Automatic Screen Printing Machine

Overview

An automatic screen printing machine pushes ink through a stencilled mesh onto a substrate, one color at a time, on a carousel of pallets that index under fixed print heads. Where the stencil is open the ink passes through; where the photo emulsion blocks the mesh, it does not. Screen printing lays down a far thicker ink film than offset or gravure, which is why it owns garment decoration, glass and bottle printing, membrane switches, and any job needing opaque or textured deposits. Each Print Head handles one color, and the Pallet Carousel steps every substrate past all of them in turn.

The machine trades speed for deposit and versatility: it prints on flat rigid sheets and stretchy fabric alike, and a single pallet can carry a shirt through eight colors with a flash cure between each.

How it works

At a Print Head, the tensioned Screen Mesh Frame holds the stencil just above the substrate at a small gap set by the Off-Contact & Registration. The Squeegee Z Drive lowers the squeegee, which strokes across and forces ink through the open mesh; as the screen peels back off the print it snaps clean because of that off-contact gap. A flood bar then drags a fresh ink layer back over the image for the next cycle.

Between colors a Flash Dryer swings over the pallet to gel the wet ink so the next color prints cleanly on top, and the last station's UV Cure Unit fully cures UV inks. For paper, film, and thin sheets the Vacuum Hold-Down pulls the stock flat against the perforated pallet so it stays in register under the squeegee. The whole index-print-flash sequence is timed by the Control System, where the operator sets stroke speed, pressure, and dwell per color.