Can Desizing Be Avoided in Textiles?

Traditional desizing cannot always be avoided in textiles, but it can be simplified, minimized, or completely eliminated when modern water-soluble sizing technologies are used. Conventional enzyme-based desizing exists mainly to remove insoluble starch and synthetic polymers. New-generation sizing systems-such as water-soluble polysaccharide-based sizing (e.g., Sizaltex)-allow fabrics to be desized using only hot water at 80-90 °C, without enzymes, acids, or harsh chemicals.

What Is Desizing in Textiles?

Desizing is the first wet-processing step in textile finishing where warp sizing agents applied during weaving are removed from the fabric.

Sizing is essential for weaving strength, but must be removed before dyeing, printing, or finishing because residual size:

• Blocks dye penetration
• Causes uneven shades
• Increases chemical consumption

Traditionally, desizing relies on enzymes (amylase) or oxidative/acid treatments to break down starch-based or synthetic sizing films.

To learn more about Desizing Process.

Why Is Desizing Necessary?

Desizing is necessary because most conventional sizing agents are not naturally water-soluble once dried on yarn.

Without desizing:

• Dyes cannot access fiber surfaces
• Printing paste penetration is restricted
• Finishing chemicals perform inconsistently
• Fabric defects like patchiness and streaks appear

In short, desizing exists to correct the chemical complexity introduced during sizing.

What Happens If Desizing Is Not Done Correctly?

Incorrect or incomplete desizing leads to downstream quality failures:

• Patchy or uneven dyeing
• Poor colorfastness
• Increased reprocessing
• Higher effluent load
• Reduced finishing efficiency

Ironically, many finishing problems originate not in finishing-but in the sizing chemistry used at the loom stage.

Are Enzymes Needed in Desizing? Can We Reduce or Stop Using Them?

Short answer: Enzymes are only needed because of traditional sizing chemistry.

Why enzymes are used:

• To hydrolyze insoluble starch films
• To break down complex polymeric sizing layers
• To reduce fabric damage compared to acids

However, enzymes:

• Add cost
• Increase process time
• Generate COD/BOD in effluent
• Are sensitive to pH and temperature control

How enzyme use can be reduced or eliminated

By switching to water-soluble sizing agents that:

• Dissolve directly in hot water
• Do not require molecular breakdown
• Leave no resistant film on fibers

This is where Sizaltex-type sizing technology becomes relevant-not as a product pitch, but as a process redesign.

What Is the Role of Sizing Agents in Desizing?

Desizing difficulty is directly proportional to sizing agent complexity.

In other words: Desizing problems are created during sizing, not finishing.

What Effluents Are Released During Desizing and How Do They Harm the Environment?

Traditional desizing releases:

• Hydrolyzed starch fragments
• Synthetic polymers (PVA residues)
• Enzyme degradation by-products
• Surfactants and wetting agents

Environmental impact

• High COD & BOD
• Increased load on ETPs
• Sludge generation
• Poor biodegradability (especially PVA)

This makes desizing one of the most environmentally expensive “invisible” processes in wet processing.

How Can Desizing Effluents Be Reduced?

Desizing effluent reduction can be achieved by:

• Lower size add-on
• Better size uniformity
• Eliminating synthetic polymers
• Reducing enzymatic hydrolysis

But the largest reduction comes from eliminating the desizing chemistry itself.

How Can Desizing Be Avoided in Textiles?

Desizing can be functionally avoided by changing sizing philosophy

Instead of asking “How do we remove size?”, progressive mills ask: “Why are we applying something that needs removal at all?”

Water-Soluble Sizing Approach

Modern water-soluble sizing systems (such as Sizaltex):

• Form a strong yet fully water-dispersible film
• Maintain weaving efficiency
• Do not crosslink irreversibly on yarn
• Dissolve completely in hot water

Practical Outcome

• Fabric desizing = simple hot wash
• No enzymes
• No acids
• No alkali
• No desizing auxiliaries

At a process level, this collapses desizing into a basic washing step.

How Sizaltex Changes the Desizing Equation (Process Perspective)

Characteristics of Sizaltex:

• Polysaccharide-based
• Fully water-soluble
• Stable sizing film during weaving
• Completely desizes via hot water

From a mill operations standpoint, this means:

• Desizing step becomes optional
• Enzyme procurement eliminated
• Shorter wet-processing cycles
• Lower effluent treatment cost
• Better dye reproducibility

This aligns sizing, desizing, and sustainability into one continuous system, instead of three disconnected problems.

How to Reduce Overall Desizing Costs

Cost reduction does not come from cheaper enzymes, it comes from not needing them.

Key cost-reduction levers

• Eliminate enzyme usage
• Reduce water consumption
• Cut heating cycles
• Lower ETP load
• Reduce reprocessing and shade corrections

Water-soluble sizing like Sizaltex directly impacts all five levers simultaneously.

What Are Sustainable Practices in Desizing?

True sustainability in desizing means designing it out of the process.

Sustainable desizing principles

• Use biodegradable sizing agents
• Avoid synthetic polymers
• Prefer thermal solubility over chemical breakdown
• Minimize auxiliary chemicals
• Reduce effluent complexity

Water-soluble sizing technologies are increasingly aligned with:

• ZDHC goals
• GOTS processing requirements
• Low-impact wet processing
• Cleaner production benchmarks

Key Insight: Desizing Is a Symptom, Not a Requirement

Desizing exists because traditional sizing chemistry creates insoluble residues.

When sizing chemistry evolves:

• Desizing simplifies
• Enzymes become redundant
• Effluent load collapses
• Sustainability improves organically

This is not a finishing innovation-it is a weaving-stage decision with finishing-stage consequences.

Frequently Asked Questions