Automated testing of drying behaviour of lacquers and paints

摘要

Testing of the drying behaviour of lacquers and paints is automated by an arrangement which uses a carriage (1) to carry the test sample (2). Above the carriage (1) is a sand sprinkler (3) and an adhesion tester (4) which presses a test strip (5) on to the test sample. If required, further instruments are arranged over the carriage, pref. a scratching tool (6), to test the coating. Preferably a coated test sample (2) is mounted on a carriage (1) which moves at 3-12 cm/hr over a distance of 20-59 cm, pref. 30-40 cm. The sand sprinkler (3) has a paper strip (8), perforated with 2.5 mm holes spaced 5 mm apart, moving with the carriage under a sand funnel (7). Each hole releases some sand as it moves clear of the housing (9). After a short period or at the end of the test the sand is swept or blown away. The adhesion tester (4) presses a test strip of paper (5) against the coating with a hemispherical plunger at a defined force. The paper strip is held loosely in a loop and is removed when the carriage reaches the end of its travel. Different phases of drying are evaluated according to the traces left.