Winding

Lecture # 5 & 10

Mujahid Mehdi Abro Indus University Karachi

Winding Process

Input = Yarn (Spinning Bobbin)

Output = Yarn (Large Cones, Tubes etc)

Objectives of Winding Process Inspect the yarn

Clearing of defects

Lubricate the yarn

Conversion of yarn from small package to bigger package

Winding Process

Bobbin unwinding zone

Tension Zone

Clearing Zone

Joining Zone

Winding Zone

Clearing Zone

Next, the yarn moves to the clearing and joining zones. The clearing device detects the defects in the yarn and activates a mechanism which cuts the yarn for defect removal. The two yarn ends are then joined back together using either a knotting or splicing device.

Yarn clearer

Faults of yarn are as follows

• Thick and thin places • Slab and neps • Loose fabric • Foreign materials

Yarn clearer is the device which is used to remove the following faults of yarn in order to increase the yarn quality and weaving efficiency.

Types of Yarn Clearer

There are two types of yarn clearer 1. Mechanical Type 2. Electronic type a. Capacitance typeb. Photo electric type

Mechanical type:

A mechanical clearer may be as simple as two parallel blades. The distance between the plates is adjustable to allow only a predetermined yarn diameter to pass through. A thicker spot on yarn (slub) will cause the tension on the yarn build up and eventually breaks the yarn. These types of devices can only detect and deal with thick places in the yarn.

Electronic type:

Capacitive:

In capacitive type detector, the variation in the mass of the yarn passing through the plates changes the capacitance of the unit. It should be emphasized that the system measures the mass of the yarn. The signal is not based on the physical dimension of the yarn. When the generated signal reaches a certain value, the yarn is cut.

Photoelectric:

In photoelectric detector, the yarn passes between light coming to the photo cell, which changes the resistance of the photocell. This resistance change is detected by a signal conditioning amplifier, which can be set to send a signal to cut the yarn and stop the winding process.The latest yarn clearing systems can also detect foreign fibers. These fibers are classified and eliminated during the winding process. As a result, the quality of the yarn can be improved during the winding process.

Comprise between mechanical and electronic clearer

• Electronic clearer are more sensitive than mechanical clearers

• In case of mechanical clearers there is abrasion between yarn and clearer parts but in case of electronic clearers there is no such abrasion

• Mechanical clearers do not prevent soft slab from escaping through clearer where as electronic type does not allow passing of any types of faults

• Mechanical type does not break the thin places and the length of the fault is not considered

• Mechanical clearer are simple and easy to maintain while the electronic clearers are costly and requires high standard of maintenance

Winding Packages

Winder packages are usually shaped into a cone, tube or cheese as shown in the slide.

The tube or cheese has all sides parallel, and the cone is formed with a tapered shape.