Draw Frame

To blend, doubled and leveled the slivers are known as draw frame. Draw frame is also known as drawing. The process by which the yarn or fiber is elongated by passing it through a series of pair of rollers, each pair moving faster than the previous one is called drawing or draw frame.

Objects of Draw Frame:

1. On the slivers the fibers should be straight.
2. To make them lie in a manner parallel to the sliver axis and neighbors.
3. To improve the evenness of the sliver.
4. To improve the uniformity of the sliver.
5. To remove the dust from the sliver.
6. To make perfect blending of the component.

Recent development of Draw Frame:

1. Production rate is higher, which about up to 1000 meter per minute delivery speed.
2. Drafting system improved, such as,
1. 4 over 3 with pressure bar.
2. 1 over 2 arrangements.
3. Pneumatic roller pressure.
3. Automatic sliver regularity controller which known as auto leveler.
4. Sliver quality monitory system.
5. Fault location indication lamp such as,
1. Red: When red lamp is on, then machine will be stop.
2. Green: If green lamp will appear, then there must be broke lapping sliver.
3. Yellow: Can fulfill.
6. We can measure pre set sliver length.
7. Rectangular can.
8. Can linking system.
9. Doffing automatically.

Defects of Draw Frame: There are many defects of draw frame, from these some are described below,

1. Fine sliver or End missing: Any sliver may break when doubling is 5-6; this is known as fine sliver or end missing. The causes of this fault are may be Faulty stop motion device and operators carelessness.
2. Irregular sliver: For two reason the sliver may be irregular, these are,

1. Roller slip: Improper roller pressure, Worn top roller, Eccentric top roller.
2. Defective drafting system: Improper roller setting.

3. Long fiber in the waste.
4. Roller lapping: The causes of roller lapping are,
1. Improper cleaning of the roller.
2. Improper temperature.
3. Improper relative humidity.
5. Excessive sliver breaks: The causes of excessive sliver breaks are,
1. Feed zone: Feed tension.
2. Draft zone: Roller lapping, Entanglement of sliver in can.
3. Delivery zone:
6. Improper stock filling.
7. Thick and thin place.
8. Uneven web.
9. Bad coiling.

Causes of Draw Frame efficiency loss:

1. Roller lapping.
2. Sliver breakage.
3. Doffing.
4. Schedule maintenance.
5. Quality test.

Process parameter of Draw Frame:

1. Delivery speed up to 1000 meters per minute.
2. Sliver weight: Feed 60-70 grain per yards and Delivery 55-60 grain per yards.
3. Draft: 6-8.
4. Doubling: 6-8.
5. Wastage 0.5%.
6. Efficiency: 80-85%.