Separation of Fibre and Shives from Decorticated Flax

Abstract

Abstract. Decorticated flax contains significant amount of shives. The separation of shives from the fibre is essential in order to use the fibre in biomedical implants, automobile industry, bio-composites, textiles, and many other applications. In this study, several methods such as ball milling (wet and dry), carding, floatation method, pneumatic method, and a 4-machine sequence were used for separation of flax fibre and shives. Preliminary testing of all these methods revealed the potential of using the latter two for separation of fibre and shives. Machine sequence tests, involving Tumbler, Picker, Sorter, and Carder, used two different decorticated flax fibres (Grade1 and Grade2). The results showed that the Tumbler could remove some shives, but caused significant fibre losses; the Picker and Sorter were able to partially separate shives from fibre, and maintain good machine yields; and the Carder did not work because the fibre were too short for this equipment. Pneumatic method was used to study the relationship of particle characteristics such as diameter, length, mass, and projected area for 25 individual fibre and shive particles with respect to their terminal velocities. The range of terminal velocities for shive and fibre particles were 1.13 to 4.09 m/s and 0.51 to 1.07 m/s, respectively, which were significantly different (p