Bioplastics: The race is on!

Mark Willliamson

Users of molded plastics are asking for alternate materials which are strong, durable, light in weight and made from renewable sources. A growing number of companies – including a Canadian one - are leading the way with wood pulp-based composites.

The field of bioplastic composites came into sharp focus with Weyerhaeuser's recent announcement that it has developed a new polymer and wood pulp composite material which will be used by Ford Motor Company to extend the range of potential automotive applications for natural fiber materials. A Ford spokesperson says that, with increased use of these renewably sourced materials, the company can significantly reduce the environmental footprint of its products while realizing a variety of benefits across the entire supply chain.

Weyehaeuser's new THRIVEtm product and other biocomposite supplier products will have far-reaching implications for the wood pulp industry which is actively looking for new revenue streams from its renewable fiber resources. Since wood fiber is not part of the food chain it has an inherent advantage.

The association with Ford certainly gives Weyerhaeuser a leg up in lucrative automotive applications and is a headline grabber, for sure. However they are one of several players in this rapidly developing industry. The race is on to develop new wood fiber-based composite materials and applications.

Weyerhaeuser's composites are also aimed at many other molded plastics applications including office furniture, kitchenware, small and large consumer appliances, and other industrial goods which currently use fibreglass reinforced plastics. The company says it plans to expand the line of products beyond the current polypropylene/fiber blend to include a range of hydrocarbon and non hydrocarbon polymer blends.

Other companies have similar application ideas and aspirations. Here is a cross-section:

Canadian-developed technology

Canada's GreenCore Composites, based in Toronto, has developed wood pulp/polymer composites that are capable of replacing more energy-intensive glass fiber reinforced compounds now used in a wide variety of products. The company says its NCell® technology is based on in-situ generation of lignocellulosic microfibers. Patent applications for this process are in progress. These fibers have high aspect ratios and surface area, enabling improved mechanical properties. The company says it is able to produce microfibers in a cost effective manner and from a variety of raw materials. Tembec is the company's supplier of specialty wood pulp.

The manufacturing process allows effective dispersion of the microfibers in the composite material while maintaining proper morphology and properties. This is due to a combination of mixing technology and chemical process aids.

The NCell composite has been successfully piloted in many applications, from automotive parts, to rigid containers, furniture, and industrial products. GreenCore's ability to replace up to 40% of synthetic polymer content with wood fibers provides weight savings of up to 20% compared to traditional glass fiber materials lowers CO2 emissions and improves recyclability.

GreenCore NCell Composite's pellets are used in injection molding processes.

Multi-colored panels made with pigmented NCell.

Europeans actively promoting biocomposites

European forest products companies are actively involved in the bioplastic market as well, using their own specialty pulps. This past summer Finland's UPM announced that its ForMi biocomposite replaced plastic as the cover material on a mobile phone microscope accessory developed by KeepLoop, a Finnish technology company. A company spokesperson says the new biocomposite is an excellent material for the injection molding process. It feels softer and warmer than the traditional PC/ABS polymer plastic.

UPM customers have already used ForMi in furniture manufacturing and in different utility consumer goods. The company has shown it meets the needs of the electronic industry as well.

UPM ForMi biocomposite is used in electronic product cases –
in this case a KeepLoop miniature microscope accessory for a mobile telephone.

Earlier this year Sweden's Södra Cell announced that it has begun commercial production of DuraPulp for use in renewable, biodegradable materials which are also very strong. The product was developed in collaboration with Sweden's Innventia research organization.

DuraPulp is made up of a specially selected pulp from a Södra Cell pulping process and a biopolymer. With further processing, these two components take on special properties such as moisture resistance, strength and hardness. Last November, DuraPulp won PPI's innovative product of the year award.

Nanocellulose: small in size, big in impact

Although it is very small in size but big in impact, nanocellulose in its various forms is also a significant player in the drive to produce biomaterials with enhanced physical properties. Some very big plastic consumers are interested. For instance, at a recent Tappi nanocellulose conference in Montréal a representative of IBM said the company is interested in alternative biomaterials to replace traditional petro-plastics used in its mainframes and data centers.

In Canada, CelluForce is leading the charge to commercialize nanocrystalline cellulose - a specialty biochemical aimed at a variety of high valued-added applications. The one tonne per day demonstration plant in Windsor, QC has been up and running since early 2012. In Europe, UPM and Stora Enso have recently opened pre-commercial demonstration plants for nano and micro scale fibril cellulose, another variation of nanocellulose.

Although the many diverse applications of nanocellulose are yet to come some bio-plastic applications of this miniscule building block material are just becoming apparent. Just announced in early 2012, the VTT Technical Research Centre and Aalto University in Finland have developed a method which enables manufacturing of nanofibrillated cellulose film, which is suitable for food packaging to protect products from spoilage.

Daicel in Japan is developing applications for its Nano Celish™. The company says that mixing nano-scale fibers into a resin produces an exceptionally strong composite product which helps to produce lighter automobiles. Since the material does not affect the transparency of resin, the company says it is now planning to manufacture a composite material substitute for glass.

Bioplastics have momentum

The bioplastic industry has considerable momentum right now, so many new products and applications will probably be announced in the not too distant future. The industry is moving so quickly it's hard to keep up with the announcements.

In fact, here is one press release just published at the end of September, 2012 headlined, "Biocomposites challenge chipboard (aka particleboard) as furniture material."

VTT Technical Research Centre of Finland has developed a new lightweight kitchen furniture framework material which can replace chipboard (particleboard). It is made from plastic polymers reinforced with natural fiber such as sawdust, wood pulp, flax, hemp or peat. According to a VTT researcher, the framework for the kitchen of the future may be made with familiar plastic molding or extrusion processes.

In addition to reducing raw material consumption by 25–30 %, the new product is stronger than particleboards and is moisture resistant.

With this, and others yet to come, the race continues.