TWO FOR ONE TWISTER (TFO)

Two for One Twister              

TECHNICAL DESCRIPTION:

TWO FOR ONE TWISTING SYSTEM

      With the two for one twisting system, the thread obtains two turns with one revolution of the spindle. The yarn receives its first turn between the yarn break in the hallow axle and the exit in the spindle rotor(Reserve disc)The second turn is given with the outer balloon between spindle rotor and pig tail thread guide. To obtain this two for one effect, the pot with the untwisted feed package is kept motionless on the spindle rotor by permanents magnets.

                                                     Spindle speed in rpm x 2

            Number of twists       = ---------------------------------

                (Twists/ meter)            Yarn length per meters per minute    

WORKING METHOD TWO FOR ONE SPINDLE

The untwisted yarn, unwound from the feed package by means of an unwinding aid called as flyer (in the case of assembly wound feed packages), or without unwinding aid in the case of sun spool or sun packages feeding), passes through the capsule portion and the hollow axle enters the reserve disc and leaves through the opening in the reserve disc.  The yarn at this  point with one twist already inserted winds around the reserve disc and then enters in the pig tail forming a balloon, thereby the second twist also inserted.

            The twisted yarn runs over the pre take up roller and with the help of the traversing thread guide gets wound on to cross wound bobbin which is kept in a cradle between two centering discs.

ADVANTAGES OFFERED BY THE TWO FOR ONE TWISTER

·         Two turns with one spindle revolution.

·         Large knot-free yarn length.

·         Direct delivery of the twisted yarn on cones or cheeses eliminating rewinding process.

·         Twisting without ring and travellers.

·         No deformed twister bobbins.

·         no double threads.

·         Higher production per spindle.

·         Possibility of getting hard, medium and soft packages with less adjustment.

·         Easier change over from ‘S’ type twist to ‘Z’ type and vice versa.

·         Possibility of twisting different yarn counts with same twist on the machine.

·         Increased loom shed efficiency.

·         Low maintenance.

YARN TENSION

The yarn path on a Two for one spindle is devided into four sections with different yarn tensions.

y        Delivery tensions( unwinding tension)

y        Internal tension with in the hollow axle.

y        Balloon tension

y        Take up tension

The maximum yarn tension on a two for one spindle occurs above the apex of the balloon (i.e) at pig tail thread guide, a region where the twisting process is already completed.

 Delivery tension :-

The delivery tension is influenced by the diameter and shape of the feed package and the weight on delivery aid(flyer).  This tension can be controlled by adding or removing the flyer weights on to the flyer.  Needs attention while processing coarser count yarn.

Internal tension with in the hollow axle. :-

The internal tension within the hollow axle is controlled by the multiple tension device and wrapping at the reserve disc can be adjusted thereby.

Balloon tension :-

The balloon tension is influenced by the spindle speed, yarn count and adjustment in height of the pig tail.

Take up tension :-

The take up tension can be controlled by adjusting the speed of pre take up roller.

MAIN FEATURES OF EACH MECHANISM :-

Two for one spindle Bolster

It is clamped on the spindle  rail. The tip of the spindle blade rests at bottom and the neck bearing is a roller bearing.

Spindle Rotor :-

It is made free from vibration and finished to high degree of accuracy. It consists of spindle blade, steel wharve, reserve discs and bearing assembly.  Ceramic guides are mounted where ever necessary.

Attention  :-

Never use sharp tools like scissors, knifes, etc. For cleaning the reserve discs and spindle wharve.  Damages to these parts cause hairiness and end breaks and further lead  to the damage of spindle tapes.

Protection pot or inner pot :-

It is provided to prevent interference of unwinding yarn with ballooning yarn.  It remains stationery by virtue of the magnetic force, while the spindle is rotating.  Even a fine scar or scratch on this pot may damage the yarn to cause ends down because the yarn touches the upper edge of the pot while starting.  Special care is requested when handling this pot.

Magnets :-

In the spindle unit, the pot is provided to prevent the interference of unwinding yarn with ballooning yarn. It stands still by virtue of the magnetic force while the spindle is rotating.

The magnets have been fixed in the holder radially inside and outside the pot as shown in the figure such that the nearer magnet poles are unlike poles.  Magnets have been white painted at south poles for identification. Any wrong position of the magnet in the assembly will reduce the magnetic force and will lead to the rotation of the pot.  If the pot starts rotating, it may be thrown out of the spindle causing damages to the adjacent parts/personnel. Hence, it is advised not to dismantle the magnet holders. When it happens to dismantle the magnets from the holders, they have to be refixed ensuring position of poles referring to the figure of respective models.

Internal Thread Brake  :-

The untwisted yarn passes through the entry pipe, then through the internal thread brake (yarn holding assembly) and there by it is pressed between capsule and ceramic bush. This tensioning device is adjustable in multiple steps.  It influences the inner delivery tension and thus the reserve around the reserve  disc on the rotor. The capsule has its highest braking effect in position 4 and the lowest in position 1

Flyer :-

In case of assembly wound packages, the flyer serves as an unwinding and delivery aid. It is not required when two single wound bobbins ( For VJ190-o model) are fed.

Balloon limitor or ABC Ring :-

The balloon limitor provided for an overall support of the yarn balloon, reduces the balloon diameter and thereby lowers the balloon tension.  The inside surface of the balloon limitor is specially finished and therefore may only be cleaned with cloth to avoid any possible damage to the surface.

Separators :-

The separators serve to separate the individual spindle from each other in case of ends down to prevent broken ends falling on the yarn path of neighboring spindles.

PIG TAIL THREAD GUIDE :-

The adjustment in height of the pig tail thread guide determines shape and size of yarn balloon.  The height of the tail support is adjustable.

Take up parts :-

Cradle:

Even a little slip of the take up bobbin may lead to uneven twisting.  Self aligning centering discs are mounted at both side of the cradle which ensures smooth bobbin rotation. A contact pressure is given to the package by means of spring. It has been designed such that the pressure  is decreased in proportion to the increase in package diameter.

Take up roller:

The take up rollers shafts are driven from from the gear end. Friction synthetic rubber ring is mounted for stable transmission of drive to take of bobbin.  The speed of the take up roller determines number of twists inserted to the yarn.

Pre take up roller :-

The high ballooning tension is reduced to take up tension by this roller.  It is not a delivery system, it only supports the yarn during winding up on to the take up package.  The density of the take up package can be varied by increasing or decreasing the rotations of this roller.

Traversing thread guide :-

The thread guides are mounted on a reciprocation tube which are actuated by individual cams on either side.

Anti pattering device :-

Synchronized with the drive and prevents ribbon formation.

Gear box :-

The driving gears are mounted in gear end. The gear end transmits and drives the take up unit and consists twist change wheel, Twist direction wheel and twist constant change wheel which are easily exchangeable. The off end contains cam driving system for which drive is transmitted from gear end to off end through the take up roller bearing shaft.  The gear end door has been provided with a limit switch.

Spindle driving system :-

It consists of individual pulley with double jockey pulley system.  Self aligning ball bearing supports are provided to the individual pulley drive shafts at every section.  The speed of the spindle is kept uniform at every section.  The spindles are driven by endless tapes and each tape drives four spindles.

Stop motion and cradle lifting arrangement :-

When yarn break occure the drop wire falls down and stops in the feed yarn from the feeding package, simultaneously a lover connected to this engages with the continuously oscillating bracket which oscillates radially up and down and lifts that particular cradle. This can be easily identified and attended by the operator. The cradle lifting arrangement is an optional attachment.

Top tray arrangement :-

It is an optional attachment provided for storing/keeping the delivery/feeding materials to facilitate easier change over of doffing.

Electrical equipment :-

The panel box is kept by the side of the motor unit.  All control elements are provided according to the current data as well as electro technical direction valid in the country. Further details may please be referred from the electrical circuit diagram.

Motor unit and drive :-

The machine is driven by 3 phase induction motor of squirrel cage type.  The motor is mounted on to a motor plate, the height of which can be adjusted to set the required tension of the V belts.  By rotating studs by a spanner, the motor can be moved  up or down.  After setting it at required position, clamping nuts are to be tightened for locking.       

   

TECHNICAL ADJUSTMENTS

SETTING SPEED :

The spindle speed is altered by exchanging the motor pulley  or main drive pulley. this can be done  in the following manner. After  removing the  guard un stretch v belt  by lowering the motor,  tighten loosen the  stud  nuts   and the pulley can be  removed from the hub. while mounting the required pulley, apply grease to the loading  portion of the hub and pulley .

ADJUSTMENT OF YARN RESERVE  :

A sufficient reverse is  absolutely necessary  to achieve optimum results  on a two for one spindle. Amount of thread  around the reserve disc  of rotor should be  11/2  to 2 turns  with full feed package. The reserve must  be atleast  1/2 round where package is empty. This can be achieved by adjusting the  feed package tension or un winding tension slightly. And adjusting the capsule  and tension  variator system( internal thread brake ) in connection with the  flyer weights, depending on the spindle speeds , yarn count ,  inserted twist and friction resistant of the yarn.

                                                           

The tensioning  device  has its  highest braking effect  at  position ‘4’  and lowest in position ‘1’, the machines are supplied  with one set of   capsules  according to the requirement. According to the different spring  tensions  the capsules  are marked with  grooves. The adjustment  of reserve can  be made as follows .

1.Tension device  and  flyer weights  in certain  uniform  position .

2.Start the machine  with full  feed package  and at recommended  spindle  speed .

3.By absorbing the with a stropo scope correct the yarn reserve   by changing the tension  and flyer weight .

increase in spindle speed  will result  increase  of yarn reserve .  a wrong     adjustment of  the reserve will  result  in high rate of yarn breakage .

FLYER WEIGHTS :

Loading the  flyer  by means of  flyer weights  influence  the reserve  i.e. the reserve reduces the  with increased  weight of  flyer weights .

ADJUSTMENT OF PIG TAIL GUIDE :

size and shape of the yarn balloon  depends upon spindle speed   yarn count and  adjustment of the pig tail guide .

SETTING OF OVER FEEDING  RATIO : 

This can be adjusted  by changing the gears  on the tilting bracket  in side the gear end frame .

Dia of  take up roll * take up roller driving wheel  *100               dia of  pretake up roller * pretake up roller end wheel

CHANGING THE TWIST DIRECTION  :

After  changing the direction of the moter, by shifting the   bracket having 36 T wheel  engaged with   the 32 T  wheel  to get engaged with the other   32 T wheel, the direction of rotation  of take up roller  is brought to its   original direction  of  rotation. since the  gear wheel 36 T wheel , the hand of  wheel to be changed .

ADJUSTMENT OF  TRAVRSING  GUIDE  :

The guide setting  can be  done  with the delivery package of size  about 130  to 140 mm  dia  at this position  adjust the  guide  to a maximum  extent  closer to the package  with a clearance of   only  about  2 mm  between  the package  and top surface of the  ceramic guide .

The position of the guide   should be adjusted  such that  it catches the yarn automatically  when it  reciprocates. Care should be taken  that it should not  touch the take up roller.  Also it should be properly  positioned having   winding of yarn  with in the limits of cone. winding should   be  effected  with a gap of  at least  10 mm  from the small end of the cone .

ADJUSTMENT OF  CAM SPEED  :

The speed ratio of  take up roller  and  cam  can be  adjusted  by changing  the gear wheels suitably. The no of strokes per minute  of traversing guide   can be varied   by lease angle   change gear wheels .

ADJUSTMENT OF THE   V BELT TENSION  :

The slackness of the belt   to 12 to 14 mm   the motor plate  can be lowered  or  raised  to do adjustment  as well as  for mounting     the belts .

SPINDLE SPEED :  1450* d*0.97*350. 5

                      D* 32. 5

TPI      :   2*350. 5*84* b * 28* 72* 25. 4

              32. 5* 30* a* c* 36* 3.14 *77

     

TFO MAINTAINENCE SCHEDULES

y        BREAK ROLLER GREASING                                                - 1 YEAR

y        PERIODICAL SETTING                                                      - 6 MONTHS

y        G.E & O.E OVER HAULING                                     - 6 MONTHS

y        MAIN SHAFT OVER HAULING                                          - 1 YEAR

BREAK ROLLER GREASING :

y        ALL BREAK ROLLERS GREASING.

y        ALL JOCKY PULLYS GREASING.

PERIODIVAL SETTING :

y        PIG TAIL CENTERING.

y        STOP MOTION WORKING CHECKING.

y        SPINDLE BEARING GREASING.

y        ALL GEAR BOX OIL CHECKING & CHANGING.

y        changing of cam lubrication oil.

G.E & O.E OVER HAULING :

y        All the gear wheels at gear end and off end removed and cleaning with C.T.C. Oil checking of all teeth at gear wheels and if any damage is there that is to be replaced.

y        Checking of all studs and if any damage in bearings that is to be replaced.

y        Changing of greases at all gear wheels.

     

MAIN SHAFT OVER HAULING :

      All main shaft roller bearings to be removed, cleaning with C.T.C., Checking of all bearings, if any damage that is to be replaced.

Spindle oil  using type             :synlub 10

recommendation :servo spin 12 or equalant

gear box oil recommendation   :servo spin 68 or equalant

grease for all wheels using   :servo gem 2

recommendation :servo gem 3

suggestions for smooth working of veejay lakshmi model TFO

      Reserve wrapping on reserve disc to be maintained at 1.5 turns in the beginning of cheese and it should above 1 turn at cheese exhaust. For that we have to select particular capsules, correct stem no. and if necessary tension weights also we can change.

            Pig tail height to be maintained according to the ballooning tension.

Capsules are devided into 3 types

y        plain                                   - useful for above2/24^s 

y        single groove                      -  below 2/24^s

y        double groove                     -  3 ply