Fluid-Bags have been the premier bulk packaging solution for one-component polyurethane (1K PUR) adhesives since the 1990s.

Henkel, a global leader in adhesive technologies, has relied on the system for its LOCTITE® PURBOND line throughout that period – and today, Fluid-Bags are found in nearly every industrial CLT production in Europe.

Why the right packaging of 1K PUR adhesives is crucial

One-component polyurethane adhesives are high-value and highly sensitive. 1K PUR adhesives cure on contact with moisture, which means any air entering the container during handling is a direct threat to product integrity. Premature curing raises viscosity, causes skin formation and can foul dosing pumps, a costly interruption on any glulam or CLT production line.

Where rigid IBCs are still used, the challenges are well known.

• A rigid IBC must typically be new for 1K PUR (reuse is rarely possible with a moisture-curing product).
• An IBC tank also takes up significant space when empty, and – at locations without a collection or ticket system for empty containers – the receiver is left to dispose of it at their own cost.
• V-bottom IBCs reduce residue but come at a higher price.
• For production with high demands, a partially used rigid IBC can degrade the quality of the adhesive faster than expected (Kiilto case).

The Fluid-Bag system eliminates these issues

The aluminum barrier liner in the Fluid-Bag achieves a water vapour transmission rate (WVT) of less than 0.1 g/m²/24h, significantly tighter than standard HDPE rigid IBCs. The bag collapses with the product during discharge, keeping air out entirely.

No vents. No filters. No nitrogen blanketing.

How Squeeze Solution works for 1K PUR adhesives

One-component polyurethane adhesives for engineered wood move efficiently in the Squeeze Solution system; from precise filling to the last gram at discharge.

Squeeze Solution offers two logistics models for bulk PUR adhesive distribution:

• • Regional rotational system (up to 200-300 km). The Fluid-Bag with steel pallet serves customers within established return routes. Empty bags return collapsed, requiring far less transport space than rigid IBCs.

• • One-way distribution (beyond 300 km or international). The Fluid-Bag with wooden pallet reaches distant markets without the cost and complexity of return transport. For sea freight, the 900-liter bag is dimensioned for shipping containers; 20 filled bags fit in a standard 20-foot container. After discharge, all components are separated for local recycling.

Both formats use the same closed-system principle with aluminum barrier inner liner and 2-inch outlet valve.

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1K PUR adhesives used in structural engineered wood, for example glulam (glued-laminated timber), CLT (cross-laminated timber) and finger-jointed KVH are governed by EN 15425, the European standard for one-component polyurethane adhesives for load-bearing timber structures.

These adhesives typically have viscosities in the range of 9,000-32,000 mPa·s at 20 °C, based on published technical data sheets from major PUR adhesive suppliers. They are shear-thinning, which means equipment that applies mechanical pressure actively assists flow to the outlet.

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Typical set-ups for transport of bulk 1K PUR adhesive

Recommended Fluid-Bag configuration for 1K PUR wood adhesives

Note: Outlet size, pump specification and machine configuration are set based on your 1K PUR adhesive’s specific viscosity profile and temperature range. We assess this during the consultation.

For PUR adhesive producers: filling the Fluid-Bag

The Squeeze Solution filling process is closed from the moment the bag is stretched to the moment it is sealed, eliminating air contact at the most critical step in bulk polyurethane adhesive handling.

The filling station stretches the empty bag to full capacity before filling begins. This maximizes volume, positions the outlet valve correctly and prevents air ingress. Stations can be placed on weigh scales for precise, repeatable filling weights.

For 1K PUR producers currently using drums or rigid IBCs, the Fluid-Bag system integrates into existing production flows. Configuration is adapted based on production volume, adhesive viscosity and fill-location constraints. No air filters. No nitrogen blanketing. The bag does the work.

For engineered wood producers: efficient 1K PUR discharge at the application site

Squeeze Solution’s concept recovers near-complete product from every Fluid-Bag, including one-component polyurethane adhesives that can leave substantial residue in rigid IBCs.

The stretching station pulls the bag and, when the bag is elevated, gravity assists flow directly to the application line. Combined with a weigh scale, operators can monitor remaining content in real time and optimize discharge for minimal residue.

No intermediate open-transfer step, no air entering the system.

The Fluid-Bag fits all common set-ups used in engineered wood adhesive applications. The result is consistent material flow and less waste per shipment; on a glulam line, CLT press or finger-jointing system where uptime is everything.

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Case: Kiilto – 1K PUR adhesive handling with Fluid-Bags

Kiilto, a Finnish family-owned chemical company with over a century of experience, uses 1000-liter Fluid-Bags with aluminum barrier liners to protect polyurethane adhesive quality across wood-industry applications.

”What’s really beneficial is that when our customers use our product in the Fluid-Bags, the adhesives can be emptied without any additional air entering, since the bag is squeezed together.”
– Jussi Hänninen, Head of RDI, Kiilto

Following customer requests, Kiilto adopted Squeeze Solution for the performance and consistency their operations require. The closed system eliminates the need for air filters during discharge. The bag collapses around the product, dispensing adhesive without air contact and maintaining quality to the last gram.

For Kiilto, unassembled Fluid-Bags require minimal warehouse space; 20 units in just two pallet positions.

”I’ve been packing and assembling the Fluid-Bags for about ten years, and I can’t remember any faulty ones. Personally, I think Squeeze Solution works great.”
— Kimmo Laaksonen, Production Operator, Kiilto

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Henkel Engineered Wood – three decades with Fluid-Bags

Henkel, through its LOCTITE® PURBOND brand, supplies one-component polyurethane adhesives to the majority of CLT and glulam producers worldwide. Since the 1990s, Henkel has relied on 1000-liter Fluid-Bags with aluminum barrier foil liners and 2-inch outlets for both regional and global distribution.

The system operates on two logistics models: Fluid-Bags with steel pallets for customers within approximately 200 km of production, and one-way Fluid-Bags with wooden pallets for distant markets globally.

The aluminum barrier foil protects the moisture-curing adhesive throughout its journey, extending shelf life and eliminating the need for nitrogen blanketing or air filters. The closed system prevents premature curing from filling to final application at CLT plants, glulam factories and finger-jointing lines.

A 2019 industry feature on CLT production documented that Fluid-Bags filled with LOCTITE® HB-S PURBOND adhesives were present at essentially every industrial CLT production facility profiled, a practical reflection of how established the system has become for structural 1K PUR distribution.

Talk to a 1K PUR adhesive bulk-handling specialist

Whether you produce one-component polyurethane adhesives or receive them in bulk for glulam, CLT or engineered wood production, we start with your specific operation and recommend the configuration that fits.

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