Inspection Rewinds Yield Press Productivity

By performing off line inspection and various finishing functions, inspection rewinders allow presses to focus on printing.

INSPECTION REWINDS HAVE one primary purpose—increase press productivity. Although inspection rewind is an off-line operation, it all goes back to printing press uptime and productivity.

"Off-line rewinding equipment should increase productivity in a label shop by taking work off of printing presses," says Nick Knezic, applications engineering, KOR Engineering Inc. "A good quality-finishing machine should perform all inspection, editing, and slitting operations, allowing press operators to focus on the task of printing. By increasing press time, rewinders increase productivity in a shop, which translates into a healthier bottom line."

Jaime A. Dagnino, international sales manager for Arpeco, a Division of Precision Automation, Co. Inc., separates the productivity benefits obtained from inspection rewind into the different process enhancements it provides.

"In the printing process, it allows for improvements in web optimization, increases in printing speeds, reduction in roll change frequency, and decreases in operating costs. In the finishing process, it allows for the removal of defects, while performing finishing functions of count, slitting, and rewinding at speeds over 930 fpm (approximately two to three times faster than press speeds). In the inspection process, it allows for dedicated focus on quality control prior to product shipment to customer."

Rewind selections

There are numerous options available in inspection rewind systems for both the inspection functions and the conventional finishing functions they perform. Inspection options offered by Arpeco include stroboscope visual inspection, automatic missing label/matrix detection, automatic flag and millsplice detection, and integration of the latest vision inspection systems.

For improved finishing productivity, Dagnino points out features such as hydraulic roll lifts for ease of roll loading, removable cartridge shear slitting for fast job setup, web advance unit for fast roll cycle change, easy access nip rollers and sophisticated tension control systems.

At Labelexpo, Arpeco will display its Tracker Premier inspection rewind system. This rewinder handles diameters of up to 30˝ in web widths of 13˝ and 16˝. Options include core label imprinting, choice of web guides, single-station diecutter, matrix/missing label detection, hydraulic roll lifter, and a 24˝ rewind diameter.

At KOR Engineering, versatility is a key feature built into its rewinders, says Knezic. He highlights the capability for quick changeovers of slitting technologies (rotary shear, razor, crush cut, etc.) to handle a variety of jobs; rewind shafts of various sizes for quick interchanged as core requirements change; and closed-loop tension controls for winding a broad range of substrates.

KOR's SR1-350 Inspection Slitter/Rewinder is designed for narrow-web applications using pressure-sensitive labels and unsupported films. It is available for 13.75˝, 16.75˝, and 20.75˝ web widths, with a 30˝ unwind and 20˝ rewind capability.

Rotoflex has a line of inspection slitter/rewinders ranging from the smaller VSI series to the larger, more sophisticated VLI and VLI eDRIVE models. The VLI series is available in six models handling from 10.25˝ web widths to 28˝ widths and with unwind diameters up to 40˝ and rewind diameters to 24˝. Rotoflex offers a long list of available options to tailor the VLI series for the application. These include shear, crush, or razor knife slitting; semi-automatic two-spindle turret; roll lift; flag/millsplice detector; missing label/matrix detection; strobe light; auto tension control; and diecutting station.

For table model rewind and inspection machines, Web Techniques offers its WT-25 Series. The WT-25LCI offers a synchronizes strobe light or high-speed visual inspection and a photoelectric counting system that allows it to be used for pharmaceutical roll label printing and packaging industries where label count reconciliation is required. It also has options for the integration of a camera or bar code reader for automatic inspection, and missing label or unremoved matrix detection.

Development trends

Both Knezic and Dagnino mentioned two trends that will impact the development efforts for inspection rewind equipment—thinner film substrates and digital inspection.

The printing and processing of film substrates has become commonplace in label shops, says Knezic. "Filmic labels and unsupported films present many challenges for the average converter familiar with traditional paper labels, mainly in the areas of web handling and slitting. Today's rewinders must be capable of running these challenging substrates in addition to traditional label jobs."

On the inspection side, "improvements in vision systems are expected to continue," says Dagnino. "As technology costs decrease, on-press vision systems and electronic flagging systems (for off-line correction) will become more prevalent."

By Tom Polishuk

Editor-In-Chief