Certified sustainability: Rotoflex’s PU printing inks series 22 for flexible packaging recognized as fully recyclable
50 years Rotoflex – Innovative power, precision and close partnerships
von Ansgar Wessendorf,
Bettina Lanz (Head of Marketing Support by Rotoflex) and Klaus Pfanner (Head of Development by Rotoflex) are proud of the certification of the PU ink series 22 by the “cyclos-HTP Institut”. The inks have been recognized as fully recyclable and compatible with PP-based flexible packaging under tested conditions
(Source: Ansgar Wessendorf)
Since its founding in 1975, Rotoflex AG has stood for the highest quality, technical precision und continuous innovative power in the field of solvent-based printing inks and technical varnishes for the packaging industry. Based in Grenchen, Switzerland (Canton of Solothurn), the company has established itself as a major player in the international market.
As part of the Daetwyler Group, which alongside Rotoflex also includes by Daetwyler Industries and leading doctor blade manufacturer Daetwyler SwissTec, Rotoflex benefits from a strong network that creates synergies and enables technological progress.
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A company with a vision
Rotoflex has established itself as a highly specialized supplier of inks and technical varnishes for flexo and gravure printing. Since the incorporation in the Daetwyler Group in 2017, the company has benefitted from the strengths of a global network and close technical collaboration with its sister company Daetwyler Swiss Tec. This close cooperation makes it possible to develop market orientated solutions with high innovation level. Today, Rotoflex employs over 60 people and produces around 6,500 tons of printing inks and technical varnishes annually. About 75 percent of the production is exported – a clear sign of the company’s international orientation and competitiveness.
Special attention is paid to sustainability. Rotoflex relies on environmentally friendly production processes and technologies such as thermal afterburning plants in order to minimize solvent emissions.
A current milestone in this development is the certification of the PU printing inks series 22 awarded by the “cyclos-HTP Institut”. The inks have been recognized as fully recyclable when used on PP-based flexible packaging – a significant step forward in terms of the circular economy.
Technological excellence and customer-specific solutions
Rotoflex’s activities focus on development, manufacturing and marketing of highly specialized ink systems for flexible packaging, which are used primarily in the food and pharmaceutical industries. Examples include: packaging for coffee, snacks, dairy products or pet food.
“Current milestone in this development is the certification of the PU printing inks series 22 by the “cyclos-HTP Institut”.
The non-food sector is also served successfully, for example with solutions for hygiene or household products. In addition, Rotoflex is dedicated to security printing with a specialized portfolio that includes special varnishes, fluorescent components, hologram-compatible coatings, screen and offset inks as well as the VISIO and SKY product lines. These meet the highest standards of forgery resistance and print aesthetics.
Research & development and global sales network
Rotoflex invests continuously in research and development. About 15 percent of the annual turnover is invested in its own R&D department, which is equipped with state-of-the-art analytics and application technology. The company’s own laboratory in Grenchen enables the development of tailor-made solutions – quickly, flexibly, and customized to customer requirements.
As part of the renowned Daetwyler Group, Rotoflex can count on the support of a strong network enabling synergies and technological progress (Source: Rotoflex)
Rotoflex’s distribution network spans more than 20 countries. Local offices, services centers and qualified distribution partners ensure customer-focused support. This network is supplemented by experienced printing technicians who support customers with commissioning, process optimization, and problem solving directly at the machine.
The problem with recycling
The discussion about sustainable alternatives to conventional binding agents focuses in particular on nitrocellulose. This binding agent is still widely used in packaging printing because of its excellent technical properties, ease of use and low cost.
However, with growing regulatory pressure and a focus on sustainability, the weaknesses of nitrocellulose are becoming increasingly apparent. The EU Packaging and Packaging Waste Regulation (PPWR) requires that all packaging be recyclable by 2030, i.e. through its design. These requirements are increasingly calling into question the use of nitrocellulose.
Technologically, nitrocellulose continues to offer many advantages. It is excellent for printing, gives printed products an attractive gloss and, thanks to its function as dispersing agent, ensures even pigment repartition, resulting in high color quality. It is also inexpensive and based on cellulose, a renewable raw material, which may seem environmentally friendly at first glance.
However, nitrocellulose has serious weaknesses in the context of the circular economy. It begins to decompose at temperature as low as around 160 °C. This is a critical point, given that significantly higher temperatures are reached when recycling polyethylene or polypropylene.
“Rotoflex looks back on 50 years of technological innovation, sustainable development and consistent customer orientation.”
(Dr. Klaus Pfanner, Head of Development at Rotoflex )
The thermal decomposition releases toxic gases such as nitrogen oxides and carbon monoxide, which are not a health hazard but also have strong odor and cause discoloration. This significantly reduces the quality of the recycled material and makes it more difficult to process further. Furthermore, nitrocellulose is difficult to remove from recycled material, making it a real disruptive factor in recycling processes.
Ink series 22: NC-free and completely recyclable
With this in mind, NC-free ink systems are a future-oriented alternative. With the development of the PU-based ink series 22, Rotoflex has created a solution that meets the requirements of modern recycling cycles without compromising printing quality. In December 2024, this series was certified by the renowned „cyclos-HTP Institut“ as completely recyclable. The certification process confirmed that the PU ink system complies with all requirements for a modern circular recyclable packaging solution – both in terms of material recyclability and sort ability in modern recycling plants.
The PU inks series 22 is specially designed for intermediate layer printing (reverse printing) on PP-based flexible packaging and has been tested under practical conditions as full-surface multi-color printing. The color concentration in the post-consumer recyclate remained below one percent by weight, which corresponds to the required upper limit for recyclable applications. The ink showed no significant negative effects on the quality of the gained recycled material used among others things in injection molding applications.
With the development and successful certification of the PU printing ink series 22, Rotoflex is making a decisive contribution to the realization of recycling-friendly packaging solutions (Source: Rotoflex)
The evaluation was carried out in accordance with the requirements specifications of the “cyclos-HTP Institut” for EU-wide certification. In addition, compliance with the minimum standard of the Central Agency Packaging Registers (ZSVR) and with the EN 13430 standard on material recyclability has been confirmed.
“This certification is a significant milestone for us”, emphasizes Dr. Klaus Pfanner, Head of Development at Rotoflex. “It confirms our commitment to sustainable product development and resource-saving packaging solutions and shows that we deliver concrete results.
With the 22-color series, we offer our customers not only a technologically mature and proven printing ink, but also an environmentally friendly solution that meets the requirements of modern recycling processes.“ The series has been used with great success for many years.
“The discussion about sustainable alternatives to conventional binding agents is focusing in particular on nitrocellulose.”
The test comprised various test paths – including for polypropylene and flexible mixed plastics – and evaluated the sortability and the suitability for manufacturing new products. The certificate is valid until December 31, 2025, and underscores Rotoflex AG’s strategic focus on future-oriented, recyclable printing solutions.
Strong roots – secure future
The history of Rotoflex is characterized by continuity and vision. In 2012, the sales team in northern Germany was expanded to strengthen market presence. The integration into the Daetwyler Group in 2017 marked a significant step forward, followed in 2018 by the founding of Daetwyler Rotoflex Türkiye in Izmir – a further sign of international expansion. The company has successfully overcome challenges such as the coronavirus pandemic and geopolitical crises by making strategic adjustments.
Rotoflex invests continuously in research and development. Around 15 percent of the annual turnover are invested in its own R&D department, which is equipped with state-of-the-art analytics and application technology (Source: Rotoflex)
Conclusion
Rotoflex looks back on 50 years of technological excellence, sustainable development and consequent customer orientation. With the development and successful certification of the PU printing ink series 22, Rotoflex is making a decisive contribution to the realization of recycling-friendly packaging solutions. The combination of high printing performance, thermal stability in the recycling process and complete freedom from NC addresses both functional and regulatory requirements of modern recycling management. With its strong R&D expertise, integrated system partnership within the Daetwyler Group, and a clear focus on quality and process reliability, Rotoflex is positioned as a leading technology provider in the segment of solvent-based ink systems for flexible packaging.
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Info Box 1
Solven-based vs. waterbased in ink systems: An environmental check
From an ecological point of view, nitrocellulose is a problem, primarily due to its solvent dependency. Although solvent-based ink systems like those containing nitrocellulose produce a good printing quality, quick drying and easy cleaning, they produce high emissions of volatile organic compounds (VOCs) and are classified as hazardous materials. Water-based inks perform better in terms of environmental impact but they have other disadvantages: they dry more slowly, require more energy, and often contain biocides, which themselves pose ecological risks. In addition, the printing speeds achievable with aqueous ink systems are often lower.
Info Box 2
Recyclable PU ink series for flexo and gravure printing
The Rotoflex ink series 22 is a highly developed, solvent-based PU printing ink series specially designed for flexo and gravure printing on flexible packaging materials. It is particularly suitable for reverse printing with subsequent lamination (interlayer printing) and sterilization. These inks are used mainly in food packaging where highest safety and quality standards are required.
Properties of the ink series:
Binding agent: Polyurethane (PU) for optimal flexibility and adhesion
Substrates: Suitable for a wide range of packaging films, including polyethylene (PE), polypropylene (PP), polyester (PET), polyamide (PA) and films with functional coatings (SiOx, AlOx, EVOH, PVOH, PVDC, acrylic)
Application weight: 1.0 g/m² – 3.0 g/m² (dry)
Printing process: Flexo and gravure printing
Color properties: High color intensity, medium gloss, excellent stability under heat exposure
Odor: Virtually odorless at recommended layer thickness and sufficient drying time
Sterilization resistance: Up to 135 °C for 1 hour
Advantages of the ink series:
Excellent laminating adhesion, especially for flexible packaging
Very low migration, ideal for food packaging
Optimized adhesive tape adhesion on various films
Very low residual solvent values
Free from critical components such as migrating plasticizers, acrylates, cellulose nitrate and PVC
If necessary, adhesion can be further improved by using primer such as L-122-22
The ink series can also be used for surface printing, provided a (NC-free) 2-component varnish is overprinted. This makes the system recyclable for surface printing as well.
