소개
In the field of painting, the appearance characteristics of paint film is one of the important indicators to evaluate the quality of painting. In addition to gloss and color, fog shadow is also a key characterization property, especially for high-gloss coatings. This paper will introduce the definition of fog shadow, related standards, and the determination method of paint film fog shadow specified in ISO 13803 기준.

Purpose and significance of paint film mist shadow measurement
Fog shadow refers to the phenomenon of diffuse reflection caused by light irradiation on the surface of a high-gloss film. ISO 13803 standard specifies the measurement range of fog shadows: applicable to coatings with a gloss value of 90 단위 (20° gloss) 이상. The purpose of fog shadow measurement is to evaluate the surface diffuse reflection of high gloss coating and to evaluate the quality of coating on this basis.

고광택 코팅 품질 평가를 위한 필름 미스트 그림자 측정의 중요성 분석

Relevant standard

ISO 13803:2000 specifies the method for determining the 20° fog shadow of paint and varnish film. The standard provides an accurate and repeatable method of determining fog shadows to ensure consistency and standardization of coating quality.

Method for determination of mist shadow in paint film
테스트 원리

The fog shadow measurement method described in ISO 13803 measures the fog shadow of the paint film by receiving the scattered light in the reflected light from both sides at an Angle close to 20°. This method can accurately evaluate the diffuse reflection of high gloss film at different angles.

고광택 코팅 품질 평가를 위한 필름 미스트 그림자 측정의 중요성 분석

운영 필수사항

테스트 플레이트의 준비: 150μm 사양의 습식 도막 준비 장치를 사용하여 깨끗한 유리판에 컬러 도료를 도포하여 도막이 매끄러워지도록 합니다..

Fog shadow determination: 코팅 방향에 평행한 테스트 필름의 서로 다른 위치에서 세 가지 판독값을 측정합니다.. 오류가 다음보다 작은 경우 0.5 단위, the average value is recorded as the linear fog shadow value. 그렇지 않으면, 6개 값 모두의 평균 및 한계값을 기록하기 위해 세 번 더 측정을 수행합니다..

For coatings on non-glass substrates: After adjusting and calibrating the instrument, measure six times in different areas or directions on the template surface (excluding textured directions such as brush marks on the surface) and record its average value. If the error of six measurements is less than 1 unit value or 20% 평균값의, the mean value and the limit value are recorded. 그렇지 않으면, 테스트 보드는 폐기됩니다.

고광택 코팅 품질 평가를 위한 필름 미스트 그림자 측정의 중요성 분석

결과 표현

ISO에 따르면 13803, the average linear fog shadow value can be used to represent the fog shadow of the paint film. It may also be agreed to use the logarithmic mean of the fog shadow as a representation.

의의와 적용

The measurement of mist shadow is of great significance in evaluating the quality of high gloss coatings. For coating with high decorative requirements, such as automobile coating, fog shadow is one of the important indicators to measure its appearance quality. The results of fog shadow determination can help to formulate a reasonable grinding dispersion time, select the appropriate additive and the concentration of the additive to ensure the high quality and consistency of the coating.

결론
코팅 분야에서는, fog shadow, as an important characterization property, is very important for the appearance quality of high-gloss coatings. ISO 13803 standard provides an accurate measurement method to assess the fog shadow of a film by measuring the scattered light in the reflected light from both sides at an Angle approaching 20°. The application of this method helps the coating industry to ensure the consistency and high quality of product appearance. 동시에, the film fog shadow measurement also provides a scientific basis for adjusting the process parameters and optimizing the formula, so as to improve the coating quality and customer satisfaction.