Sustainability is one of the biggest topics in label and package printing today. Inks play a pivotal role in the recyclability of consumer products, as the wrong ink can render a product incapable of being recycled.

In addition to sustainability, Sun Chemical has emphasized R&D in all the trending areas of the industry. To learn more about the company’s latest innovations and what to expect in the future, L&NW recently sat down with Dennis Sweet, vice president, NWTL, Commercial, Rycoline and Distributors, Sun Chemical.

L&NW: What are some of the recent trends you are seeing in ink technology?
DS: The industry’s focus on sustainability is only growing. Demand for sustainable packaging is driving advancements in sustainable technology for all the components of the end product – from pigments to inks to coatings to substrates – to allow a low waste, environmentally-friendly end-of-life scenario for more packages. As a result, washable, recycle- and compost-friendly, and biorenewable inks are all growing in popularity among converters.

L&NW: What role does ink play in the overall sustainability of packaging?
DS: Although ink is just one element of a package, if it is not designed sustainably, it can prevent the rest of the package from being properly composted or recycled, even if the substrate itself is compostable or recyclable. Sustainable inks are consequential to sustainable packaging. 

L&NW: How is Sun Chemical meeting increased demand for more sustainable inks?
DS: Sun Chemical’s “5Rs” framework of Reuse, Reduce, Renew, Recycle and Redesign guides all product design and technological innovation at the company. This guiding strategy ensures that our inks, coatings and adhesives are crafted to enable a circular economy and to align with design guidelines–for example, those published by the Association of Plastic Recyclers (APR) – from development through end-use.

In June 2024, APR recognized two of Sun Chemical’s products as meeting APR Design for Recyclability requirements. SunSpectro SolvaWash and SolarFlex CRCL both passed HDPE-CG-01 path 1B at 100% ink coverage on approved label substrates with 20% coverage for HDPE bottles. This recognition underscores Sun Chemical’s commitment to sustainability leadership by supplying converters and brand owners with products that not only perform at the highest standards on press and in applications, but that also comply with the industry’s most respected authority on recycling requirements.

SunSpectro SolvaWash flexographic inks are fully removable from plastic substrates during a packaging product’s end-of-life processing, improving overall package recyclability. SolvaWash inks’ washable/deinkable, solvent-based design leads to more recycled materials from bottle recycling streams.

SolarFlex CRCL is another range of inks that allows increased recyclability; these deinkable UV and UV LED flexo inks are designed to be removed from bottle film without using a primer. SolarFlex CRCL inks have strong dot reproduction and maintain quality performance with higher, more efficient press speeds.

L&NW: Can you talk more about the different types of inks Sun Chemical uses to enable sustainable packaging?
DS: Sun Chemical prioritizes a few different categories of sustainable inks to promote a circular economy in the packaging industry. Recycle-friendly inks are a key way to ensure the full package is recyclable at the end of its life cycle. Washable inks, like SunSpectro SolvaWash and SolarFlex CRCL, enable recyclability because they are designed with pigments and resins which can be washed without leaving residue in the wash water or on the substrate. While conventional inks discolor the plastic and downgrade its quality, washable inks promote higher-quality recycling and greater circularity by better preserving the quality of the recycled substrate. The inks also don’t discolor or contaminate recycling wash waters, which is an advantage for the recyclers. 

Biorenewable inks are another category Sun Chemical produces that minimize environmental impact. These inks use plant-based resins instead of traditional fossil-based materials for a significantly reduced carbon footprint. SunVisto AquaGreen is a range of biorenewable water-based inks for paper packaging exhibiting high resistance to rub, water and grease and with superior ink resolubility and print fidelity.

Inks that are compost-compliant also enhance packaging sustainability for those packages destined for composting at end-of-life. Inks that meet the requirements for compostability can be certified by BPI in North America or TÜV in Europe, and Sun Chemical’s SunUno Solimax AP has received the TÜV “OK Compost” certification. SunUno Solimax is a flexographic, solvent-based ink that maintains strong color performance while being compatible with a range of plastic films and suitable for heat treatment.

L&NW: Are there any other sustainable Sun Chemical products you’d like to discuss?
DS: Increasing efficiency and reducing waste are some optimal ways to improve environmental impact during production. SunScreen is a coatings monitoring system that works online, in real time, to enable printers to monitor and ensure proper coating application while it is happening. The system is compatible with a range of press configurations and immediately alerts operators of errors, effectively reducing waste, minimizing coating weight, and avoiding excess print time.

Sun Chemical offers a compact dispensing system that reduces the amount of spot ink colors typically consumed by 30%. We have developed a tool to use along with the dispenser that can estimate the total carbon footprint impact of the dispenser approach.

Another sustainable product line from Sun Chemical is the SunCure mono-web coatings, which can enable lamination replacements to allow packages or labels to use single-layer constructions. These coatings cut down on materials used, production time and carbon footprint.

As converters continue to switch from mercury lamps to LED curing lamps, we have worked with them to develop UV-LED inks that work for a wide range of applications, including in-mold labels. The challenge was developing an ink that cures with UV-LED lamps and survives the elevated injection molding temperatures. Formulated with a higher viscosity for conventional UV-LED lamps and at faster curing speeds on difficult substrates, such as films used for in-mold labels, these printing inks offer excellent adhesion to films and papers, provide good printability and lithographic performance, bring excellent color strength, have outstanding cure, and deliver high gloss and scuff properties.

Sun Chemical continues to create its inks and coatings with the recognition that all packaging components need to be designed more sustainably to work toward creating a better end-product for brand owners, consumers, and the planet.