DIN EN 12962:2011-07

This document (EN 12962:2011) has been prepared by Technical Committee CEN/TC 193 "Adhesives", the secretariat of which is held by AENOR. This document is currently submitted to the Unique Acceptance Procedure and supersedes EN 12962:2001. The responsible German committee is Working Committee NA 054-04-06 AA "Klebstoffe - Terminologie; physikalisch-chemische Prüfungen" ("Adhesives - Terminology; physical and chemical tests") at the Plastics Standards Committee (FNK). Many liquid elastomeric adhesives show, depending on the nature of basic elastomer, elastic behaviour under specific conditions. The elastic behaviour of an adhesive apart of its viscosity is of great practical significance. It affects both processability (by brush or roller) of an adhesive and its bonding properties to porous substrates like wood, leather or fabric. For achieving optimum bond strength on porous substrates it is indispensable to adjust both viscosity and elasticity to the porosity of the substrates to be bonded. At a given viscosity, if the elasticity is too high, the adhesive will only rest on the surface of the substrate without penetration and anchoring in the substrate. If, on the contrary, the elasticity is too low, the adhesive is almost completely absorbed by the porous substrate without being able to form a bond-line. In both cases a lower bond strength results. A "cone and plate rheometer" as specified in EN 12092 allows to determine viscosity and elasticity of an adhesive by measurement of shear tension and tension vertical to shear tension ("normal tension"). However, a "cone and plate rheometer" is very expensive and its maintenance, too, operating requires a skilled staff. Its cleaning is time-consuming. It is mainly used for scientific purposes.