Inspection of plexiglass print quality
Plexiglass craft products silk screen processing only the following four functions of plastic scraping to play well in order to print out the quality of plexiglass handicrafts. And the physical performance of the scraper on the above functions play a decisive role. (For example, a high hardness of the plastic scraping can be very good scraping excess ink, but can not well meet the requirements of a variety of different plexiglass products). Therefore, in the choice of plastic scraping, to take full account of the impact of scraping performance factors, to avoid the adverse effects on the printing effect. In choosing the appropriate performance of the plastic scraping, the need to consider the following four factors:
1. Hardness: plastic scraping is usually made of polyurethane, with a hardness tester to measure the hardness of rubber scraping. The hardness, size and scraper shape of the scraper determines the bendability, flexibility and pressure of the squeegee. Hardness range from 55 degrees to 90 degrees (Shore A). The hardness value is measured with a Shore A durometer. 55A-65A is a low hard plastic scraping, 66A-75A is hard, more than 75A is hard and hard
The high hardness stopper is very advantageous for the first three functions of the squeegee, pressing the ink into the screen and transferring the ink from the fine stencil to the substrate and keeping the wire in contact with the plexiglass plate. The only drawback of high hardness glue can not meet the printing of different shapes of plexiglass products, in the printing rough surface and uneven surface of the plastic scraping the quality requirements are also high.
2. Effective width: refers to the plastic scraping into the aluminum handle, from the aluminum handle out of the plastic scraping width. This width is important and determines the curvature of the squeegee under pressure. Curvature is the effective width of the cubic value. Such as twice the effective width of the bend is greater than 23 degrees.
The squeegee will cause two changes: the angle between the squeegee and the screen changes; the printing pressure delivered to the plexiglass product is reduced. For example, the plastic scraping compared to a group of springs, when the spring into a certain angle force, the spring began to bend, the transmission of the force is getting smaller and smaller. Rubber scraping printing angle is reduced, the printing pressure is insufficient, the printing effect is not ideal. Printing angle is small, the printing pressure is reduced, the amount of ink under the ink layer thickening. (In this case, the printing operator will increase the printing pressure, plastic pad bending increase, the ink layer is still not ideal. The solution is to increase the hardness of plastic scraping, plastic scraping angle increases.) This is the effective squeegee The effect of width on the four functions of glue scraping.
Usually the effective width of the squeegee between 20MM to 30MM. The choice of the best effective width is based on the flatness of the plexiglass product, the resolution of the screen image and other printing parameters such as the angle of scraping, the speed and the type of ink. In the smooth / smooth substrate printed on the high resolution of the image, the effective width of small (less than 20MM), high hard, with the appropriate ink for fast printing. In the uneven, rough plexiglass, the effective width to increase (sometimes the big son 30MM), hardness reduction, and low hardness glue to adapt to poor ability, not excessive bending, you can also use the middle of the hard three sides of the soft or two Layer scraping. In general, the effective width is increased, the printing speed is reduced and the printing angle is increased.
