rezemo GmbH develops and produces innovative packaging solutions, based on 100% renewable raw materials to create alternatives for fossil plastics and aluminium, especially in the areas of disposable packaging. Our WOODEN COFFEE CAPSULE is a first impressive example that we have brought to market. It allows our customers to continue enjoying convenient coffee capsules with a clear conscience. We also allow other coffee roasters throughout Europe to use our USP on the growing coffee capsule market and join us in creating a platform for honest, sustainable disposable packaging – no microplastics, and verified 100% organic.
We use an igus dual-axis linear robot, with a D1 dryve control system, for a pick & place application with an 0-series production system on our shop floor. Within the system, our capsules are equipped with an exterior circumferential seal of natural rubber. The system has a capacity of about 43 capsules per minute. The linear robot, equipped with a vacuum gripper, removes the capsules from the dosing process and stacks them in rows on a clocked conveyor belt that then moves the stacked capsules through a drying tunnel. The entire system is controlled by a Raspberry Pi single-board computer and its GPIO signal pins. Python scripts allow us to flexibly read out a wide variety of sensor signals and control movements, including those induced by a pneumatic cylinder and those induced by DC and stepper motors.
The 0-series production system has now completed several million cycles and continues to run smoothly.
As a startup with a relatively small budget, we had significant difficulties with the conceptual design and implementation of the associated production process.
The first step is for our capsules to be cast in an injection moulding process from our wood fibre PLA compound. This composite is remarkable for its great strength, but its resilience is low. In order to maintain pressure behind the capsules and channel it into them during coffee preparation, a process during which high water pressure is applied to the capsules in the capsule machine, we needed a solution for sealing the capsules to the machine. Our competitors use aluminium capsules sealed with silicone or plastic capsules sealed with correspondingly resilient plastics. Because we wanted to remain true to our concept of 100% renewable materials (and refrain from enriching our material with fossil plastics), we needed a solution with a circumferential seal like that used with aluminium capsules – not of silicone, but of a natural material. We decided on natural rubber and then tinkered with a solution for affixing it to our capsules in an automated, reproducible process.
So began the conceptualisation of a production system that we set up little by little and whose performance we gradually enhanced. We started with completely manual capsule feed and removal in the dosing process.
During the entire development and refinement of our system, cost was a central concern. It was important to build a reliable system with as little outlay as possible. To automate capsule removal, which had until then been manual, following the dosing procedure, we chose a handling solution that was to move to several fixed points as quickly and precisely as possible with high repeatability. Integration into our existing Python-based control system was also important to us.
The igus line robot with the D1 is a good solution to this problem. The good documentation and support (which we took advantage of several times), helped us greatly in integrating the control system into the existing solution with our Raspberry Pi without having to procure an expensive superordinate control system.
Another decisive criterion was the lubrication-free handling bearing system. Our system produces consumer goods for food packaging, so it is crucial that no operating materials contact and contaminate the coffee capsules.
The low-cost automation allows us, a startup, to make the necessary investment for a production system little by little, gradually increasing our production capacity.