Lights, Camera, Action!
Boy, there’s a lot to inspection! In-line versus off-line, rewind versus press-mounted, the human eye versus video—these are only a few, but critical, considerations. There are various inspection systems on the market, some for use on the press, and some for use on the rewinder as the web is rewound. Each inspection system is designed to take certain actions when it detects a defect in the printed product. These defects can range from registration to incorrect characters. In addition, with brand protection emerging as a growing market niche, the ability to inspect microprinting and other security markings not visible to the naked eye is becoming even more critical to the success of a print run.
Taking action
No matter what type of inspection you employ, when a fault is detected, action is taken. Alfonse Novelli, owner, Novation, notes three possible actions:
1. The web can be automatically marked or flagged by a piece of equipment for removal of the defect at a downstream process;
2. The inspection rewinder, if running slowly enough, can be stopped at the location of the defect for removal and splicing at that time; and
3. The inspection rewinder, if running too fast to be stopped at the location of the defect, can be reversed to the location of the defect for removal and splicing at that time.
Tim Lydell, Label Vision Systems cites four actions the inspection rewinder can take when an error is detected:
1. Display the error on a monitor/notification light so the operator knows a problem was detected;
2. Activate a flagging or marking device so the error is marked for extraction in subsequent operations;
3. If it is on a printer, stop the print line and make the correction to the defective area; and
4. If it is on a rewind inspection device, it can stop the rewinder and reposition the defect at the cut table so it can be corrected as needed.
Brian Ivens, manager of sales and marketing for Arpeco, states that, “Most finishing machines provide several functions [like inspection, slitting, counting, and rewinding] at the same time to maximize throughput and minimize the number of passes that the product must go through.” According to Ivens, when slitting and rewinding, it is undesirable to reverse the web direction because of potential slitting inaccuracies, so most machines that perform these functions are unidirectional. “On a typical unidirecitonal machine, traveling at speeds of up to 1,000 fpm, when an error is detected the machine slows down and forward-places the fault to a position suited for operator correction,” he says. However, after the operator makes the necessary corrections, the web is not reinspected, leaving potential errors, which may have been missed by the operator, on the finished roll and shipped to the customer. “For some products, this is not a problem,” Ivens adds.” But for pharmaceutical or the security or high value-added products, these errors are unacceptable.”
With forward placement, when a system detects a defect, it signals the rewinder. “The rewinder slows and places the defect accurately in the repair area,” says Ernest Schneider, business development manager, Erhardt+Leimer. “When the operator is finished, he restarts the machine and the web continues to move forward.” Reverse placement, on the other hand, is used on rewinders that support reinspection. “In this mode, when a defect is detected and the signal is given, the machine stops and then reverses the web to the repair area where the defect is accurately [positioned],” says Schneider. “When the operator is finished and restarts the machine, the web moves forward to the inspction system where it is reinspected. If everything is okay, the machine returns to run speed. If there is still a defect present, the signal causes the machine to stop and reverse the web back to the repair area. This way, no defects can pass the inspection area undetected.”
Some in-line systems can be used on both the rewinder and/or on a press. For instance, EyeC-America’s president, Juergen Klicker, cites the following possible combinations of his company’s in-line systems:
• 100 percent inspection in full color on the press, no inspection on the rewinder;
• 100 percent inspection in full color on the press, finishing manager software on the rewinder. Additional control equipment on the rewinder allows importation of inspection results from a press-mounted device to stop the rewinder at those positions where the press-mounted inspection device has found problems;
• 100 percent inspection in full color on the press, a finishing manager on the rewinder, and a quality manager in between. Additional software here allows users to edit a result list to eliminate unwanted stopping where deviations are considered acceptable;
• 100 percent inspection in full color on the rewinder, no inspection on the press; and
• 100 percent inspection in full color on the press, 100 percent inspection in grayscale on the rewinder.
An emerging approach to inspection is 100 percent inspection on rewinders. “The packaging 100 percent inspection solution on rewinders is relatively young as in the packaging industry automatic inspection is traditionally placed online,” says Doron Aspir, AVT’s marketing manager/packaging. “While there are technology challenges in meeting adequate detection capabilities and required supporting operations tools to accommodate high-speed operation and roll dimensions, advanced automatic inspection solutions are answering these challenges and are being implemented in packaging applications. We experienced a dramatic rise in the demand for automatic inspection and expect it to continue growing in the next few years.”
John Thome, general manager, BST Pro Mark, reminds converters that there is also the question of cost savings involved with an inspection system, and notes four elements: the cost of waste, the cost of reruns, the cost of customer returns and credits, and the cost of losing and replacing a customer. “All four of these elements should be considered when considering the purchase of a 100 percent inspection system,” says Thome.
To help you make decide what inspection/rewind system to use, packagePRINTING collected the following samples of various systems.
Slitter inspection rewinders
AB Graphic International manufactures the Omega SR range of slitter inspection rewinders, which are available in 10˝, 13˝ and 16˝ web widths. Basic models include scissor slitting, programmable end-of-roll stop, and unwind brake control without the use of a mechanical follow arm. The electronic web guide system with ultrasonic sensor is suitable for opaque and clear substrates. —A B Graphic International, www.abgintusa.com
Inspection slitter/rewinder
The PREMIER-SD 20/20 combines multi-motor, servo-drive web-transport technology with a patented Shuttle Retrieval system to provide bidirectional inspection, fault editing, and reinspection of high value-added or security-sensitive products—all in a single pass. —Arpeco, www.arpeco.com
QA for finishing equipment
PrintVision/Apollo is a direct solution for 100 percent quality assurance (QA) from press through post-press stages. Automatic defect detection in quality assurance means users catch all defects occurring on the material before they become an expensive problems or customer rejects. Quality assurance traces all defects and marks them for further handling. —AVT, www.avt-inc.com
WebEye vision system
This system provides visual inspection of a printing process by capturing and displaying a video image. It monitors print quality at web speeds of up to 500 fpm and displays a high-quality color image on a video monitor. No external computer is required, and it monitors print registration marks, diecut placement, print quality, and color consistency. —Development Solutions, Inc., www.dsiatl.com
Print Inspection
The NYSCAN product line offers a complete solution for print inspection from prepress through to off-press finishing. Inspector:2 for prepress is geared to comparing the image captured by Web:Inspector:2 on the press during job setup against the approved PDF in prepress.
Two products are available for off-press finishing: for applications requiring 100 percent inspection just prior to roll closure, Web:Inspector:2 can be fitted to any available finishing machine. Where production throughput is critical and inspection on the press is the focus for profit maximization, the company offers Roll:Scheduler:1. —Erhardt+Leimer, www.erhardt-leimer.com
Video inspection system
Fife’s low-cost, compact video web inspection system helps operators quickly detect and respond to printing errors. The InPrint Video Web Inspection system delivers an increased field of view, reduced glare when viewing reflective materials, and additional software features to help operators quickly identify and respond to printing defects. Advanced strobe technology includes a diffuser to allow better disbursement of light over the printed area of the web, eliminating glare when working with foil, metallic inks, and other reflective materials. —Fife Corp., www.fife.com
E-Pedigree-compliant inspection
The LVS 7000 is E-Pedigree compliant. It validates number sequences and bar codes, verifies linear and matrix bar codes to ISO standards, assures no duplicates, and checks for GS1 Data Matrix structure. All of this is accomplished in line at the press or rewinder line speeds. 100 percent inspection of the printed image is possible as print defects (blemishes) and human-readable text can also be inspected at the same time.—Label Vision Systems, www.lvs-inc.com
Inspection security solutions
SPI is a single-pass inspection system for the automated high-speed verification and certification of labels for security-sensitive industries, including pharmaceuticals. DPI is a dual-pass URC-G-3-controlled web processing machine for the automatic, high-speed verification and certification of labels for security-sensitive industries including pharmaceuticals. —Rotoflex, www.rotoflex.com
Flexible format rewinders
Features of these flexible format rewinders include, 18˝/457-mm rewind, motor-driven; 3˝/76-mm rewind shaft; 28˝/711-mm unwind; 3˝/76-mm unwind shaft; motor-driven unwind; Printrack Master Controller with touch screen; fixed-shear slitting with three knives; 10˝/254-mm draw roll, inside/outside rewind; electronic edge guiding; fixed horizontal inspection table; unwind and fault splicing stations; and spare parts package. —Scantech Automation, www.scantechautomation.com
In-line inspection
With EyeC ProofRunner™, users get automatic 100 percent inspection of all items across the web and content verification against a customer proof, as well as mix-up prevention—right on the press or on a rewinder. Inspection results are instantly available and can be used for immediate corrective action. This gives users the means to completely control and monitor their printing procesess and to avoid scrap.—EyeC America, LLC, www.eyec-america.com
Inspection rewinder
The VSR100 slits and finishes pressure-sensitive rolls. The VSR100 meets the web processing needs for standard label printing and converting. Features include: 13˝/330-mm and 17˝/432-mm widths, 750-fpm (230-m/min) speed, automatic web guide, roll-end stop, large 18˝/457 mm unwind capacity, automatic unwind tension control, rotary sheer slitter, and magnetic particle brake. —Mark Andy, www.markandy.com
Foil roll slitting solution
FoilSR is a low-cost solution for slitting rolls of foil to any width in minutes. FoilSR will slit most foils and film materials including hot stamping foils. It will slit web widths of 24˝ to 84˝, and materials to 1/2˝ minimum width. Other features include drop-in unwind shaft, razor blade comb, ability to rewind up to 14˝ and unwind up to 24˝, pneumatic brake or optional drag brake, and automatic tension control. —Pinnacle Converting, www.pinnacleconverting.com
Remote control for web flagging
Novation, Inc. added a remote control option for its AF2 Automatic High Speed WebFlagger. The handheld pushbutton station can be carried by an operator and will signal the AF2 WebFlagger to safely apply a flag to webs moving at speeds greater than 2500 fpm from up to 300 feet away. The remote control option can be supplied as an option on new AF2 WebFlaggers or added in the field as a retrofit. —Novation, www.novation-inc.com
