"Are you able to clean the mixing tank?" I have estimated the amount of contamination from the previous product!

As a general statement, we verified to what extent "residual product" remains in the stirring kettle (how much "residual product" could be removed through solvent washing?) from the non-volatile content.

Objective We verified how much "previous product" remains in the stirring tank (i.e., to what extent the "previous product" can be removed by solvent cleaning) through the measurement of non-volatile components. Verification Method (Solvent Cleaning Method) Immediately after producing resin solution A (dyed purple for visualization), solvent B (2 kg of new solvent) was added to the stirring tank (50L). This mixture was stirred at 40°C for 30 minutes, after which the non-volatile component 1 of the extracted solvent B was measured. Additionally, solvent B (another 2 kg of new solvent) was added, and the above process was repeated to measure non-volatile component 2. Verification Results Non-volatile component 1 = 2.9% → Extracted 58g equivalent of previous product (solid content) through solvent cleaning Non-volatile component 2 = 0.3% → Extracted 6g equivalent of previous product (solid content) through solvent cleaning * Measurement of non-volatile components: Dry weight loss method at 120°C for 30 minutes * Non-volatile component of solvent B (new) = 0.0% Discussion - The fact that non-volatile component 2 was lower than non-volatile component 1 indicates that the effectiveness of solvent cleaning has been confirmed "to some extent." However, although the "previous product" was diluted through two rounds of solvent cleaning, it was not completely removed. * To expect a cleaning method more effective than solvent cleaning, it is considered necessary to "disassemble" the stirring tank and clean the previous product adhered to the internal blades and walls.

Contract manufacturing