Screen printing Techniques

Equipment Required to Screen Print:

STENCIL: Silk Screen consists of a frame onto which a mesh is attached under tension, usually 23 newtons+. The mesh is coated with a photosensitive emulsion or a capillary film. The artwork/image to be printed is created on a film, either being drawn by hand or by using a graphic artwork package on a desktop computer and then printed using an inkjet/laser printer. A UV light source is then used to transfer the image onto the screen.

SQUEEGEE: A flexible polyurethane blade, supplied in a variety of hardness, for waterbased 65duro, for plastisol 75duro. Blade held in a rigid aluminium or wooden handle.

INK: Can take the form of a wide range of solid pigments or dyes suspended in a fluid, binders and plasticizers.

SUBSTRATE: This is a general term for the surface that is to be printed. The surfaces can range from t-shirts to plastics.

PRINTING BASE: A firm, flat printing board otherwise known as a ‘Platten’ the board provides a surface for the substrate to be printed.

FUNCTION OF THE SQUEEGEE

In textile screen-printing the squeegee carries out two functions. It floods the stencil and brings it into contact with the substrate. The squeegee is held at an angle of typically 75 degrees to the horizontal, using a ‘D’ cut squeegee blade, or 45 degrees to the horizontal using a square cut blade.

During the printing action the squeegee is pulled across the stencil, pushing the ink through the mesh and onto the substrate. Using the appropriate angle in contact with the stencil, this is known as the “Printing Point.”

Our short flash animation shows the squeegee held at the correct angle, all the way through the pull. The screen is set at 2mm offset (aka ‘snap-off’) from the substrate, depending on the specifics of the printing job.