Print Process Descriptions: Printing Industry Overview: Screen Printing

Reclaiming screens involves 2 to 3 steps.

1. Remove the ink:

Any and all excess ink in the screen should be "carded off" for reuse on another job. The screen must then be washed to remove any remaining ink because the ink will interfere with the process of removing the stencil. Screen cleaning solvents are a source of VOC emissions.

2. Emulsion removal:

The stencil or emulsion is removed by spraying the screen with a solution of water and emulsion remover chemicals which is comprised mainly of sodium metaperiodate. Then rinsing the solution away with fresh water.

The emulsion remover solution should not be permitted to dry on the surface of the screen. The emulsion and remover will become virtually impossible to remove if allowed to dry. Repeated rinsing will result in excess waste water that must be disposed of as a regulated waste and will not significantly improve the situation.

3. Haze or ghost image removal:

Finally, if any haze or "ghost image" remains, a haze remover must be applied. Some haze remover products are caustic and can damage or weaken the screen. Haze removers make screens brittle and tear easily, therefore only small amounts should be used. Ghost image is a shadow of the original image that remains on the screen caused by ink or stencil caught in the threads of the screen.