Rotary Screen Printing Presses

High printing output (several 1000 prints per hour) is achieved on rotary screen printing machines.There are various designs on the market, for printing web or sheet material.

The combination of a flat screen with a sheet-guiding cylinder, that is, the flat-to-round, comes closest to classical screen printing. The sheet is taken from the feeder pile by single-sheet or stream feeders, aligned, and fed to the stationary printing cylinder.The sheet is held on the cylinder by grippers or vacuum pressure, depending on the manufacturer. Te screen and the cylinder move synchronously while the squeegee remains static. The sheet is taken over by vacuum belts, approximately 90°

downstream of the nip, and either fed through the dryer to the next printing unit or delivered.

Screen printing presses with the most varied drying and delivery systems are available on the market as single- or two-color machines and with sheet formats of up to 1.45m x 1.88m. Printing speeds of up to 3000 sheets/hour can be reached. The metal screen is exposed and developed flat.

The screen is fastened round the open cylinder by means of suspension rails and is also clamped axially. The squeegee is lifted off during printingin the area where the screen is suspended (cylinder gap). Only single- and two-color machines have so far

been made available.

Web-fed screen printing presses use closed screens that are either glued or welded together at the seam or produced as seamless rotary screens. Printing speeds of up to approximately 2m/sec. can be achieved.

A twelve-color textile printing machine is equiped with unwinder, printing section, hot-air dryer, and fan-fold delivery. Seamless rotary screens are used, so that printing can be done without gaps in the image.

The screen printing plate/stencil is produced using thermal writing heads. Special stencil material is used, on which the structure is stabilized by the fibers of the base material. This screen printing system, which digitally images stencils with high resolution (up to 600 dpi) using thermal heads directly in the machine, is used for office applications.