Japan’s Daio Paper plans to start sample shipments of polypropylene (PP) compounds reinforced with cellulose fiber this coming November. A 10% cellulose-reinforced PP compound features a flexural modulus of 2.5 GPa, which is 1.3–2.1-times higher than conventional unreinforced PP.

Daio Paper kicked off sample shipments of cellulose nanofiber (CNF) aqueous dispersions back in 2013, while in 2016, the company started up a 100-tonnes/year pilot plant in Mishima, Japan, whose purpose was to reduce the manufacturing cost of the materials to a commercially-sustainable level. Further, in December 2017, Daio Paper completed a CNF dry fiber pilot plant with capacity of 10 tonnes/year with the specific aim of developing fiber products with reduced moisture levels suitable for use as reinforcing media for plastic composites.

Research efforts subsequently proved that it was not necessary to process cellulose fibers to the nanolevel in order to achieve appreciable enhancements of mechanical properties in composites. The cellulose fibers were also cheaper to produce and easier to disperse throughout the resin matrix. Daio Paper has now started to use such cellulose fibers in the PP compounds it aims to commence shipping this November.

Daio Paper says the pellets it will be shipping can be molded with conventional processing machinery in a cost-competitive manner. Further, fiber size can be tailored to the needs of individual applications. The company is ready to discuss volumes and pricing with potential end users.