BS EN 927-10-2019 Paints and varnishes – Coating materials and coating systems for exterior wood Part 10: Resistance to blocking of paints and varnishes on wood.
This document specifies a test method for determining, under specified optional conditions, whether a single-coat film or a multi-coat system of paints and varnishes on wood after a specified drying period is sufficiently dry to avoid damage when two painted surfaces or one painted surface and another surface are placed in contact under pressure and subsequently separated. The method is intended to simulate the conditions when painted articles come into contact which each other. In comparison to EN ISO 9117-2, the conditioning and parameters which influence the behaviour of wood coatings are more specific.
NOTE In some countries, the test is called a Thlock or blocking resistances test.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content constitutes requirements of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.
EN 927-1. Paints and varnishes – Coating materials and coating systems for exterior wood – Part 1:
Classification and selection
EN ISO 1513, Paints and varnishes – Examination and preparation of test samples (ISO 1513)
EN ISO 2808, Paints and varnishes- Determination offllm thickness (iSO 2808)
EN ISO 15528, Paints, varnishes and raw materials for paints and varnishes – Sampling (ISO 15528)
ISO 554, Standard atmospheres for conditioning and/or testing – Specifications
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
ISO and IEC maintain terminological databases for use in standardization at the following addresses:
— IEC Electropedia: available at http://www.elcctropcdia.org/
— ISO Online browsing platform: available at http://www.iso.org/obp
3.1 blocking
unwanted adhesion between two surfaces, at least one of which has been coated, when they are left in contact under load after a given drying period
Note ito entry: Blocking does not apply to bonding of coated surfaces after insufficient drying.
Note 2 to entry: In practice, blocking can occur if coated wood panels are stacked on each other or on windows and doors If the frames are in direct contact with the faces. Blocking depends on temperature and load (pressure).
Note 3 to entry: The term blocking is also sometimes used to describe agglomerated caked powder. Note 4 to entry: Unwanted adhesion can lead to damage upon separation.
ISOtJRCE: EN ISO 4618:2014, 2.30, modified – added Notes to entry.BS EN 927-10 pdf download.