What Are the Primary Chemicals Used for Textile Sizing?

Textile sizing relies on adhesives that create a protective film around warp yarns. These chemicals fall into two major groups:

Natural Sizing Agents

• Native starch

• Modified starch

• Hydroxylated starch (used in Alpenol)

• Gum-based agents (guar gum, tamarind)

• Protein-based agents (gelatin, casein – rarely used today)

Synthetic Sizing Agents

• PVA (Polyvinyl Alcohol)

• CMC (Carboxymethyl Cellulose)

• Acrylic binders / copolymers

• Polyester or polyurethane-based binders

• Wax emulsions and fatty lubricants

Modern high-speed weaving often requires blends of these agents, but single-shot systems—like Alpenol’s compound products—offer superior performance without multi-chemical mixing.

Why Are Sizing Chemicals Applied to Textile Yarns and Fabrics?

Sizing chemicals are applied to warp yarns to:

• Increase yarn strength

• Reduce surface hairiness

• Improve abrasion resistance

• Minimize shedding and linting

• Enhance fiber cohesion

• Reduce warp breaks under high tension

• Improve loom efficiency at high insertion speeds

In high-density fabrics and complex dobby constructions, the right sizing chemistry is critical for maintaining fabric appearance and quality.

Alpenol’s formulations use engineered hydroxylated starch molecules that create highly adhesive, flexible films, ideal for today’s 1200+ picks/min weaving conditions.

To understand deeper why sizing chemicals are applied to yarns and fabrics, click here.

What Are the Common Synthetic Sizing Agents Used in Textile Manufacturing?

Chemical suppliers such as BASF, Clariant, Sekisui, SNF, and various textile chemical manufacturers provide the following synthetic agents:

1. Polyvinyl Alcohol (PVA)

• Forms strong, flexible films

• Excellent adhesion to cotton and blends

• Good abrasion resistance

• High cost and poor biodegradability

• Significant COD/BOD burden in effluent

2. CMC (Carboxymethyl Cellulose)

• Improves viscosity stability

• Enhances flexibility

• Works well in blends with starch

• Lower adhesion compared to PVA

3. Acrylic Copolymers

• Used as binders

• Improve elasticity & film strength

• Offers controlled film hardness

4. Polyester/PU Binders

• High toughness

• Used for synthetics with smooth surfaces

5. Wax & Fatty Lubricants

• Reduce yarn-to-metal friction

• Improve weaving smoothness

Alpenol formulations replace the need for multiple synthetic agents by providing single-shot blends that eliminate complexity while maintaining high performance.

What Is the Environmental Impact of Sizing Chemicals?

Environmental Concerns (Traditional Chemistry)

• PVA contributes heavily to COD/BOD in effluent

• Acrylics create microplastic-like residues

• Excess synthetic blends complicate wastewater treatment

• Solvents, if used, pose VOC concerns

Sustainable Alternatives

• ZDHC-compliant sizing agents

• GOTS-approved bio-based polysaccharides

• Easily desizable hydroxylated starch systems

• Starch-only systems with high adhesion (Alpenol FNR, JV, KV)

• Cold-soluble natural compounds (e.g., siZaltex LVn)

Alpenol’s environmental advantages

• Zero restricted substances

• ZDHC Level 3 certified

• GOTS approved for organic cotton

• No PCP

• Rapid biodegradability

• Reduced chemical consumption due to low pick-up

Comparison: Starch vs. PVA as Textile Sizing Agents

Modern trend:
Advanced modified / hydroxylated starch solutions—such as those used in Alpenol provide film strength comparable to PVA without its environmental drawbacks.

What Are the Best Sizing Chemicals for Cotton Textile Processing?

Cotton requires a film that:

• Penetrates hairiness

• Offers strong adhesion

• Maintains flexibility

• Supports high-speed loom stresses

Best choices:

• Hydroxylated starch compounds (Alpenol JV, FNR, KV)

• Modified starch + CMC blends

• Small amount of acrylic binder (optional)

• Natural wax emulsions

Alpenol products often outperform traditional mixtures because they are engineered specifically for cotton’s absorbency and surface roughness.

What Types of Natural Sizing Compounds Are Used in Textiles?

Natural compounds include:

• Native starch (maize, tapioca, potato)

• Modified starch (oxidized, etherified, cross-linked)

• Hydroxylated starch (Alpenol’s patented method)

• Gums (guar, tamarind, locust bean)

• Proteins (rarely used now)

These are favored when:

• Mills want GOTS compliance

• Effluent load must be reduced

• Easy desizing is required

• The yarn is cotton or viscose

How Are Sizing Chemicals Applied to Textile Yarns?

Sizing chemicals are applied through a hot aqueous solution using:

• Slasher sizing machines (most common)

• Multi-cylinder drying systems

• Immersion size boxes

• Squeeze rollers to control pick-up

• Stretching zones to equalize tension

• Final re-beaming

The chemistry must be:

• Stable in viscosity

• Adhesive

• Flexible

• Able to form a clean, non-tacky film

Alpenol compounds are engineered for stable viscosity and excellent wet pick-up, resulting in consistent performance on slasher ranges.

What Are the Functions of Different Components in Sizing Formulations?

Alpenol’s single-shot systems integrate many of these functions into one product, reducing complexity and formulation errors.

How Do Recommended Sizing Chemicals Vary by Fiber Type?

How Do Sizing Chemicals Mechanically and Chemically Affect Yarn Strength & Loom Performance?

Mechanical Effects

• Create a surface film that reduces friction and abrasion

• Bind protruding fibers, lowering hairiness

• Provide compressive strength during bending

• Reduce warp breaks

Chemical Effects

• Adhesive bonding strengthens yarn structure

• Moisture retention stabilizes tension

• Polymer chains impart flexibility or hardness depending on chemistry

Result:
Higher loom speed, better efficiency, fewer stoppages, and superior greige quality—especially when using high-performance systems like Alpenol’s hydroxylated-starch-based formulations.

Frequently Asked Questions (FAQs)

 1. Is starch still the most widely used sizing agent?

Yes—especially modified and hydroxylated starches due to cost-effectiveness, sustainability, and strong performance on cotton and viscose.

 2. Why do mills still use PVA?

Because PVA offers strong, flexible films and excellent adhesion—but its environmental drawbacks are pushing mills toward greener alternatives.

 3. What is the best sizing for PC or PV blends?

Balanced compound systems like Alpenol ALTRA, TTL, EXC-2 work best due to their hybrid chemistry.

 4. Are natural sizing agents effective for high-speed looms?

Modern natural agents—especially engineered starches—perform extremely well, even at >1200 picks/min.

 5. Do single-shot sizing systems reduce costs?

Yes. They reduce chemical consumption, inventory, preparation errors, and energy use—while boosting loom efficiency.

Reference Links

1. https://www.oekotex.com

2. https://www.roadmaptozero.com (ZDHC Gateway)

3. https://global-standard.org (GOTS)

4. https://www.basf.com

5. https://www.clariant.com

6. https://www.snf.com

7. https://www.sekisui.co.jp

8. https://textilelearner.net

9. https://textiletoday.com.bd

10. https://sciencedirect.com

11. https://mdpi.com/journal/textiles

12. https://tandfonline.com