US3457602A

US3457602A - Tensionless bulking apparatus and method

Info

Publication number: US3457602A
Application number: US682804A
Authority: US
Inventors: John C Oatfield; Samuel J Davis; John W Couick
Original assignee: Monsanto Co
Current assignee: Monsanto Co
Priority date: 1967-11-14
Filing date: 1967-11-14
Publication date: 1969-07-29
Anticipated expiration: 1986-07-29

Description

July 29, 1969 J. c. QATFIELD ET 3,457,602

TENSIONLESS BULKING APPARATUS AND METHOD Filed Nov. 14, 1967 2 Sheets-Sheet 1 INVENTORS JOHN C. OATFIELD SAMUEL J. DAVIS JOHN W. COUICK ATTORNEY y 1969 J. c. OATFIELD ET AL 3,457,602

TENSIONLESS HULKlNG APPARATUS AN!) METHOD Filed NOV. I4, 1967 2 Sheets-Sheet D //Y Ma ,5 OIVC N T m m m WOJ.C "H N L .ICMW A HMH United States Patent 3,457,602 TENSIONLESS BULKIN G APPARATUS AND METHOD John C. Oatfield, Cary, and Samuel J. Davis, Chapel Hill, N.C., and John W. Couick, Etowah, Tenn., assignors to Monsanto Company, St. Louis, Mo., a corporation of Delaware Filed Nov. 14, 1967, Ser. No. 682,804

Int. (:1. D02g 3/00 U.S. c1. 2s 1.2 11 Claims ABSTRACT OF THE DISCLOSURE BACKGROUND OF THE INVENTION Field of the invention This invention relates to the development of all of the available bulk and shrinkage in textured yarns and, more specifically, to the method and apparatus for raising the temperature of the textured yarn sufiiciently to allow all of the available bulk to be developed while maintaining the yarn in a tensionless and frictionless state.

Description of prior art The yarns including but not limited to, acrylonitrile polymer filament yarns may be textured in a variety of ways. One method for texturing acrylic yarns for example is disclosed in US. Patent No. 3,022,565 to Fitzgerald wherein the yarn was drawn from a supply source, stretched while heated to a temperature above the second order transition temperature [normally for polyacrylonitrile yarns 160 F. to 170 F. in wet heat and 195 F. to 215 F. in dry heat] to produce a conventionally unstable yarn and concurrently therewith to insert twist in the yarn, cooling the yarn to set the twist, untwisting the yarn and taking the yarn up by a suitable means. Fitzgerald developed the crimp or bulk by heating the yarn above the second order transition temperature while the yarn rested in a relaxed state.

The prior art methods of relaxing and bulking textured yarn include the following: treating the yarn while in the skein form at 185 F. for five minutes in a steam atmosphere; utilizing radiant heat lamps to relax the yarn under dry heat conditions after the yarn has been piddled onto a continuous conveyor belt followed by immediate takeup under controlled tension; and fabricating the textured yarn into piece goods such as carpets and treating the goods in accordance with one of the above methods or developing the bulk by the dying of the piece goods.

Bulking processes of this type rarely develop more than 50% of the available bulk due to the tension forces and frictional forces exerted on the yarn while at a temperature of above the range of 185-225 F. Even the yarns own weight is enough to prevent the full development of the available bulk.

Another bull-ting means employed in the past is that of bulking a textured yarn while the yarn is traveling in the vertical path, either upwardly or downwardly; however, such a method develops only about 60% of the available bulk for as mentioned above, the weight of the yarn alone is sufiicient to prevent bulk development to 3,457,602 Patented July 29, 1969 ice the degree that is inherent in the yarn. Therefore, it can be seen that a method for developing all of the available bulk in a textured yarn would be a tremendous advancement over the prior art.

SUMMARY OF THE INVENTION In accordance with this invention, a method and apparatus is provided which is capable of developing all of the available bulk in certain textured yarns. The essential parts of the apparatus include a substantially enclosed chamber, a feeding device for pulling the textured yarn from a source and directing it into the chamber, an open meshed conveyor belt which partially resides in the chamber and which extends outwardly through a selected wall thereof, heating elements positioned in the chamber beneath the conveyor belt, fans mounted for rotation in the chamber for directing air into contact with the heating coils and upwardly through the conveyor belt and takeup means for further cooling the bulked yarn after it has passed out of the chamber and means for packaging the yarn.

The method according to this invention includes the steps of directing textured yarn into a heated chamber at a predetermined rate, receiving the yarn in the chamber by an open meshed conveyor belt which moves laterally at a speed being less than the speed of the incoming textured yarn, raising the temperature of the textured yarn to above the range of -225F. while simultaneously supporting the yarn above, the surface of the conveyor belt in a substantially tensionless and frictionless state by upwardly moving air to develop all of the available bulk, moving the bulk yarn out of the chamber without subjecting the yarn to external forces and lowering the temperature of the yarn below 185 F. before subjecting the yarn to any frictional or tension forces. After the yarn has been cooled to a temperature of below 185 F., it is then further cooled and taken up in the usual manner.

Therefore, an object of this invention is to provide a method for developing substantially all of the available bulk in textured yarns.

Another object of this invention is to provide a bulked yarn that is capable of being packaged into a hard package which will retain its full bulk after packaging.

A further object of this invention is to provide a means for fully developing the bulk in synthetic textured textile yarns while the yarn is in a completely tensionless and frictionless state.

Still another object of this invention is to provide a means for setting the fully developed bulk in the yarn so that the yarn retains all of the bulk developed during the bulking process.

DESCRIPTION OF THE DRAWINGS FIGURE 1 is a prospective view of the apparatus of this invention having portions of the apparatus cut away to show selected interior components; and

FIGURE 2 is an elevation, section view taken along lines 2-2 of FIGURE 1 illustrating the path of the yarn through the apparatus.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT A base plate or floor 10 is provided to support and locate the elements of apparatus. Base plate 10 supports an insulated chamber 11 which defines a cavity 1 and includes top wall 13, end Wall 14 and side walls 17 and 18. Top wall 13 is provided with an opening 15 which is adapted to receive cover 16 for providing easy access to cavity 12. A thermocouple 20 is mounted on and extends through cover 16 and is adapted to monitor and record the yarn treatment temperature within chamber 11. The temperature control and recording means which are of the conventional type are not shown.

Textured yarn 24 is pulled from a source [not shown] by means of

feed rollers

25 and 26 and is directed into cavity 12 through slot 27 in top wall 13. Any number of strands of yarn may be processed by the apparatus of this invention simultaneously.

Feed rollers

25 and 26 are journaled in a pair of spaced-apart plates 28 and 29 [plate 29 not shown] which are secured to and extend upwardly from top wall 13. Feed roller 25 is positively driven by motor 30 and feed roller 26 is tangential and frictional contact with roller 25 and is driven thereby.

Open meshed conveyor belt 32 has its major portion residing in cavity 12 and moves in a path beneath slot 27 outwardly from cavity 12 through slot 33 in end wall 14 and returns to cavity 12 through slot 34 in end wall 14 to its point of beginning. Conveyor belt 32 is received by and is suspended between

conveyor drums

35 and 36. Conveyor drum 35 is securely mounted onto shaft 37 which is appropriately journaled in side walls 17 and 18 and which extends through side wall 17 to be driven by motor 38. Roller drum 36 is securely mounted onto shaft 39, shaft 39 being journaled in suitable brackets which are cantilevered outwardly from end wall 14 [the brackets not being shown].

In order to preheat yarn 24 to insure that it is properly lain on conveyor belt 32, tubes 40 and 41 are positioned parallel to each other in cavity 12 and directly beneath

feed rollers

25 and 26. Tubes 40 and 41 are respectively connected to supply

pipe

42 and 43 which also serve to support tubes 40 and 41 in cavity 12. Tubes 40 and 41 are provided with openings 45 which direct the incoming heated air downwardly toward conveyor belt 32 in a converging manner so that yarn 24 which passes between tubes 40 and 41 is preheated and properly deposited onto conveyor belt 32.

"Electrical resistant heater elements 46 are supported in cavity 12 by means of

brackets

47 and 48 which are secured to side walls 17 and 18 by any convenient means. Heating elements 46 are provided with fins 50 which direct the air by heating elements 46 and upwardly toward conveyor belt 32.

Fans

52, 53 and 54 are respectively mounted on the ends of shafts 55, 56 and 57 adjacent side wall 18, shafts 55, 56 and 57 being journaled for rotation in side walls 17 and 18. Shafts 55, 56 and 57 also receive fans on their ends adjacent to side wall 17, however, only one of them is shown and it has been given the reference numeral 59 [fans adjacent side wall 17 hereinafter being referred to as fans 59]. Shafts 55, 56 and 57 extend through side wall 17, are interconnected by a pulley mechanism which is of the conventional type and is driven by motor 61. The fans as herein shown are adapted to blow the air away from their adjacent side wall toward the center of cavity 12 so that the air comes into contact with resistant heating elements 46 and is directed upwardly through conveyor belt 32 by fins 50 to engage yarn 24.

After yarn 24 exits chamber 11, it immediately begins to cool upon contacting the ambient air surrounding chamber 11 and is further cooled by means of forced air which exits pipe 62 through openings 63 therein. Pipe 62 is supported by any conventional means [not shown] and receives air from a suitable source [not shown].

After yarn 24 has been cooled below 185 F. it is removed from conveyor belt 32 for further cooling. Takeup rollers 70 and 71 are respectively mounted on

shafts

72 and 73 which in turn are journaled in

support brackets

75 and 76 and

support brackets

77 and 78, respectively. Takeup rollers 70 and 71 and parallel to each other and to conveyor drum 36 and receive an open meshed conveyor belt 80. Shaft 72 is connected to shaft 39 by a sprocket and chain arrangement 81 and is adapted to provide takeup roller 70 with a peripheral speed which is equal to the peripheral speed of conveyor drum 36 so that the rate of speed of

conveyor belts

80 and 32 are equal.

Pinion rollers

82 and 83 are respectively mounted on shafts 84 and 85 and are parallel to and are spaced vertically above takeup rollers 70 and 71, respectively.

Pinion rollers

82 and 83 are in frictional contact with belt so that movement of belt 80 produces a rotation in

pinion rollers

82 and 83. Shafts 84 and are respectively journaled in slot 86 of support bracket 75 and a like slot in support bracket 76 which is not shown and in slot 87 of support bracket 77 and in a like slot in support 78 which is not shown. Shafts 84 and 85 in effect float in their respective slots to compensate for the differential thicknesses of yarn 24 and belt 80. Motor 90 which is mounted on an L-shaped bracket 91 which in turn is secured to base plate 10 drives fan 92 to cause air to move upwardly through the conveyor belt 80 and contact yarn 24 so as to further cool the same. Pinion roller 82 cooperates with belt 80 to feed yarn 24 onto belt 80 and pinion roller 83 cooperates with belt 80 to provide a tensioning means for the yarn take-up. Yarn 24 may be taken up by any convenient means such as by bobbin 95.

The product obtained from this apparatus and the following method is a fully bulked continuous filament acrylic yarn having not less than 40% bulk, a tenacity of not less than 1.6 -g.p.d. and at least 30% elongation in the bulked form. Bulking by the best of the previously cited prior art processes produces a yarn having a bulk of 27%, a tenacity of 1.9 g.p.d. and elongation of less than 18%.

The method of this invention is concerned with the full bulk development of textured yarn 24 which is obtained from any suitable yarn source. Yarn 24 is fed vertically downwardly at a constant rate of speed by means of

feed rollers

25 and 26 into cavity 12 which may be called the bulk development zone. In cavity 12, yarn 24 is received by the upper surface of conveyor 32 which conveys yarn 24 across heater elements 46 which define a heat zone at a speed which is significantly slower than the rate of yarn infeed so that yarn 24 may realize its full shrinkage and bulk development while being suspended in a substantially frictionless and tensionless state. Yarn 24 is maintained in a tensionless state by

fans

52, 53, 54 and 59 which blow air across heating elements 46 and upwardly through conveyor belt 32. The temperature of the upwardly moving air is greater than the second order transition temperature of the yarn which is approximately 210 F. in dry heat. With yarn 24 suspended above the surface of conveyor belt 32, it is heated to a temperature being greater than its second order transition temperature and full bulk is developed in the yarn due to the absence of any tension or frictional forces which normally act on the yarn. The yarn must not be in contact with any surface for even its own weight and the friction resulting therefrom while in contact with the surface is enough to prevent the full bulk development of the yarn.

The bulked yarn departs chamber 12 and resultingly the bulking environment through slot 33 whereupon it is immediately subjected to ambient conditions surrounding the apparatus for immediate cooling to about 177 F. before leaving the surface of belt 32. Yarn 24 is then forwarded to yarn cooling conveyor belt 80 where fan 92 forces air upwardly through conveyor belt 80 to further cool yarn 24 to a temperature of below approximately F. The full bulked yarn is then fed between belt 80 and roller 83 whereupon it is subjected to a tension force by means of take-up bobbin 95.

Multifilament yarns of a large range of denier and varying degrees of twist may be processed by this apparatus and method so long as the yarn can be applied to the belt in a manner which is completely free from tension.

Example Acrylic fibers which were comprised of a copolymer of 97% acrylonitrile and 3% vinyl acetate were texturized by means of a false twist process and were fed into cavity 12 by means of feed rolls 25 and 26 at a rate of 80 f.p.m.

The yarn which is comprised of a plurality of acrylic fibers was laid onto conveyor belt 82 which was traveling at a rate of 25 f.p.m. The differential speed between feed (80 f.p.m.) and belt (25 f.p.m.) allowed for contraction during bulk development. The belt speed provided a residence time of four seconds in chamber 11. The yarn was subjected to a bulking temperature of 368 F. while in the heat zone and while being suspended above the surface of conveyor belt 32. The yarn was then quenched to a temperature of below 176 F. after exiting chamber 11 while remaining on conveyor belt 32. The resulting yarn had the physical properties of 1.9 grams per denier, 34 percent elongation in the bulked form and developed bulk of 40%.

What is claimed is:

1. A method for fully developing the bulk in textured yarn comprising the steps of:

(a) drawing continuous multifilament textured yarn from a source of supply at a first selected rate;

(b) feeding said yarn at said first selected rate of speed into a substantially enclosed chamber and onto an open-meshed, endless conveyor belt means, said conveyor belt means traveling at a second selected rate of speed being slower than said first selected rate of speed;

(c) transporting said yarn through a heat zone located in said chamber by said conveyor belt means to raise the temperature of said yarn above the range of 185-225 F. and to fully bulk said yarn;

(d) directing a continuous blast of a heated gas upwardly through said conveyor belt means and against said yarn while in said heat zone to lift said yarn upwardly and to support said yarn in a substantially tensionless and frictionless state above said conveyor belt means during full bulking;

(e) moving said yarn out of said heat zone and out of said chamber by said conveyor belt means; and

(f) cooling said yarn to a temperature being below 185 F. before said yarn is subjected to external forces.

2. The method of claim 1 wherein the filaments of said multifilament yarn are comprised of an acrylom'trile copolymer.

3. The method of claim 2 wherein the heated gas is heated air.

4. The method of claim 3 wherein the first selected rate of speed is at least twice that of the second selected rate of speed.

5. The method of claim 4 wherein said yarn is cooled to a temperature below 185 F. before being removed from said conveyor belt means.

6. The method of claim 5 wherein said yarn after being removed from said conveyor belt means is further cooled to a temperature being less than 120 F. prior to packaging.

7. An apparatus for fully developing the bulk in a continuous multifilament textured yarn comprising:

(a) a substantially enclosed chamber;

(b) open-meshed moving conveyor belt means partially residing in said chamber;

(c) a heat zone located in said chamber through which passes said conveyor belt means;

(d) yarn feeder means for drawing said yarn from a source and for depositing said yarn on said conveyor belt means prior to said conveyor belt means entering said heat zone; and

(e) air blower means for introducing air to said heatzone where said air is heated and for forcing said heated air through the portion of said conveyor belt means residing in said heat zone at a velocity sufficient to lift said yarn from said belt and to suspend said yarn above said belt in a substantially tensionless and frictionless state while in said heat zone, said heated air raising the temperature of said yarn to above -225 F. to allow full bulk to develop while being suspended in said tensionless and frictionless state.

8. An apparatus for fully developing the bulk in continuous multifilament textured yarn comprising:

(a) a chamber defining a cavity and having a yarn inlet, a conveyor exit slot and a conveyor inlet slot;

(b) means located adjacent said yarn inlet for draw- .ing said yarn from a source and for feeding said yarn into said chamber through said yarn inlet at a first selected rate of speed;

(c) first and second conveyor rollers respectively mounted for rotation in said chamber cavity and externally of said chamber;

((1) anopen-meshed conveyor belt being mounted on said defining a path around said first and second conveyor rollers, said path extending through said conveyor exit and inlet slots and beneath said yarn inlet in said cavity to reveive said incoming yarn;

(e) means for driving a selected one of said rollers and resulting said conveyor belt at a second selected rate of speed being less than said first'selected rate of speed;

(f) heating elements positioned in said cavity and beneath a length of said conveyor belt to define a heat zone encompassing said length of said conveyor belt; and

(g) blower means for directing air against said heating elements and upwardly through said conveyor belt to lift and suspend said yarn in a substantially tensionless and frictionless state above said conveyor belt and to raise the temperature of said yarn to above the range 185-225 F. while in said suspended state.

9. The apparatus of claim 8 wherein a second blower means is mounted externally of said chamber and adjacent said second conveyor roller, said second blower means adapted to direct sufiicient quantities of cooling air onto yarn to lower the temperature thereof to below 185 F. before said yarn is removed from said conveyor belt.

10. The apparatus of claim 9 wherein a pair of spacedapart and parallel takeup rollers are horizontally positioned so that a selected one of said takeup rollers is located adjacent to and in communication with said second conveyor roller, means for driving said takeup roller, a takeup open meshed conveyor belt mounted for movement on said takeup rollers and a pair of parallel pinion rollers positioned vertically above respective ones of said takeup rollers and in frictional contact with said takeup belt whereby a movement of said takeup belt produces a rotation in said pinion rollers, said pinion rollers and said takeup belt cooperating to pull said yarn from said conveyor belt means and to provide a tensioning means for yarn packaging.

11. The apparatus of claim 10 wherein a fan is positioned beneath said takeup belt between said takeup rollers, said fan adapted to direct air upwardly through said takeup belt to contact and further cool said yarn.

References Cited UNITED STATES PATENTS 2,974,391 3/1961 Speakman et al. 3,235,935 2/1966 Daruwalla 28-72.2 3,241,212 3/1966 Evans et al. 3,268,971 8/ 1966 Lockwood.

LOUIS K. RIMRODT, Primary Examiner US. Cl. X.R.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3,457,602 July 29, 1969 John C. Oatfield et a1.

It is certified that error appears in the above identified patent and that said Letters Patent are hereby corrected as shown below:

Column 2, line 66, "1" should read l2 Column 6, line 18, "said" should read and line 39, after "onto" insert said Signed and sealed this 14th day of April 1970.

(SEAL) Attest:

Edward M. Fletcher, Jr. E.

Attesting Officer Commissioner of Patents