This European Standard specifies the determination of the ability of an adhesive to Vet' a solid surface by measuring the contact angle and determining the critical surface tension of wettability. It allows the prediction of what adhesive will wet which adherent It may be used to characterize surfaces after priming, coating and bonding.
NOTE. 1 In general the contact angle is dependent on the proceeding motion of the borderline of the liquid (i.e. on the mode of application), a value between two borderline values,the advancing angle (e.g. after an extension of a drop) and the receding angle (e.g. after a reduction of a drop). Only if this difference between both, termed hysteresis of contact angle, is negligible, does the contact angle express the critical surface tension defined in thermodynamics as a substrate-specific characteristic value. Normally, the hysteresis will not be negligible when the rugosities are above 0,5 mm and when the heterogeneous phase is not smaller than 0,1 mm. The shape of the rugosity is essential for the hysteresis.
NOTE. 2 For a comparison of wetting behaviour, the advancing angle should always be measured here.
BS EN 828:1998 history
2013BS EN 828:2013 Adhesives. Wettability. Determination by measurement of contact angle and surface free energy of solid surface
1998BS EN 828:1998 Adhesives. Wettability. Determination by measurement of contact angle and critical surface tension of solid surface