Screen printing has always been considered by the industry and outsiders as a traditional printing process. This may be due to its originating thousands of years ago, perhaps because it has not been replaced by current digital or computer technology. So today, we have come to understand the new squeegee technology of German SPS company known as "Heidelberg in the screen printing industry".

Each SPS STOP roller screen printer is equipped with a unique hydro-pneumatic squeegee bridge. Once this innovative technology came out, it became the object of many equipment manufacturers to imitate. But until today, no one has been able to develop technology comparable to SPS PEH squeegee technology, so it still firmly occupies the market's leading position.

During the design of the squeegee of the high-speed cylinder printing press, the biggest problem faced by engineers is how to prevent the squeegee from touching the gripper under the premise of guaranteeing the quick start of the printing press. Causes the paper to be distorted and damaged at the beginning of printing (first few centimeters), and it is also easy to print the ink to the edge of the doctor blade. The scraping knife basically needs to pass after the gripper teeth pass. Before you can start exercising - it must be fast enough to not delay the start-up time of the press.

Traditionally used in traditional printing presses is a mechanical system consisting of a cam and a roller. However, as the speed of operation of the equipment continues to increase, the deficiencies of such systems have become increasingly apparent: it mainly causes the paper to be unstable three centimeters before printing, and when the squeegee is lowered above the roller gripper , It is also easy to cause damage to the screen.

In a cam-controlled system, the squeegee blade will move downward from the turning point above the gripper and stop after a 15 mm drop. In the case of high-speed operation of the apparatus, the descending motion of the squeegee will cause the mesh to be impacted and scratch the upper surface of the gripper installed under the mesh. At higher operating speeds, the squeegee can even fall to the top of the gripper.

Another problem is caused by the physical influence of the doctor blade drive cam on the cam roller. During the downward movement of the squeegee (at the beginning of the printing), the cam control can cause a sudden movement of the cam roller, shifting certain changes to the edge of the squeegee.

In response to these problems, SPS engineers invented a hydro-pneumatic squeegee bridge that cleverly tackled the technical difficulties that have plagued the screen printing industry for many years. Although this self-made system can also keep in sync with the printing equipment, there is no mechanical connection between them.

The SPS PEH Scraper Bridge is based on characteristic engineering principles and has the following features:

A pneumatic/hydraulic combined drive is used for the squeegee blade, so fine adjustment of the downstroke of the squeegee blade can be performed. The time and speed of this drive can be adjusted as needed, and will not be affected by the kinematic relationship between the roller drive and the squeegee.

The downstroke of the squeegee begins with the turning point of the screen holder. At this point, the squeegee still has plenty of time to pass through the screen as smoothly as the "kiss" mesh, keeping the mesh clean and tidy. Once the SPS(r) STOP roller starts to rotate, the squeegee comes into contact with the substrate on the roller, behind the gripper. This step is very important. With the rotation of the printing cylinder, the printing process is started at the same time, so that the operator can better control the gap of the mouthwash and keep the printing tolerance within the minimum range.

When the squeegee falls to the surface of the drum, the accumulated pressure inside the system can be released to the screen - this power is powerful and stable, without any fluctuations. Pneumatic-hydraulic synchronous drive enables the drive to slowly return to an incompressible hydraulic pressure reducer; it is controlled by precision pressure to float at a medium height position.

Setting the squeegee pressure and keeping it stable during the printing process and adjusting the height of the squeegee are two separate tasks. As long as the squeegee is within the range of the hydraulic cushion (leaving 2-3 mm margin), the system can control the actual printing pressure through a pressure gauge or digital pressure gauge. As long as the operator defines the printing speed, the rest of the work can be done automatically by the system.

The use of this unique squeegee control system gives the user extraordinary flexibility: People can change the starting point of the printing and the blank of the mouth as needed. And different types of SPS STOP roller printers can preselect different squeegee start paths.

In addition, SPS can provide customers with other optional equipment to increase press productivity and print quality:

This fully automated system can set the height of the press when it changes the doctor (changing the squeegee parameters) so that the print edge is always parallel to the print cylinder. In addition, the system has the advantages of rapidity, accuracy, and reduced wear of the rubber squeegee during the printing process.

The SPS Cl05 (tm) squeegee (RKS is exclusively manufactured by SPS) combines the advantages of a carbon fiber squeegee with a high-quality scratch-resistant rubber. The stability of the carbon fiber allows people to better control the working angle of the squeegee. Together with the good performance of the SPS PEH squeegee bridge, users can get unparalleled printing accuracy, especially when printing fine lines and halftone dots. . If necessary, its pneumatic support can also be easily interchanged with a standard doctor blade holder.