The Toyo Ink Group, a Japan-based global ink manufacturer, announced a new pilot project in combination with ITOCHU Corp. to scale a material recycling technology that targets and removes ink layers surrounding multi-film structures. The collaboration, which started in 2019, relies on a deinking agent and delamination adhesive in combination with alkaline treatment to release the film substrate’s ink layers and recover the film layers for recycling.
The deinking solution and pilot plant demonstration is focusing on oriented polypropylene (OPP), cast polypropylene (CPP), polyethylene (PE) and other olefin-based films. According to ITOCHU, a demonstration plant will be built in 2021 to commercialize the technology and achieve a 40% material recycling rate for multi-layer flexible packaging.
This ink technology is another example of value-chain partners coming together to promote solutions for a circular economy and meet consumer packaged goods’ (CPG) company targets for 2025. According to a 2020 McKinsey report on circular economy trends for the flexible packaging industry, “packaging converters should be proactive and collaborate with their value-chain partners sooner rather than later, adopting an experimental approach to delivering solutions and communicating narratives about them clearly.”
After completion of the plant with ITOCHU, Toyo Inks will also pursue a post-industrial recycling business in 2022, and a post-consumer and recycling business via commercial plants by 2025. And ITOCHU will offer services to consumer packaging goods (CPG) companies, retailers and brand owners on how to design and build packaging film structures for this type of material recycling technology.
Currently, large amounts of plastic film aren't recycled in Japan. Approximately 16% of plastic in Japan is burned, buried or not reused, while 56% relies on incineration methods, such as thermal recycling and heat reclaiming, according to ITOCHU.
While Toyo Inks and ITOCHU deliver a new recycling solution by targeting solvent-based inks in flexible packaging, many global CPGs are evaluating water-based inks for different packaging applications, including wraparound labels. Suntory, a Japanese-based global food and beverage producer, recently chose a new water-based ink called Marine Flex LM-R from Japanese-based DIC Graphics. This new direction aligns its sustainability goals with its need for high-quality labels, according to Suntory.
Many U.S. and European beverage producers have adopted water-based inks in flexographic applications, but wraparound labels for water bottles are different due to rough exterior environments in the supply chain and customer settings.
“The supply chain evaluation process provided us with a solid understanding of how harsh an environment PET bottles are placed in between shipment from the factory through to sale and use,” says Rikei Sasaka, manager at DIC Corporation. “Balancing print quality and environmental performance is a difficult challenge.”
With these challenges, the water-based ink relies on a “revamped resin binder to prevent the ink’s high density from weakening during lamination and increase solubility of ink remaining on the printing plate following the transfer to the print substrate,” according to DIC Graphics.
The revamped resin binder is essential since wraparound label applications include two laminated film layers: an ultra-thin substrate and a reverse-printed top layer. Plus, the ink must hold its colors due to bottles being soaked in coolers or in C-story refrigerated units.
Other challenges included DIC Graphics development of an exclusive white ink — for white underprinting — that creates opacity and doesn’t allow for any discoloration from the beverage product.
“Considering whether to adopt water-based flexo inks, we weighed the risk of being the first company in Japan to do so against the risk of not taking this step,” says Hiroyuki Iwai, general manager of the packaging material department at Suntory. “Recognizing the potential impact of environment-friendly water-based inks on the packaging industry as a whole, we became the first company to adopt water-based flexo ink."
The impact and savings is strong as the water-based ink removes volatile organic compounds (VOCs) by more than 55% compared to traditional, solvent-based inks.
Water-Based Primers And Coatings
A recent webinar on smooth roll priming for an extrusion coating line featured Bruce Foster, technical advisor at Indo Straits Pvt. Ltd. in Thailand, and he provided insights into market share for water-based, roll coating primers versus solvent-based options.
“Although both solvent and water-based primers are widely used in the flexible converting industry, water-based primers fill about 80% of the global market,” says Foster. “And, they’re continuing to replace solvent-based primers as the water-based technology continues to become more versatile.”
In Asia, Foster also adds that some converters are using methanol or alcohol, and most consider alcohol a solvent-based material. With this in mind, Foster adds that Asia uses more solvent-based roll coating material, with an approximate market share 60% for solvents and 40% water-based for primer material.
On coatings, Foster says that water-based formulations are rapidly replacing solvent-based systems. “The broad range of properties available from water-based acrylics, urethanes and many other chemistries makes it possible to formulate water-based coatings for almost any packaging structure,” says Foster. Foster believes water-based coating systems outnumber solvent based by about three to one, and water-based coatings continue to grow while solvent-based coatings use is declining.
Says Foster, “The world is changing primarily to water-based material for obvious reasons.”