WLS, a ProMach brand, introduced an innovative height-adjustable labeling option for its popular VR-72 labeler. This first-of-its-kind solution automatically adjusts the height of the conveyor, and thus the containers, to effectively change the label height right at the point of application when conditions call for it. The high-speed VR-72 can be programmed for a label height for one entire batch or programmed to dynamically adjust the height of each label applied.
When equipped with the height-adjustable labeling option, the VR-72 primarily runs vials and bottles containing liquid pharmaceuticals, biotech products, nutraceuticals, personal care products, cosmetics, and other consumer goods. According to WLS sales engineer Harry Anderson, there are a couple of scenarios where this heigh-adjustable capability is useful. One scenario might involve an injectable drug product that must be administered in varying concentrations. For Batch A the health professional or consumer may need to add some other solution to a fill line, preprinted on the label, that is exactly X millimeters from the bottom of the vial. But for Batch B, that solution must be added to a fill line that is Y millimeters from the bottom of the vial. Without the adjustable-conveyor feature, two different labels would have to be inventoried, one printed with a fill line for Batch A and one printed with a fill line for Batch B. But with the height-adjustable menu-driven VR-72, the same label can be used for both batches and still the fill line will be exactly where it needs to be for both batches. Not only does that reduce cost, it simplifies inventory and improves production efficiencies.
Another scenario has more to do with how consistent the placement of a pressure-sensitive label is on its release liner. Where the label is positioned on the release liner may be different in the middle of a reel of labels than it is at the beginning or end. The new feature on the VR-72 lets the conveyor dynamically adjust to compensate for these inconsistencies so that every label is applied accurately.
Anderson says the adjustable-height function is suitable for speeds to 200 containers/min. He emphasizes that the only portion of the flex link tabletop chain conveyor that gets adjusted is the section right at the vacuum drum that actually receives the label from the release liner and applies it to the container. “While the label is on that drum we have a vision system detecting where the bottom of the label is on the drum,” says Anderson. “Once we know where the bottom of the label is, that data is sent to a linear motor that determines if any adjustment in conveyor height is needed.” The vision system on the labeler demonstrated at PACK EXPO Las Vegas was from Cognex and the linear motor was provided by Linmot.
“This is the only labeler in the world that moves the conveyor, not the label web, to adjust the label height,” says Lisa Propati, vice president and general manager of WLS. “The problem with traditional height-adjustable labeling systems is that, once you’ve established the perfect roll, pitch, and yaw, you don’t want to touch the labeling mechanism – it’s too risky. Our solution to preserving labeling repeatability and precision is to adjust the container height instead of the label web. We developed this in response to a specific customer request. They asked for a high-speed, height-adjustable labeler that was more reliable and more accurate than any existing technology – and we delivered.”
