BS/EN 204-2016 pdf download.Classification of thermoplastic wood adhesives for non -structural applications.
This BS/EN 204 classifies thermoplastic resin based wood adhesives for non-structural applications into durability classes Dl to D4 based on the dry and wet strengths of bond-lines measured under specified conditions after various conditioning treatments.
For special applications, further tests that do not fall within the scope of this European standard can be applicable.
The adhesives specified in this European standard are suitable for the bonding of furniture and interior structures, panelling, doors, windows, stairs etc. made of wood or derived timber products.
This European Standard does not specify the temperature resistance of bond-lines.
2 Normative references
The following documents, in whole or in part, are normatively referenced in this document and are indispensable for its application. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.
EN 205:2016, Adhesives — Wood adhesives for non-structural applications — Determination of tensile shear strength of lap joints
EN 923, Adhesives – Terms and definitions
3 Terms and definitions
For the purposes of this document, the terms and definitions given in EN 923 and the following apply.
thermoplastic resin thermoplast
polymer or copolymer capable of being softened by heating and hardened by cooling
[SOURCE: EN 923:20 15, modified — NOTE 1 to entry has been removedi
3.2
thermoplastic wood adhesive
adhesive whose main constituent is a thermoplastic resin and which has been formulated for bonding wood
4 Classification
An adhesive shall be classified in accordance with Table 1, which gives examples of climatic conditions and fields of application in which the bonded member is to be used. The classification shall be based on tests on thin bond-lines as defined in EN 205 : 2016
5 Test method
The adhesive shall be tested in accordance with EN 205:2016 and as follows:
a) bond-lines shall be tested according to their assigned durability class (see Table 1);
b) the tests shall be performed using the appropriate conditioning sequence given in Table 2;
c) the individual strength values r in N/mm2 rounded to 0,1 N/mm2 and the mean value of the 20 test pieces for each conditioning sequence shall be recorded. Results from tests in which failure occurred in the wood at values below the specified minimum are invalid. Test pieces that are twisted, bended or showing other irregularities in form are valid if they reach the requirements; otherwise, or if visual examination shows that the adhesive was not correctly applied, the results are invalid. All results, valid or invalid, shall be reported. Explanation of the invalid values shall be reported.
The standard atmosphere used as a control climate Is either (20 ± 2) °C and (65 ± 5) % relative humidity (RH), (20/65), or (23 ± 2) °C and (50 ± 5) % relative humidity (RH), (23/50).
6 Requirements
When tested in accordance with EN 205:20 16 the mean strength of an adhesive shall conform to the values shown in Table 2.BS/EN 204-2016 pdf download.