URLem_06_OK

LEM Srl is a manufacturer that specializes in the production of sunglasses and ski goggles. It was established in the mid-1980s as a producer for a major eyewear company that had market outlets but no production facilities. The company has pioneered the implementation of techniques such as over-injection and the automation of processes like lens cutting and the assembly of eyewear parts. Together with this type of requirement relating simply to the production process, there has been very strong pressure from the market to cut production costs by improving workflows, which propelled LEM to look into automation. As far as production is concerned, in Italy automation plays a key role if you want to remain competitive. This is for two main reasons: first, the achieved product quality is easier to replicate and control and, no less important, the financial benefits enable you to stay in a market that is becoming increasingly competitive in terms of both production prices and sales prices. The challenge with this automation project was to achieve laser marking on this cylindrical lens. So we had to maintain a constant distance between the laser focal point, which is approximately 50 mm, and the curvature of the lens, which has a radius of about 100 mm. Automation has brought two other benefits. The first is that the workstation is now fully autonomous. Because the work cycle lasts about 3 minutes and the loader provides from 20 to 40 lenses, the workstation operates entirely unmanned for about an hour. Second, and equally important, since lens handling has been automated, the repeatability of the lens marking process has achieved a precision that would not be possible with manual handling. The requirement met by this gluing station is to apply the glue on a very precise trajectory and avoid the areas that are not glued to the frame. The operator then transfers the padding to a drying stage. We have achieved two benefits. One is the extreme precision and uniformity of glue distribution, which is therefore highly repeatable. The second benefit is the regularity of the process time: the glue has a very narrow usability window, so the gluing stage has to keep to very precise cycles that are difficult to achieve with a human operator. We are working on a mezzanine floor here, which meant there were limits on the weights that could be installed. We transported the cobot ourselves with no particular installation difficulties and it required a very lightweight structure, so there were no weight problems on the mezzanine. With this application we used a cobot to tend an injection molding press. The operation was a demanding one from the point of view of the human operator. It involves fairly heavy metallic parts which are difficult to manipulate over a period of several consecutive hours. A secondary consideration was the need to stabilize the machine cycle time. So cycle times, pressure and temperature are constant and as a result product quality has improved. We have developed a collaborative cell exploiting the ability of these cobots to work alongside the operator. The operator collaborates with the cobot at various stages, assisted by audio and visual signals that tell him when he can move close to the robot safely and when to move away and let the cobot perform the injection press operation.