NEWLONG SEIMITSU KOGYO CO.,LTD.

　

Screen printing and rubber? What does that have to do with anything? This is a story with a title that makes you ask such a question. But they are very related. Rubber has an important role in screen printing.
The "squeegee" used when printing is a "spatula" made of rubber. Now apply a gentle but firm force to the paste to push it out of the screen plate.

By the way, there are many kinds of rubber. Natural rubber made from rubber trees, silicone rubber made from rocks, and synthetic rubber made from petroleum. Among them, urethane rubber, which is a member of synthetic rubber, is most commonly used as a squeegee. The characteristic of urethane rubber is that it has the highest abrasion strength among rubbers. Simply put, it is hard to remove.Therefore, it is often used for shoe soles and belts.

The squeegee is constantly rubbing against the plate when printing. Therefore, materials that are hard to wear are good. In addition, urethane rubber can withstand most organic solvents used in pastes. For these reasons, urethane rubber is the most suitable material for squeegees. But it's not perfect. It is weak against solvents such as NMP and DMF, which are called polar solvents. When immersed in this type of solvent, it swells in no time. It's like baking rice cakes. Urethane rubber cannot be used when printing paste using this polar solvent, so EPT rubber or silicon rubber is used as a squeegee. However, its wear strength is inferior to that of urethane rubber, so its service life is shortened.

Well, one day I was asked a question like this.
"I was able to print beautifully at first, but recently it's not going well."

I immediately visited the person who asked the question and saw where they were printing. Then, the edge of the squeegee I was using was crumbling. When I asked "When did you polish?", the answer was "What is polishing?"

If the edges of the squeegee are not uniform, the contact between the plate and the squeegee will be uneven, and uniform force cannot be applied to the plate, resulting in uneven printing. This person had not polished the squeegee even once since he bought it, so the edges of the squeegee were rattling and the printing was not clean. It seems that you didn't know about squeegee polishing. Therefore, our small squeegee grinder "SA-1”, and now it is printed beautifully every day.

The squeegee is the "face of screen printing" and requires careful maintenance.