Handling the curves

In selecting the VarioFlow, Ophthonix received a single-strand conveyor designed to meet the unique needs of the packaging, material handling, and assembly industries.

Rexroth’s VarioFlow conveyors are available in various sizes, ranging in width from 65 to 320 mm. Within that range, Bosch Rexroth offers two solutions appropriate for optical lens tray transfers: the VarioFlow 90 and VarioFlow S 100. Eagle Technologies recommended VarioFlow S 100 for its wider width and patented UltraCurve™ design.

The features of the curves in the conveying system were particularly important for the Ophthonix layout, which has 40 horizontal curves in the production line, comprising 45, 90, and 180 degrees. With traditional conveyors, a complex layout like this would be extremely difficult to implement. Even with more traditional styles of modular chain conveyors like VarioFlow 90, a complex layout can be more challenging because each tray has to wait until the previous tray clears the curve before it can enter the curve itself.

Rexroth’s UltraCurve horizontal curve technology produces minimal friction and maximum production output, and also allows trays to accumulate in curves. With a layout of this type, the curves reduce the number of drives required, thereby reducing up-front costs and overall power consumption.

Quality up, costs down

Because the entire production process is now automated, including the insertion and retrieval of the lenses within each machine, costs affiliated with staffing have been reduced.

“Most labs are loaded with carts and people and the entire process works in batches,” says Lemperle. “With the Rexroth VarioFlow conveyor system and automated equipment, there is now a constant and continuous flow. We’ve noticed our product cycle time is now approaching the process time of the equipment. Quality is improving daily, currently putting us at a 90% yield range, even though production of our lenses is more intensive. If this process was done manually, we would need more people and a facility twice as large.”