Packaging manufacturers are increasingly using mono-materials, as they are easier to recycle than packaging made from multiple materials. However, it is a challenge to process mono-materials in a limited processing window and to reliably bond them together. The German Dresden-based start-up Watttron has developed cera2seal, a digital heating system that enables consistent sealing in packaging machines through the targeted use of heat. The system also saves energy in production.

This week, Watttron presented its digital heat seal system for packaging to a specialist audience and journalists at its in-house factory event in Freital on the occasion of the Dresden Packaging Conference, December 5-6. The cera2seal system was presented in operation on several packaging machines including Grunwald and Velteko, demonstrating that the precise sealing of yogurt lids and stand-up pouches is possible with the watttron technology.

Cooperation partner FormerFab from Freital demonstrated an innovative process: Horizontal forming shoulders for packaging machines, which ensure that the plastic film is optimally positioned before sealing, eliminating manual adjustments and package wrinkles.

50 percent energy saving and return on investment in six months

The targeted temperature control in the cera2seal system enables up to 50 percent energy savings compared with the conventional method, which, like a hot iron, has one uniform temperature setting causing unnecessary, residual heat. Because the heat is applied precisely and only to the required area of the sealing surface, significant energy savings result.

“We expect some 30 percent compensation of productivity losses. Our precise process reduces both product and packaging waste as well as lost labor. The retrofit version could offer a return in just six months, depending on the volume,” said Dr. Sascha Bach, Chief Technology Officer at Watttron.

Digital heat sealing suitable for mono-materials

Mono-materials such as polyethylene (PE) or polypropylene (PP) are increasingly used for packaging. Although these are more suitable for recycling, they require special handling during the sealing process.

While the cera2seal method is suitable for all packaging and products using heat sealing, its flexible, precise temperature control is a particular advantage for mono-materials required for recyclability, as these are traditionally difficult to bond reliably, potentially compromising efficiency, productivity and product quality.

Capable of sealing mono-materials for yogurt cup lids, coffee pods, zipper-seals for pet food and pouch seals for blood plasma, Watttron’s patented cera2seal solution consists of multiple heating pixels - each with individual temperature control - that delivers the optimal heat to the sealing point for reliable and durable bonding including for round, square or polygon shaped packaging.

Dairy products and chocolate benefit

“Sealing in food packaging, especially dairy, must control moisture to preserve product quality. This can be problematic to achieve consistently with current methods. cera2seal reliably seals peelable, flexible lids to the very rim of rigid plastic containers. That is an advantage for perishable products with a high food safety component,” explains Bach.

Because chocolate easily melts, it needs protection during heat sealing, a requirement that cera2seal’s controlled heat process fulfils: neither the machine, packaging nor the product are exposed to residual heat. The chocolate product therefore retains its properties, reducing unnecessary waste in manufacturing.

Temperature fluctuations avoided

“We developed cera2seal for uniform bonding, to supply heat at the required temperature and precisely where it is needed. For mono-materials which have a small processing window, the temperature must be precise to achieve strong bonding without the fluctuations of some 10 degrees Celsius, which we typically see in standard heating tools,” explains Bach.

Positioned close to the contact surface, up to 16 heat pixels, each with an integrated temperature sensor provide the heat required for sealing. The smallest pixels measure a few millimeters and are integrated in bars that are 12-32 centimeters long.

“We offer up to 250 degrees Celsius and the system monitors at 100 times per second. With heating rates of up to 50 K/second and a power range that goes up to 200 watts per square centimeter. “This level of temperature control has not been possible up until now,” adds Bach.

Creative packaging like polygons benefit

The manufacturer can program the cera2seal tool to target the sealing area, allowing for packaging design freedom when it comes to unique packaging shapes, like creative geometrical shapes.

The innovation cera2seal has three patents that cover the system design and sealing method. Earlier this year, Watttron`s cera2seal received Gold in DLG’s International Food Tech Awards. The top distinction recognized cera2seal’s applicability for dairy cup lids.

With its improved functionality and energy efficiency, cera2seal offers a contribution to environmental protection, sustainability and reduced food wastage.

Watttron wins orders for cera2seal in several industries

This year, Watttron received orders for its patented cera2seal solution to retrofit packaging machines in four industries - dairy, pet food, beverages and pharmaceuticals - over a 12-month period. The innovative system offers energy savings of up to 50 percent through targeted temperature control in order to precisely seal not only complex packaging shapes, but also mono-materials for recyclable packaging.

Retrofit contracts, won with large Consumer Packaged Goods (CPG) companies, have since led to collaborations with packaging machinery manufacturers, including Volpak, Mespack and RA Jones. Watttron’s digital sealing solution is expected to be offered as part of machinery lines.