New Cure for the Headaches of In-Mold Labeling/Decorating

Travis calls it “perf-in-place labels,” and Robert Harvey, v.p. of sales and marketing for CBW Automation, calls it “precut, roll-fed IML.” The secret is delivering labels on a roll, but already die cut so that 98% of each label’s periphery is precut and the label is held in place only by narrow tabs 0.011 in. wide, three to five tabs on a side of a 3-in.-wide label. In this way, labels can be pulled out of the web easily by a robot for delivery directly to the tool, with no intermediate stacking.

InkWorks supplied perf-in-place labels as far back as six years ago, but in sheet form. A version of the new roll-fed approach was exhibited at NPE2015, where a CBW side-entry robot picked the labels out of the web and placed them in the mold (see June ’15 show report here and here). CBW’s new “standalone” unwind system for roll-fed precut labels can be integrated with the user’s choice of label- and parts-handling automation. 

Tormoen notes that while the first system was designed for a two-cavity mold, the second system is for a single cavity. The latter has simpler automation, with only a single three-axis WEMO robot, not requiring the handoff from a six-axis Fanuc robot.

O’Connor is delighted with the performance of the system, which had been running for two months at press time with zero rejects. It is unaffected by humidity or by the curl of laminated labels (which have to withstand 500 wash cycles). It has no difficulty handling thinner labels, which save money and allow for easier overmolding.

Changing labels requires a change in the CBW system’s hold-down plate and robot EOAT, but there’s no more need for a new set of label magazines with unique guarding. “This system is more flexible,” O’Connor says. “It can run three different jobs that have the same web width. We just change the hold-down and touch a button on the control to call up a new operating program. There’s less downtime and tooling cost. Before now, we had to wait for the automation change-over to run a new part. Now, we can change the automation faster than we can change the injection mold. In effect, that opens up more capacity for us.”

In addition, the robots in the system are standard, not dedicated, models, which can be used for other purposes if an IML job is not running. O’Connor concedes that the new system requires the press to stop while changing rolls of labels, unlike a cut-and-stack IML system. On the other hand, a roll holds 2000 labels, vs. 200 in a typical label stack. “So we change label rolls from twice a day to every two days, instead of refilling stacks every hour or two.”

He also notes that the new system is more expensive initially than a cut-and-stack IML system. But he considers it cost-effective, with an ROI estimated at one year or less—although CPC has shared some of the savings with its customers. “Dedicated label magazines are not cheap,” he notes. He adds that thinner labels cut costs (as does the elimination of antistat), since the label can account for half the cost of a container. What’s more, the label-on-a-roll system helps keep control in an environment of short runs of an increasing number of SKUs: “You don’t have to keep track of innumerable stacks of different labels in your shop.”

O’Connor’s bottom line is that he’d prefer to use the precut, roll-fed system for every IML job, except perhaps for a stack mold with many cavities, which might take too long for the robot to load with labels. O’Connor is talking to other customers about using the new system in parts other than medical waste bins. He sees the system as uniquely advantageous for smaller parts with smaller labels, which are more difficult to handle in precut stacks.

The labels currently used in the system are PP based, and CPC regrinds the leftover web skeleton and blends it into other PP parts (ones that are colored black). The partners are now testing polycar bonate labels for parts molded of similar resin.