No Wasted Efforts (Web Inspection)

Web inspection's ultimate aim is to eliminate waste. How can printers maximize a system's reject reduction potential?

by Kate Tomlinson, Assistant Editor

Given the chance, what package printer would not be interested in running its presses up to 50 percent faster, while reducing waste by up to 11 percent?

According to a recent research survey of BST PRO MARK customers, the right video inspection systems make this possible, says John Thome, VP, marketing. "Sixty-five percent of the respondents said these systems allow them to significantly increase their press speeds," he says. "While the average customer said they were running about 20 percent faster, many were able to double press speeds. They also were found to have experienced significant improvements in waste and set-up time. The research clearly shows that presses with inspection systems produce a higher quality product, more efficiently."

Whether printers need to adhere to strict FDA regulations or simply turn out mass quantities, today's web inspection units can save time, money, and sanity, ultimately by reducing waste.

Waste Reduction Tactic #1: Be clear about inspection methods

Usually, 100 percent is a very definitive number, but when referring to web inspection, it can mean one of two very different things. Doug Radant, sales manager at PC Industries, explains that 100 percent inspection is a term used most often in theory. "Many people confuse this phrase with what we call 'sampling,'" he says. "One hundred percent inspection means that 100 percent of the web is being watched 100 percent of the time, as opposed to sampling, where 100 percent of a repeat is being inspected over time."

Radant says there are applications where both approaches are acceptable. Wide-web printers tend to rely on sampling because they are usually looking for repeat defects. One hundred percent inspection systems are critical in applications requiring perfection, such as in the printing of pharmaceutical labels and lottery tickets. "If a patient purchases a bottle of medicine and a critical element of the directions is missing, the situation could quickly go from bad to worse," Radant says. "These systems are especially crucial when the FDA is monitoring a printer and they are audited; that printer must be able to account for every single foot of the web."

AVT President Lance Shumaker expands on these technologies, specifying sampling systems are much better for detecting small process defects before they become print waste. "This equipment is typically much more sensitive than 100 percent inspection systems," says Shumaker. "It allows printers to identify changes on the press which may affect both quality and productivity." Shumaker explains 100 percent inspection systems will detect most larger random defects, which represent only about five percent of all printing defects. The biggest difference between sampling and 100 percent systems lies in the ability to identify a printing process problem versus a random print defect.

"Because a 100 percent inspection system will find more defects than an operator using a strobe or video system, initially, such systems could temporarily increase the amount of waste being produced," points out Ignatius Manning, president of Geiger America. "The corresponding savings at this point are more marketing-related than production-related."

Waste Reduction Tactic #2: Inspection timing, location count

Manning stresses inspection timing can be a big cost saver. "We have two prime targets," he states, "online, which means the inspection is done on press and off-line, on a slitter/rewinder/inspection machine." He notes both applications have distinct benefits and related cost reductions and savings. "Many customers looking for 100 percent inspection start in the finishing department instead of the press department. This offers the immediate benefit of allowing the printer to know that the product going out the door is done to the customer's specifications."

When it comes to the "when" of inspection, Radant believes in-line is the way to go. "Inspection on the rewinder can actually result in more waste because the damage has already been done," he contends. He explains on-press sampling takes about one minute to see 100 percent of the stored image. Once a defect is found, most systems activate a stop circuit or an alarm. Without such a system, it might take an operator several minutes to realize a problem and stop the press. "Depending on the speed of press, you could have just turned out 2,400 sq. ft.-3,600 sq. ft. of waste (in the extra time it took to be detected by manual inspection)," he concludes.

Manning believes superior quality ensurance not only eliminates customer rejects and reworks, but increases customer retention and generates new opportunities. Printers can use statistical data to implement quality control procedures which ultimately result in greater waste reduction. "We have one customer that discovered 75 percent of his waste was coming off of the same press," he recalls. "Armed with this information, remedial actions were taken to solve the problems."

Waste Reduction Tactic #3: Operator skills still factor in effectiveness

Jim Doerr, VP, sales/marketing at TruColor Video Systems, believes while inspection systems take much of the responsibility off the press operator, personnel must still be able to collect and make sense of the data. On many systems, customized parameters can be set for use alone or in conjunction with the computer's built-in parameters.

Thome notes analyzing the press waste stream is necessary in order to properly determine the best system for a press. An understanding of the root cause is an invaluable tool for determining what kind of system will be most effective.

Doerr says an inspection system's ease of use is one of the most important factors to consider when making a purchase. "This equipment is meant to simplify the press operator's job," he says. "If it complicates their day what good is it?" The operator must be able to trust that what they are seeing on the screen is accurate. "Ensure that the monitor delivers high-quality images and the processor is powerful enough to handle the job," he advises.

Thome believes converters can help themselves maximize the results they get from any video system with a few simple practices. "First, for any web larger than 7˝, don't even consider a system without a motorized traverse. Second, always get the largest possible field of view. You will end up spending a bit more, but you can be absolutely assured that the additional investment will be paid back many times over in just a short period of time."

"Installation of web inspection systems is a first step toward a quality improvement program that can have effects spanning company-wide," concludes Manning. "And hopefully, they all lead to the same place—the bottom line."