Screen Room Design

Screen Room Design - How it affects exposure quality

In last month’s newsletter we discussed exposure lamps and their effect on emulsion exposure. (See ‘Exposure Lamp Comparison’). The screen room also plays an important role in exposure quality and how the screen performs on press. In most shops the screen room is given little thought other than to make it somewhat light safe to avoid exposed screens. But what about Humidity? Air Flow? Reclaiming Procedures? Sinks? Heating? Racks? Pressure Washers? All of these processes affect productivity and profits.

We go out on technical sales calls to solve exposure issues as part of our effort to sell and provide support for our emulsions. What do we encounter? The screen room was designed as an after thought to the overall layout of the production area. A good exposure unit goes a long way in achieving the ‘perfect screen’ but a poorly laid out screen room area can negate all the qualities of a good lamp. The ultimate goal is non-stop press production, few pinholes, no breakdowns on press, all of which generate better profits. A well planned screen room prevents poor exposure, standardizes the environment of the room, and leads to predictable stencil performance.

Labor Steps in the Screen Cycle:

1. Screen Cleaning - Non Screen Room Job: Keep plastisol ink out of your screen room, it contaminanates mesh, sinks, and work areas. Keep solvent wash tanks nearby but not in reclaim area. If you use water based cleaners to remove plastisol this MUST be in a separate sink from your reclaim and developing sink. Encourage your press personnel, break down crew, and screen washers to keep the frames free of plastisol. Once you allow plastisol into the reclaim, degrease, coat, and storage areas your screens will always have pinhole and fish eye problems that will decrease production yields.

2. Screen Reclaiming - Dip Tanks help keep this a non-stop process in busy shops. Four screens in a dip tank provides the needed time for the emulsion remover to work towash of the emulsion instantly. Put a new screen in every time one is taken out to keep production owing. Use a dedicated Reclaim Sink where possible. Reclaiming and Degreasing in the same sink leads to pinhole issues. If you have only one sink you MUST rinse it down thoroughly before starting to degrease. During the degreasing process splash back will occur causing the reclaim solution to bounce back onto your screen which will lead to pinholes or fish eyes later.