Suggestions for the use of glass ink defoamers
1. Usage method
Direct addition and batch addition
The defoamer can be directly added to the ink system. It is recommended to add in batches: 1/3 to 2/3 of the
total amount is added for the first time, and the rest is added in the subsequent process. This method can avoid
the problem of shrinkage caused by excessive local concentration, and ensure that the defoamer is evenly dispersed.
Differential treatment in the grinding and paint mixing stages
Grinding stage: Silicone defoamers are preferred. When adding, the amount of water must be strictly controlled to
ensure that it is fully dispersed and the amount can be reduced to a minimum.
Paint mixing stage: It is recommended to use non-silicon defoamers to balance the defoaming effect and ink stability.
Special scene treatment
If the foam position is scattered, the defoamer can be added by spraying to ensure uniform coverage.
2. Dosage control
Regular dosage range
The amount of defoamer added is usually 0.1% to 0.8% of the total ink, which needs to be adjusted according to the
amount of foam. Excessive addition may cause the ink fluidity to decrease or shrinkage to appear on the film surface.
Experimental verification
Before the first use, a small test is required to test the defoaming effect by measuring cylinder method, high-speed stirring
method, etc., and observe whether there are defects such as shrinkage holes on the appearance of the ink film.
3. Cooperative use suggestions
Combined with leveling agent
Defoaming agent is easy to cause shrinkage holes. It is recommended to add leveling agent at the same time to balance
the quality of the film surface.
Choose different types in stages
The grinding stage focuses on the anti-foaming effect, and the paint mixing stage emphasizes the ability to break bubbles.
The overall defoaming efficiency is improved by combined use.
4. Precautions
Storage conditions
Avoid low or high temperature environment to prevent the performance of the defoaming agent from deteriorating.
Evenly stir
After adding, the ink needs to be fully stirred to ensure that the defoaming agent is evenly dispersed to avoid excessive local
concentration.
Environmental protection requirements
Environmentally friendly defoaming agents are preferred to reduce the impact on the environment.
5. Application scenario optimization
Glass screen printing ink
If the bubbles are not eliminated in time after printing, the defoaming can be assisted by adjusting the ink fluidity or printing
speed.
Tempered glass ink
The process temperature (3-25 minutes) needs to be set according to the material and thickness of the substrate, and a gradient
temperature rise and fall method is used to reduce the generation of bubbles.
6. Common Problems
Pitting problem
If pitting occurs, the amount of defoamer can be reduced or the proportion of leveling agent can be increased.
Turbidity phenomenon
When the silicone oil in the defoamer is completely consumed or reacts with the system, it may become turbid, and the defoamer
type needs to be replaced.
Failure problem
If the defoamer has poor acid and alkali resistance, it may cause the silicone oil to decompose, and silicate needs to be added to
inhibit decomposition.
