Resistance to water vapor



A specimen from the laminate under test is held in place over the neck of a flask containing boiling water, so that the decorative surface of the specimen is exposed to the water vapor. After 1 h, the specimen is removed and allowed to recover for 24 h in normal ambient conditions before examination for any change in appearance.

1. Wide-necked Erlenmeyer flask, of capacity 250 ml and mouth diameter 50 mm (or equivalent apparatus).
2. Specimen holder, and heat screen, (see Figure 5).
3. Filter paper, or tissue.
4. Electric hotplate, or other suitable heat source.

Test specimen
The specimen shall be a square of side approximately 100 mm, cut from the laminate under test. One specimen shall be tested.

Place approximately 200 ml of water in the flask and bring it to the boil on the electric hotplate. Place the heat screen in position around the neck of the flask.
Place the specimen, decorative face down, centrally over the mouth of the flask and fix it in position with the wire specimen holder.
The specimen holder shall be heavy enough to prevent the specimen from curling away from the mouth of the flask.
After the decorative face has been exposed for 1 h to the vapour from the boiling water, remove the specimen and use the filter paper or tissue to remove excess water from the surface of the specimen.
Allow the specimen to recover for 24 h in normal ambient conditions and then examine the central area of the specimen with the naked eye, corrected if necessary, for any change in appearance.

Expression of results
The result of the examination for change in appearance shall be expressed in accordance with the following rating scale:
Rating 5: No visible change.
Rating 4: Slight change of gloss and/or colour, only visible at certain viewing angles.
Rating 3: Moderate change of gloss and/or colour.
Rating 2: Marked change of gloss and/or colour.
Rating 1: Blistering and/or delamination.