In the standard “Toyota TSH 1508G Paint film resistance to volatile solvents” developed by Toyota vehicle company, a method is described for examining the effect of volatile solvent etc. on paint film.
When applying Method A, which is used to determine the volatile solvent resistance, a glass container as shown in the figure is prepared for each test panel prepared by the prescribed method and each glass container is filled with the test volatile solvent to a depth of approximately 90 mm. It is kept at a temperature of 20 degrees plus/minus 2 degrees. The test panel is immersed in the volatile solvent to a depth of approximately 80 mm for 24 hours and hung with a clip and a rope. After removing the test panel from the volatile solvent, the coloration and turbidity of the volatile solvent (if any) and the condition of the paint film are immediately checked. If it is not possible to hang the test panel with a rope, the test panel is immersed from its lower end to a depth of 80 mm. If no wrinkling, cracking, swelling or peeling is observed in the paint film immediately after removing it from the volatile solvent and keeping it at a temperature of 20 degrees plus/minus 2 degrees for 2 hours, the change in gloss, discoloration, increase in tackiness and change in hardness (if any) of the paint film are checked by comparing it with a part of the paint film to which the volatile solvent has not been applied. As for the tackiness, the surface of the paint film is checked by touching it with fingers. For the change in hardness, the paint film is examined by the pencil scratch method after 24 hours. In the test, three areas (the immersed part, the boundary part between the immersed and unimmersed part) are checked, and the paint film on the area approximately 6 mm from the peripheral edge of the test panel is excluded from observation. The volatile solvent used in the test contains the compositions (by volume) shown in the table. The number of reagents corresponds to those specified in the standard for the relevant paint.
When applying Method B, which is used to determine volatile solvent resistance, a polyethylene cylinder with an inner diameter of 38 mm and a height of 15 mm is placed on the test panel prepared with the recommended method and pressed with a suitable compression device to ensure that it adheres tightly to the test panel. 5 mL of volatile solvent is dropped into the mouth of the cylinder, then left undisturbed for 20 hours at a temperature of 2 degrees plus/minus 3 degrees. After the test, the test panel is dried in air. Then, the color difference around the cylinder and wrinkling, cracking, swelling or peeling are checked. If a polyethylene cylinder with an inner diameter of 25 mm and a height of 15 mm is to be used, 3 mL of volatile solvent is dropped for the test.
When applying Method A (point method) used to determine xylene resistance, 0,2 mL of xylene is dropped onto the test panel prepared with the recommended method and left undisturbed for 20 minutes at 2 degrees plus/minus 30 degrees. The xylene is wiped off and the paint film conditions are checked immediately afterwards and after 24 hours. The degree of swelling of the paint film is measured with a two-dimensional roughness meter. The test is carried out within the scope of comparison with the currently used material for at least n-2 (taking into account the variation in the test data).
When applying Method B (rubbing method) to determine xylene resistance, a load of 4,9 N (flat bottom cylinder with a diameter of 40 mm) is applied using a gauze soaked in xylene and rubbed back and forth eight times on the test panel prepared by the prescribed method. The surface condition of the paint film is observed for tackiness, wrinkling, swelling, peeling, etc.
Among the numerous tests, measurements, analyses and evaluation studies carried out for businesses in various sectors, our organization also provides testing services defined in the standard “Toyota TSH 1508G Paint Film Resistance to Volatile Solvents” with its trained and expert staff and advanced technological equipment.
To get an appointment, to get more detailed information or to request an evaluation, you can ask us to fill in our form and reach you.
