The viscosity control of screen printing silicone needs to be achieved through diluent adjustment, ambient temperature management, mechanical stirring, thickener addition and other methods, and needs to be combined with viscometer monitoring and storage conditions optimization. The following is a specific description:
1. Viscosity adjustment method
Adding and subtracting diluent:
Diluent is a direct means of adjusting viscosity. Increasing the amount of diluent will reduce the viscosity of silicone, and vice versa. It needs to be added in proportion according to actual needs to avoid excessive damage to the performance of silicone.
Adjusting ambient temperature:
Temperature has a significant effect on the viscosity of silicone. When the temperature rises, the molecular movement speeds up and the viscosity decreases; when the temperature decreases, the viscosity increases. By controlling the ambient temperature, the viscosity of silicone can be indirectly adjusted.
Stirring:
Mechanical stirring can evenly disperse the solid particles in the silicone, destroy the network structure, and reduce the viscosity. The stirring time and speed need to be adjusted according to the amount of silicone and the viscosity requirements.
Adding thickener:
When the viscosity of silicone is too low, thickener can be added to increase the viscosity. The selection and dosage of thickeners need to be determined according to the type of silicone and process requirements.
Using viscometer:
Viscometer is a tool for accurately measuring the viscosity of silicone. By measuring the viscosity value regularly, the amount of diluent or thickener can be adjusted in time to ensure stable viscosity.
2. Notes on viscosity control
Storage conditions:
Silicone should be stored in a cool, dry, light-proof environment to avoid high temperature and humidity that may cause viscosity changes. At the same time, pay attention to the storage period to avoid expired use.
Mixing uniformity:
When adding diluents, thickeners or stirring, ensure that the silicone is mixed evenly to avoid local viscosity differences affecting the printing effect.
Printing process stability:
During the printing process, the downtime should be minimized to keep the viscosity of the silicone stable. If downtime is required, measures should be taken to prevent the silicone from solidifying or viscosity changes.