Resin Appearance and Transparency Detection

1. Definition and content

Identification of whether the liquid resin (lacquer) contains mechanical impurities and the degree of turbidity present.

2. Measurement method

(1) standard

GB 1721 — 1979 Method for Determination of Appearance and Transparency of Varnishes, Clear Oils and Thinners. (2) Principle The resin is compared with a series of standards under specified conditions to obtain the appearance and transparency.

(3) Operation

①Determination of appearance. Put the sample into a dry and clean colorimetric tube, and observe whether it contains mechanical impurities under the transmitted light in a dark box at a temperature of 23 °C .

② Determination of transparency. Pour the sample into a dry and clean colorimetric tube, and mix it with a series of standard solutions of different degrees of turbidity under the transmitted light in a dark box at a temperature of 25°C (use the colorless part for the colorless one, and the colored part for the colored one) Compare and select the primary standard solution that is closer to the sample . If you find flocculent suspension or sediment in the standard solution during the test, shake it well and then compare it with the sample.