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Web-Fed Screen Printing

(December 1999) posted on Mon Dec 13, 1999

The author explains how automation and flexibility make web technology a competitive option.

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By Peter Max Weber

Efficiently utilizing web material is important, as is determining the most economical printing/diecutting area. For each production day, the scheduling department is responsible for selecting the following: the amount of jobs for specific web widths (different types of web material will already be slit to the standard range of web widths) the amount of jobs with similar color sequences and ink systems (to minimize changeovers and setup times) the most profitable printing/diecutting line (the tooling cost for small- and medium-size production runs is a serious item in job-cost calculations) the necessary screen frames, squeegee/floodbar sets, inks, etc. (to minimize changeovers/setup times and maximize equipment utilization)

2. Unsupported web-loop technology

Web screen-printing equipment with "unsupported web loop" technology offers sequential makeready and setup procedures. This means that individual in-line modules are set up as the beginning of the web reaches them. After the first print station is made ready, the web advances to the next print station. While the first print station still prints at a minimum speed, the second print station can be set up. During setup of the second print station, the web material being printed at the first station will accumulate into the "loop" or buffer zone between the first and second print stations. Once the second print station is made ready, the print speed on this station can be accelerated (without changing the production speed of the first print station) until the accumulated web material is withdrawn from the "loop."

3. Elimination of run-in waste

Sequential setup procedures are efficient and virtually eliminate "run-in" waste. As a matter of fact, web screen-printing equip-ment in general produces less costly waste than automated sheet-fed cylinder presses. Because web material exhibits better stability than individual sheets, handling rolls of material is much easier than handling sheets, so spoilage is reduced. Such spoilage is imminent in sheet-fed short runs where a few sheets have to be handled quickly and often.

4. Leader web material


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