RING MACHINE PARTS

SPINNING RING:

Spinning ring is a narrow, vertical, cylindrical steel band with a horizontal flange. The function of steel ring is to serve as a track upon which traveler may revolve. In this way it assists in twisting the yarn and guiding it to the bobbin as well. Vertical part is known as web and horizontal part at the top of the ring is called as flange. For course count, diameter of the ring will be more and vice versa. Range of ring diameter is 35-75mm.life of spinning ring depends upon,
Ø Quality/material of spinning ring
Ø Spindle speed
Ø Count of yarn

1.1 RING TRAVELER
Twisting and winding both requires assistance of the traveler which revolve s freely around the spindle on the ring. Traveler is a short steel wire having shape like ‘C’. As it travels on a ring track so is called as ring traveler. It is hardened, tampered and polished. Its motion is free on the ring flange. For course yarn/count heavy traveler is used and vice versa. To clean the traveler from lint there are some projecting pieces called traveler cleaners/clearer.
1.2 SPINDLE
After drafting yarn come on spindle which has duvet on it known as bobbin. Spindle is short, light shaft which may be rotated on its own lengthwise axes to insert twist and to wind yarn into some desired form of package. For ring spinning frame, each spindle carries a small pulley by which it is driven. Function of spindle is.
Ø To rotate delivered fibres from front roller nip for twist insertion.
Ø To wind the yarn produced on bobbin as fast as it is twistead.

BOBBIN:

As it is practically not possible to spin directly on the bare spindle, so, some form of bobbin on spindle is used. A spinning bobbin is long, narrow cylinder usually made of plastic. A bush inside the bobbin in upper half portion is used to fit it on spindle firmly. So, bobbin speed will be the same as spindle speed.

RING SPINNING

RING FRAME
OBJECTIVES:
Ring machine may perform four basic operations continuously and simultaneously which are,
1. DRAFTING:

“Reduction of bulk of strand into desired size”
2. TWISTING:

“Fibers spiral around each other and building themselves together to provide strength”
3. WINDING:

“Coiling the twisted strand of yarn around the bobbin as rapidly as it is delivered by the drafting rollers”
4. BUILDING:

“Regulating the pattern of winding of the yarn to give package, a desired shape and size, to suit the requirements of the use of the yarn.
1. DRAFTING
1.1 DRAFTING REQUIREMENTS:
ð Strand of fibres must be gripped in two or more pairs of rollers.
ð Successive pairs of rollers must move at higher speed.
ð The pairs of rollers must be separated by a distance suited to the staple of the fibre being processed.

1.2 DEGREE OF DRAFTING:
It depends upon roller speed differential e.g. If we want to know back zone draft then it can be determined by difference of surface speeds of back and second rollers. If speed differential is more then back zone draft will be more and vice versa.
1.3 DECISION OF DEGREE OF DRAFTING:
­ Degree of drafting depends upon,
i. Hank roving available
ii. Yarn count required to be spun.
iii. How much preparation of roving strand is required in back zone (BZ degree of drafting).
iv. Draft range available at Ring.
­ Back zone preparation depends upon roving TM and moisture content in roving. If roving TM and moisture content is more in roving then there will be more back zone draft and vice versa.

­ There are two drafting arrangements in spinning mills.
i. PK225: Low drafting system having draft range 15-30
ii. PK255: High drafting system having draft range 16-45
Major advantage of high drafting range is that coarse hank roving can be fed to the machine. Hence degree of drafting also depends upon draft range available at ring.

2. TWISTING

To obtain a yarn having suitable strength as per requirement or any use we have to insert twist. At ring machine twisting system involves spindle, bobbin, ring traveler and steel ring. Here directly related part is spindle, others are indirectly related. Yarn coming from nip of front roller pass through a guide known as lappet and enters in another revolving guide known as ring traveler. Traveler is traveling on the ring so called as ring traveler. After ring traveler, yarn winded on bobbin which is firmly fitted on spindle. Each revolution of the spindle inserts a twist. The relationship between TPI, spindle speed and front roll delivery is as follows,

TPI=spindle speed/front roll delivery

Normally when we increase spindle speed the speed of all parts will be increased. So, front roll speed will also increase. In this way by changing spindle speed twist in yarn will not change. To change twist, front roll delivery have to change by changing twist wheel.

3. WINDING SYSTEM

As spinning is a continuous process, so yarn being drafted and twisted is required to wind regularly on bobbin. Spindle is revolving to twist the yarn as well as wind the yarn on bobbin. Bobbin speed is same as spindle speed because it is firmly fitted on the spindle. Actual revolution of the yarn around the spindle through a revolving guide are the turns in a specific length i.e. TPI.
These revolutions or turns will be less than the spindle revolutions because spindle is required to revolve with more speed to wind the yarn as well. So, actual twist can be determined by traveler speed.
Winding rate = delivery rate = S.S of spindle¾ S.S of traveler (A)
π×D×N = delivery rate
N = delivery rate / π×D
So, it is the requirement of winding that yarn revolution through a revolving guide must be less than the spindle revolutions. Revolving guide which is traveling on the ring is called as ring traveler. Its weight is responsible to increase or decrease its speed. Each revolution of the traveler insert one turn of the twist in the yarn.
Above equation (A) stats that,
Ø Winding speed/rate must be equal to delivery rate otherwise material will be too tight t or too slack resulting in yarn breakage.
Ø Winding is done due to the difference in surface speeds of spindle and traveler, otherwise winding will not take place.
As we know that around the spindle a yarn guide (traveler) is revolving on the ring. The speed of traveler is lagging behind the spindle due to which material will be winded on the bobbin. In other words spindle speed is more than traveler speed results in winding of the yarn on bobbin. Actual twist in yarn will be as per revolutions of traveler.
FOR EXAMPLE:
Spindle speed = 22,000 rpm
Traveler speed = 21,700 rpm (responsible for twisting)
Winding speed =300 rpm (responsible for winding)
Now if front roll delivery is 687 in/min and we are preparing a count of 50 then
TPI = =32.02 (theoretical)
TPI = = =31.58 (actual)
DETERMINATION OF TRAVELER SPEED:

From equation (A,
S.S of traveler = S.S of spindle¾ delivery rate
= π×D×N¾687 in/min
=3.14×21.75(mm) ×22000 ¾ 687 in/min
=3.14×0.856 inches ×22000 ¾ 687 in/min
=59132 in/min OR 81.20 ft/sec
Traveler rpm = spindle speed ¾ winding speed
=22,000 rpm ¾ 300 rpm
=21,700 rpm