The author explains how automation and flexibility make web technology a competitive option.
4. Initial web-line configurations can always be changed, and additional modules (printing station, dryers, etc.) can be added at any time. On a single-color web line, additional colors can be printed by reintroducing the web for each subsequent color. Once the technology of web processing has been successfully "digested" by the production staff, other print stations or manufacturing modules can easily be added.
5. Individual web screen-printing lines can be operated separately or can be connected with each other to benefit from additional in-line print stations. For example, two two-color print lines can produce two separate jobs, or, if connected with each other, can print one four-color job. Connecting two separate web lines is easily accomplished by threading the web material accordingly.
6. One web screen-printing line or separate web lines can feed a separate and self-contained finishing line that can incorporate processes such as top or bottom laminating, embossing, hot-foil stamping, diecutting with steel rules or hard tools, waste removal, slitting, and sheeting. Setup of screen-printing stations takes only 5-10 min; finishing stations require setup times of 1 hr or more. This is an important reason to keep screen printing separated from finishing, if possible.
7. Sequential makeready and setup, as previously described, make these processes more efficient.
8. Registration capability and print quality is equal if not better than comparable sheet-fed, high-speed screen-printing methods.
9. Net production is faster than with comparable sheet-fed, high-speed screen-printing methods, especially when considering handling and finishing requirements.
10. One operator and one assistant are usually all that is needed to operate a single or multicolor web line.
11. The finished product can be sold in roll or sheet form--a flexibility that will never be available to sheet-fed printing. (Thus, printed roll material can be finished on either web-fed or sheet-fed finishing equipment, another important example of web flexibility.) Automating supporting processes
Introducing a higher level of automation in the form of web screen printing and finishing requires a serious look at supporting areas such as screenmaking. Under a complete process philosophy that includes process control and effective process management, making screens uniformly and consistently becomes a necessity. Automation is available for a number of other procedures, which will further enhance the automation of the screen-printing process: Automatic screen coating guarantees uniform emulsion thickness. Computer-to-screen imaging technology eliminates film positives and their related shortcomings. Automatic screen washing, reclaiming, and developing guarantees uniformity, consistency, and savings in solvent and fresh water usage. Web: The way of the future
Web screen printing, applied intelligently and correctly, will be the next wave of automation. For many applications, it provides a means of retaining screen printing as a viable production method that can successfully compete with electrostatic and other forms of digital printing. Turnaround times for web screen printing are extremely fast; the print quality is much better than comparable digital or related print technologies; climate, chemical, and mechanical resistance is unequaled; and most importantly--the production flexibility that web manufacturing offers will remain a strong sales advantage for a long time to come. With filmless screenmaking and other automated support processes, the cost factor per square foot of web screen printing will be half or less compared with electrostatic printing. This competitiveness of web screen printing offers a positive outlook for the future of our industry--at last.
About the author
Educated in Switzerland, Peter Max Weber began his screen-printing career 20 years ago as sales manager for a US distributor of screen-printing equipment. For the last 14 years, he has been president and co-owner of Fineline, Ronkonkoma, NY, a supplier of European-made screen-printing equipment. Weber specializes in all aspects of automation for both sheet- and web-fed screen printing, screenmaking/prepress procedures, and post-press processes.
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