Hemp Fibers for Production of Speciality Paper and Board Grades
Hemp fibers for production of speciality paper and board grades Janja Zule, Marjeta Černič, Matej Šuštaršič Bled, November 22, 2012 Papermaking fibers Origin • Softwood - spruce, fir, pine • Hardwood - eucalyptus, aspen, birch • Annual plants – hemp, flax, kenaf, bagasse, cotton, straw Properties • morphological • chemical • physical, mechanical • optical HEMP fibers in papermaking • the oldest surviving piece of paper from hemp – China (140 – 87 B.C.) • the first European papermaking in the 16th century • until the 19th century - rags (hemp and flax fibers) • growing need for paper - rag supply insufficient • exploitation of wood – abundant and cheap • today, only about 5 % of world s paper is made from annual plants (hemp, flax,…) HEMP fibers in papermaking • renewed interest in hemp – environmental reasons • excessive deforestation (TREES - oxygen supply, CO2 removal, natural balance) • 1 t of PAPER – 3 t of WOOD - up to 17 TREES • HEMP has about 4 times higher yield / hectare compared to TREES (20 years) • TREES need 50-100 years to grow, HEMP can be cutivated in 100 days HEMP fibers in papermaking Hemp bast Hemp core cellulose 70 % 35 % hemicellulose 15 % 35 % lignin 5 % 23 % length, mm 5 - 40 0,5 diameter, µm 25 - 50 22 thickness, µm 10 - 25 1,4 HEMP fibers in papermaking hemp bast hemp core long fibers short fibers HEMP fibers – charactesristics WOOD HEMP cellulose 40 – 50 % 70 % hemicellulose 25 – 35 % 15 % lignin 25 – 35 % 5 % Fibers SW HW length, mm 3 - 6 (0,5 - 1,8) 5 - 40 diameter, µm 25 - 45 (10 - 36) 25 - 50 thickness, µm
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