PFAS-free Polymer Processing in Polyolefin Extrusion Applications

AddWorks PPA 101 FG is a PFAS-free polymer processing aid (PPA) for polyolefin extrusion applications, based on Clariant's proprietary organic material technology. In PE blown and cast films, it solves melt fracture – commonly called sharkskin – and it prevents die build-up. For decades, fluoropolymer-based polymer processing aids have been the standard solution to these challenging production issues but tightening global PFAS regulations and even selective bans in certain regions and applications are the driving forces behind the emerging conventional fluoropolymer technology phase-out. Clariant’s AddWorks PPA 101 FG is suitable for LLDPE based packaging, agricultural and building & construction film applications amongst others.

Unlike fluoropolymer-based PPAs, it contains no PFAS, no silicone nor inorganic substances, it is nonhazardous, label-free and holds broad food contact approvals under FDA, EFSA, Mercosur, China GB and Japanese regulations. Why the PE film industry needs PFAS-free processing aids Fluoropolymer-based polymer processing aids have long been effective tools in PE film extrusion. The challenge is that they contain per- and polyfluoroalkyl substances (PFAS) – the so-called forever chemicals that are highly persistent in the environment and harmful to human, animal and plant life. Regulators across the EU, USA, and Asia are progressively restricting PFAS use across chemical sectors, and polymer additives are within scope. PE film converters supplying packaging markets face both PFAS restrictions on the additive itself and recyclability mandates under the EU Packaging and Packaging Waste Regulation (PPWR), which create additional incentives to eliminate PFAS from packaging film formulations.

How AddWorks PPA 101 FG works

AddWorks PPA 101 FG is a 100 % active fine grain formulation with an approximate bulk density of 500–600 g/l. It lowers apparent shear stress at the extruder die wall, which raises the critical shear rate and allows higher output without melt fracture. Sharkskin removal typically begins 20 to 40
minutes after line start-up, depending on let-down ratio (LDR), resin type, film configuration and process- and equipment parameters. At a 0.2 % LDR, performance is near-equivalent to conventional fluoropolymer-based PPAs in critical shear rate testing. The product is thermally stable, with less than 0.5 % weight loss below 280 °C and less than 0.9 % below 320 °C. It can be incorporated via the host resin, as a concentrate, or via a masterbatch carrier. AddWorks PPA 101 FG typically works in Ziegler-Natta LLDPE as well as in more difficult to process metallocene LLDPE resins. And this in fully formulated film configurations without antagonistic effects with typical film co-additivation.

The benefits of AddWorks PPA 101 FG in polyolefin extrusion

• Sharkskin elimination: Effective melt fracture control at standard production output rates
• Die build-up prevention: Efficient die build up reduction, tunable through LDR and process conditions
• Improved film surface: Enhanced surface smoothness and quality with improved haze vs. neat LLDPE, facilitating downstream film converting
• Neutral film properties: No negative effect on film optics, coefficient of friction (CoF), dyne level, or tensile properties; no interference with the typical post-treatment operations including corona treatment, printing, lamination and heat-sealing
• No silicone contamination risk: Free of silicone and polysiloxane substances; film converters working with corona treatment or adhesive lamination have specifically cited this as a reason to avoid silicone-based PFAS-free alternatives

AddWorks PPA 101 FG is suitable for a broad range of polyolefin film applications:

• LLDPE blown film for packaging: In blown film extrusion, sharkskin and die build up are frequent causes of film quality issues and production slowdown and/or downtime. AddWorks PPA 101 FG resolves these issues while maintaining the optical film quality and mechanical properties required for consumer- and industrial packaging films. Additional blown film applications include blown agricultural PE films – including mulch
  film, silage film and greenhouse covering – and construction films such as vapour barriers and protection films requiring consistent processability and film integrity. AddWorks PPA 101 FG addresses the extrusion processability challenges of these applications while maintaining the film properties each end use requires.
• LLDPE PE cast film: During cast film production, die build-up control is of crucial importance to manage die service life, maximizing die cleaning intervals and avoiding excessive cleaning stops. AddWorks PPA 101 FG has been validated and adopted in cast film production on the basis of significant die service interval improvements while maintaining best possible optical film quality. It exhibits outstanding thermal stability required to run on state-of-the-art cast lines operating at melt temperatures of up to 280 °C or higher without causing chill roll deposits. Typically used for industrial stretch film applications, AddWorks PPA 101 FG shows no negative impact on film stretch behavior.
• HDPE pipe extrusion: Beyond film, proof-of-concept work in HDPE pipe extrusion is showing encouraging early results. Efficient processing and smooth inner pipe surfaces are the key performance requirements in this application, and initial trials across multiple regions indicate AddWorks PPA 101 FG can address both.

Expert Q&A with Diederik Goyvaerts, Market Manager, Clariant Additives

What is the difference between AddWorks PPA 101 FG and AddWorks PPA 122 G? 

Diederik Goyvaerts: AddWorks PPA 101 FG is a 100 % active fine grain used in EMEA, Americas and SEAP markets. AddWorks PPA 122 G is a ready-to-use PE based masterbatch on the same proprietary technology, targeted primarily at Greater China and SEAP. Both products are PFAS-free and contain no silicone, no polysiloxane nor inorganic substances.

Can AddWorks PPA 101 FG be used as an ingredient in masterbatch production?

Yes. Its fine grain format is designed for flexible incorporation, including as the active ingredient in PFAS-free PPA masterbatch formulations that masterbatch producers develop for their own film converter customers. Alternatively, it can also be incorporated directly into a host resin ex-works
by resin producers. In such case it is offered to the market as a ready-to-use resin.

Why do we highlight that AddWorks PPA 101 FG is silicone- and polysiloxane-free?

Alternative PFAS-free processing aid technologies can be based on polysiloxane and/or silicone chemistry. The film producing industry typically tries to steer away from these for reasons of production line contamination and/or for reasons of interference with the downstream film posttreatments
e.g. printing, lamination, sealing etc.

Is AddWorks PPA 101 FG a drop-in replacement for fluoropolymer-based PPA’s?

AddWorks PPA 101 FG is a different chemistry compared to fluoropolymer-based PPA’s and will require some getting used to and some minor adjustments in the way it is used in the film extrusion process. The loadings are typically higher in the range of 0.1 to 0.3 % while the shark skin removal time will be largely similar to fluoropolymer PPA references. The overall cost-in-use is expected to be at the same level.

Is AddWorks PPA 101 FG suitable for food packaging applications?

Yes. AddWorks PPA 101 FG is non-hazardous, label-free, and holds broad food approvals across five major food contact jurisdictions:

• EU: Listed on Annex I of Regulation (EU) 10/2011 (EFSA)
• USA: Approved for polyolefins per 21 CFR 177.1520 (FDA)
• Mercosur: Cleared for all plastics
• China: Listed under GB 9685-2016 for polyolefins
• Japan: MHLW Positive List, issued November 2023

Conclusion

The shift away from fluoropolymer-based processing aids is driven by regulation, but the transition does not require a performance compromise. AddWorks PPA 101 FG, as a PFAS-free alternative, delivers sharkskin elimination, die build-up control and maintained film quality in several PE
extrusion processes.

(Source: Clariant)