Textile Yarn Treatment and Weaving Process

Questions and Answers

What is the primary purpose of using starches in the sizing process?

To reduce the cost of production

To improve the color of the fabric

To give strength to the warp sheet (correct)

To make the yarn extensible

Why are softening agents used during the sizing process?

To improve the durability of the yarn

To increase the brittleness of the yarn

To enhance the color of the yarn

To make the yarn soft and pliable (correct)

Which of the following is NOT a type of softener used in the sizing process?

Polyester (correct)

Glycerin

Japan wax

Oils

What effect does friction between metallic parts have on yarn during the sizing process?

It increases abrasion of yarn by 200-300% Signup and view all the answers

What additional chemicals can be used in the sizing process?

Humectants Signup and view all the answers

How are multiple warper's beams combined during the sizing process?

They are combined on to the weaver's beam Signup and view all the answers

What is one of the roles of whitening agents in fabric production?

To improve the appearance of the fabric in its loom state Signup and view all the answers

What is a common consequence of using starch alone in the sizing process?

Yarn becomes hard and brittle Signup and view all the answers

What is the maximum recommended yarn spacing in the size box for effective sizing?

50% Signup and view all the answers

Which section of the sizing machine contains the sizing liquor that is applied to the warp sheet?

Sizing section Signup and view all the answers

What type of arrangement is typically found in the creel section for loading warp beams?

Staggered two-tier arrangement Signup and view all the answers

Which section of the sizing machine is responsible for drying the wet sized warp sheet?

Drying section Signup and view all the answers

What component in the sizing machine is associated with the cooking of sizing liquor?

Cooking section Signup and view all the answers

Which section has motors to rotate and wind the sized warp sheet onto the weaver's beam?

Winding/headstock section Signup and view all the answers

What is the function of the separating or splitting section in the sizing machine?

To split the sized warp sheet into constituent back beam sheets Signup and view all the answers

Which of the following statements about the arrangements in the creel section is incorrect?

Only a single-tier arrangement is used. Signup and view all the answers

What is the primary function of the catwalks in the sizing section?

To facilitate safe access to warp beams Signup and view all the answers

What does the negative let-off of the yarn imply?

Beams are not motor-driven Signup and view all the answers

What is the purpose of the pre-wetting process in sizing?

To improve the adhesive force of size Signup and view all the answers

What components does a conventional two box-sizing machine typically use in the first size box?

Hot water for pre-wetting Signup and view all the answers

What is the function of the guide rollers in the sizing machine?

To guide the warp sheet towards the size box Signup and view all the answers

What is the maximum capacity of a mono-rail used in the loading of beams?

2-3 tons Signup and view all the answers

At what temperature is the hot water used during the pre-wetting treatment typically maintained?

90 °C Signup and view all the answers

What is the range of creel capacity for a sizing machine?

16 - 36 Signup and view all the answers

What is the primary purpose of weighting agents in warp sheets?

To increase the weight of warp sheets Signup and view all the answers

Which of the following qualities should sizing materials possess to be effective?

Compatible with machinery used Signup and view all the answers

In the general composition of sizing materials, what percentage does starch contribute?

90% Signup and view all the answers

What does the term 'percentage sizing material (S %)' refer to?

Weight of unsized yarn Signup and view all the answers

Why are antistatic agents included in the sizing process?

To eliminate static charges Signup and view all the answers

What is one of the negative consequences of using inadequate sizing materials?

Increased exfoliation in the dry state Signup and view all the answers

Which component of sizing material contributes the least to its composition?

Other chemicals Signup and view all the answers

Which statement best describes an ideal sizing material?

Must yield desired results with minimal quantity Signup and view all the answers

What is the formula used to calculate the size percentage (S %)?

Oven-dry weight of size material / Oven-dry weight of unsized yarn x 100 Signup and view all the answers

What does the percentage size concentration (C %) represent?

The weight of size material in relation to water used Signup and view all the answers

Where is the sizing solution typically prepared?

In a sizing cooker separate from the sizing machine Signup and view all the answers

What does the term 'size take-up' refer to?

The mass of paste picked up per unit weight of unsized yarn Signup and view all the answers

What is meant by size liquor concentration?

The mass of solid contents in the size paste expressed as a percentage Signup and view all the answers

How is the sizing solution transferred to the sizing machine?

With the help of a pump and piping system Signup and view all the answers

Which of the following accurately defines size percentage?

The mass of dry size material stored on the yarn expressed as a percentage of unsized yarn weight Signup and view all the answers

What is the primary purpose of valves in the sizing machine?

To control the flow of sizing solution Signup and view all the answers

Study Notes

Friction and Yarn Sizing

Friction between metallic parts increases yarn abrasion by 200-300%.
Yarn is treated with chemicals during sizing to cover thick and thin places, making it smooth and pliable.
The total number of ends necessary for weaving is determined and combined from warp beams to the weaver’s beam.

Sizing Materials

Starches: Primary ingredient providing strength to warp sheets; derived from various sources.
Softeners: Used to make yarn soft and pliable, classified as lubricants.
- Common softeners include oils, synthetic and natural fats, glycerin, soaps, and Japan wax.
Other Chemicals: Optional additives to enhance performance.
- Humectants maintain moisture in the warp sheet.
- Antiseptics prevent bacterial attack.
- Weighting agents increase weight for fine counts.
- Antistatic agents eliminate static charges.
- Defoamers restrict foam formation.
- Starch thinning agents make starch thinner.

Quality of Sizing Materials

Ideally, sizing materials should minimize yarn breakage during weaving.
Should have low exfoliation in a dry state and be easily de-sized.
Must improve fabric characteristics and be compatible with machinery.
Should be non-hazardous and not degrade textile materials.
Minimum quantities should achieve required results.

Composition of Sizing Materials

General composition includes:
- Starch: 90% (9 parts by weight)
- Softener: 9% (0.9 parts by weight)
- Other chemicals: 1% (0.1 parts by weight)

Sizing Material Concentrations

Percentage Sizing Material (S%): Reflects oven-dry size material's weight against the unsized yarn's weight.
Percentage Size Concentration (C%): Indicates oven-dry size material weight as a percentage of water used.

Preparation of Sizing Solution

Sizing solutions are mixed separately from the machine in a sizing cooker.
Ingredients are cooked until the required viscosity is achieved before transferring to sizing machines.

Key Sizing Process Terms

Size Liquor Concentration: Mass of solid contents in size paste.
Size Take-up: Mass of paste pickup per unit weight of unsized yarn.
Size Percentage: Mass of dry size material on yarn as a percentage of unsized yarn weight.
Size Box Occupation: Determines yarn spacing, should be less than 50% for optimal sizing.

Sizing Machine Components

Creel Section: Holds warp beams to accommodate multiple beams efficiently.
Sizing Section: Contains size box applying sizing liquor on the warp sheet.
Drying Section: Rapidly dries the wet sized warp sheet, using cylinders or chamber.
Leasing/Splitting Section: Splits the sized warp sheets into constituent beams.
Winding/Headstock Section: Winds the sized warp sheet onto the weaver’s beam.
Cooking Section: Prepares sizing liquor and includes storage for the cooked solution.

Creel Section Details

Warp beams are organized for efficient unwinding, typically in staggered or tiered arrangements.
Features catwalks for easy access to beams and includes a pneumatic brake system for control.

Sizing Section Workflow

Pre-wetting with hot water before size solution application enhances adhesive forces.
First size box may be used for pre-wetting to clean out impurities from yarns.

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Description

This quiz explores the techniques involved in treating yarn to minimize friction and enhance its smoothness and pliability. It also covers the importance of sizing and the necessary number of ends for weaving fabrics. Test your knowledge on the specifics of yarn processing and weaving methods.