Sappi’s Symbio - Injection Moldable Cellulose Fiber Composite

October 8 2015, 03:00

Injection molded plastics dominate audio consumer electronics products. Stylish shapes and consistency are readily achieved with an established supply chain and well known design rules. Yet injected molded products of plastic are perceived as “cheap” and have mediocre acoustic characteristics. Wood fiber based products, typically MDF with a wood veneer or vinyl wrap skin, have good acoustical qualities but curved and shaped parts add greatly to the cost, and the weight and bulk of MDF thick wall construction is high.
Symbio injection moulded plates (with surface structure) in different colors.
Natural fiber composites enable the best of both wood and plastics. A new cellulose reinforced polypropylene composite is being developed at Sappi by their Symbio team. Sappi is a leading diversified woodfiber group, focused on dissolving wood pulp, paper pulp and paper-based solutions. The Symbio team believes their composite has the potential to become a mainstream material for consumer electronics enclosures such as Bluetooth speakers and docking stations. For audio engineers, Symbio’s composites will be a unique enhancement using existing tooling for headphones, speaker parts from enclosures, tweeter baffles, and compression driver phase plugs, back chambers, horns and possibly speaker cones.

Symbio cellulose reinforced
raw material (granules)
Symbio’s cellulose reinforced polypropylene is primarily being developed for standard injection molding and extrusion processes. The stiffness is higher than talcum filled polypropylene and in many products the weight per unit will be able to be reduced. It can be used as an alternative for talc, mica filled polypropylene or ABS plastics, for example. It can easily be colored, including white, and fibers are not visible resulting in a great freedom of design. It will initially be available with 20% and 40% cellulose content. The cellulose fibers come from sustainable and controlled sources.

The Symbio team, led by Jacob Hartstra, is looking for more audio companies interested in injection molding and extruding the composite and in benchmarking it compared to existing plastics enabling further development according to needs and requirements of a diversity of audio applications.
Those interested can contact Jacob by email here.
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