A combination of knowledge to develop sustainable packaging from cellulose

2023-11-12

Thermoforming is the most common method for producing low-cost plastic trays, plates and containers; However, many consumers are critical of the use of plastic as a packaging material. Renewable cellulose, on the other hand, offers a solid alternative, which is why Hamer has joined forces with Beckhoff to develop a thermoforming machine for water-based cellulose pulp.
Asked about the factor that prompted Hamer to embark on such an ambitious project, Joan Ferrer, a member of the company’s electrical and software department, responds: “Concern for the environment led us to develop an ecological cellulose packaging technology and totally recyclable”. The particularity of this technology is the way in which the cellulose is dried using a specific combination of pressure and temperature. This creates dimensionally stable packaging with clearly defined contours that can adapt to the dimensions and shape of the item they contain, making them suitable for a wide range of products. “With the HP96 thermoforming machine for paper pulp, we can offer our customers for the first time a sustainable alternative to conventional plastic packaging,” says Joan Ferrer.

Hamer has developed the HP96, a thermoforming machine for sustainable packaging based on recyclable cellulose.

The process is totally respectful of the environment, both in the extraction of the raw material and in its subsequent recycling. The packaging material is biodegradable and 100% compostable, and thanks to their breathability, pulp-based trays are also suitable for fruits and vegetables. Once laminated, the material can even be used for products that must be packaged under inert gas; Since cellulose is not electrostatically charged, it can also be used to safely package electronics.

The Hamer HP96 also offers numerous advantages in terms of technology and productivity. With four cycles per minute, it performs more than double compared to comparable machines on the market, with a forming area of ​​900 × 600 mm and a forming depth of up to 100 mm. The machine can process up to 300 g of CTMP (chemothermomechanical pulp) pulp per cycle, which is equivalent to about 72 kg per hour or 576 kg per shift.

Cellulose packaging is a sustainable alternative to conventional plastic trays.

Extensive vertical integration and open automation platform

The foundations of this innovation were laid more than 40 years ago, when the Swiss Schiess family founded Hamer in the Catalan town of La Granada, at the beginning of the 1980s. Today, this company from the province of Barcelona has four decades of experience in the packaging sector. With a high level of vertical integration, the company firmly controls all processes, including design and automation technology. “This is how we can enter new markets and develop solutions in line with current needs,” confirms Joan Ferrer.

Wet fiber thermoforming, a process Hamer has developed together with Beckhoff, is the latest proof of this claim. “The development project has been a real technical challenge,” says Octavi Martí, from the sales team at the Beckhoff branch in Barcelona. The commercial relationship between both companies has been very close throughout the entire project; Furthermore, Beckhoff’s complete automation portfolio has piqued the interest of the Hamer team. Special process conditions require components offering IP65 protection, including the control panel and AM8700 servomotors, designed for the food and packaging industry with anodized housing and IP69K protection rating.

Wet fiber thermoforming for sustainable packaging

The process begins with the preparation of the fibers, which consists of mixing the basic materials with water to achieve the necessary consistency. The cellulose pulp is then transported from the main tank to the thermoforming machine through a vacuum absorption process. It is at this point that high-quality 3D molded products are created in the thermoforming mold, with sophisticated control of temperature, pressure, pressing time, vacuum and hot drying. The result of this process is a container with a high level of mechanical resistance, together with an ideal surface finish and shape. Excess production materials are returned directly to the production cycle via closed conveyors and water circuits, reducing both material consumption and disposal costs.

The project has been a real challenge not only due to the control of movement, but also due to the need to control the energy consumption of the drying and forming stations in real time. The typical consumption of an HP96 is about 140 kWh. EtherCAT EL3443 power measurement terminals are used in conjunction with SCT3215 and SCT1111 high-precision ring current transformers to record and monitor power consumption in real time. “By observing the energy and power consumption, we can easily check if everything is working correctly and how the energy consumption behaves in different working conditions,” explains Joan Ferrer.

Precise control of movement sequences and temperature regulation are essential aspects of thermoforming processes.

For this reason, Hamer relies on the AX8000 multi-axis servo system and TwinCAT 3 extensions for this machine.

The anodized housing and high IP69K protection rating of the AM8700 series servomotors offer ideal protection against the large amounts of steam and water generated.

during the process. Additionally, the One Cable Technology (OCT) of the servo motors also reduces wiring work. Other key elements for the development manager are the CP3916 control panel with IP65 protection and the TwinCAT HMI (TF2000). “Both allow intuitive control of all the processes carried out with the equipment, as well as increasing the efficiency and safety of the thermoforming machine,” says Joan Ferrer. The display is entirely based on HTML5 and is therefore platform independent; Thanks to this feature, the Hamer HMI is future-proof, as the machines can be operated from any PC or other mobile device. The TwinCAT application even allows data to be extracted from the machine in different ways; Object-oriented programming makes it easier to reuse code, and Git version management software also offers notable advantages.

There is no doubt that this project is an important milestone for Hamer, demonstrating the role that innovation and collaboration play in creating unique and effective solutions. “I am sure that our collaboration will lead to more innovative and efficient packaging solutions in the future,” says Joan Ferrer enthusiastically. “In fact, we have already identified the Beckhoff technology that we have our sights on from now on: TwinCAT Vision, TwinCAT Analytics and TwinCAT Cloud Engineering.”