US2788542A - Apparatus for heat treating tows of filamentary material - Google Patents

Description

April 1957 J. M. SWALM, JR.. EFAL APPARATUS FOR HEAT TREATING TOWS 0F FILAMENTARY MATERIAL 4 Sheets-Sheet 1 Filed NOV. 18, 1953 INVENTORS JOHN M. SWALM JR ATTORNEY FRANClS J. SHEETS M Z MW April 16, 1957 J. M. SWALM, JR.. ETAL' 2,788,542

APPARATUS FOR HEAT TREATING TOWS 0F FILAMENTARY MATERIAL Filed Nov. 18, 1953 4 Sheets-Sheet 2 INVENTORS FRANCIS J. SHEE TS BY cl g S: HMWL, ATTORNEY JOHN M. SWALM,JR.

April.l6, 1957 J. M. SWALM, JRi. ETAL 2,788,542

, APPARATUS FOR HEAT TREATING TOWS 0F FILAMENTARY MATERIAL Filed Nov. 18, 1953 4 Sheets-Sheet 3 it 9. INVENTORS JOHN M. SWALM,JR. FRANCIS J. SHEETS ATTORN EY A ril 16, 1957 J. ,M. SWALM, JR.. EI'AL 2,733,542

APPARATUS FOR HEAT TREATING TOWS OF FILAMENTARY MATERIAL Filed NOV. 18, 1953 4 Sheets-$heet 4 INVENTORS JOHN M. SWAUVLJR. FRANCS J. SHEETS BY M Z M ATTORNEY United States Patent 2,788,542 APPARATUS FOR HEAT TREATING TOWS F FILAMENTARY MATERIAL John M. Swalm, Jr., and Francis J. Sheets, Charleston,

W. Va., assignors to Union Carbide and Carbon Corporation, a corporation of New York Application November 18, 1953, Serial No. 392,820

6 Claims. (Cl. 18-8) This invention relates to novel apparatus for the continuous treatment of filamentary materials. More especially it concerns a novel apparatus for continuously annealing, stretching, drying, or otherwise treating a running yarn, filament or continuous tow of a filamentary material with a circulating stream of a high temperature isin operation at high temperatures. The following description is directed principally to the form of the invention adapted for the continuous annealing of running tows made from synthetic resins.

Processes already are known for improving the physical properties of filaments and yarns made from synthetic resinous materials by subjecting such articles to various conditioning treatments, some of which involve heating the filaments and yarns and concurrently relaxing the same. Such processes were not practicably applicable for the treatment of large bundles or tows of these filamentary materials moving through an enclosed treating zone because it was necessary to partially cool the chamber to lace the moving tow on the canted rolls manually. This, coupled with the time necessary to reestablish the operating conditions, temperature and roll speeds, resulted in the production of considerable unusable material.

Moreover, heretofore the temperatures of the apparatus parts within the heat-treating zone could not be maintained uniform during the time required to thread the heavy tow around the various hot rolls within the enclosed zone at the early stages of the operation, and subsequent thereto when for any reason the threads of the tow were broken or otherwise injured and the tow had to be again rethreaded around the rolls within the hot chamber.

Among the more important objects of this invention are the following: a novel apparatus for heat-treating a moving filament, yarn or tow of filamentary material moving continuously under. a uniform tension through an enclosed heat-treating chamber while maintaining such;

material at a uniform preselected elevated temperature, and while regulating the amount of relaxation and annealing or of stretching of the filamentary material; and the provision of novel means for threading or lacing a moving tow or yarn of a filamentary material around and between two or more canted driven rolls within an enclosed heat-treating chamber while preventing substantial cooling of the chamber and enclosed operating parts or objectionable change in the selected operating conditions within the chamber.

Another object is the provision of apparatus having means for concurrently moving two or more moving continuous tows or masses of filamentary material around sets of canted, tapered driven rolls Within the same enclosed heat-treating chamber in which a highly heated vapor of.fluid is circulating and having means controlled "ice from outside of the chamber for rethreading or lacing the tow around and between the canted rolls during rotation of the latter while avoiding substantial temperature drop in the chamber or interruption of the fiow of heated vapors therethrough.

These and other objects will be evident from the following description and the accompanying drawing.

In the accompanying drawing, wherein a preferred embodiment of the invention is shown,

Fig. l is a side elevation of a heat-treating chamber and associated parts;

Fig. 2 is a section taken along the line 2-2 of Fig. 1, looking in the direction of the arrows, parts being omitted;

Figs. 3 to 6, inclusive, designate diagrammatically successive stages in the threading of a tow through the apparatus;

Figs. 7 and 8, respectively, are aside view and a bottom view of the tow lacing guide member;

Figs. 9 and 10, respectively, show diagrammatically in plan and in elevation a modification of annealing oven having a mechanically driven tow-lacing device, parts being omitted; i t

Fig. 11 is an end view of a tapered roll having taperregulating means; and

Fig. 12 is a view taken along the line 12-12 of Fig. 11, looking in the direction of the arrows, parts being broken away.

Referring now to Figures 1 and 2 of the drawing, the heat-treating and annealing apparatus comprises a fluid tight housing 11 formed of sheet metal members and suitably mounted upon a supporting base 13. The housing members are covered on both sides with heat-insulating material 15, preferably in the form of transite board or the like.

A plurality of horizontally disposed partitions 17 of heat-insulating material are mounted within the housing 11 and divide the same into a plurality of similar superposed elongated treating chambers, A, B, C, D, each having a tow inlet duct 18 and a tow outlet duct 20 for a tow T.

For circulating hot air, steam, or other hot gas or vapor through each chamber A, B, C, D there is provided a circulating blower fan 19 driven by a motor 21 through driving belt 23. The fan 19 discharges air into contact with a suitable heating element 25, which may be an indirect heat exchanger, an electric heating element, or the equivalent, mounted in an enlarged area 26 of a conduit 27, which conducts the heated fluid through inlet headers 29 and vertically disposed inlet ducts 30 into each chamber A, B, C, D, adjacent the tow inlet end of such chamber. The inlet end of fan 19 is connected with the tow outlet end of each chamber by a conduit 31 having branch linesv connected respectively with an outlet duct 32 opening into each chamber adjacent the tow outlet end of such chamber.

Extending within each chamber transversely thereof adjacent the respective tow inlet and outlet end walls and supported upon shafts 33, 35, mounted for rotation on horizontal axes on bearings 37, 39, carried by brackets 40, 40 supported on the frame are two laterally spaced tapered or cylindrical rolls 4]., 43, each having a flanged end and a free end, the latter end being spaced from the chamber wall opposite that housing the flanged end.

The bearings 37, 39 are adjustable laterally by means of adjusting screws and associated parts, and can be locked in selected position on the brackets by lock nuts associated with the adjusting screws. Thus, the rolls can be canted to move their free ends toward and away from each other as desired, and to hold them in selected canted position.

For driving each pair of rolls in the respective chambers A, B,- C, D at a uniform selected rate there is provided a variable speed motor 47 having its shaft 49 connected through shafts in interconnected transmission gear boxes G to corresponding driven shafts 51. Each of the latter are operatively connected with the shaft'of a roll 41 ofa respective heat-treatingchamberthrough a shaft 53, transmission gears 54, shaft 55, transmission gears 56 and flexible coupling 57. A clutch assembly 59- is mounted on shafts 51, 53.

- Each driven shaft 51 also is operatively connected with the shaft of a roll 43 of a corresponding heat treating 1 chamber through driven shaft 51, gear box 54 and flexible coupling 60. p

' Forrotating'the respective rolls 41, 43, of each chamber A, B, C, and D independently of the rollsin the other chambers there isprovided a conduit 63 connected'with at source of compressed air and having its discharge end connectedthroughconduit 65'with the piston of an. airoperated valve 67 which isoperatively connected with clutch 59 through linkage members 68, 69. A valve 70 in each air conduit.65. adjacent the tow dischargeend of a corresponding chamber controls-operation of the clutch 59. The arrangement of parts is such that, upon opening any valve 70 the corresponding clutch 59 is actuated and the'rolls 41, 43 in. the. chamber associated therewith are rotated at a uniform selected rate.

For threading or lacing a. continuous tow or a yarn of filamentary material through each and any heat-treating chamber andaround each of the rolls 41, 43, and in contact therewith during the heat-treating operation, there are provided two spools 72, 73, rotatably mounted upon brackets 74, 75, located respectively at the tow inlet end of the chamber adjacent the side housing the shaft of roll 41, and at the tow outlet end of the chamber adjacent the free end of roll 43. The axis of each spool is provided with a crank 77 for rotating the spool. A wire cable 79'has its free ends wound around the spools 72, 73, for movement from one spool to the other, and extends into the chamber through apertures in the walls thereof. Tow guides 80, 81 are secured, respectively, to the brackets 74, 75.

Mounted in each chamber for rotation upon bearings supported in the wall opposite that housing the roll shafts 33, 35, and in substantial axial alignment with the said rolls are respective sprocket wheels 82, 83, larger in diameter than the free ends of rolls 41, 43, the sprocket nearest the tow outlet port being provided with a hand crank 84. An'endless pintle chain 85 engages each of the sprockets '82, 83, and has associated therewith a chain tension mechanism 86 of well-known type mounted on the chamber wall.

Secured to the chain 85 for movement therewith, and extending laterally thereof toward the rolls, isa tow lacing guide L of a corrosion-resistant metal such as stainless steel. This guide comprises essentially two open spiral pigtailloops 89, 91 of. metal mounted upon orintegral with a supporting member 93 adapted .tonbe secured to a link .of chain v SS-by suitable means for free pivotal movement around its own longitudinal axis. The tow guide issoconstructed and supported" that, during operation, the loop 89extends inwardly beyond the free end of rolls 41, 43, with the plane of the convolutionzapproximately perpendicular to the roll axes, whilethe other loop 91 is disposed between .the roll axes and the chain Withtheplane of the convolution vertical andapproximately parallel to.

the rollaxes, the tow'guide swivelling on the chain for this purpose. An electric light 95 is mounted in each chamber to permit inspection of the interior.

In the modification shown in Figures 9 and 10, a mechanical drive is shown for the chain 85 and tow lacing guide of each chamber A, B, C, D. The mechanism shown comprises a variable speed electric motor 101.havmg its shaft connected through transmission gears. 102, shaft 103, gears 104 and shaft 105 with a sprocket 107 meshing with a pintle chain109 having a chain tightcner 110 and idler sprockets 111 operatively associated therewith. The shafts of the sprockets-82, 83 in each chamber, extend through the chamber wall; and the outer end of each sprocket 83 is connected through a manually operated clutch 113 with ashafthaving thereon a pintle sprocket 11S meshing with chain 109. The arrangement of parts is such that, upon actuation of motor 101, the chain 109. and lacing device in each chamber is operated until the clutch 113 controlling such operation infany selected chamber, is disconnected manually.

The adjustable-taper roll shown in Figures 11 and 12 comprises five partial frusto-conical segments 121 of corrosion-resistant metal, each of which has its larger end pivotally mounted upon a link 123 secured to the roll shaft 125. The small end of each segment 121 is pivotally connected with a link 127 which in turn is pivotally connected to an ear of an externally threaded collar 129' keyed upon shaft 125. The collar cooperates with an internally threaded adjusting nut 131 having a set screw 133 and snap ring 135 for locking'it in selected position on the shaft 125. By turning adjusting nut 131 the colhr 129 is moved along the shaft whereby linkage 127 raises one end of the roll surfaces and varies the taper of the roll.

Each chamber A, B, C and D has at the tow inlet end and tow outlet ends glass doors to permit cleaning of the rollsand observing the operation conducted therein. Similarly, each of the chambers has an access door adjacent the free end of roll 43 to permit threading of the advance end of the moving tow in the two pigtails of the tow guide.

In the operation of the apparatus, the fan 19 is actuated, and the heater 25 is turned on and a hot fluid, such as hot air or a mixture of air and superheated steam, is circulated until the chambers A, B, C, D have reached the desired operating temperatures. Then the advancing end of a tow T is secured to a cable 79 and the handle 77 operated to conduct the tow to a point'near roll 43, with the tow guide L in position adjacent thereto. Then door 139 is opened briefly and the forward end of the tow is threaded in. turn through the open loops in pigtails 81 and 91 of the tow guide and then is extended through the tow outlet port in the chamber wall to a suitable take up mechanism or the equivalent. Conveniently it is anchored yieldably by means of an air jet until the threading of the tow has been completed. Then door 139 is closed and the roll-operating clutch 59 is actuated, whereupon the rolls 41, 43 revolve in the same direction at the same uniform speed.

Concurrently the tow guide-carrying chain 85 is actuated by means of crank 84or by the motor 101 and associated parts (Figs. 9 and l0)whereby the tow guide is traversed once around the chain path during which the tow being withdrawn uniformly under a selected low tension from the chamber by suitable means passes successively through loops 89 and 91 of the guide and thence to the tow outlet port 20 while the guide, and tow moving therethrough, is laced over and around roll 43 and then under, around, and over. roll 41. Figs. 3 to 6 show diagrammatically the positions of the tow during four successive stages of a single traverse of the tow guide during an annealing operation with tow moving through a heat-treating chamber.

When the desired number of convolutions of tow have been laid in position upon and between the rolls 41, 43, actuation of the link chain 85 and tow guide L. is dis: continued, and the tow can readily be lifted manually from the two open pigtail guides of the tow guide L while the tow is in motion. 7

The tow continues to move through the inlet port 18 of each chamber, and progresses, due to the cant of rolls 41, 43, through a multiplicity of closely spaced paths, to the outlet port 20. By increasing the number of such paths of tow in a chamber and the speed of rolls 41', 43,

M the contact time of the tow with the heated fluid can be varied widely to meet any requirements. The time of contact is limited only by the permissible close proximity of adjacent paths of the tow and the lengths of the rolls.

The following further illustrates the invention. Using apparatus of the type described and shown in Figs. 1 to 8, a 7500 filament, three denier-per-filament tow, made from a copolymer of acrylonitrile and vinyl chloride and containing about 60% of vinyl chloride, was fed at a rate of 430 feet per minute into a heating chamber maintained at 138 C. and was lapped twenty times around the canted rolls 41, 43, each of which was tapered inwardly in the direction of their free ends a sufficient amount to permit a 28% relaxation and shrinkage of the tow (in length) during a 55 seconds dwell of the tow within the chamber. The thus annealed tow was coated with a lubricant and was ready for cutting and crimping into staple fibers suitable for commercial use, and for crimping such fibers.

Physical properties of individual filaments in a tow Prior to Alter Annealing Annealing By regulating the degree of taper of the rolls 41, 43, the extent of relaxation or shrinkage of the tow in length during the dwell thereof in the heating chamber is ,controlled.

By employing canted tapered rolls 41, 43, which are supported at their ends of smallest diameter, the tow can be heat-treated and concurrently stretched a preselected amount during the dwell thereof in the chamber.

Cylindrical rolls can be substituted for the tapered rolls 41, 43 when the apparatus is used for drying tows or yarns and shrinkage of the material is small. The construction of the apparatus and its operation is otherwise the same.

By the use of the novel apparatus and tow-threading mechanism of this invention it is now possible to avoid or minimize the losses of tow normally occurring when the moving tow must be threaded a plurality of times around hot annealing rolls. Heretofore, it has been necessary to at least partially cool the heat-treating chamber in order to permit manual threading of the moving tow on the canted rolls. The resultant incompletely heat-treated tow ordinarily is unsatisfactory and is discarded or used for a less exacting purpose.

Furthermore, the loss of service time of the heat-treating apparatus during which the chambers are open and are cooling to permit full manual threading of the tow around the rolls have been minimized, for the tow threading can now be done with the chambers and rolls at full operating temperatures.

The invention is susceptible of modification within the scope of the appended claims.

We claim:

1. Apparatus for heat-treating a running tow of filamentary material, which comprises an elongated enclosed chamber having side walls and end walls, and having a tow inlet port and a tow outlet port; means for directing a stream of hot air through said chamber; two laterallyspaced canted rolls mounted for rotation within said chamber on approximately parallel axes; means for rotating the rolls in unison at the same rate; and means for threading the tow between each of said rolls, which comprises two rotatable members mounted in the chamber wall adjacent the free ends of said rolls for rotation on axes respectively in at least approximately longitudinal alinement with the axis of rotation of a corresponding roll, said rotatable members being positioned between the free ends of the rolls and the adjacent wall of the chamber, thediameter of each of said rotatable members being greater than that of the free ends of the rolls, an endless conveyor operatively connected with the two rotatable members, means for driving the rotatable members and conveyor at a selected rate, a tow lacing guide member carried by said conveyor and having an open tow guide portion adapted to travel in a plane embracing the free ends of the rolls, and having a second open tow guide portion adapted to travel in a path disposed between the free ends of the rolls and the adjacent Wall of the chamber; an access door in the chamber wall adjacent the roll nearest the tow outlet end, said door having a closure; and means for conducting the forward end of an advancing tow into the tow inlet port, through the chamber, and out through the tow outlet port.

2. Apparatus for heat-treating a running tow of filamentary material, which comprises at least one elongated substantially closed chamber, each having a restricted tow inlet port and a restricted tow outlet port; two laterally spaced tow supporting rolls extending transversely of said chamber, each supported at one end for rota tion on its longitudinal axis, and having the free end spaced from the opposite wall of said chamber, said rolls being in canted relation to each other; means for rotating each of said rolls in unison at a uniform rate; means for circulating heated air in a closed path that includes said chamber, which comprises a fluid outlet conduit connected with said chamber at the tow outlet end; a fluid inlet conduit connected with the chamber adjacent the tow inlet end; means for withdrawing vapors from said fluid outlet conduit and for introducing the same into said fluid inlet conduit; heater means: operatively connected with the last-named means for heating vapors flowing to said fluid inlet conduit; and mechanism for threading a tow of filamentary material around said rolls while the chamber and rolls are at high operating temperatures and moving at high operating speeds, which mechanism comprises two rotatable members mounted in the chamber wall adjacent the free end of the rolls and having their axes of rotation, respectively, in line with the axis of rotation of a corresponding roll, and an endless conveyor operatively connecting the two rotatable members, means for driving the rotatable members and conveyor at a selected rate, and tow lacing guide means carried by said conveyor having a tow guide portion adapted to travel along a path lying in a plane intersecting the free ends of the rolls, and having a second tow guide portion adapted to travel in a path disposed between the free ends of the rolls and the adjacent wall of the chamber; a door mounted in the chamber wall adjacent the tow outlet end of the chamber; and means for conducting the forward end of an advancing tow into the tow inlet port, through the chamber, and out through the tow outlet port.

3. Apparatus as defined in claim 2, wherein the towsupporting rolls are tapered inwardly in the direction of their free ends.

4. Apparatus as defined in claim 2, wherein the towsupporting rolls have cylindrical lateral surfaces.

5. Apparatus as defined in claim 2, wherein the towsupporting rolls are tapered inwardly in the direction of their supported ends.

6. Apparatus as defined in claim 2, wherein the towsupporting rolls are tapered; together with means for regulating the degree of taper of the rolls; and means for regulating the degree of cant of the rolls.

References Cited in the file of this patent UNITED STATES PATENTS 2,055,820 Gram Sept. 29, 1936 2,155,324 Moritz Apr. 18, 1939 2,319,812 Gram May 25, 1943 2,516,157 Stanley -July 25, 1950

Claims (1)

1. APPARATUS FOR HEAT-TREATING A RUNNING TOW OF FILAMENTARY MATERIAL, WHICH COMPRISES AN ELONGATED ENCLOSED CHAMBER HAVING SIDE WALLS AND END WALLS, AND HAVING A TOW INLET PORT AND A TOW OUTLET PORT; MEANS FOR DIRECTING A STREAM OF HOT AIR THROUGH SAID CHAMBER; TWO LATERIALLYSPACED CANTED ROLLS MOUNTED FOR ROTATION WITHIN SAID CHAMBER ON APPROXIMATELY PARALLEL AXES; MEANS FOR ROTATING THE ROLLS IN UNISON AT THE SAME RATE; AND MEANS FOR THREADING THE TOW BETWEEN EACH OF SAID ROLLS, WHICH COMPRISES TWO ROTATABLE MEMBERS MOUNTED IN THE CHAMBER WALL ADJACENT THE FREE ENDS OF SAID ROLLS FOR ROTATION ON AXES RESPECTIVELY IN AT LEAST APPROXIMATELY LONGITUDINAL ALINEMENT WITH THE AXIS OF ROTATION OF A CORRESPONDING ROLL, SAID ROTATABLE MEMBERS BEING POSITIONED BETWEEN THE FREE ENDS OF THE ROLLS AND THE ADJACENT WALL OF THE CHAMBER, THE DIAMETER OF EACH OF SAID ROTATBLE MEMBERS BEING GREATER THAN THAT OF THE FREE ENDS OF THE ROLLS, AN ENDLESS CONVEYOR OPERATIVLELY CONNECTED WITH THE TWO ROTATBLE MEMBERS, MEANS FOR DRIVING THE ROTATABLE MEMBERS AND CONVEYOR AT A SELECTED RATE, A TOW LACING GUIDE MEMBER CARRIED BY SAID CONVEYOR AND HAVING AN OPEN TOW GUIDE PORTION ADAPTED TO TRAVEL IN A PLANE EMBRACING THE FREE ENDS OF THE ROLLS, AND HAVING A SECOND OPEN TOW GUIDE PORTION ADAPTED TO TRAVEL IN A PATH DISPOSED BETWEEN THE FREE ENDS OF THE ROLLS AND THE ADJACENT WALL OF THE CHAMBER; AN ACCESS DOOR IN THE CHAMBER WALL ADJACENT THE ROLL NEAREST THE TOW OUTLET END, SAID DOOR HAVING A CLOSURE; AND MEANS FOR CONDUCTING THE FORWARD END OF AN ADVANCING TOW INTO THE TOW INLET PORT, THROUGH THE CHAMBER, AND OUT THROUGH THE TOW OUTLET PORT.

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