One of the famous cosmetics companies in Europe is facing challenges that are brought by high labor cost for its factory in China. In the subsequent procedures of production line, most of the workers manually work on the line. For instance, the workers have to take heavy loads during packaging and stacking procedures, which as a result may cause health issues because the workers constantly turn their waist and exert heavy loads. From an economic point of view, batches of products are switching more constantly, requiring more flexible production techniques, and the current production line should be able to produce multiple types of products in large batches. Therefore, it adds new requirements to production equipment which should be easier to operate and switch, flexible to deploy, and safe to work collaboratively with workers.
Based on experiences in Europe and previous risk analyses of ergonomics, Chinese factories quickly realized that workers needed to do more manual work in the assembly and packaging stages. The stacking procedure, for example, requires workers to place each batch of boxes with different sizes on pallets. A single worker can take up to 1,000 kilograms per hour, which, if calculated on an eight-hour shift, adds to a total weight of up to 8,000 kilograms. This almost reaches the highest level of ergonomic danger level specified by our customer’s standards, and long-term work at this intensity will cause serious damage to human body. In addition, Chinese factories are finding it increasingly difficult to find workers willing to take on such a heavy workload for a long and stable shift, even after they have raised their wages by 30% in 2019. In addition, the production department often complains that staff turnover affects work efficiency and has to conduct on-site training repeatedly.
In fact, this kind of problem is common in other industries. The conventional automation solution is to replace human labor with traditional industrial robots. At the input and output sides of the production line, industrial robots are deployed to carry out stacking and unstacking operations, which are used to supply materials to the production line or transfer semi-finished products or finished products. The problem with industrial robots, however, is that once production line space utilization is taken into account, there will be some practical limitations – including limitations on factory structures such as column spacing. Once the unstacking and stacking work station designed with traditional industrial robots is deployed, its layout cannot be adjusted greatly if not completely nonadjustable. This is obviously unable to meet the needs of customers for rapid switching of multiple types of products.
Flexible and compact collaborative robots that share the workspace with people have great advantages. The standard pallet is 0.8 – 1.2m square in general, and the stomp height is below 1.8m. The robots that are fixed in space and meet the requirements of the working range will be the industrial robots that weigh hundreds of kilograms. With high weight, large volume and safety fence installation, it is difficult to adapt to the layout changes of the production line and cannot be installed in a narrow space. Although the collaborative robot’s arm span may not be able to meet the height requirements, it is light in weight and flexible in installation, and only with only lifting column, it can complete the application of stacking and unstacking without additional space and cost, thus improving the overall efficiency of the factory and workers’ working environment.
Eventually our customer chose ELITE EC612 collaborative robot (arm span 1304mm, maximum payload 12kg). In the testings, the robot runs at a speed of 50% and takes 15 seconds to pick up and put one carton. If running at full speed, it takes a total of 95 seconds to complete the stack. It is worth noting that the advantage of collaborative robot lies in that it can quickly realize the planning and debugging of robot’s motion trajectory through interactive programming and drag-and-record instruction, thus greatly shortening the project integration cycle. In practice, when the product batch is switched, the customer can quickly invoke the pre-set program and slightly tune the points to allow the robot to start working in accordance with the new stack requirements.
ELITE robots adopt standard interfaces, through IOs on flange or 485 communication interface, IOs on the control box or Ethernet; 485 communication interface can achieve the adaptation of common terminal actuators of various manufacturers in the market (including pneumatic and electric gripper, air suction, electric vacuum suction actuators). The customer was engaged in beauty industry (cosmetics), and the introduction of collaborative robots will make life and production better.