MATERIALS | WOOD PLASTIC COMPOSITES


also be used as a coupling agent for PP-based WPCs in food applications in North America, such as wood fibre-PP compounds used for production of cutlery. The additive is an MAH-grafted PP produced by a reactive batch process rather than extrusion. According to the company, this produc- tion method results in minimal heat history and low residual organic compounds, which also makes it suitable for applications needing low-VOCs, such as interior automotive parts. The ST-G-PP30LO additive is said to display high


Above: WPCs have built a strong position in construction for their durability and performance


40,000 pounds [9-18 tonnes] of recycled plastic film — Trex will pick up and transport the material to its manufacturing facilities in Virginia or Nevada, where it will begin its new life as high-performance Trex composite decking,” the company says. Trex also organises an annual competition for students in school and community groups to collect and recycle polyethylene plastic film. “The goals of our Grassroots program are to engage more partners, establish more recycling outlets for consumer collection, and to increase overall accessibility to recycling by removing hurdles that prevent the organic growth of local plastic film recycling initiatives,” said Stephanie Hicks, materials sourcing manager at Trex. Trex also continues to expand its WPC decking


offerings, most recently with two new colours in its Trex Transcend Lineage luxury line. The new shades, a creamy taupe called Carmel and a deep shade of mocha called Jasper, incorporate a heat-mitigating technology that keeps them cooler than other boards of comparable colours. Trex has also doubled its warranty for its high-end products to 50 years.


Right: Symbio masterbatch from Sappi Biotech contains


wood-based cellulose fibres (page 18)


Performance additives WPC compounds incorporate a range of additives to improve physical properties, appearance, durability, and weatherability. Compatibilisers and coupling agents, for example, are used to help bind wood fibres or particles to the thermoplastic. Denmark- based Nordic Grafting Company, which was founded in 2016 as an affiliate of Bjørn Thorsen, produces Acti-Tech compatibilisers for various applications, including a maleic anhydride (MAH)- functionalised product designed for WPC and natural-fibre compounds (NFCs). Most recently, it announced that its Acti-Tech compatibiliser 16MA11F is compliant with EU food regulation 10/2011 and is suitable for food-contact applications. A new food-safe compatibiliser from US-based CAI Performance Additives, ST-G-PP30LO, can


12 PIPE & PROFILE EXTRUSION | November/December 2023


hydrophobicity and anhydride reactivity, as well as low stickiness. According to the company, the MAH is adsorbed into the polymer’s microporous structure. This microporous technology can be used with other polymers as well as other additives. CAI is the sole supplier in North America for this product, which is sourced from an Asian producer. Mexico-based AddiCo says its grafted copoly-


mer AddiCo 5901 (a PP grafted with styrene-co- glycidyl methacrylate [GMA]) has been evaluated in PP-cellulose fibre composites. The company reports that the additive improves melt uniformity and inter- facial adhesion between the fibre and the PP, which improves physical properties. Its researchers have also evaluated the use of AddiCo 9080 (ethylene butyl acrylate grafted with styrene-co-GMA) in biopolymer-natural fibre composites and they report that the additive improved melt uniformity while maintaining impact properties. US-based AFI Global’s Addisperse says it is partnering with AddiCo for possible US manufacturing. Another characteristic of WPC that can benefit


from improvement in some applications is static build-up, according to Japanese additive producer Adeka.


It says that while WPC building materials are


drawing attention for their eco-credentials and durability, appearance can be marred due to dust adhesion caused by static electrical charge. To


www.pipeandprofile.com


IMAGE: TREX


IMAGE: SAPPI BIOTECH


Page 1  |  Page 2  |  Page 3  |  Page 4  |  Page 5  |  Page 6  |  Page 7  |  Page 8  |  Page 9  |  Page 10  |  Page 11  |  Page 12  |  Page 13  |  Page 14  |  Page 15  |  Page 16  |  Page 17  |  Page 18  |  Page 19  |  Page 20  |  Page 21  |  Page 22  |  Page 23  |  Page 24  |  Page 25  |  Page 26  |  Page 27  |  Page 28  |  Page 29  |  Page 30  |  Page 31  |  Page 32  |  Page 33  |  Page 34  |  Page 35  |  Page 36  |  Page 37  |  Page 38  |  Page 39  |  Page 40  |  Page 41  |  Page 42  |  Page 43  |  Page 44