Attention on additives: Innovators boost safety and recyclability in plastic food packaging

09 Feb 2022 --- Plastic food packaging faces increasing scrutiny, centered around low recycling rates and reports of potential human health damage caused by toxic chemicals. Additive suppliers are working to overcome these challenges with increasingly sophisticated material blends that can enhance the environmental and hygiene credentials of food-grade packaging when integrated into polymers.

The COVID-19 pandemic has accelerated the use of packaging materials and elevated consumer safety concerns to an all-time high. Additives can enhance the recyclability and safety of plastic packaging and are also essential in delivering its shape, color and shelf life capabilities.

PackagingInsights explores the latest food-grade additives innovation with bio-based pioneer Palsgaard and chemical giants BASF and Lanxess.

Bio-based safety boosts
Palsgaard offers a portfolio of renewable, food-grade additives branded as Einar. The additives are derived from polyglycerol esters, monoglycerides and other vegetable sources, providing alternatives to fossil-based additives without compromising mechanical or barrier properties.

The portfolio comprises migratory solutions tailored to polyethylene, polypropylene, ethylene-vinyl acetate and polyvinyl chloride packaging films. The additives are available in pellet, paste and liquid form – ideal for dust-free blending in film extrusion compounds and masterbatches. The Danish food emulsifier specialist’s target application is additives used as anti-stat or anti-fog in polyolefins packaging.

Anti-fog additives are instrumental in maintaining consumer appeal, extending shelf life and preventing food waste. However, conventional additives in film polymers have become a target of concern, as research increasingly points to health impacts such as obesity and pregnancy issues.

Palsgaard’s anti-fog testing: Einar additives are exclusively based on renewable plant sources also used in food additives.“There is good reason for this concern, since anti-fogs and anti-stats in, for example, polyolefin packaging normally work by migration, and it is important to make sure that no traces of them will compromise the safety of the food,” Ulrik Aunskjær, director for bio-specialty additives at Palsgaard, tells PackagingInsights.

“This is why many synthetic fossil-based anti-fogs are subject to strict migration and concentration limits, which can be difficult to meet even with innovative film structures for thin-wall packaging.” Overcoming chemical migration concerns, Einar additives rely on natural chemistry and are exclusively based on renewable plant sources, which are also widely used in food additives.

“They [Einar additives] are not governed by any migration limits and have full food-contact, kosher and halal approvals,” adds Aunskjær. “Moreover, as they migrate and increase the surface tension of the film, they develop outstanding anti-fog performance even at reduced concentrations, which maximizes their cost-efficiency.”

The food emulsifier specialist wants to broaden its portfolio’s market scope through R&D and customer collaborations. It is developing its additives to deliver enhanced anti-stat protection in applications including cups, trays, thin-walled components and multilayer films.

“The trend continues to favor bio-based additives over fossil alternatives,” concludes Aunskjær. “This trend has even been accelerated by COVID-19 – driven by the high attention to consumer safety.”

Raising recycling rates
Meanwhile, BASF’s focus remains on increasing packaging’s recyclability and reusability with fossil-based additives that can reduce recyclate processing challenges and boost durability. The chemical company plans to expand its recently introduced IrgaCycle range to increase the use of recycled content and overcome key technical challenges, such as gel formation.

BASF wants to expand its IrgaCycle range to overcome key technical challenges, such as gel formation, and raise recycled content levels.“The packaging industry is aiming toward more recyclability, but also using an optimal level of additives,” Sebastian Heitkamp at Business Segment Packaging & Consumer Goods, BASF Plastic Additives, tells PackagingInsights.

“We, therefore, focus on more effective additive systems for a lower dosage, to reduce the overall additive content, which may increase throughout multiple cycles, but also on phenol-free solutions. One example here is phenol-free solutions Irgastab FS 301 – an additive system providing superior processing stabilization and low yellowing.”

BASF experienced surging demand for its food-safe additives during the pandemic, driven by convenience food packaging. The company provides state-of-the-art food contact additive solutions from its established Irganox, Irgastab and Tinuvin ranges.

“We could maintain IrgaCycle manufacturing grades despite the phenomenal demand [during COVID-19] from classical applications for materials made short by economic recovery and logistical disruptions,” says Heitkamp.

“In addition to new solutions, we are also focused on delivering clear [environmental] sustainability benefits to the market. These benefits range from reduced waste and energy during processing to improved health and safety profiles.”

New life for black plastic
Lanxess is another chemical giant helping manufacturers meet their circular economy targets, including in more technically challenging markets like black plastics. Its latest development – Bayferrox 303 T – enables black plastics to be identified efficiently and cost-effectively by near-infrared radiation (NIR) detectors for improved sorting and recycling.

“Consumers, environmental organizations, politicians and industry are increasingly taking action to reduce microplastics. Reusing plastic waste as a raw material also contributes to this, but requires that the different plastics be separated according to type first,” Stefano Bartolucci, global market segment manager for plastics in the Inorganic Pigments business unit at Lanxess, tells PackagingInsights.Lanxess’ inorganic pigment for coloring black plastic overcomes long-standing sorting challenges.

“Bayferrox 303 T can help increase the recycling rate for plastic packaging, which is still far too low around the world. This inorganic pigment for coloring black plastic reflects 20% of near-infrared radiation, enabling plastics to be identified. Plastic packaging colored with carbon black, on the other hand, as is used in large part today, does not reflect any radiation and therefore cannot be detected in sorting plants.”

NIR spectroscopy is used in automated recycling plants to quickly sort plastic waste into different types, with infrared cameras generally installed above the conveyor belts. However, black plastic packaging like foils cannot be identified correctly by the optical sensors due to its color, meaning it cannot be sorted.

“Unlike the carbon black pigments often used in the plastics industry, Bayferrox 303 T reflects infrared radiation, thus allowing identification with the aid of NIR detectors. As a result, black plastic items such as packaging films or trays can be better identified with the iron-manganese mixed oxide and sent for recycling,” explains Bartolucci.

Hype about hemp
Back in the bio-based space, Heartland has created hemp additives to help manufacturers reduce plastic’s cost, weight and carbon footprint. The US biotech company has executed a joint development agreement with recycling leader Ravago to produce “the next generation of plastic resins.”Heartland says its hemp additives can reduce carbon footprint by up to 44% against fossil-based additives.

Ravago says it can offer composite products that are stronger, lighter and cheaper by leveraging carbon-negative and renewable plastic additives like industrial hemp. Heartland’s engineered hemp additives reportedly reduce the carbon footprint of virgin plastics by up to 44%.

The biotech company also focuses on verifying the impact of hemp-filled recycled plastics versus traditional virgin plastics that are typically compounded with mineral fillers like talc and calcium carbonate.

After the 2022 farming cycle, Heartland estimates that it will be able to process over 100 million pounds of hemp additives for plastic compounding. Ravago and Heartland indicate they will continue to research and develop products for packaging and other markets, including automotive and building materials.

By Joshua Poole