There are several aspects of attention to the production of steel plates for pad printing?
1. Steel plate: When the etching depth is not enough, the amount of ink adsorbed on the rubber head is less; pay attention to the depth and fineness of the graphic on the steel plate; the plane of the steel plate is placed perpendicular to the rubber head to make the rubber head evenly.
2. The rubber head: the rubber head is not good for the ink, so the plastic head should have a proper angle and shape. The loose surface of the rubber head is too soft, which will cause less ink to be absorbed.
3. Ink: The ink is too thin or transparent to affect the hiding property, so you should choose ink with high color density and ink with suitable viscosity. 4. Substrate: The surface is too oily, it is removed with alcohol before printing; the surface color is too dark, it needs to be printed twice or more; the surface is rough, you can replace the hard rubber head or replace the ink. 5. Other aspects: The squeegee is too soft, should be replaced hard, so that the steel mold groove is filled with ink; be careful to clean the stencil and squeegee before printing.
There are three points to note the pad printing process:
1. Pad printing glue is a room temperature vulcanized rubber which can be vulcanized at room temperature. The curing time depends on the amount of the curing agent. The more the curing agent is used, the faster the curing, and the weaker the tear resistance of the rubber head. However, it has a certain relationship with the temperature of the environment. The room temperature is high, and the curing agent should be reduced appropriately. When the temperature is lowered, the component should be appropriately increased; when the humidity is high, the component should also be increased. If the curing agent is added unevenly, the vulcanization effect is not good, and it is difficult to demold and is not durable.
2. The working contact surface of the plastic head cannot be cleaned in principle by using a highly corrosive solvent such as washing water or Tianna water, which greatly destroys the network structure of the molecules on the surface of the plastic head. If such a rubber head is easy to oil, the number of times of printing will be reduced. Directly affect the service life. Therefore, it is best to clean the surface of the plastic head with face water, industrial alcohol or white oil.
3. The hardness of the rubber head can be adjusted by increasing or decreasing the amount of silicone oil. The more the silicone oil is added, the softer the rubber head is. Adding more silicone oil should add more curing agent at the same time, otherwise there will be oil. If the hardness of the rubber head is below 10°, it needs to be prepared with soft glue.