Pentik, the northernmost ceramic factory in the world, located in Posio, Finland, wanted to automate its high mix/low volume production without losing its craftsman identity. The company chose two UR10 collaborative robots from Universal Robots to replace the heavy, repetitive tasks of glazing and molding tableware, ensuring a uniform outcome that also improves the ergonomics of Pentik’s employees. The cobots now work in tandem with humans, delivering the same touch of human handicraft as before, while increasing the work efficiency at the workstation tenfold.
Nearly all ceramic factories in Western countries have moved their mass production to low-cost regions. Ceramic artist Anu Pentik who founded Pentik in 1971 proudly defends craftsmanship. His company wanted to swim against the tide by creating all its ceramic products in Posio, a Finnish municipality located only a few kilometers south of the Arctic Circle.
The making of ceramics is manual labor. When a worker glazes tableware and shape dishes with a tool, they will repeat the same task hundreds of times a day. Tasks that are hard on the hands, shoulders and backs of the workers.
Pentik wanted to find a solution that enabled production automation while utilizing experienced employees’ skills for tasks of higher added value such as quality control. Freeing up workers from having to perform ergonomically unfriendly, monotonous tasks would also improve the employer’s image.
There are over a thousand Pentik ceramics designs with low production numbers. A traditional industrial robot was therefore not a viable solution as they usually stay bolted down in caged cells, dedicated to one task only. Pentik makes its tableware out of English clay. The material is like dried plasticine (putty-like modelling material). Before firing, the pieces are fragile. The automated machinery must be gentle in its work, and must be able to repeat its movements as identically as possible. Even the smallest indentations or depressions made at the start of the process can render an item second-rate, as firing only exacerbates any mistakes. The collaborative robot meets these requirements well.
Pentik started developing the cobot applications with Oulu University of Applied Sciences (Oamk). The then project engineer of Oamk and current factory manager of Pentik, Lassi Kaivosoja directed the students in designing two collaborative robot cells for glazing and shaping the tableware. The first cobot, the UR10e cobot forms “dents” into tableware plates. The signature of the Kallio plate is its uneven edges, which were difficult to make by hand. Kaivosoja designed the cobot to do this work instead.
Lassi Kaivosoja, Factory manager, Pentik
By introducing the cobot to automate some of the more ergonomically demanding and repeatable production tasks, the company is able to maintain its tradition and improve throughput.
The dents are made using two 40 mm wet orbital sanding sponges. In the plate finishing cell, the cobot picks up the tableware from an automatic moulding line, and then - depending on the product - the robot places it up against either a horizontal or vertical sanding sponge used for forming. According to Lassi Kaivosoja, the greatest challenge was to pinpoint the accurate pressure in order for the cobot to produce the desired form when working with clay.
Sanding sponges are springy, so their pressure is not monitored. With a bit of testing the programmer got it adjusted to the needed pressure for Pentik’s creamics production. The vacuum grippers include a motor with a bevel gearbox and a pneumatic slip ring. These enable the unlimited and programmable rotation of the suction cup.
The second UR10 cobot, is focused on glazing the tableware. The tableware is dipped in glaze, which gives the item a hard and shiny coating when fired.
Before the arrival of the cobot, this part of the process was done by a human. The tableware made by the cobots needed to retain the hallmarks of being made by hand. The robot picks up the item from the tray with a self-made vacuum gripper. The tray has a sensor that ensures that the item is in place. The vacuum is created by a smart vacuum ejector. It detects the strength of the vacuum and turns off suction automatically when the desired vacuum has been achieved.
The cobot lowers the pieces of ceramics into the glazing mixture. After dipping the item, the robot places it on one of two deposit points. If the deposit points are full, the robot will wait. “The cobot imitates the movements of hands of Inkeri, a beloved worker who was responsible for this process for 30 years,” Kaivosoja explains.
An employee takes the piece from the deposit point and checks its quality. They wipe away excess glaze from the bottom of the piece so that it does not get stuck to the firing equipment. Finally, the employee places the ceramic piece onto a cart to await firing in the kiln. After the piece is fired, it has a hard, durable surface.
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