What is PD CEN/TS 927-9-Coating system about?
PD CEN/TS 927 discusses paints and varnishes. PD CEN/TS 927-9 is the ninth part of the PD CEN/TS 927 multi-series and discusses the determination of pull-off strength after water exposure for coating materials and coating systems for exterior wood.
PD CEN/TS 927-9 specifies a method for assessing the resistance of a coating system on wet wood to separation from the substrate by measuring the force necessary to detach or rupture the coating system by a normal tensile strain applied through an attached stud (dolly).
Additional information is gained by noting the type and locus of failure. A procedure for wetting the wood substrate is described. The test method is only suitable for wood and wood-based substrates.
Note: For dry adhesion, the test method is allowed to be carried out without wetting in which case it will differ very little from EN ISO 4624.
Who is PD CEN/TS 927-9-Coating system for?
PD CEN/TS 927-9 on paints and varnishes (Coating materials and coating systems for exterior wood) is useful for:
- Paint manufacturers
- Wooden furniture manufacturers
- Interior and exterior designers
- Quality control personnel
Why should you use PD CEN/TS 927-9-Coating system?
PD CEN/TS 927-9 is one of two methods for assessing the resistance of the coating system to removal by external forces provided by either crosscutting or direct pull-off, both methods are carried out under wet conditions.
Most of the currently used exterior coating systems are characterized by their propensity to being penetrated by moisture both into and out of the wood. It might therefore be difficult to achieve good adhesion of these coatings under high moisture conditions. In cases of an already damaged coating film or an increased presence of moisture in the boundary zone to the wood surface, even a short-term exposure to water can be sufficient to weaken the adhesion of a coating film either to the substrate or within the coating system.
The described method in PD CEN/TS 927-9 is suitable for the testing of coatings for exterior wood or wood-based materials and applicable for testing the wet adhesion of a single coat or multi-coat system. In the test procedure in PD CEN/TS 927-9, the force, which is necessary to detach or pull off the coating perpendicular to the substrate is measured. PD CEN/TS 927-9 helps you in improving the quality of paints on woods for wet conditions.
