Silk screen silicone will become thicker after being stored for a long time, which is mainly caused by the evaporation of water in the silicone. The following is a detailed analysis of the problem:
1. Cause
Water evaporation:
A certain amount of water will be added to the silicone during the production process to facilitate the long-term storage of the silicone and maintain its fluidity. However, during long-term storage, especially if the storage environment is not sealed or the temperature is high, the water in the silicone will gradually evaporate.
The evaporation of water will cause the viscosity of the silicone to increase, the fluidity to deteriorate, and even clumping may occur.
Silicone type:
Silk screen silicone is usually divided into condensation type and addition type. These two types of silicone will have problems of increased viscosity and deteriorated fluidity when lacking water.
When condensation type silicone lacks water, not only will the viscosity increase, but it may also appear dry on the surface but not dry inside, because condensation type silicone solidifies by absorbing water.
When addition type silicone lacks water, it is also easy to increase viscosity and produce precipitation problems.
2. Solution
Add Diluents:
For silk screen silicone that has become thick, you can try to add an appropriate amount of diluents and stir evenly to restore its fluidity. However, it should be noted that the amount of diluents added should be appropriate. Too much or too little may affect the performance of the silicone.
Electric stirring:
After adding diluents, using an electric stirrer for high-speed stirring can more effectively restore the fluidity of the silicone. Especially for addition-type liquid silicone, stirring can redisperse the sediment in it evenly.
Improve storage conditions:
In order to prevent the silicone from thickening during storage, the storage conditions should be improved. For example, store the silicone in a cool, ventilated, and dry environment, and ensure the sealing of the storage container.
In addition, you can also consider storing the silicone in a constant temperature box to maintain a suitable temperature and humidity.
3. Preventive measures
Regular inspection:
Regularly inspect the stored silk-screen silicone to detect and deal with the thickened silicone in time.
Pay attention to the shelf life:
Pay attention to the shelf life of the silicone and use it up within the shelf life. If the silicone has expired or is close to expiration, it should be used with caution or necessary treatment should be carried out.
Correct storage:
According to the storage requirements of silicone, store the silicone correctly and avoid long-term exposure to high temperature, humidity or direct sunlight.
In summary, the thickening of screen printing silicone after long-term storage is mainly caused by water evaporation. This problem can be effectively solved and prevented by adding an appropriate amount of diluents, stirring with an electric stirrer, improving storage conditions, and taking preventive measures.