Density tester Model 419

saggingfor paintR&D

Sag tester for flow testing and levelling assessment of coatings. Parallel strips of wet film are applied to a substrate using a special stainless-steel paint applicator frame; sag tendency is determined in a vertical flow test and levelling tendency is ascertained when the specimen is horizontal; the specimen panel is examined visually after the coating has hardened.


Sag test according to DIN 55 677
Strips of wet film are applied (preferably to a standard steel specimen panel). After application the specimen panel is positioned vertically (film strips running across the panel with the thinnest strip uppermost) and the coating is allowed to dry. A thickness gauge is used to determine the thickness of the thickest layer where no change is evident due to sagging; this layer is regarded as the flow index for the sag properties.


Levelling test according to ASTM D 2801
The wet film strips are applied to a predefined substrate using the doctor blade for levelling tests.
After the specimen has hardened in the horizontal position, the number of double strips which have merged with each other is established. (This standard was withdrawn in 1990)


Sagging test according to ASTM D 4400
Method A: The strips of wet film are applied to a black-and-white contrast card using the doctor blade of the applicator for sag tests (application rate approx. 150mm/s).
Immediately after application, the card is positioned vertically in such a way that the strips of film are horizontal, with the thinnest strip at the top. After hardening, the level is determined which has not quite spread to the strip below. Further evaluation details are described in ASTM D 4400, Procedure A. (Contrast cards, model 451, are suitable for this purpose.)


Method B: The strips of wet film are applied to a contrast card as described in method A. Prior to application, however, two marking lines are drawn on the carton at right angles to the direction of application. 15 seconds after application the specimen is placed in a vertical position in such a way that the strips of film are vertical and the reference markings are horizontal. After hardening, the level is determined at which a shift of marking is just recognizable in relation to the original reference line. A detailed description is given in ASTM D 4400, Procedure B. (Contrast cards, model 451, are suitable for this purpose.)


Standards

• DIN 55 677
• ASTM D 2801
• ASTM D 4400

Characteristics / technical specifications

• Width: 115 mm
• Applicable standard: DIN 55 677 / ASTM D 2801 / ASTM D 4400