Why Is the Textile Sizing Process Important in Weaving?

Before understanding the machines, it’s important to understand why sizing is required.

Warp yarns undergo:

• Constant tension

• Friction from heald wires and reed

• High-speed weft insertion (1200+ picks/min)

• Abrasion during shedding

According to industrial documentation from sizing and weaving operations, warp preparation directly impacts loom efficiency and breakage rate.

Sizing:

• Increases tensile strength

• Reduces hairiness

• Improves smoothness

• Enhances weaving efficiency

Alpenol’s hydroxylated starch-based compound sizing agents are designed to reduce dependency on polyvinyl alcohol (PVA) and synthetic binders while maintaining adhesion and flexibility .

Machine-by-Machine Breakdown of the Mechanical Sizing Process

1. What Is a Creel and Why Is It the Starting Point?

Function:

The creel holds multiple warp yarn packages (cones or beams) in parallel arrangement.

Mechanical Role:

• Ensures uniform unwinding tension

• Aligns sets of yarns into a warp sheet

• Prevents snarling and crossovers

Importance:

Uniform tension at the creel prevents uneven size penetration later in the sizebox. If tension varies here, weaving defects such as uneven warp and weft density occur.

In high-performance sizing systems using Alpenol compound sizing agents, controlled tension helps maintain optimal size add-on percentage .

2. What Is the Premixer in Textile Sizing?

Function:

The premixer blends water and sizing ingredients to form a homogeneous slurry.

Key Role:

• Dissolves starch derivatives

• Prevents lump formation

• Ensures chemical uniformity

Modern starch-based sizing agents such as Alpenol’s single-shot systems reduce the need for complex multi-ingredient blending .

3. What Is the Cooker and Why Is Controlled Cooking Essential?

Function:

The cooker gelatinizes starch at high temperature and pressure.

Technical Importance:

• Activates adhesive properties

• Controls viscosity

• Enhances film formation

Alpenol documentation specifies high-pressure autoclave cooking for optimal performance .

Improper cooking leads to:

4. What Is the Storage Tank Used For?

Function:

Stores cooked sizing solution before application.

Importance:

• Maintains constant temperature

• Prevents retrogradation

• Ensures continuous supply

Stable starch systems such as Alpenol are engineered to remain stable without frequent viscosity fluctuations .

5. What Happens Inside the Sizebox?

Function:

The warp sheet passes through the heated sizing solution.

Process:

• Yarn immersion

• Adhesion of sizing film

• Controlled penetration

Temperature typically maintained around 85–90°C as recommended for compound sizing agents .

Proper sizebox control ensures:

• Uniform coating

• Controlled add-on

• Better abrasion resistance

6. Why Are Squeeze Rolls Critical in Sizing?

Function:

Remove excess sizing solution.

Importance:

• Controls pick-up percentage

• Maintains consistent warp diameter

• Prevents sticky yarns

For high-density fabrics, minimum size add-on is crucial, especially for fine cotton and viscose yarns .

7. How Do Drying Cylinders Improve Warp Strength?

Function:

Evaporate moisture from sized warp yarns.

Mechanical Role:

• Film formation

• Moisture stabilization

• Strength development

Improper drying can cause:

• Brittleness (over-dry)

• Poor film strength (under-dry)

Balanced drying supports weaving efficiency and smooth shed formation.

8. What Is PLEVA (Moisture Control System)?

Function:

Online moisture monitoring system.

Importance:

• Ensures consistent residual moisture

• Prevents over-drying

• Reduces loom breakage

Moisture control is essential for sustainable sizing operations aligned with green chemistry principles .

9. What Are Lease Rods Used For?

Function:

Maintain warp yarn separation.

Importance:

• Prevents yarn entanglement

• Maintains order of warp threads

• Facilitates easier drawing-in

10. What Is the Head Stock in Sizing?

Function:

Winds the sized warp sheet onto the warp beam.

Importance:

• Uniform winding tension

• Correct beam density

• Smooth unwinding in weaving machine

Proper beam formation ensures trouble-free operation during weaving process.

Complete Sizing Flow Summary

Sustainability and Modern Sizing

Traditional sizing often relied heavily on polyvinyl alcohol. Modern starch-based systems aim to reduce PVA and synthetic dependency while complying with sustainability standards such as ZDHC and OEKO-TEX .

Alpenol’s starch-based compound sizing systems are engineered to:

• Reduce synthetic polymers

• Lower effluent load

• Maintain high weaving efficiency

• Support environmentally responsible manufacturing

FAQs

1. What is the main purpose of warp sizing?

Warp sizing increases yarn strength, reduces hairiness, and improves abrasion resistance during the weaving process.

2. What temperature is maintained in the sizebox?

Typically 85–90°C depending on the sizing solution used .

3. Why are squeeze rolls important?

They control size pick-up percentage and ensure uniform coating thickness.

4. What happens if warp yarn is over-dried?

It becomes brittle, increasing warp thread breakage during weaving.

5. How does moisture control improve weaving efficiency?

Online moisture systems like Pleva ensure optimal residual moisture, preventing brittleness and loom stoppages.

References

ZDHC Wastewater Guidelines (Sizing Effluent & Sustainability), https://downloads.roadmaptozero.com/output/ZDHC-Wastewater-Guidelines

​ZDHC Wastewater Guidelines V1.1 (Textile Chemicals Context), 

https://wastewater.sustainabilityconsortium.org/downloads/zdhc-wastewater-guidelines-verson-1-1/

​Textile Industry Wastewater Standards (Sizing COD/BOD), 

https://wastewater.sustainabilityconsortium.org/downloads/textile-industry-wastewater-discharge-quality-standards/

​GOTS Implementation Manual (Sustainable Sizing Processes), 

https://global-standard.org/images/Implementation_Manual_7.0_Second_Revision_Draft.pdf

​GOTS Official Site (Organic Textile Sizing Standards), 

https://global-standard.org

​OEKO-TEX Standards (Chemical Compliance in Sizing), 

https://www.oeko-tex.com/en/our-standards/

​OEKO-TEX STeP (Sustainable Warp Preparation), 

https://www.oeko-tex.com/en/our-standards/oeko-tex-step/

​ZDHC-OEKO-TEX Collaboration (Green Sizing Chemicals), 

https://www.oeko-tex.com/en/news/infocenter/zdhc-and-oeko-tex-strengthen-collaboration

​PMC: Synthetized Potato Starch as Eco Sizing Agent (Creel to Beam), 

https://pmc.ncbi.nlm.nih.gov/articles/PMC6572457/

​PMC: Starch Graft Copolymer for Warp Sizing (Cooker/Sizebox Process), 

https://pmc.ncbi.nlm.nih.gov/articles/PMC10820382/

​PMC: Corn Starch Derivatives for Cotton Sizing (Gelatinization/Viscosity), 

https://pmc.ncbi.nlm.nih.gov/articles/PMC7361798/

​PMC: Sustainable Starch Bio-Sizing (Drying & Film Formation), 

https://pmc.ncbi.nlm.nih.gov/articles/PMC11137591/

​ACS ES&T: Biodegradable Sizes Replacing PVA (Squeeze Rolls/Pick-up), 

https://pubs.acs.org/doi/10.1021/es504988w

​PubMed: Sustainable Slashing with Modified Proteins (Sizebox Immersion), 

https://pubmed.ncbi.nlm.nih.gov/25687520/

​ScienceDirect: Keratin-Based Pollution Reduction (PVA in Sizing Effluent), 

https://www.sciencedirect.com/science/article/abs/pii/S0959652613006598

​Persistence Market Research: Textile Sizing Chemicals Market (Modern Compounds), 

https://www.persistencemarketresearch.com/market-research/textile-sizing-chemicals-market.asp

​Markets and Markets: Textile Chemicals Market (Sizing Machines Impact), 

https://www.marketsandmarkets.com/Market-Reports/textile-chemical-market-12380328.html

​Mordor Intelligence: Textile Chemicals Analysis (Starch Systems), 

https://www.mordorintelligence.com/industry-reports/textile-chemicals-market

​Textile Excellence: Sizing Chemicals Market to $33.1B (Head Stock/Beam), 

https://textileexcellence.com/single-news/5862/textile-chemicals-market-to-reach-us-33-1-billion-by-2026-report

​Biopol Chemicals: Textile Chemicals Growth (Premixer/Cooker), 

https://biopolchemicals.com/textile-chemicals/market/textile-chemicals-market/

​TextileSchool: Sizing Process Machines (Creel, Sizebox, Drying Cans), 

https://www.textileschool.com/

TextileLearner: Warp Sizing Machines (Squeeze Rolls, Lease Rods), 

https://textilelearner.net/warp-sizing-machines/

Slideshare: Sizing Process Breakdown (Gelatinization, Viscosity Control), 

https://www.slideshare.net/slideshow/23mt02-concepts-of-sheddingpicking-and-beatuppptx/264954690

​Study.com: Textile Preparation Processes (Sizing for Abrasion Resistance), 

https://study.com/academy/lesson/textile-weaving-terminology.html

​CottonWorks: Warp Preparation Basics (Tension Control in Creel), 

https://cottonworks.com/learning-hub/weaving/weaving-basics/

​Heuritech: Fabric Innovations 2026 (Sustainable Sizing Trends), 

https://heuritech.com/articles/fashion-fabric-innovations/

​Tessuti: Fabric Forecast 2026 (Sizing for High-Density Weaves), 

https://www.tessuti.in/blog/learn-with-tessuti-1/fabric-forecast-2026-what-textiles-will-define-the-next-year-22

​Vaaritex: Sustainable Fabric Trends 2026 (Green Sizing), 

https://vaaritex-intl.com/sustainable-fabric-trends-2026/