ISO 15184:2020 pdf download Paints and varnishes — Determination of film hardness by pencil test
6 Sampling
Take a representative sample of the product to be tested (or of each product in the case of a multi-coat system), as specified in ISO 15528.
Examine and prepare each sample for testing, as specified in ISO 1513.
7 Test panels
7.1 Substrate
Unless otherwise agreed, select the substrate from one of those specified in ISO 1514, using, where possible, the same type of material as will be used in practice. The substrate panels shall be plane and free from distortion.
7.2 Shape and dimensions
The shape and dimensions of the test panels shall be such that, during the test, the panel will stay in the horizontal position.
7.3Preparation and coating
Unless otherwise agreed, prepare each test panel in accordance with lS0 1514 and then coat it by thespecified method with the product or system under test.
7.4Drying and conditioning
Dry (or stove) and age, if applicable, each coated test panel for the specified time under the specifiedconditions. Before testing,condition the coated panels at (23 ± 2)C and a relative humidity of(50±5]%, unless otherwise agreed, for a minimum period of 16 h.
7.5Thickness of coating
The thickness of the coating shall be as specified or as agreed between the interested parties.Determinethe thickness of the coating by one of the procedures specified in ISO 2808.
8Procedure
8.1Carry out the test at a temperature of (23 ± 2) °C and a relative humidity of (50±5) %,unlessotherwise agreed.
8.2Remove approximately 5 mm to 6 mm of wood from the point of each pencil using the specialmechanical sharpener (5.3), being careful to leave an undisturbed,unmarked, smooth cylinder ofpencil lead.
8.3 Flatten the tip of the lead by holding the pencil in a vertical position and moving the pencil backand forth over abrasive paper (5.4), maintaining an angle of 90°.Continue until a flat, smooth, circularcross-section is obtained, free from chips or nicks in the edges.
Repeat this procedure each time a pencil is used.
8.4 Place the coated panel on a level, firm, horizontal surface.
Insert a pencil in the test instrument (5.1) and clamp it in position so that the instrument is horizontal,with the tip of the pencil resting on the surface of the paint film (see Figure 1).
8.5Immediately after the tip of the pencil has come to rest on the coating, push the pencil in thedirection away from the operator at a slow constant speed sufficiently long enough to perform a visualinterpretation.
8.6Unless otherwise agreed, inspect the coating after 30 s, using normal corrected vision, for markingof the kind defined in Clause 9
The damage can be assessed more easily after cleaning all fragments of pencil lead from the paintsurface, using a soft cloth or swab of cotton wool (5.5) and an inert solvent. If this is done,take care thatthe solvent does not affect the hardness of the coating in the test area.
By agreement, a magnifying lens(magnification x6 to x10) may be used to assess the damage. If amagnifying lens is used, this shall be reported in the test report.
lf no marking has occurred, repeat the test (8.3 to 8.6) without overlap of the test areas, moving up thehardness scale until marking occurs over a distance of at least 3 mm.
lf marking has occurred, repeat the test (8.3 to 8.6) down the hardness scale until marking nolonger occurs.
Determine which of the defects of the kinds defined in Clause 9 has been produced.
9 Types of defect
Marking by pencil leads covers a range of defects in the surface of the paint film.
These defects are defined as follows:
a) Plastic deformation: a permanent indentation in the paint surface without cohesive fracture.
b) Cohesive fracture: the presence of a visible scratch or rupture in the surface of the paint film,material having been removed from the paint film.
c) Combinations of the above.
These defects can occur simultaneously.
10 Precision
No precision data are available.
NOTE The applicability of the method is discussed in Annex A.
11 Test report
The test report shall contain at least the following information:
a) all details necessary to identify the product tested;
b) a reference to this document, i.e. ISO 15184;
c) details of the preparation of the test panels, including
1) the material and surface preparation of the substrate (see 7.1 and 7.2),ISO 15184-2020