Additives Boast Sustainability Without Sacrificing Performance

This year’s long-awaited NPE2024 did not disappoint in the realm of new developments in additives. Not surprisingly, sustainability ruled but so do performance attributes of replacements that claim to be at least equivalent if not better performers. 

Leading the pack of plastics for which these additives are targeted are polyolefins used in the food packaging arena. As such, this year’s highlights included non-PFAS processing aids, barrier boosters, oxygen scavengers and nucleating agents. Colorants, lubricants and carbon blacks based on biobased feedstocks also factored in. Other new additives include color masterbatches for PBT optical fiber cable and a secondary antioxidant for polyolefins and engineering resins.

Non-PFAS Processing Aids for Polyolefins

Some key additives suppliers highlighted their latest portfolios of polymer processing aids (PPA) that are free of per- and polyfluoroalkyl substances PFAS. Environmental concerns about PFAS are growing because studies have shown many PFAS break down very slowly over time and can persist in water and soil. As a result, some countries are restricting PFAS, and there is growing pressure to ban all PFAS. This is causing processors to search for non-PFAS alternatives

Clariant showcased its new line of PFAS-free processing aids for blown film applications. The AddWorks PPA product line represents Clariant’s proprietary polymer processing aid (PPA) compositions as a safer alternative to PFAS, intended for use in extruded polyolefin materials and addressing specific market needs in a tightening regulatory framework limiting the use of PFAS-containing substances. In addition, these processing aids have neither inorganic nor silicone content.

According to the company these PPAs eliminate melt fracture or sharkskin effect and reduce die buildup. Their use has been shown to result in optimum aesthetic film performance — in terms of haze reduction, transmittance and clarity, with no negative effects on film mechanical and sealing properties. Low or no migration, along with high thermal stability, are also claimed.

Benefits to users, in addition to providing a safer and more sustainable alternative, is said to include production efficiency combined with highest possible film performance and quality. Moreover, low letdown ratios (LDR) needed are said to ensure competitive cost-in-use. 

Avient Corp. launched its new Cesa non-PFAS Process Aid for extrusion. This PPA was developed specifically for use in PE and PP applications. Said to deliver comparable processing performance as traditional processing aids, Avient’s Cesa non-PFAS Process Aid is said to reduce friction between the polymer and the metal, enabling the polymer to be more easily extruded. It aids in reducing melt fracture, eliminating die buildup and lowering torque for higher throughput. Reducing melt fracture (sharkskin) has the additional benefit of improving optical properties and providing a higher quality product appearance.

As previously reported, Baerlocher USA has aimed to ensure a smooth transition in a range of PE blown film, pipe, and wire and cable applications that are free from PFAS. Its new Baeolub AID PPAs have been shown to deliver rapid melt fracture clearing for metallocene and Ziegler-Nattia LLDPE and HDPE, said to equal or surpass clearing times of traditional PPAs containing PFAS and siloxanes.

Barrier Boosters, Oxygen Scavengers, Nucleating Agents 

Milliken launched two new additive masterbatches for polyolefins — one an expansion of its UltraGuard 2.0 barrier booster, which has been shown to improve barrier performance by cutting up to 70% of the transmission rate of any substance (moisture, oxygen) and promoting both the use of monomaterial packaging and material downgauging. UltraGuard additives can also be used to bring higher barrier levels to certain flexible packages, providing more protection to the food and potential shelf life extension.

More recently, UltraGuard additive masterbatches have been used for pharma bottles. White opaque HDPE bottles are commonly used for over-the-counter drugs, prescription drugs and nutraceutical products because they have good moisture barrier and light protection properties. Barrier enhancement in HDPE pharma bottles is particularly valuable because it can help extend the potency of drugs toward the end of their shelf life.

As an added benefit, UltraGuard solutions also provide sustainability benefits. To meet the barrier requirements, pharma bottles typically have much thicker walls than needed from a purely functional point of view. However, HDPE resin formulated with these additives enables bottle makers to reduce the weight of these bottles by up to 20%, while still providing enhanced barrier properties.

An emerging technology over the last couple of years developed for monolayer PET or rPET packaging is Avient’s ColorMatrix Capture liquid oxygen scavenger. Undergoing testing with major brand owners, it works to create an active barrier against oxygen ingress, helping to enhance product protection and extend shelf life. This fully recyclable oxygen barrier has APR Critical Guidance Recognition. It boasts clarity with no discoloration, enabling higher rPET content or use of any PET grade, and with no negative impact to the recycle stream.

Capture is added to the bottle closure, effectively removing the barrier from the bottle. The scavenger in the closure can be separated from the PET during recycling and closures are 100% compatible with the closure recycle stream. By moving the oxygen scavenger to the cap, there is greater flexibility and even lightweighting options for the bottle design.

The company has also expanded its Amosorb oxygen scavenger line with the launch of Amosorb 4020R, which is said to deliver full, consistent oxygen scavenging performance with 25%, 50% and even 100% rPET content. This new solution is also demonstrated to improve the aesthetics of recycled packaging in terms of haze and color, including a reduction in the yellowing effect that may occur during recycling. In addition, the additive is compatible with many different rPET grades to help brand owners achieve their sustainability targets.

Meanwhile, a new nucleating agent has been added to Milliken’s Hyperform product line. The new Hyperform HPN 58ei has been developed to enhance the appearance and performance PP sheet and thermoformed parts. Typical applications include food and beverage packaging, meat packaging, microwavable food packaging, electronics packaging processing sheet extrusion and thermoforming.

Biobased Colorants, Lubricants and Carbon Blacks

The first in a new series of renewable, biobased colors and effects was launched by Ampacet. The Natura Shades Collection colors are described at once enveloping, meditative and serene. The six carefully selected hues include Charcoal Night, Desert Garnet, Abyss Indigo, Evergreen Depths, Taupe Slate and Sunlit Dunes.

While the formulation of dark colors typically requires the use of carbon black, Ampacet pushed the boundaries, leveraging a new bamboo-based colorant as an alternative to the traditional black pigments derived from petroleum or tar that are commonly used in plastics. The collection is suitable for PE/PP injection molding and applications such as furniture, durable goods, housewares and home decor.

Orion launched two sustainable specialty carbon black grades suitable for wire and cable, and other applications such as piping, film, packaging and automotive applications produced from end-of-life tire pyrolysis oil. They are said to match the performance of regular, fossil-based specialty carbon black, with similar conductivity properties, high purity level, jetness and tinting strength.

UV Stabilizers for Food Packaging

A proprietary UV additive masterbatch launched by Tosaf has been shown to ensure that clear packaging films offer a high blocking effect against UV radiation in the wavelength range from 200 nm to 380 nm, even at low thickness. UV9389PE EU is said to efficiently protect foods from discoloration, vitamin and flavor loss as a result of the degrading effects of artificial light to which they are exposed during storage, shipping and on the shelf. Unlike conventional mineral-based products of this type, the optical properties and, in particular, the transparency of films finished with UV9389PE EU are almost completely retained.

Another proprietary UV barrier masterbatch for food and industrial packaging from Ampacet is said to offer a sustainable alternative to conventional phenolic benzotriazoles — which have faced strong regulatory pressure due to environmental concerns; some grades have been added to the European ECHA candidate list of Substances of Very High Concern (SVHC). Ampacet’s UVBlock 1496, formulated without the intentional addition of SVHC, boasts excellent optical properties and good UV barrier performance in the low UVA and UVB wavelength range, and is approved for food contact applications in Europe and the U.S.

Songwon’s latest addition to its UVA offerings and a complement to its triazine-based UV absorbers for plastics is Songsorb 1164 UVA. Compared to conventional benzotriazole products, it has been shown to extend the service life of end products made from polyolefins and engineering plastics exposed to outdoor weathering, but was specially developed to maximize the UV stability of polyolefins intended for use in food contact packaging applications.

Other Additives

Ampacet recently expanded its ElTech portfolio to include a range of high-performance color masterbatches based on a PBT carrier resin and specifically designed for optical fiber cable PBT jacketing, often selected for indoor optical fiber cables used in building and construction as well as in data centers. For ease of installation, optical fiber cable manufacturers use a color coding system such as the RAL system to identify individual optical fibers.

According to the company, ElTech masterbatches for optical fiber cable preserve high-performance signal transmission and feature excellent opacity at a low addition rate, high resistance to heat and color fading, and include 16 colors that comply with RAL color references. Additional shades using custom colors or color coding systems such as RAL or Pantone can be developed upon request.

The ELTech product range also includes masterbatches combining color with functional additives.