Silk Screen Printing Basics Part 2

Textile items printed with multi-color designs often use a wet on wet technique, or colors dried while on the press, while graphic items are allowed to dry between colors that are then printed with another silkscreen and often in a different color after the product is re-aligned on the press.There are three common types of screen-printing presses. The flat-bed ‘,’ cylinder and the most widely used type, the ‘rotary’.[8]

Screen After Cleaning

The silkscreen can be re-used after cleaning. However if the design is no longer needed, then the screen can be “reclaimed”; that is, cleared of every emulsion and used again. The reclaiming process involves removing the ink from the silk screen then spraying on a stencil remover. Stencil removers come in the form of liquids, gels, or powders. The powdered types have to be mixed with water before use, and so can be considered to belong to the liquid category. After applying the stencil remover, the emulsion must be washed out using a pressure washer.

Screen Printing Basics

Most silk screens are ready for recoating at this stage, but sometimes screens will have to undergo a further step in the reclaiming process called dehazing. This additional step removes haze or “ghost images” left behind in the screen once the emulsion has been removed. Ghost images tend to faintly outline the open areas of previous stencils, hence the name. They are the result of ink residue trapped in the mesh, often in the knuckles of the mesh (the points where threads cross).[13]

While the public thinks of garments in conjunction with screen-printing, the technique is used on tens of thousands of items, including decals, clock and watch faces, balloons, and many other products. The technique has still been adapted for more advanced uses, such as laying down conductors plus resistors in multi-layer circuits using thin ceramic layers as the substrate.