BS EN 927-10 pdf free download

BS EN 927-10-2019 pdf free download.Paints and varnishes – Coating materials and coating systems for exterior wood Part 10: Resistance to blocking of paints and varnishes on wood.
7.3 Substrate s2 – Other wood species In case of customer-specific requirements or if it might be assumed that other types of wood might give a different result an alternative wood species should be used as substrate. It is also an option for manufacturers to provide an already coated test specimen from which test panels can be cut. The chosen panel shall be precisely described in the test report. The surface of the specimens provided shall be plane. The test substrate shall be conditioned until constant mass at standard conditions according to ISO 554 [(20土2)。C and (65土5) % relative humidity]. 7.4 Substrate s3 – Inert substrate
7.4.1 Test panels (“strips”) made of polyvinyl chloride (PVC) film free of migrating plasticizers, of sufficient rigidity to ensure a flat surface, impervious to and unaffected by water or aliphatic organic solvents and of nominal thickness 0,25 mm. Other types of plastics flm might be used where the coating material contains solvents which can adversely affect the PVC film. If the coating delaminates from the substrate before or during the test, another, more suitable substrate should be used. NOTE PVC foils can have different properties on the two sides, only one of the sides being intended for coating.
7.4.2 Film applicator, preferably automatic, used at an application speed of 10 mm/s to 15 mm/s and fitted with a doctor blade (see 8.3) with an appropriate gap clearance and a gap width of at least 60 mm.
7.4.3 Use cutting knife, metal template or straight-edge ruler to cut the foils. 7.5 Substrate s4 – Other plane substrates The selected substrate should be precisely described in the test report. Alternatives that may be used include absorbing substrates (e.g. plywood) as well as non absorbing substrates (e.g. glass, aluminium, coated paper, polymer panels). Absorbing substrates should be conditioned until achieving constant mass at standard conditions according to EN 23270 [(23土2) °C and (50土5) % relative humidity].
8.2 Application to substrate s1 – spruce, s2 – other wood substrates, or substrate s4 – other plane substrates If nothing else is specified by the manufacturer of the coating system, the conditioned, planed wood specimens (test panels), shall be manually sanded with abrasive paper (180 grade) just before application. Dust shall be removed completely. The test panels are coated with the coating system to be tested, closely following manufacturer’s instructions or specification. Examples of possible suitable application methods and their specification are given in Annex B.
8.3 Application to substrate s3 – inert substrate or substrate s4 – other plane substrates Use an automatic film applicator ftted with a doctor blade with an appropriate gap clearance and gap width somewhat wider than the intended final width (at least 60 mm)]. Make a draw-down of the prepared sample of coating material on the test panel to achieve a uniform even film at least 10 mm longer than the intended final test surface. Apply the coating material under test on the matt surface of the foil. Ensure that the gap clearance is suficient to achieve a final dry film thickness corresponding with the paint manufacturer’s specification. The applied wet and the resulting dry film thickness of the coating under test shall be reported. Recommended application speed is 10 mm/s to 15 mm/s.
8.4 Typical dry film thickness on stable wood constructions Coating systems should be applied according to the manufacturer’s instructions. For reference, the dry film thicknesses below refer to first factory- applied coating systems on bare wood. 一Spray applied coating systems:1) Coating thickness > 80 um for high build opaque, transparent and semi-transparent wood coating systems (according to EN 927-1). Coating thickness > 100 um for opaque coating systems. -Brush applied coating systems:1) Coating thickness approximately 30 um to 50 um for medium to high build opaque, transparent and semi-transparent wood coating systems (according to EN 927-1). Coating thickness approximately 60 um to 100 um for opaque coating systems.BS EN 927-10 pdf download.