Overview
LENETA Form 24B is a gray scale cardboard used primarily to evaluate the hiding power of paint. The cardboard contains white, light gray, and black areas with six stripes numbered 1 to 6 in the white area. These stripes represent a uniform standard for gradually increasing contrast ratios. Usually used with scraping blades, the covering performance is assessed by looking at the number of the darkest stripes that the paint can completely (or nearly completely) mask at a specified Spreader thickness or diffusion rate.
Features
1. Using white, light gray and black gray scale design, providing standard contrast background.
2. The white area has six stripes numbered 1 to 6, and the contrast ratio increases to facilitate quantitative evaluation.
3. Specially optimized for blade coating method to ensure uniform test conditions.
4. Encasement specification is 250 sheets/box, easy to use in batches in laboratories or production sites.
Principle
The gray scale cardboard uses its preset stripes with an increasing contrast ratio as a reference standard. During testing, the paint to be tested is evenly Spreader on the cardboard at a specific thickness (e.g. using a scraping blade). After the paint is dried, observe its covering effect. The number of the darkest stripes that can be completely (or almost completely) obscured by the paint layer represents the hiding power level of the paint under the test conditions. The larger the number, the stronger the hiding power.
Applications
Paint hiding power evaluation, paint development, quality control, production site testing
Steps
1. Prepare the paint sample to be tested and the LENETA Form 24B gray scale cardboard.
2. Using a scraping blade, apply the paint to the striped area of the cardboard at a uniform thickness and rate.
3. Wait for the paint to dry through.
4. Standard light source, determine the number of the darkest streaks completely (or almost completely) covered by paint.
5. Record the number as the result of the paint hiding power evaluation.
Notice
* Spreader with a scraping blade is recommended to ensure consistent film thickness and uniformity.
* Standard light source conditions should be observed and assessed to avoid environmental light affecting the judgment.
* Paint must be evaluated through drying.
* Pay attention to the distinction between "complete cover" and "almost complete cover", and maintain the conformity of the assessment criteria.
* Cardboard should be stored in a drying, flat environment to avoid damage to the test surface.
