the apparatus includes a plurality of semi-circular tables, with each having an opening within which is rotatably mounted an individual nozzle. The apparatus may be equipped to revolve the tables which support each pair of nozzles through an angle of only 180", with the direction of revolution of such tables being reversed after each relative movement of the nozzles of such pairs of nozzles and the direction of relative movement of the nozzles also being reversed after each revolution of the nozzles of each such pairs of nozzles. The pairs of nozzles may be arranged in a circular array in which instance the apparatus would be adapted to revolve each pair of nozzles through 360 or further multiple of 360 As in conventional extrusion apparatus for making netlike structures, suitable means, such as nip rollers, are provided for continuously advancing the finished net-like structure away from the extrusion apparatus concomitantly with its production.

The teachings of the present invention are applicable for use with a variety of materials, which are referred to by the terms plastic or strand-forming materials, including materials which are thermoplastic, such as polyamides or superpolyamides, polyesters, polyvinyl chloride, copolymers thereof, polyolefins, cellulose acetates, etc., natural or synthetic rubbers, thermosetting materials or wet-spinnable materials, such as viscose, cuproammonium cellulose, or carboxymethyl cellulose. Such materials may include various additives such as stabilizers, dyes, foaming agents, etc., if so desired. It will be apparent that the manner by which the extruded streams are set will de pend upon the particular material which is being employed.

For a greater understanding of this invention, reference is made to the following detailed description and drawing in which FIG. 1 is a vertical section taken longitudinally of the apparatus of the present invention;

FIG. 2 is a horizontal section taken substantially along the line II--II of FIG. 1;

FIG. 3 is a partial vertical section, on an enlarged scale, taken transversely through the apparatus substantially along the line IIIIII of FIG. 2;

FIG. 4 is a view of the bottom of the apparatus of the present invention as viewed along the line IV-IV of FIG. 3;

FIG. 5 is a fragmentary section taken substantially along the line VV of FIG. 3;

FIG. 6 is a section of a portion of the apparatus taken substantially along the line VIVI of FIG. 3; and

FIG. 7 is a perspective view of one of the elements of the apparatus.

With reference to the drawing, the apparatus includes a pair of

vertical support members

15 and 17,

side walls

19 and 21, which terminate well above the lowermost ends of the

support members

15 and 17 and a top wall 23.

Walls

25 and 27 project from each of the opposing sides of the

walls

19 and 21 and together define channels 29 within wihch are slidably received

elongated plates

31 and 33.

Openings

35 and 37 are provided in the

support members

15 and 17 for the passage of the

plates

31 and 33 therethrough. The

plates

31 and 33, together with the

support members

15 and 17, side Walls 19 and 21 and top wall 23, define a chamber 39.

Flowable strand-forming material is continuously delivered under pressure into the chamber 39 through a conduit 41 from a suitable source, not shown. Gaskets are provided in the area of the

openings

35 and 37 in the

support members

15 and 17 to prevent leakage of strandforming material during sliding movement of

plates

31 and 33. A tank 43 is provided for containing a suitable setting liquid 45 in the area below the

plates

31 and 33.

In the specific embodiment illustrated, the contacting opposing

longitudinal edges

47 and 49 of the

plates

31 and 33 lie in a common plane and are each formed with a series of like, equally spaced,

semi-circular recesses

51 and 53, respectively. Tables 55 and 57, having portions which correspond in shape to

recesses

51 and 53, are positioned within respective of such recesses for movement relative thereto, as hereafter described. The tables 55 and 57 are of like construction and, as best shown in FIG. 7, each include a straight or fiat surface or wall 59, a semi-circular wall 61 and a top flange 63 which projects over and rests on the top surface of the

respective plates

31 and 33. Gear teeth 65 are formed along the walls 61 of the respective tables 55 and 57 at a location as to be exposed below the bottom surfaces of the

plates

31 and 33.

Each of the tables 55 and 57 is formed with a suitable opening 67 within which is rotatably mounted a nozzle 69 having a flange 71 at one end and a plurality of openings 73 at its opposite end. The nozzle flanges 71 are seated within recesses extending annularly about the openings 67 in the respective tables 55 and 57, as shown in FIG. 3. Each of the nozzles 69 is formed with teeth 75 along its outer periphery, by means of which the nozzles are continuously rotated as hereafter described in detail.

With the flat surfaces '59 of the tables 55 and '57 aligned with each other and with the opposing

longitudinal edges

47 and 49 of the

plates

31 and 33, at least one of the

plates

31 and 33, and the tables 5 5 and 57 carried thereby, is moved or shifted longitudinally. Preferably, both of the

plates

31 and 33 are shifted longitudinally in opposite directions relative to each other. This relative longitudinal movement of the

plates

31 and 33 is effected through

pins

77 and 79 which project from the

respective plates

31 and 33 and ride along

grooves

81 and 83 formed in opposing surfaces of

cams

85 and 87.

The earns 85 and 87 are of like construction and are fixed, in out-of-phase relationship, to a shaft 89 which is supported by bearings, such as shown at 91, and is intermittently driven by suitable means, not shown. As more fully described hereafter, the

plates

31 and 33 are preferably moved a distance substantially equal to one-half of the center-to-center spacing of the respective recesses '51 and 53 so as to move the tables 55 and 5-7, which are carried by the

plates

31 and 33, into diiferent positions of alignment with each other.

Alternately with the longitudinal sliding movement of the

plates

31 and 33, aligned tables 55 and 57 which are carried by such plates are together revolved as a unit through an angle of 180 or further multiple thereof so as to at least exchange the positions of such pair of aligned tables. If in the practice of the method the tables are revolved through an angle of only 180, each such revolving movement is in a direction opposite to the previous revolving movement thereof so as to provide for interlacing of yarns, as more fully described hereafter.

Revolving of the tables is effected by

gear racks

93 and 95, which mesh with the gear teeth 65 formed along the semi-circular walls 61 of such tables 55 and 57. The

racks

93 and 95 are themselves intermittently driven by

gears

97 and 99, respectively, which are fixed to

shafts

101 and 103. The

racks

93 and 95 are guided for straight line motion by channels 105 which are formed by rabbeting the projecting walls 25, as shown in FIG. 3.

In the arrangement illustrated in the drawing, the racks 93 and '95 are designed to revolve aligned tables 55 and '57 through an angle of only 180, alternately with the shifting of the

plates

31 and 33, and thus gear teeth are present only along selected lengths of the

racks

93 and 95 are omitted from portions indicated at 107 and 109. To provide for movement of the racks 93 and 95 a distance necessary for revolving aligned tables 55 and 57 through an angle of only 180, the

gears

97 and 99 may be in the form of segment gears which are intermittently driven by oscillating the

shafts

101 and 103 in opposite directions.

Fixed to and depending from each of the

plates

31 and 33 are a pair of angle members 111 each having a vertical flange 113 and a horizontal flange 115. As best seen in FIGS. 5 and 6, the vertical flanges 113 of the angle members 111 are each formed with rigid support hangers 117 which extend through spaced elongated slots 119 in the walls 25 and are secured by screws 121 to the

respective plates

31 and 33. By this arrangement, the angle members !111 will both travel with the

plates

31 and 33 during their reciprocating movements.

Elongated platforms 123 are dovetailed to the horizontal flanges 115 of the angle members 111 for sliding movement generally perpendicular to the common plane, as defined by the abutting longitudinal edges of the

plates

31 and 33. As shown in FIG. 4, each of the platforms 123 is formed with a series of arms 125 which project toward the abovementioned common plane. A sprocket 127, carried by a shaft 129, is rotatably mounted to the free end of each of the arms 12 5. Laced about the sprockets 127 carried by the respective platforms 123 is an endless chain 131 which is adapted to engage with the teeth 75 projecting from the periphery of the nozzles 69. The endless chains 131 are continuously driven through gears 133-, each of which is fixed to one of the shafts 129 carried by each of the platforms 123. The gears 133 mesh with and are driven by gears 135 which are fixed to the output shafts of separate electric motors 137.

The motors 137 serve to advance adjacent reaches of the pair of endless chains 131 in opposite directions so that the nozzles 69 are continuously rotated in the same direction. To insure continuous engagement of the endless chains 131 with the nozzle teeth 75, notwithstanding the movement of the nozzles as their supporting tables 5-5 and 57 are revolved, the platforms 123- are resiliently urged toward such nozzles by a series of leaf springs 139 located between the respective platforms and the adjacent flanges 113 of the angle members 111.

In the practice of the method with the apparatus of the present invention described above, flowable strand-form ing material is delivered under pressure through the conduit 41 and into the chamber 39. With the elements of the apparatus positioned as shown in FIG. 2, the flowable strand-forming material issues from the orifices 73 of the nozzles 69 as a group of straight streams, which are rapidly set into filaments, as by the liquid 45.

The motors 137 are then placed and maintained in continuous operation to drive the endless chains 131. The adjacent reaches of the pair of endless chains 131 are driven in opposite directions and are maintained engaged with the teeth 75 on the nozzle peripheries by the action exerted upon the platforms 123 by the leaf springs 139. Thus, the movement of the endless chains 131 serves to continuously rotate the nozzles 69 so that the group of streams issuing from the orifices of the respective nozzles 69, and preferably the filaments formed from such streams, are twisted into yarns.

The cams 8-5 and 87 are now operated to shift the

plates

31 and 33 in opposite directions, preferably a distance equal to one-half of the center-to-center spacing of the plate recesses 51 and 53. During this movement, the angle members 111 travel with the

respective plates

31 and 33, as heretofore explained.

With different tables 55 and 5-7 now aligned with each other,

plates

31 and 33 are held stationary while the

racks

93 and 95 are shifted by the

gears

97 and 99 to revolve only aligned pairs of tables 55 and 57 through an angle of only 180. The nozzles 69 which are mounted within and moved with such tables are continuously rotated by the endless chains 131 so that the twisted yarns formed from the streams of strand-forming material issuing therefrom are moved from one side of the common plane to the other thereof.

The

plates

31 and 33 are now shifted by the earns and 87 to the same degree but in opposite directions to their prior movement to align different tables 55 and 57 with each other. Again with the

plates

31 and 33 held fixed, the racks 93 and are driven to revolve only aligned tables 55 and 57 through an angle of only The direction of revolution of the tables 55 and 57, howver, is in a direction opposite to that in which aligned tables were previously revolved. By continuously repeating the above-described steps, a net-like structure results having twisted multifilament yarns which are interlaced with each other.

As heretofore mentioned, in lieu of revolving the aligned tables 55 and 57 through an angle of only 180, the tables may be turned through 360 or a further multiple of 180 to provide a net-like structure in which individual extruded twisted multifilament yarns are themselves twisted With other of such yarns at their crossing points. Moreover, if the movement of the tables '55 and 57 is limited to complete 360 turns, or further multiples thereof, the various elements of the apparatus may be arranged in a circular array to thereby produce tubular net-like structures in which the twisted yarns are twisted with other yarns at their points of crossing.

I claim:

1. Apparatus for making net-like structures including cylindrical extrusion nozzles arranged as a plurality of spaced pairs, means for delivering flowable strand-forming material to said nozzles, a multiplicity of orifices in each of the nozzles whereby strand-forming material is extruded therefrom as a group of separate streams, means for setting the extruded streams of strand-forming material into filaments, means for rotating the nozzles of each pair of nozzles whereby the filaments formed by the individual nozzles are twisted into yarns, means for periodically revolving each pair of nozzles through an angle equal to a multiple of 180 about an axis located between the respective nozzles of each such pair of nozzles, and means operative alternately with said revolving means for relatively moving nozzles of each pair of nozzles into positions as to be arranged in different pairs.

2. Apparatus as defined in claim 1 wherein said revolving means includes a plurality of semi-circular tables which are disposed with their flat sides in abutting relationship, and an opening in each of said tables for ro-, tatably supporting therein an extrusion nozzle.

3. Apparatus as defined in claim 1 wherein said means for relatively moving said nozzles includes means for reciprocating the nozzles of each pair of nozzles in 180 out-of-phase relationship and wherein said revolving means moves the pairs of nozzles through an angle of only 180 in opposite directions alternately with each stroke of said reciprocating means.

4. Apparatus as defined in claim 1 wherein said revolving means moves the pairs of nozzles through angles equal to a multiple of 360 5. Apparatus as defined in claim 7 wherein said nozzle rotating means turns each of the nozzles continuously and with all of said nozzles moving in the same direction.

References Cited UNITED STATES PATENTS 2,919,467 1/1960 Mercer l813 X Q 3,331,903 7/1967 Mine 1812 X N J. SPENCER OVERHOLSER, Primary Examiner L. R. FRYE, Assistant Examiner US. Cl. X.R.

1813 N; 26417, Dig. 81

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent 3,613,161 Dated October 19, 1971 Inventor(s) Theodore H. Fairbanks It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

Col. 2, line 42, "alternative" should read --alternate. Col. 3, line 47, "pairs" should read -pair Col. 4, line 21, "wi'hch" should read which-. Col. 5, line 28, after "95" insert and-. Col. 7, line 14, "7" should read l Signed and sealed this 4th day of April 1972.

(SEAL) Attest:

EDWARD M.PLETCHER,-'JR. ROBERT GOTTSCHALK Attesting Officer Commissioner of Patents RM P0 10 0! 0 69) USCOMM-DC 60376-P89 UYS. GOVERNMENT PRINTING OFFICE I965 0-3ii-S3