MATERIALS | WOOD-PLASTIC COMPOSITES


presented a lightweight-construction material that combines expanded PLA foam and layers of beech plywood.


“Our goal is to develop a high-quality hybrid Above:


Novowood is used for a wide range of outdoor applications


company to consider alternatives – including developing its own WPCs. “The aim was to fine-tune and develop formulas


through study, applied research and field experi- mentation,” said the researchers, in Discover Civil Engineering. “An attempt was made to find the most suitable components to achieve the charac- teristics required to obtain extruded profiles for decking in the marine environment.” The first stage was to perform Oxidation Induction Tests (OITs) on its WPC samples, to predict the lifespan of each extrusion batch. Five samples were initially compared: 100% virgin PE; a blend of 70% virgin and 30% recycled PE; a blend of 30% virgin and 70% recycled PE; regrind from WPC obtained with the previous blend; and a WPC from a primary producer from China. These analyses underpinned the product development process for the material. Here, the goal was to minimise the use of plastic compo- nents in favour of materials from high-quality production waste. The aim was then to find components on the market that were as natural and recycled as possible, as well as the best coupling agents and antioxidants – to obtain a recyclable, renewable product. One strategy is to recover composite wood


waste from construction sites, so it can be used to create new products. This can cut CO2 in the production and transportation stages by up to 50%, it says. Future research may include OIT studies on co-extrusions to determine their durability. “Our area of interest also concerns the develop-


ment of new building systems using WPCs, as the material can be designed for more complex components in the building envelope,” said the researchers.


Foam advantage At Hannover Messe earlier this year, Fraunhofer Institute for Wood Research (WKI) in Germany


28 PIPE & PROFILE EXTRUSION | Winter 2025


material that meets the requirements for design, comfort and functionality in vehicles such as caravans and small houses,” said Peter Meinls- chmidt, project manager at the Fraunhofer WKI. The sandwich top layers – made from hardwood and biodegradable EPLA foam – enable the production of lightweight, thermally insulating components for applications in the construction and vehicle industries, he added. One advantage is the integration of heating functions in furniture and interior components. Instead of a panel heating system through which water flows, an electric panel heating system can be integrated. The researchers’ approach relies on a heating paint made by the Austrian company Villinger.


Other wood species such as cherry, alder or


maple, as well as durable wood species such as robinia, can also be used. The project – called LeihMM-I sources local raw


materials, helping to cut dependence on fossil raw material sources, said the researchers.


Compatabiliser-free Research from Brazil aims to produce, optimise and characterise high-density polyethylene (HDPE)- based WPCs loaded with sawdust and glass fibre – without using compatibilisers. The researchers, based at the Federal University


of Technology Paraná (UTFPR), say this is the first time this has been achieved, in a paper published in ACS Omega. The amounts of sawdust (0−40%, w/w) and glass


fibre (0−40% w/w) were optimised for compressive strength using a Simplex Lattice mixture design. The WPC composites had densities of 780-987 kg/ m3, low moisture retention (0.83−2.45%), and mechanical properties of 0.97−10.89 kN. Scanning electron microscopy (SEM) micro-


graphs showed homogeneous materials in mixtures containing sawdust. Random distribution of silicon on the material surfaces was identified by energy dispersive spectroscopy (EDS). Further- more, the WPC loaded with 40% sawdust created the most compression-resistant composite. Results suggest a 17% greater strength than that of the control. However, a simple calculation indicates a 37% reduction in the production cost for the optimised 40% sawdust (US$ 0.53/kg) amount compared to pure HDPE (US$ 0.84/kg). In addition, replacing HDPE with sawdust could


www.pipeandprofile.com


IMAGE: IPERWOOD


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