PU Shoe

Water-Based PU Shoe Adhesives

Water-based polyurethane dispersions are used for sole attaching and other footwear bonding steps where brands or factories want less solvent at the adhesive station. They work as part of a system — cleaning, primer or halogenation, hardener, drying and heat activation — so a switch is judged on the whole process, not the adhesive alone.

An application we assess on request. Share your substrates, process and target requirements and we will confirm suitability, available documentation and sourcing feasibility — no stock grade is listed yet.

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Sole and upper prepared with water-based PU adhesive, with the tub and brush on the bench

Sole Materials and Their Preparation

A water-based adhesive does not change what each sole material needs before bonding. Uppers matter too: leather is roughed, coated synthetics may need a primer on the upper side, and textiles can let adhesive strike through.

Sole	Usual preparation	Watch for
Vulcanised rubber	Buffing, then halogenation or a rubber primer	Treated soles have a working window before they must be bonded
TR / TPR	Halogenation or a primer matched to the compound	Compounds vary between sole suppliers; re-test when the supplier changes
EVA / Phylon	A primer matched to EVA	A rubber primer on EVA is a common cause of separation
PU	Cleaning to remove mould release, sometimes a primer	Release agent left on the sole is the usual failure
PVC	A primer suited to plasticised PVC	Plasticiser migrating from the sole can soften the bond over time

One or Two Components

Sole bonds usually need a crosslinker (hardener) mixed into the dispersion to reach the heat and hydrolysis resistance brands test for. That brings a mixing ratio to control and a pot life: mixed adhesive left at the end of the shift is discarded as its SDS directs, not thinned and reused. Lighter-duty steps may run without hardener. Our shoe adhesive guide explains how cleaners, primers, halogenation agents and hardeners differ.

Drying, Heat Activation and Pressing

Dry completely. Water left in the film when it is activated weakens the bond. Drying tunnels sized for solvent adhesive are often too short.
Activate to a film temperature. The adhesive film must reach the activation temperature on its TDS; the unit's setpoint is not the same thing. Check with a surface thermometer or indicator.
Press within the window. An activated film stays bondable only briefly. Record how long pairs wait between activation and the press.
Press evenly. Pressure and time come from the sole press and the sole shape; uneven pressure shows up as edge separation.

Heat, Hydrolysis and Flex Requirements

Brands specify bond strength before and after ageing — heat, humidity, sometimes flexing. Standards such as EN 1392 (bond strength of footwear adhesives) and ISO 17708 (upper-sole adhesion on the whole shoe) describe how to test; the pass mark comes from the brand. Tell us the method and the values you have to meet, and test aged pairs, not only fresh ones: hydrolysis is where an under-crosslinked bond fails after shipping.

Restricted Substances and Brand Requirements

Water-based does not mean compliant. Brand restricted substance lists and the ZDHC MRSL apply to each chemical product on the line — adhesive, hardener, primer and cleaner — and documentation has to name those products. Ask for declarations per product rather than a general statement about the adhesive type.

What to Tell Us

Parameter	Why it matters	What to tell us
Bonding step	Sole attaching, lasting and insole lamination need different adhesives.	The step, not just "shoe glue"
Sole material and compound	Decides the preparation and the primer.	Material and supplier compound name if known
Upper material	Leather, coated synthetics and textiles wet and absorb differently.	Material and finish
Current preparation	A water-based adhesive is judged with the primer or halogenation it will run with.	Cleaner, primer and halogenation products now used
Drying and activation equipment	Water must dry fully before activation; tunnel length and activation units set what is achievable.	Dryer type and length, activation unit
Brand test and limit	Brands name the method and set the pass mark, before and after ageing.	Method, required values, ageing conditions
Current adhesive and any problem	Gives a baseline to compare against.	Product name, TDS, failure description

For the solvent-borne grades we list, see PU shoe adhesive and neoprene shoe adhesive; for diagnosing a separated pair, see reading a sole failure.

Frequently Asked Questions

Does a water-based PU shoe adhesive need a hardener?

For sole attaching, usually yes. A crosslinker mixed in before use raises heat and hydrolysis resistance, which most sole bonds need. Once mixed, the adhesive has a limited pot life and cannot be saved for the next day. Some less demanding bonding steps use it without hardener; the brand requirement decides.

Do I have to change my production line?

Often the drying section, rarely the whole line. Water takes longer to leave the adhesive film than solvent, so the dryer before activation may need more length or airflow. Spray or brush equipment has to suit a water-based product, and activation settings are re-checked against the film temperature actually reached.

Are the primers still solvent-based?

They may be. Water-based primers and halogenation agents exist, but they must be matched to the sole compound and proven on it. A factory can switch the adhesive to water-based and still run solvent-borne primers, so check the whole system if the goal is a solvent-free station.

Does water-based adhesive automatically meet brand chemical requirements?

No. Restricted substance lists and the ZDHC MRSL apply to every named chemical product used, including primers, hardeners and cleaners. The documentation has to cover each of them, whatever the carrier.

Can one adhesive system bond both EVA and rubber soles?

The adhesive may be the same, but the preparation will not be: EVA and rubber need different primers or treatments. Treat each sole material as its own qualification.

How should we trial a switch from solvent-based adhesive?

Run pairs on the same line with each system, record preparation, drying time, activation temperature and press settings, then test peel both fresh and after the heat and humidity ageing your brand specifies. Compare failure location as well as the numbers.

Sources

These references describe the technology in general. Performance figures from other manufacturers apply to their products, not to PACT grades, and a citation does not imply endorsement. Content reviewed September 14, 2026.

Related guidance for footwear bonding

Choosing shoe adhesive by bonding step
Primers, hardeners and how to read a separated sole.
The solvent-borne PU shoe adhesive we list
Sole bonding grade — ask for the bond-strength report on your own materials.
The footwear bonding process step by step
From roughing to cold setting.
What footwear factories specify
Materials, climates and brand testing.
All water-based adhesive options
Chemistries compared by application.
Check the VOC limit for your destination market
Which instrument actually governs adhesives in the US, EU and China — and which ones are wrongly cited.
Review our certifications and test reports
ISO 9001, ISO 14001, REACH statements and SGS reports, and what each one covers.
Send a specification and get a quote
Substrate, volume and destination market are enough for us to price it.

Share Your Materials and Process

Share the materials you need to bond or coat, your application process and any target specification. We will review the request and confirm sourcing feasibility, available documentation and next steps.

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