Eyecare products require to be manufactured with well controlled surface finishes and accuracies. Handling such products requires precision engineering and world-class automation.
On this project, SP Automation & Robotics was tasked with designing a machine to pad print features on an eye care product at high speed.
The main challenge was to provide a fully automatic printing, curing and inspection system which could operate at a speed of 200 parts per minute,
Many handling technologies were considered. However, a rotary indexing system gave the best balance of functionality and compactness.
The requirements of the machine were as follows:
The system was designed around a 16-station rotary indexing system with cassette handling conveyors, pad printing modules and vision inspection stations positioned around the periphery of the machine. The product was fed into the machine in banks of multiple parts on trays, with the trays being fed in on cassettes or towers.
The trays escaped from the cassette and were picked and placed onto the indexer. The product was made up of two halves and separated, with one half parked on a bank of secondary locations on the indexer. The products were then pad printed over two stations. The pad-printed products were then indexed to a station where banks of UV lamps were used to cure the ink.
A vision system, mounted to a servo-driven X-Y gantry, then inspected all 36 of the products to ensure that the print was present and was of acceptable quality. Any products that failed the vision inspection were ejected from the indexing system using a pick and place into a segregated collection area.
The remaining ‘good’ product was then coupled back together with its mating half. The printed products were then transferred back to their respective cassettes before being conveyed back out of the machine.
