BS EN ISO 2409:2020 Paints and varnishes – Cross-cut test

BS EN ISO 2409:2020 pdf free.Paints and varnishes – Cross-cut test.
Six parallel cuts are introduced in the coating and another six cuts are introduced perpendicular to the first cuts. Any loose paint particles are removed. The cut area is examined visually and compared to a six-step classification.
5 Apparatus
5.1 General
Use ordinary laboratory apparatus, together with the apparatus specified in 52 to 5.4.
5.2 Cutting tool
5.2.1 General requirements
it is particularly important to ensure that the cutting tool is capable of creating the specified V-shape throughout the total coating thickness, and that the cutting edges are in good condition. Suitable tools are described in 522 and 5.2.3 and shown in Figures 1 and 2.
A single-blade cutting tool (52.2) as well as the multi-blade cutting tool (5.2.3) are suitable for all coatings and substrates; it shall be ensured that all cuts mark or scratch the substrate. The depth of indentation into the substrate shall be as low as possible, however.
The tools described in 5.22 and 523 are suitable for manual use, which is the more usual method of use, but the tools may also be mounted on a motor-driven apparatus, which gives more uniform cutting. The application of the latter procedure shall be subject to agreement between the interested parties.
The apparatus (manual or motor-driven) and the type of cutting tool used have an influence on the test result. Results obtained with different types of cutting tool cannot be directly compared. For each test series, the same cutting tool shall be used.
5.2.2 Single-blade cutting tools
5.2.2.1 Hand-held single-blade cutting tool with a cutting edge as shown in Figure 1 a).
5.2.2.2 Single-blade cutting tool used in motor-driven apparatus as shown in Figure 3.
5.2.2.3 Cutter with a rigid blade with a V-shaped cutting edge as shown in Figure 1 b).
The specific thickness of the blade is not specified, as long as the blade is rigid and the cut produced is V-shaped through the whole thickness of the coating.
NOTE The cutter blade is designed to be broken in a defined manner so that a sharp blade is available at any time.
5.2.3 Multi-blade cutting tools
5.2.3.1 Hand-held multi-blade cutting tool with cutting edges as shown in Figure 2.
5.2.3.2 Multi-blade cutting tool used in motor-driven apparatus as shown in Figure 3.
The multi-blade cutting tool shall have six cutting edges spaced 1 mm, 2 mm or 3 mm apart. In addition,two guide edges (see Figure 2) are necessary to make handling easier. The guide edges and the cutting edges shall lie in one plane (see Figure 2).
5.3 Guiding and spacing edges
In order to space the cuts correctly, a series of guiding and spacing edges is necessary when using a single-blade cutting tool.
A folding ruler suitable for use with hand-held single-blade cutting tools (5.2.2.1) is shown in Figure 4a).
A series of guiding edges suitable for use with cutters with a rigid blade with a V-shaped cutting edge (see 5.2.2.3) is shown in Figure 4 b).
5.4 Viewing lens
Use a hand-held lens with a magnification ofx2 or x3.
6 Sampling
Take a representative sample of the product to be tested, as described in ISO 15528.
Examine and prepare each sample for testing, as described in ISO 1513.
7 Test specimen
7.1 Substrate
The test specimen shall be plain and free from deformations, preferably test panels. The dimensions shall be such as to allow the test to be carried out at three different positions not less than 5 mm from each other and from the edge of the panel.
Where panels consist of a relatively soft material such as wood, the minimum thickness shall be 10 mm. Where panels consist of a hard material, the minimum thickness shall be 0,25 mm.
NOTE In cases where the panel Is made of wood, the direction and the structure of the grain can inrluence the test, and a pronounced grain will render the evaluation impossible.
7.2 Thickness of coating
Determine the thickness, in micrometres, of the dried coating by one of the procedures specified in ISO 2808. Make the measurement at, or as near as possible to, the positions at which the cross-cut is to be made. The number of thickness determinations is dependent on the method used.
8 Procedure
8.1 General
8.1.1 Test conditions
Carry out the test at a temperature 01(23 ± 2) °C and a relative humidity of (50 ± 5) %.
In field tests, the ambient conditions shall be measured and recorded [see Clause 12, d)].
8.1.2 ConditIoning of the test panels
Condition the test panels immediately prior to the test at a temperature of (23 ± 2) °C and a relative humidity 01(50 ± 5) % for a minimum of 16 h.
NOTE This paragraph is not applicable for in field tests.
8.1.3 Number of cuts
The number of cuts in each direction of the lattice pattern shall be six.
8.1.4 Spacing of cuts
The spacing of the cuts in each direction shall be equal and shall depend on the thickness of the coating and on the type of substrate as follows:
up to 60 um: 1 mm spacing, for hard (e.g. metal and plastics) substrates;
up to 60 um: 2 mm spacing, for soft (e.g. wood and plaster) substrates;
61 um to 120 um: 2 mm spacing, for both hard and soft substrates;
121 um to 250 μm: 3 mm spacing, for both hard and soft substrates.
The cross-cut test is not suitable for coatings of total thicknesses greater than 250 um.
NOTE For coatings of total thickness greater than 250 μm, the X-cut method described in ISO 16276-2 can be used.
8.1.5 Number of determinations
For routine testing, carry out a single determination.
If a higher precision is required, carry out the test In at least three different places (see 7.1) on the panel. If the results do not match, the differences being more than one classification unit, repeat the test at three other places, if necessary using different panels, and record all the results.
8.2 Cutting the coating using the manual procedure
8.2.1 Place the test panel on a rigid. Aat surface to prevent any deformation of the panel during the test.
8.2.2 Before the test, inspect the cutting edge of the blade and maintain its condition by sharpening or replacement.
Perform the cutting manually, following the specified procedure.
If the panel is of wood or similar material, make the cuts at approximately 450 to the direction of the grain.
8.2.3 Hold the cutting tool (52) with the blade normal (perpendicular) to the test panel surface. With uniform pressure on the cutting tool and using the appropriate spacing guide (5), make six cuts in the coating at a uniform cutting rate. The minimum cut length shall be significantly longer than the width of the multi-cut tool. All cuts shall mark or scratch the substrate. The depth of indentation into the substrate shall be as low as possible, however. For some substrates, e.g. plastics, there is the risk of tearing and flaking of the coating if the cutting tool penetrates the substrate too deep.
If it is not possible, due to the hardness of the coating, to penetrate to the substrate, the test shall be declared invalid and so reported.
8.2.4 Repeat this operation, making a further six parallel cuts, crossing the original cuts at 900 to them so that a lattice pattern is formed.
8.2.5 Remove any loose paint from the area of cutting. Examples of suitable methods are given in Annex A. The method for removing the loose paint shall be agreed between the interested parties and shall be stated in the test report.BS EN ISO 2409 pdf download.BS EN ISO 2409:2020 Paints and varnishes – Cross-cut test