Test Background
The phenomenon of discoloration of the newly applied paint film on the upper layer caused by the migration of the pigment contained in the lower paint film is called bleeding. This phenomenon can occur immediately after application or at any stage of drying of the paint film. The pigment bleed resistance test can determine the pigment bleed resistance by comparing it with a standard sample.
Zhongke Testing Reliability Experiment Center has the capability of reliability testing of various pigments and provides professional bleeding resistance testing services for pigments.
Scope of tests
1. According to the chemical composition of pigments, they can be divided into two categories: inorganic pigments and organic pigments. According to their sources, they can be divided into natural pigments and synthetic pigments.
2. Pigments are classified according to their function, such as anti-rust pigments, magnetic pigments, luminescent pigments, pearlescent pigments, conductive pigments, etc.
3. From the perspective of production and manufacturing, it can be classified into titanium pigments, iron pigments, chromium pigments, lead pigments, zinc pigments, metallic pigments, and organic synthetic pigments.
4. From the perspective of application, it can be classified into paint pigments, ink pigments, plastic pigments, rubber pigments, ceramic and enamel pigments, pharmaceutical and cosmetic pigments, art pigments, etc.
Test method
After the topcoat film is dry, compare it with the method described in GB/T 9761 under scattered sunlight. The degree of bleeding is expressed by the color difference between the sample surface painted only with white topcoat and the sample surface covered with white topcoat on the pigment dispersion of the test sample.
Use the bleeding degree of the standard sample as the standard and record whether it is equal to, greater than or less than the bleeding resistance degree of the standard sample. If daylight is not available, compare under standard light sources. Repeat the comparison after 24 hours.
Test standard:
HG/T 3834-2006 Comparison of pigment bleeding resistance
ISO 787/22-1980 General test methods for pigments and extender pigments Part 22: Comparison of the bleed resistance of pigments
GB 9285 Raw materials for paints and varnishes Sampling
GB/T 9761 Paints and varnishes Visual color comparison of paints
