Highly durable adhesives for wood that exceed the D4 classification and meet XT durability norms
The XT classification for outdoor adhesives refers to standard, DIN EN 17619:2022, which classifies non-structural wood adhesives for exterior use. This standard fills the gap between structural and non-structural applications. It provides a clear guideline for adhesives used in outdoor environments, where wood is directly exposed to weathering without any protection.
The classification includes different durability classes, such as XT5, XT6 and XT7. The XT5 durability class requires adhesives suitable for outdoor applications with rare exposure to direct weathering, where the glued wooden product is covered by protection from weather. For example, wooden products behind cladding and products completely protected by roofs, coverings, etc. As such, it extends beyond standard D-class adhesives, requiring resistance to extreme moisture and temperature fluctuations. The XT6 and XT7 classes define the use of wood adhesives in exterior wood applications with rather occasional and frequent exposure to weathering and no protective cover. The reference norms EN 17619 and EN 205 guide XT classifications by defining durability standards and testing methodologies.
Benefits:
The 2K wood adhesive formulations we develop confirm that PVAc-isocyanate hybrid adhesives effectively meet XT5 classification for exterior wood bonding:
- Durability: XT5 classification adhesion strength after drying, oven exposure, and boiling water immersion.
- Workability: 8-hour pot life, making them suitable for industrial applications while maintaining strong, water-resistant bonds.
Key materials:
To achieve XT durability performance, formulations require highly durable polymer and crosslinking chemistry formulated in a 2K system:
- Polyvinyl Acetate (PVAc) Polymers: Provide strong adhesion and flexibility while ensuring ease of application.
- Crosslinkers (Isocyanates): Improve water resistance and bonding strength, enhancing the adhesive’s durability in extreme conditions.
Formulation support:
Developed in our laboratories, our formulations use best-performing raw material combinations to meet market and customer requirements, ensuring optimal performance for different applications and conditions.
Discuss your formulation challenges directly with our experts!
Use the form to request more information.
Souhaitez-vous lire l'article complet ?
Connectez-vous pour un accès complet à
