Title
Why Polyester Fabric Develops Crease Marks During Dyeing and Finishing
Content
Polyester fabric is known for durability, shape retention and easy care.
But during dyeing and finishing, one quality issue can sometimes appear:
crease marks.
These marks may look like:
- Dark or light lines
- Fold marks
- Shiny streaks
- Uneven dyeing
- Permanent creases
- Surface distortion
For fabric buyers and garment manufacturers, crease marks can become a serious problem because they may remain visible even after cutting and stitching.
In this guide, we’ll explain why polyester fabric develops crease marks during dyeing and finishing, how to identify them, and how textile processors can reduce the risk.
What Are Crease Marks in Polyester Fabric?
Crease marks are visible lines or bands created when the fabric folds, bends or remains under pressure during processing.
The problem can happen during:
- Dyeing
- Washing
- Heat setting
- Drying
- Finishing
- Fabric transportation
Some creases disappear after relaxation.
Others become permanently set into the polyester structure.
That is where the problem becomes more serious.
Why Polyester Is Sensitive to Crease Setting
Polyester is a thermoplastic fibre.
This means heat can change and stabilize its shape.
That property is useful during heat setting because it helps control:
- Fabric width
- Shrinkage
- Shape
- Dimensional stability
But it also creates a risk.
If polyester fabric remains folded while exposed to heat, pressure or high processing temperatures, the crease can become fixed into the fabric.
In simple terms:
Heat can lock the fold into the polyester structure.
1. Fabric Folding During Dyeing
One of the most common causes of crease marks is uncontrolled fabric folding inside the dyeing machine.
During wet processing, fabric moves continuously through liquor.
If it forms a tight fold and remains in the same position for too long, the folded area may experience different:
- Pressure
- Temperature
- Dye penetration
- Mechanical stress
After dyeing, this may appear as a visible line.
2. High Processing Temperature
Polyester is commonly dyed at relatively high temperatures.
High temperature helps disperse dyes enter the fibre.
However, if the fabric is folded at the same time, heat can make the crease more permanent.
The combination of:
Fold + heat + pressure
can create a strong crease mark.
This is especially important in polyester because the material can remember the shape created during heating.
3. Too Much Fabric Loaded Into the Machine
Overloading the dyeing machine can increase the risk of crease formation.
If too much fabric is packed into a limited space, the fabric may not move freely.
This can cause:
- Tight folds
- Fabric compression
- Uneven circulation
- Repeated creasing
Proper machine loading helps maintain smoother fabric movement.
4. Incorrect Fabric Speed
Fabric movement must be controlled during dyeing.
If the fabric moves too slowly, folds may remain in the same position for longer.
If movement is irregular, the same area may repeatedly crease.
Correct machine speed helps distribute the fabric more evenly.
5. Poor Fabric Relaxation
Knitted polyester fabric can contain internal tension from:
- Knitting
- Rolling
- Transportation
- Previous processing
If the fabric is not properly relaxed before wet processing, it may naturally fold or distort.
Relaxation allows the fabric structure to stabilize before dyeing.
This can reduce unexpected creasing.
6. Crease Marks During Heat Setting
Heat setting is one of the most important finishing processes for polyester.
The fabric is exposed to controlled heat to improve dimensional stability.
But if the fabric enters the stenter or heat-setting machine with folds, those folds may become fixed.
This is why the fabric must be:
- Open
- Flat
- Properly tensioned
- Free from wrinkles
before heat setting.
7. Excessive Fabric Tension
Too much tension can also create problems.
High tension may distort the fabric structure and create:
- Lines
- Stretch marks
- Width variation
- Permanent surface distortion
The correct balance between tension and fabric relaxation is important throughout finishing.
8. Uneven Cooling
After heat treatment, polyester should cool in a controlled condition.
If hot fabric is folded or compressed before it cools properly, new creases may form.
These marks can become difficult to remove later.
Proper cooling helps stabilize the fabric after heat setting.
9. Improper Fabric Handling After Dyeing
Crease marks are not always created inside the dyeing machine.
They can also happen afterward.
Common causes include:
- Folding wet fabric
- Stacking fabric under heavy weight
- Improper rolling
- Leaving fabric compressed for long periods
Wet and hot polyester should be handled carefully.
How Crease Marks Affect Dye Appearance
Creases can change how dye reaches the fabric.
The folded area may receive:
- Less dye
- More dye
- Different heat exposure
- Different liquor flow
This can create visible shade differences.
The crease may appear:
- Darker
- Lighter
- Shinier
- More compact
Even if the colour difference is small, it can become noticeable on the final garment.
Crease Marks vs Shade Variation
These two issues are different.
Crease Marks
Usually appear as lines or fold-related defects.
Shade Variation
Can appear as wider colour differences across rolls, panels or batches.
Sometimes a crease can create local shade variation, so the two problems may appear together.
Which Polyester Fabrics Are More Sensitive?
Crease risk depends on construction and weight.
Some fabrics may be more sensitive, including:
- Lightweight polyester knits
- Smooth fabrics
- Fine-gauge fabrics
- High-stretch fabrics
- Soft-finished polyester
- Certain textured knits
Heavy or structured fabrics may behave differently.
This is why processing conditions should match the exact fabric type.
How to Identify Crease Marks
Fabric inspectors should check the fabric under proper lighting.
Look for:
- Long linear marks
- Fold lines
- Shiny streaks
- Uneven colour
- Surface flattening
- Width distortion
Crease marks can sometimes become more visible when light hits the fabric from an angle.
Can Crease Marks Be Removed?
Some mild crease marks can be improved.
Possible methods include:
- Relaxation
- Controlled steaming
- Re-finishing
- Re-heat setting under correct conditions
However, if the crease has been permanently heat-set, it may not disappear completely.
That is why prevention is much better than correction.
How Textile Mills Can Reduce Crease Marks
Control Machine Loading
Do not overload the dyeing machine.
Fabric needs enough space to move freely.
Maintain Proper Fabric Movement
Machine speed and circulation should prevent the fabric from sitting in the same fold for too long.
Use Correct Temperature Profiles
Temperature should increase and decrease gradually according to the process.
Sudden thermal changes can increase stress.
Relax Fabric Before Processing
Proper relaxation helps reduce internal tension.
Avoid Folding Hot Fabric
Allow fabric to cool before tight rolling or stacking.
Keep Fabric Flat During Heat Setting
Wrinkles should be removed before entering the heat-setting stage.
What Bulk Fabric Buyers Should Check
Before accepting polyester fabric, buyers should inspect:
- Surface uniformity
- Long crease lines
- Shade consistency
- Shine marks
- Fabric width
- GSM consistency
- Edge-to-centre appearance
- Roll-to-roll quality
If crease marks are visible before cutting, they can create problems during garment production.
Why Crease Marks Matter in Garment Manufacturing
Once the fabric is cut, crease marks may appear across:
- Front panels
- Sleeves
- Back panels
- Collars
- Leg panels
This can cause finished garments to look defective even if stitching quality is good.
For solid-colour garments, marks can be especially noticeable.
Simple Example
Imagine a navy polyester sportswear fabric.
The fabric is dyed at high temperature.
During processing, one section remains tightly folded.
After finishing, a shiny dark line appears across the roll.
When the fabric is cut into T-shirts, the mark becomes visible across several garment panels.
The problem did not start during stitching.
It started during dyeing and finishing.
Final Thoughts
Polyester crease marks usually happen because of a combination of:
Folding + heat + pressure + improper fabric movement
The risk becomes higher during:
- High-temperature dyeing
- Heat setting
- Overloaded processing
- Improper cooling
- Poor fabric handling
For textile mills, controlling fabric movement and temperature is critical.
For clothing brands and bulk buyers, proper fabric inspection before cutting can help identify these defects early.
At Walrus – Yes India Can, we work with clothing brands, garment manufacturers and fabric buyers looking for polyester fabrics for different apparel applications.
Understanding processing defects helps buyers evaluate fabric quality beyond just GSM, colour and price.
Walrus – Yes India Can
Every Great Brand Begins With the Right Fabric.
