Domed labels-printed or embossed labels encapsulated in a thick resin coating-are becoming increasingly popular, thanks to their trim, high-quality appearance. Traditionally associated with high-end consumer goods, they are becoming common in medical devices, home appliances and cars, as well as industrial equipment and promotional items.
When it first began manufacturing the labels, Steven Label (Santa Fe Springs, CA) contracted out its doming operations. But as demand grew, the company decided to take the job on itself in order to ensure both quality and predictability.
"In the past, doming was one of the few operations that we contracted out," says Ken Klein, Steven Label's director of engineering. "As with any subcontracted work, we had less control of lead times than we would have with an in-house operation, and this sometimes created problems for our customers."
The company purchased a PluraShot dispenser from Fluid Research Corp. (Tustin, CA), which uses a progressive cavity pump for two-part polyurethane doming resins. Steven Label also ordered a custom manifold for multilabel dispensing. The machine is equipped with a three-axis robot and programmable microprocessor that stores dispensing coordinates, shot sizes and other data for all production runs.
The PluraShot can be programmed for shot sizes from as low as 1.2 cc through continuous flow. It handles material viscosities up to 50,000 centipoise. Typical shot sizes (by weight) for Steven Label are 1 to 4 grams, depending on the specific label design. With the custom manifold, individual shots as small as 0.15 cc are possible. The unit can handle mix ratios from 1:1 to 20:1, with flow rates as low as 0.1 centimeter per second to as high as 6.0 cc per second.
According to Klein, with the manifold in place, the company can dispense from up to six points at a time using a single static mixing tip. He says this is especially advantageous when working with sheets that hold as many as 150 labels.
"Most of our domed products are between 1 and 10 square inches in size," says Klein. "But now we have the capacity to manufacture this type of label anywhere from 0.5 to 15 square inches."
To control dust and other contaminants, Steven Label built a soft-walled, environmentally controlled workspace with a filtered air supply. It also installed new shelving for curing the labels after the resin solidifies. Fluid Research designed and built two work tables for the doming area: one for the tabletop robot and dispensing machine, and a second for work in progress.
For more information on dispensing, visit www.fluidresearch.com or call 714-258-2350.