News

Two new ISO standards for the world of non-structural wood adhesives were published last March 1. The two documents are the following: 

• ISO 34256:2024 Adhesives for non-structural wood applications - Test method and requirements for resistance to static load

• ISO 34257:2024 Adhesives - Wood adhesives - Determination of tensile strength of lap joints at elevated temperature (WATT '91)

 Particularly interesting is that these two technical references transpose, and thus correspond to, two European standards that are respectively the: 

• UNI EN 14256:2008 Adesivi per legno per utilizzi non strutturali - Metodo di prova e requisiti per la resistenza al carico statico 

and

• UNI EN 14257:2019 Adesivi - Adesivi per legno - Determinazione del carico di rottura a trazione a temperatura elevata di giunti a sovrapposizione (WATT '91)

 
This was made possible by the presence of dr. Fabio Chiozza in ISO/TC61/SC11/WG5 convenor of CEN/TC193/SC1 Working Group “WG12”, of which CATAS is also a member, and which at the European level has the direct management of documents concerning wood adhesives for nonstructural applications.
 
The ISO 34256 (as EN 14256) specifies a method for determining the ability of a test piece bonded with a thermoplastic adhesive, to support a given load for a specified time without fracture or excessive distortion and specifies performance requirements for mean survival time.
While the ISO 34257 (as EN 14257) specifies a method for testing the strength of wood adhesives at 80 °C. The procedure described is based on a test developed in Germany known originally and historically as the WATT '91 test.
 
These two standards are added to two other important documents, published in the same manner in 2017, which are respectively:
 

• “ISO 19209:2017 Adhesives - Classification of thermoplastic wood adhesives for non-structural applications”which corresponds to “UNI EN 204:2016 Classification of thermoplastic wood adhesives for non-structural applications”

and

• “ISO 19210:2017 Adhesives - Wood adhesives for non-structural applications - Determination of tensile shear strength of lap joints” which corresponds to “UNI EN 205:2016 Adhesives - Wood adhesives for non-structural applications - Determination of tensile shear strength of lap joints”.

 
For an easy reading below the UNI EN and corresponding ISO standards, are collected in a table:

UNI CEN	ISO
UNI EN 204:2016 Classification of thermoplastic wood adhesives for non-structural applications	ISO 19209:2017 Adhesives - Classification of thermoplastic wood adhesives for non-structural applications
UNI EN 205:2016 Adhesives - Wood adhesives for non-structural applications - Determination of tensile shear strength of lap joints	ISO 19210:2017 Adhesives - Wood adhesives for non-structural applications - Determination of tensile shear strength of lap joints
UNI EN 14256:2008 Adhesives for non-structural wood applications - Test method and requirements for resistance to static load	ISO 34256:2024 Adhesives for non-structural wood applications - Test method and requirements for resistance to static load
UNI EN 14257:2019 Adhesives - Wood adhesives - Determination of tensile strength of lap joints at elevated temperature (WATT '91)	ISO 34257:2024 Adhesives - Wood adhesives - Determination of tensile strength of lap joints at elevated temperature (WATT '91)

For info:
Paolo Tirelli
+39 0432 747246
tirelli@catas.com