BS EN 17456:2021 pdf free download – Wood flooring and parquet一Determination of top layer delamination of multilayer elements一Test method.
6.2.2 Aging treatment AT1 oven drying
Each test specimen shall be dried in the convection dry oven described in 5.4 for (100 ± 4) h at a temperature of (60 ± 2) °C. The cut edge of the test pieces shall be parallel to the air flow. The arrangement of test specimen shall ensure a constant drying on all sides. The loading of the dry oven shall ensure a reproducible drying process.
NOTE For example, see EN 321:2001, § 6.1.2.1, step 5.
6.2.3 Aging treatment AT2 humid climate storage and re-drying
a) each test specimen shall be put in a climate chamber or a climate box according to 5.7 with 95 % (- 2/+4) relative air moisture content (avoid dew point) at a permanent temperature of (23 ± 2) °C for 72 h. The test specimens shall be put in an upright position. A distance of at least 10mm is to adhere between the test specimens;
b) after humid climate storage each test specimen shall be stored for 24 h to 48 h at a relative humidity of (50 ± 5) % and a temperature of (23 ± 2) °C in the conditioning room (5.1). The arrangement of test specimen shall ensure a constant drying on all sides;
c) afterwards each test specimen shall be dried in the convection dry oven described in 5.4 for (8 ± 1) h drying at a temperature of (60 ± 2) °C followed by (16 ± 1) h at a temperature of (80 ± 2) °C. The drying conditions shall comply with 6.2.2.
6.3 Evaluation of delamination
The evaluation of the delamination shall be carried out after the last drying. For each test specimen:
a) the delamination length of top layer (Dr) bonding shall be evaluated visually at both cross sections (A and B);
b) if a delamination of top layer bonding is visible, it shall be tested with the feeler gauge described in 5.6. In so doing the feeler gauge shall be held at 65 mm from its free tip. Where the feeler gauge can enter the opening deeper than 5mm, it shall be marked at the cross sections with a pen;
c) failure in top layer or substrate layer, shall not be counted as delamination of top layer bonding, but shall be reported (e.g. “failure substrate layer”);
d) the delamination length of top layer bonding shall be measured with the sliding calliper described in 5.5 and the sum of delaminated length of adhesive joints of each layer type (top layer and substrate layer) at each cross section shall be recorded.
7 Calculation and expression of results
The delamination as a percentage of delaminated length related to the top layer width in the initial state shall be calculated for each cross section.
Calculate the mean of the delamination length of top layer (Di) of at least 10 cross sections.