For common liquid coatings, the four stages of drying are as follows:
1. The first stage is the so-called pear visual impression, which corresponds to the time required for solvent evaporation.
2. The second stage is the cutting off of continuity, which is equivalent to the sol-gel transition.
3. The third stage is the interruption of track, which corresponds to surface drying time.
4. In stage 4, the needle no longer penetrates the membrane, which corresponds to the final drying time.
The linear drying time recorder developed according to ASTM D 5895 and has been widely used in the paint and coating industry for 20 years.The instrument is equipped with a needle holder which can hold six needles (each with spherical ends) and is powered by a constant speed motor.Six glass test strips (330*24mm) are installed on the instrument;Needle base need to spend some time to uniform through the test strips (time selected by the operator, 6, 12, 24, and 48 hours to four), the time scale is installed on the side panel, its scale is suitable for the four different kinds of speed (6, 12, 24, 48 hours) or, the speed is obtained by adjusting the adjustable motor on the instrument.The instrument also comes with a LCD screen showing the running time of the pin holder.At the end of the test, the operator can judge the drying characteristics of the sample in each time stage by taking the glass bar to check the time scale.
100-240V AC 50/60Hz
Number of scriber
Row needle diameter