Textile Technology: Winding Process

Questions and Answers

What is the movement of yarn from one end of the core to the other end called?

Traverse Ratio

Wind

Traverse (correct)

Coil

What is Traverse Ratio?

Half of the wind

Number of coils wound on per complete traverse cycle (correct)

Twice the wind

Number of coils of yarn wound on per single traverse

Why is the winding process significant?

It is a simple process where yarn is unwound from ring bobbins and wound on a new package

It is not significant as it is a simple process

It helps to reduce defects in the woven fabric

It saves time and cost by avoiding frequent replacement of ring bobbins (correct)

What problem arises if ring bobbins are used to make warper’s beam?

The ring bobbins will keep on exhausting very quickly Signup and view all the answers

What is the effect of defects in the beam prepared from ring bobbins?

The woven fabric will have defects and resources will be wasted Signup and view all the answers

Why does the winding time and cost increase if ring bobbins are used to make warper’s beam?

Because of the frequent replacement of empty bobbins with new ones Signup and view all the answers

What is the effect of thin places in the warp threads on weaving efficiency and production?

It decreases weaving efficiency and production Signup and view all the answers

What is produced in a Ring Spinning Frame?

Yarn in the form of Ring Bobbins Signup and view all the answers

What is the main purpose of the winding process?

To prepare a bigger package with enough length of yarn for short or long-term storage Signup and view all the answers

What is the purpose of applying wax to the yarn during the winding process?

To reduce the friction and abrasion of the yarn Signup and view all the answers

What is an angle of wind?

The angle between a wrap of yarn on the surface of a package and the diametrical plane of the package Signup and view all the answers

What is the purpose of changing the cone weight of the yarn during the winding process?

To change the cone weight as required in warping Signup and view all the answers

What is the purpose of sizing beams during the winding process?

To prepare the yarn for warping Signup and view all the answers

What is an angle of reversal?

The angle made by the same coil after reversal at the edge of yarn Signup and view all the answers

What is the rule of winding?

One end is fixed on a package, and other end is rotated w.r.t. fixed end around the package axis to impart coils at an angle to the diametrical plane of the package Signup and view all the answers

What is the purpose of doubling or plying of yarn during the winding process?

To increase the thickness of the yarn Signup and view all the answers

What is the main disadvantage of using a rotary drive for package winding?

The surface speed of the yarn increases as the package diameter increases. Signup and view all the answers

What is the primary advantage of using a negative or indirect drive for package winding?

It maintains a constant surface speed of the yarn throughout winding. Signup and view all the answers

What is the main disadvantage of using a negative or indirect drive for package winding?

It can damage delicate yarns due to friction. Signup and view all the answers

Which of the following is a disadvantage of the knotting method of yarn joining?

It can create problems in knitting and weaving. Signup and view all the answers

What is the primary advantage of the splicing method of yarn joining over the knotting method?

It produces a virtually invisible joint. Signup and view all the answers

What technology is used to create the splice joint in yarn joining?

Compressed air Signup and view all the answers

What is the primary function of a splicer in the context of yarn?

To join broken ends of yarn Signup and view all the answers

Which component is actively involved in sucking the yarn during the splicing process?

Retie pipe and suction mouth Signup and view all the answers

How does the splicer ensure that the ends of yarn are cut correctly?

By using upper and lower yarn cutters Signup and view all the answers

What determines the length of yarn to be untwisted in the splicing process?

The staple length of fibres in yarn Signup and view all the answers

Which mechanism is employed to hold the yarn in place during splicing?

Yarn holding lever Signup and view all the answers

What role do the guide levers play in the splicing process?

They push the yarn ends into the splicer Signup and view all the answers

What occurs immediately after the cutting of yarn ends in the splicing operation?

The yarn ends are twisted together Signup and view all the answers

What ensures that the splicing of yarn is completed successfully?

Proper air pressure release Signup and view all the answers

What is the minimum strength percentage that a splice should achieve relative to the inherent strength of yarn?

80% Signup and view all the answers

What type of withdrawal method involves removing yarn from the side of the package?

Side End Withdrawal Signup and view all the answers

What is the main function of the cradle in a winding machine?

To keep the package on the surface of the drum Signup and view all the answers

How does the Full Package Indicator Lamp signal that the package is full?

By lighting up when a specific diameter is detected Signup and view all the answers

What is the function of the drum start button during doffing?

To reset the yarn length counter and start drum rotation Signup and view all the answers

What is the consequence of using side end withdrawal at high speeds?

Increased tension caused by package wobbling Signup and view all the answers

What range of twisting pressure is specified for the winding machine?

5 - 6 bars Signup and view all the answers

What is the role of the piston and cylinder in the winding machine?

To control cradle pressure Signup and view all the answers

Study Notes

The Winding Process

Winding is the process of wrapping yarn onto a package for efficient storage and use.
Packages serve as convenient tools for handling and retrieving yarn during processing.

Objectives of Winding

To create larger yarn packages from ring bobbins for short or long-term storage.
Important for operations such as sizing beams, doubling or plying yarn, and converting cone weights.
Enables transformation between various package types (cone to pirn/quill).
Removes spinning faults like thick and thin places, improving yarn quality.
Wax application enhances yarn’s durability by reducing friction during winding.

Rules of Winding

Winding involves fixing one yarn end and rotating the other around the package's axis.
Coils can be oriented parallel or at angles relative to the package’s diametrical plane.

Angles in Winding

Angle of Wind: Relationship between yarn wrap and the diametrical plane.
Angle of Crossing: Angle where two coils intersect on the package.
Angle of Reversal: Angle created by the same coil when reversing at the edge of yarn.
Taper Angle: Angle between the package's surface and the diametrical plane.

Traverse Mechanics

Traverse refers to the movement of yarn from one end of the core to the other.
Traverse Ratio: Total coils wound per complete traverse cycle; it is twice the wind count.
Wind Count: Number of coils created during a single traverse.

Advantages of Winding

Prevents rapid depletion of ring bobbins, saving time and reducing costs.
Minimizes defects in beams prepared from ring bobbins, which can compromise the quality of woven fabric.
Reduces frequent breaks in warp threads due to thin spots, enhancing weaving efficiency.

Splicing Process

Splicing connects broken yarn ends using air pressure and involves several mechanisms:
- Retie Pipe & Suction Mouth: Facilitates yarn transfer during splicing.
- Untwisting & Twisting Nozzles: Handle the untwisting and re-twisting of yarn ends.
- Clamping Plates, Yarn Cutters, Yarn Guide Lever: Tools for ensuring precise yarn control and cutting.

Yarn Take-in and Cutting

Guide levers clamp yarn ends for cutting, adjusted to align with staple length.
Upon cutting, yarn ends are untwisted and repositioned for splicing.

Splicing Details

Utilizes specific pressures (6-6.5 bar for untwisting, 5-6 bar for twisting) to ensure strong joins.
Splice strength should retain 80-85% of the original yarn strength.

Winding Machine Components

Drum: Indirectly winds yarn onto packages, featuring grooves for cross winding.
Cradle: Supports packages under controlled pressure during winding.
Indicators: Full package indicators cease operation when the desired length is reached.

Withdrawal Techniques

Side End Withdrawal: Yarn is removed from the side of a mounted package; suited for low speeds to prevent wobbling.
Over End Withdrawal: Involves a vertical unwinding technique, allowing better control of surface speed.

Drive Methods for Winding

Negative/Indirect Drive: Maintains constant surface speed, though it risks damaging delicate yarns due to friction.

Yarn Joining Techniques

Knotting: Traditional but problematic for knitting and weaving.
Splicing: Introduced in the 1970s, invisible joint formation using compressed air ensures a smoother transition in yarn.

Winding Production Calculations

Production calculations aid in determining efficiency and required output in the winding process.

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Description

This quiz covers the winding process in fabric technology, including its definition, objectives, and importance in yarn storage and handling.