Wet Pick-Up vs. Dry Chemical Add-On in Digital Textile Pretreatment: Which Number Should You Control?

Wet pick-up and dry chemical add-on describe two different parts of digital textile pretreatment. Wet pick-up tells the mill how much pretreatment liquor the fabric retains after application, while dry chemical add-on tells the mill how much nonvolatile chemistry is actually deposited on the textile after water is removed. Wet pick-up is therefore a key machine and moisture-control parameter; dry add-on is the more direct chemistry/dosage parameter. Neither should be used alone. A stable production process controls the liquor concentration, measures wet pick-up or deposited wet add-on, calculates the resulting chemical add-on, verifies drying and residual moisture, and then confirms the finished print after fixation and washing.

Wet Pick-Up vs. Dry Chemical Add-On: Which Number Should You Control?

The most useful answer is:

Control both—but use them for different purposes.

Wet pick-up tells you how much pretreatment liquor is retained by the fabric immediately after application.

Dry chemical add-on tells you how much chemical or active solids are actually delivered to the fabric after the water carrier is removed.

In production:

• Wet pick-up is a direct application / machine-control parameter.
• Bath concentration or solids is a formulation-control parameter.
• Dry chemical add-on is the calculated or verified dosage result created by those two variables together.

A practical control chain is:

Bath Concentration × Wet Pick-Up → Chemical Add-On → Drying / Residual Moisture → Printing → Fixation → Wash-Off

Controlling only wet pick-up can miss changes in bath concentration.

Controlling only dry add-on can miss changes in water load, drying demand and chemical distribution.

What Is Wet Pick-Up?

Wet pick-up describes the mass of pretreatment liquor retained by the fabric relative to the original dry fabric mass.

It answers the question:

How Much Liquid Did the Fabric Take from the Application Process?

Wet pick-up is affected by:

• Fabric absorbency
• Fiber type
• GSM and construction
• Nip pressure
• Roll condition
• Bath viscosity
• Fabric tension
• Line speed
• Application route

It is therefore a process output, not simply a machine setting.

What Is Dry Chemical Add-On?

Dry chemical add-on describes the amount of retained nonvolatile chemistry relative to the dry untreated fabric mass.

It answers:

How Much Functional Chemistry Did the Fabric Actually Receive?

Depending on the purpose of the calculation, this can mean:

• Total pretreatment solids add-on
• Polymer add-on
• Alkali add-on
• Urea / moisture-management add-on
• Another individual component add-on

This distinction matters because the total bath may contain both active chemistry and water.

For formulation comparison, component-specific add-on is often more informative than product dosage alone.

How Wet Pick-Up and Dry Add-On Are Related

The basic mass-balance relationship is:

Dry Add-On = Wet Pick-Up × Chemical Concentration

when both values are expressed on compatible mass-percentage bases.

This means:

• Higher wet pick-up increases chemical add-on when bath concentration stays constant.
• Higher bath concentration increases chemical add-on when wet pick-up stays constant.
• The same dry add-on can be produced by different combinations of wet pick-up and concentration.

This relationship is the key to understanding why wet pick-up and dry add-on should not be treated as competing measurements.

They are linked variables describing different stages of the same mass balance.

Wet Pick-Up Calculation

A standard gravimetric calculation is:

Wet Pick-Up (%) = (Wet Fabric Weight − Dry Fabric Weight) ÷ Dry Fabric Weight × 100

Example:

• Dry fabric = 100 g
• Fabric immediately after pretreatment = 180 g

The retained liquor is:

180 − 100 = 80 g

لذلك:

Wet Pick-Up = 80%

The wet fabric should be weighed promptly because evaporation before weighing will underestimate the actual pick-up.

Dry Chemical Add-On Calculation

If the retained pretreatment liquor contains 5% active solids by weight and wet pick-up is 80%:

Dry Add-On (%) = 80 × 5 ÷ 100 = 4%

This means that, theoretically, 100 g of original dry fabric carries approximately 4 g of active dry chemistry after the carrier water is removed.

The simplified formula is:

Dry Add-On (% owf) = Wet Pick-Up (%) × Active Bath Concentration (wt%) ÷ 100

This calculation assumes:

• The bath is homogeneous.
• The retained liquor has the same concentration as the measured bath.
• No significant chemical is selectively lost before drying.
• The concentration and pick-up use compatible mass bases.

Supplied Product Concentration vs. Active Solids

A common calculation error is to treat supplied product dosage as if it were dry solids.

Consider a liquid pretreatment product that itself contains only part active solids.

The mass balance becomes:

Dry Active Add-On = Wet Pick-Up × Product Concentration in Bath × Product Solids Fraction

When expressed as percentages:

Dry Active Add-On (%) = WPU (%) × Bath Product Concentration (%) × Product Solids (%) ÷ 10,000

For powder products that are essentially all nonvolatile material, product dosage and solids dosage can be much closer.

For liquid emulsions, dispersions or compound products, solids content should be known before making a dry-add-on comparison.

How to Handle Bath Concentration in g/L

Textile formulations are often written in g/L rather than weight percent.

For accurate conversion, bath density should be considered.

A practical relationship is:

Concentration (wt%) = Concentration (g/L) ÷ [10 × Bath Density (g/mL)]

If bath density is close to 1.00 g/mL, then 50 g/L is approximately 5 wt%.

But for higher-solids or high-density baths, assuming density = 1 can introduce calculation error.

Use measured density when accurate add-on comparison matters.

Worked Example: Same Fabric, Same Bath

Assume:

• Dry fabric mass = 100 g
• Wet pick-up = 80%
• Active bath solids = 5 wt%

The fabric retains:

80 g of pretreatment liquor.

Theoretical active solids delivered:

80 g × 5% = 4 g

Dry chemical add-on:

4 g ÷ 100 g fabric × 100 = 4% owf

This example illustrates why wet pick-up is not the same as chemical add-on.

The fabric picked up 80% liquid but only 4% dry active chemistry.

Same Dry Add-On Can Still Give Different Printing Results

This is one of the most important points.

Consider two theoretical routes:

Condition	Wet Pick-Up	Bath Active Solids	Theoretical Dry Add-On
A	80%	5.0%	4.0%
B	60%	6.67%	Approximately 4.0%

The dry chemical add-on is approximately the same.

But Condition A carries more water into the fabric and dryer.

This can change:

• Drying energy
• Drying time
• Residual moisture
• Chemical migration
• Fabric swelling

لذلك:

Same Dry Add-On ≠ Same Pretreatment Process.

The water carrier still matters.

Same Wet Pick-Up Can Give Different Dry Add-On

The reverse is also true.

If two baths both run at 70% wet pick-up but one contains more active solids, the chemical add-on is different.

على سبيل المثال:

Condition	Wet Pick-Up	Bath Active Solids	Theoretical Dry Add-On
A	70%	4%	2.8%
B	70%	6%	4.2%

Therefore, a mill cannot say:

“Both fabrics had 70% pick-up, so they received the same pretreatment.”

The bath concentration must also be controlled.

Which Number Should Production Control First?

For a padding process, production should normally control:

1. Bath composition / concentration
2. Actual wet pick-up
3. Calculated chemical add-on
4. Residual moisture after drying

These variables serve different functions.

Wet pick-up is usually easier to measure frequently on the line.

Dry add-on is the more useful number when comparing chemical dosage across:

• Different bath concentrations
• Different application routes
• Different pretreatment products

The strongest control plan links them rather than choosing one.

Wet Pick-Up Is a Machine Result; Dry Add-On Is a Chemistry Result

A useful way to separate responsibilities is:

Machine / Application Side → Wet Pick-Up

Formulation Side → Bath Concentration / Solids

Fabric Chemistry Side → Dry Add-On

Drying Side → Residual Moisture / Distribution

This makes troubleshooting clearer.

If wet pick-up changes while bath solids remain stable, investigate application mechanics.

If pick-up is stable but add-on changes, investigate bath concentration or formulation preparation.

Padding: Why Wet Pick-Up Is Essential

Padding applies chemistry by wetting the fabric and then squeezing out excess liquor.

The wet pick-up is directly influenced by:

• Nip pressure
• Roll hardness / condition
• Fabric absorbency
• Fabric speed
• Bath viscosity
• Fabric tension

Nominal padder pressure is only a machine input.

Measured wet pick-up is the more direct process result.

For reactive digital pretreatment, changing pick-up changes both:

• Chemical add-on
• Water carried into drying

which is why it should be recorded in every meaningful trial.

Coating: Why Coating Weight Can Be More Useful Than Pick-Up

For a coating process, especially surface-localized coating, the most practical control may be:

• Wet coating weight
• Dry coating weight
• g/m² add-on
• % owf add-on

rather than a padding-style pick-up number.

The same mass-balance principle still applies:

Wet Coating Add-On × Solids Fraction → Dry Coating Add-On

Coating also requires control of:

• Gap
• Tension
• علم الريولوجيا
• Fabric thickness

because the dry add-on must remain uniform across width.

Spray: Control Deposited Mass, Not Pump Flow Alone

In spray application, pump flow or nozzle output does not automatically equal fabric add-on.

Some sprayed liquid can be affected by:

• Overspray
• Nozzle overlap
• Edge loss
• Droplet bounce / poor wetting

Therefore, production should verify actual deposited mass on fabric.

Useful controls include:

• Total wet spray add-on
• Dry solids add-on
• Widthwise deposition uniformity

Do not compare spray with padding solely from liters of liquor used.

Wet-on-Wet Printing: Pick-Up Also Becomes a Moisture Variable

In controlled wet-on-wet printing, wet pick-up does two jobs at once.

It determines:

• Chemical add-on
• Moisture present when printing begins

This makes wet pick-up especially important.

Two fabrics with the same theoretical dry add-on can behave differently if one carries more water at the moment of inkjet printing.

السجل:

• Initial wet pick-up
• Time between pretreatment and printing
• Fabric moisture immediately before printing

The correct target is a reproducible wet-state window—not maximum wetness.

Dry Pretreatment: Dry Add-On Becomes More Visible

In the conventional dry route:

Pretreat → Dry → Print → Steam / Fix → Wash

most carrier water is removed before printing.

Therefore, the remaining dry chemistry becomes a central variable.

However, the drying process can redistribute that chemistry.

Two fabrics with equal total dry add-on can still differ if:

• One has more surface-localized polymer.
• One has more face-to-back migration.
• One has uneven alkali distribution.

Dry add-on should therefore be connected to distribution—not treated as the complete pretreatment description.

Water Load and Drying Energy

Wet pick-up directly changes the amount of carrier water entering the dryer.

Higher wet pick-up generally increases:

• Water to evaporate
• Drying energy
• Required residence time

Textile finishing references have long used lower-wet-pick-up application methods to reduce drying load when the same required dry add-on can be maintained through a more concentrated bath.

But lower wet pick-up is not automatically better.

The pretreatment must still:

• Apply uniformly
• Wet the textile correctly
• Deliver the required chemical add-on

Wet Pick-Up and Chemical Migration During Drying

More water means more liquid must move through and out of the textile during drying.

Soluble pretreatment chemicals can move with that water.

Possible effects include:

• Surface concentration changes
• Face-to-back migration
• Edge-center distribution differences

Therefore, two routes with the same dry add-on but different wet pick-up can produce different final chemical distribution.

This is another reason wet pick-up remains important even after dry add-on has been calculated.

Dry Add-On Does Not Describe Chemical Distribution

Dry add-on is a mass value.

It does not tell you whether chemistry is:

• On the printable face
• Inside yarns
• On the reverse side
• Even across fabric width

For digital printing, distribution strongly affects:

• Ink localization
• الاختراق
• معدل إنتاج الألوان
• التثبيت

لذلك:

Dry Add-On Controls “How Much”; Application and Drying Control “Where.”

Component-Specific Add-On: Polymer, Alkali and Urea

Total dry solids can hide component differences.

A reactive pretreatment may contain:

• Migration-control polymer
• Alkali
• Urea / moisture-management chemistry
• Other auxiliaries

For a fixed wet pick-up, the add-on of each component follows its concentration in the bath.

This means mills can calculate separate theoretical add-ons for:

• Polymer
• Alkali
• اليوريا

when troubleshooting color or fixation.

This is more informative than total solids alone when the formulation itself changes.

Effect on Color Yield

Low chemical add-on can reduce the ability of pretreatment to:

• Control ink localization
• Provide sufficient alkali
• Manage moisture during fixation

Increasing add-on into the useful range can improve post-wash color.

But:

More Add-On ≠ Unlimited Color Increase.

Excess polymer or total chemistry can increase:

• Surface-film thickness
• Drying demand
• Wash-off demand

and can change hand.

Build an add-on working curve instead of maximizing dosage.

Effect on Bleeding and Edge Definition

Insufficient polymer add-on can reduce migration control.

Excessive wet pick-up can also create too much moisture before drying or printing.

Therefore, bleeding can appear at both ends of the process window for different reasons.

تقييم:

• Wet pick-up
• Polymer add-on
• Residual moisture
• Printed line width

together.

Effect on Ink Penetration

The amount and location of polymer affect how deeply ink penetrates.

If dry polymer add-on is too low, ink can move deeper into the textile.

If polymer is high but distributed too deeply because wet pick-up is high, the surface may still not receive the same localization effect as a lower-pick-up surface-biased route.

Compare:

• Face-side K/S
• تظهر الصورة من الجانب الخلفي
• Dry add-on

rather than treating total add-on alone as proof of correct distribution.

Effect on Reactive Dye Fixation

Reactive fixation depends on sufficient alkali and moisture.

If wet pick-up or bath concentration changes, alkali add-on changes unless the formula is compensated.

This can produce:

• Different fixation
• Different wash-off loss
• Different post-wash K/S

For reactive printing, component-specific alkali add-on can therefore be more useful than total pretreatment solids when fixation is the problem.

Effect on Wash-Off and Fabric Hand

Higher dry chemical add-on means more pretreatment material must remain useful during printing and later be removed or tolerated after fixation.

Excessive add-on can increase:

• Wash-off demand
• Residual film
• Harsh or coated hand

The commercial target is the lowest stable chemical add-on that achieves the required:

• اللون
• Definition
• التثبيت
• نسيج يدوي

القطن

Cotton wet pick-up varies with:

• Scouring
• Mercerization
• GSM
• Weave / knit structure

A pick-up target developed on one cotton construction should not be transferred automatically to another.

Normalize trials by:

• Measured wet pick-up
• Calculated dry add-on
• Final print result

Viscose / Modal

Viscose and modal often absorb more liquid and swell strongly.

قد يؤدي ذلك إلى زيادة:

• Wet pick-up
• Water load
• Drying demand

For viscose, a lower bath concentration may still produce high chemical add-on if wet pick-up is high.

This is why bath recipe alone cannot define the treatment level.

Lyocell

Lyocell should be validated independently because moisture uptake and fabric construction can differ from both cotton and viscose.

Record actual wet pick-up and add-on rather than relying on fiber category alone.

Woven vs. Knit

Knitted fabrics can change:

• Width
• GSM
• Thickness
• Absorbency under tension

during processing.

This can change measured wet pick-up even at the same padder pressure.

Woven fabrics are often dimensionally more stable but still require fabric-specific validation.

Widthwise Uniformity

Average wet pick-up can hide left-center-right differences.

Use fixed positions such as:

Left → Left-Middle → Center → Right-Middle → Right

At each position, compare:

• Wet pick-up / coating add-on
• Calculated dry add-on
• Residual moisture
• Post-wash K/S

If dry add-on differs across width, investigate application uniformity before changing the formulation.

Why Pick-Up and Add-On Drift During Production

Wet pick-up can drift because of:

• Roll wear / pressure changes
• Fabric-lot changes
• Line-speed changes
• Bath viscosity / temperature changes
• Fabric tension changes

Bath concentration can drift because of:

• Water evaporation
• Make-up errors
• Incorrect replenishment
• Incomplete mixing

This means dry chemical add-on can drift even when only one side of the equation changes.

Monitor both.

Calculated Add-On vs. Measured Add-On

Calculated add-on is useful for process design and daily control.

But it is theoretical.

Measured add-on can be useful for verification, especially when:

• A new application route is introduced.
• A new product has different solids.
• Production differs from laboratory results.
• Bath carryover or nonuniformity is suspected.

Calculated and measured values should be compared on the same conditioned mass basis.

How to Verify Dry Add-On

A gravimetric verification can compare the conditioned fabric mass before treatment with the conditioned dry mass after pretreatment and drying.

However, the method must account for:

• Residual moisture
• Fabric conditioning
• Natural fabric-weight variability
• Volatile or thermally changing components

For critical component-specific verification, a chemical analytical method may be more appropriate than total weight gain.

Routine production usually relies on:

Controlled Bath Concentration + Measured Pick-Up + Periodic Verification

Wet Pick-Up vs. Dry Add-On Control Table

المعلمة	What It Tells You	Best Use
Wet pick-up	How much liquor the fabric retains	Padding / application control, water load
Bath concentration	How much chemistry exists per unit liquor	Formula / preparation control
Calculated dry add-on	How much chemistry should reach the fabric	Dosage comparison / process design
Measured dry add-on	How much total retained dry mass is actually present	Verification / troubleshooting
Residual moisture	How much water remains after drying	Printing / fixation moisture control

No single column replaces the others.

Build a Pick-Up × Solids Working Window

Condition	Wet Pick-Up	Bath Solids	Calculated Add-On	Print Evaluation
A	Lower	مرجع	Calculate	Color / bleeding / penetration
B	مرجع	مرجع	التحكم	Current benchmark
C	Higher	مرجع	Calculate	Drying / hand / wash-off
D	مرجع	Lower	Calculate	Chemical sensitivity
E	مرجع	Higher	Calculate	Add-on sensitivity

Change one factor at a time in the first screen.

Then test interactions only after the individual effects are understood.

Build a Same-Add-On / Different-Pick-Up Matrix

This is one of the most useful advanced trials.

Create two or more conditions with approximately the same dry chemical add-on but different wet pick-up.

على سبيل المثال:

• Higher pick-up + lower solids
• Lower pick-up + higher solids

ثم قارن بين:

• Drying energy / time
• Residual moisture
• Chemical migration
• النزيف
• الاختراق
• Post-wash K/S

This reveals whether the process is sensitive to the water carrier independently from the dry chemical dose.

سير العمل الموصى به في المختبر

1. Condition and weigh one representative dry fabric lot.
2. Prepare the pretreatment at a measured bath concentration / solids level.
3. Apply under a defined padding, coating or spray condition.
4. Measure actual wet pick-up / wet add-on immediately.
5. Calculate total and component-specific theoretical add-on.
6. Dry under controlled conditions.
7. Measure residual moisture.
8. Where needed, verify dry add-on gravimetrically.
9. Print one diagnostic pattern.
10. Steam / fix and wash identically.
11. Compare K/S, bleeding, penetration, fastness and hand.
12. Build a production working window rather than one perfect number.

For controlled pretreatment matching, use العينات والمطابقة.

Production Control Plan

A practical production sheet can record:

• Fabric fiber / construction / GSM
• Bath product concentration
• Bath solids / active content where relevant
• Bath density where required
• Bath pH / viscosity / temperature
• Measured wet pick-up
• Calculated dry add-on
• Widthwise variation
• Dryer temperature / speed
• Residual moisture
• Post-wash color / quality checks

Production does not need to measure every variable continuously.

The control plan should identify:

• Which variables are checked every run
• Which are checked periodically
• Which trigger a requalification

The objective is stable chemical delivery—not paperwork for its own sake.

Common Pick-Up / Add-On Mistakes

1. Treating Wet Pick-Up as Chemical Add-On

Wet pick-up includes mostly carrier liquid; chemical add-on depends on bath concentration.

2. Controlling Only Bath Concentration

The same bath can deliver different chemistry when pick-up changes.

3. Comparing Two Products Without Correcting for Solids

Liquid products with different active solids should not be compared by supplied-product dosage alone.

4. Comparing Padding and Spray by Liters Used

Actual deposited dry active mass is the more useful basis.

5. Assuming Same Dry Add-On Means Same Process

Different wet pick-up changes water load, drying and migration.

6. Measuring Pick-Up Too Late

Evaporation between application and weighing lowers the measured wet weight.

7. Ignoring Residual Moisture in Dry-Add-On Verification

Moisture regain can distort gravimetric dry-add-on measurements.

8. Maximizing Dry Add-On

Excess chemistry can increase wash-off demand, hand problems and cost without improving print quality.

جدول استكشاف الأعطال وإصلاحها

المشكلة الملاحظة	المتغيرات الأولى التي يجب التحقق منها	لا تفترض
Wet pick-up stable but color changes	Bath concentration / solids, ink, fixation	Pick-up proves chemical add-on is unchanged
Bath concentration stable but color changes	Actual pick-up, fabric absorbency, application uniformity	Same recipe means same fabric dose
Same dry add-on but drying behavior differs	Wet pick-up / water load, fabric structure	Equal add-on creates an equivalent process
High pick-up causes bleeding	Residual moisture, polymer add-on, drying	More chemistry always improves control
Low pick-up gives weak post-wash color	Polymer / alkali add-on, steaming	More ink is the first correction
Production differs from lab	Actual pick-up, bath solids, drying, width profile	Lab machine settings transfer directly
Liquid product appears inefficient vs. powder	Product solids / active content and actual add-on	Equal kg dosage means equal dry chemistry
Measured dry add-on looks too high	Conditioning, residual moisture, fabric-weight variation	All measured weight gain is pretreatment solids

التكلفة الإجمالية أثناء الاستخدام

Wet pick-up and dry add-on affect cost in different ways.

Wet pick-up changes:

• Water load
• Drying energy
• Line capacity

Dry add-on changes:

• Chemical consumption
• Wash-off demand
• نسيج يدوي

ومن النماذج المفيدة ما يلي:

Total Cost in Use = Pretreatment Dry Add-On + Water / Drying + Printing + Fixation + Washing + Rework + Quality Loss

The lowest-cost process is not automatically the lowest wet pick-up or lowest chemical add-on.

It is the lowest stable combination that delivers the required finished quality.

What Information Should You Send to a Supplier?

For useful pick-up / add-on matching, provide:

• Fabric fiber / construction / GSM
• Current pretreatment product / TDS
• Product solids / active content if known
• Bath concentration
• Application method
• Measured wet pick-up / coating / spray add-on
• Calculated or measured dry add-on if available
• Bath viscosity / pH
• Drying conditions
• Residual moisture
• Ink system
• Steaming / washing
• Main target: lower chemical cost, lower drying load, better color, less bleeding or more uniform fixation

يمكن لشركة FSX Chemical الاستفادة من هذه المعلومات من خلال العينات والمطابقة to compare pretreatment dosage on a consistent dry-add-on basis.

مراجعة Digital Textile Printing Pretreatment, معايير اختبار المُكثِّف في طباعة المنسوجات و Textile Printing Applications for related process control.

How Should a Mill Control Wet Pick-Up and Dry Chemical Add-On?

A practical workflow is:

Control Bath Concentration → Measure Actual Wet Pick-Up → Calculate Chemical Add-On → Verify Width Uniformity → Dry → Measure Residual Moisture → Print → Fix → Wash → Confirm Final Performance

المبادئ الأساسية هي:

1. Wet pick-up tells you how much pretreatment liquor the fabric retained; it does not directly tell you how much dry chemistry was delivered.
2. Dry chemical add-on is calculated from wet pick-up and bath active concentration, but the calculation should use compatible mass bases and product solids where relevant.
3. Wet pick-up remains important even when dry add-on is matched because it changes water load, drying and chemical migration.
4. Dry add-on tells you how much chemistry is present but not where it is distributed through or across the textile.
5. For production, wet pick-up is an excellent application-control variable while dry add-on is a stronger chemistry-normalization variable.
6. The most reliable digital pretreatment process controls both and validates the final result after fixation and washing.

الأسئلة الشائعة

1. What is wet pick-up in digital textile pretreatment?

It is the mass of pretreatment liquor retained by the fabric after application, expressed relative to the original dry fabric mass.

2. What is dry chemical add-on?

It is the amount of dry or active pretreatment chemistry delivered to the fabric relative to the untreated dry fabric mass.

3. How do I calculate wet pick-up?

Wet Pick-Up (%) = (Wet Fabric Weight − Dry Fabric Weight) ÷ Dry Fabric Weight × 100.

4. How do I calculate dry add-on?

For a homogeneous bath on a compatible mass basis, Dry Add-On (%) = Wet Pick-Up (%) × Active Bath Concentration (wt%) ÷ 100.

5. Which is more important: wet pick-up or dry add-on?

Both. Wet pick-up controls liquid and water load; dry add-on describes chemistry dosage. Production should link the two rather than choose one.

6. Can two fabrics have the same wet pick-up but different chemical add-on?

Yes. If bath concentration differs, the dry chemical add-on differs even when wet pick-up is identical.

7. Can two processes have the same dry add-on but different wet pick-up?

Yes. A lower-pick-up process can use a more concentrated bath to achieve similar dry add-on. Drying and migration can still differ.

8. Is dry add-on the same as pretreatment product dosage?

Not always. Liquid commercial products may contain only part active solids, so product concentration and product solids content must both be considered.

9. Why is bath density important when using g/L?

Because g/L is mass per liquid volume, while add-on calculations are often performed on a mass fraction basis. Bath density allows conversion to wt% more accurately.

10. Should coating and spray also be controlled by wet pick-up?

The same mass-balance principle applies, but wet/dry coating weight or deposited spray add-on may be more practical than padding-style wet pick-up.

11. Why can equal dry add-on produce different color?

Because water load, penetration, drying, migration and where the chemistry is located can differ even when total retained dry mass is equal.

12. What should I send FSX Chemical for pick-up and add-on troubleshooting?

Send the fabric, current pretreatment/TDS, product solids if known, bath concentration, measured pick-up or wet add-on, application route, drying, moisture, ink, steaming and final print problem.

Control the Liquid Applied and the Chemistry Left Behind

If your digital textile pretreatment shows unstable color, bleeding, drying cost or fabric-to-fabric variation, FSX Chemical can help separate wet pick-up from actual dry chemical add-on and build a controlled trial around your fabric and application equipment.

ابدأ بـ العينات والمطابقة and provide your current bath concentration, product solids and measured application add-on.

مراجعة Digital Textile Printing Pretreatment for current FSX pretreatment routes📧 البريد الإلكتروني: Service@fsxchemical.com

The correct control strategy is not wet pick-up versus dry add-on. Wet pick-up controls how much liquor and water enter the fabric; dry add-on controls how much chemistry remains. Stable digital pretreatment requires both numbers to remain inside a validated process window, together with uniform distribution, controlled drying and acceptable final printing performance.