There are some tasks for which a machine may truly be the best man for the job.
By Johnny Shell
Most automatic coaters allow the operator to choose from a variety of settings, including independent control of the number of passes on each side of the mesh, the speed the troughs move during coating, the amount of pressure exerted at the trough edge against the mesh, and the dwell time (the amount of time the machine pauses after the troughs have been tilted to allow the emulsion to flow to the mesh before coating begins). Some manufacturers offer several coating edge radiuses to give the operator further control over stencil thickness. Many automatic coaters can store job settings to further ensure quality control for shops that use several mesh counts. Instead of a faded, torn piece of paper taped to the wall with the coating procedure for each mesh, they’re stored in the machine’s memory.
Besides their coating consistency, many automatic coaters allow you to coat two or more small- to medium-format screens at once. You’ve just improved productivity by at least 100 percent; keep in mind that the operator who simply loads the screens into the machine, selects the desired program, and pushes “Start” can walk away to handle other tasks. The machine doesn’t suffer the variable conditions that make it virtually impossible to get consistent stencils manually. Workers may get tired toward the end of the day, resulting in variances between screens coated at the beginning and end of a shift. If multiple workers coat screens in your shop, there’s a good chance that the stencil thickness on screens coated by one employee won’t be the same as those done by another.
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