Flax, kenaf, wood pulp-fiber and paper

Flax (Linum usitatissimum) straw is an agricultural waste product from harvesting of seed flax from flax plant (Seed flax). The seed is used to make linseed oil. Flax is grown primarily in the North Dakota and Manitoba farm regions and is harvested with combines, much the same as wheat. The flax straw consists of two kinds of fibers: East and Shive. The outer layer consists of East fibers (about 30%) whereas the inner woody core consists of Shive fiber (about 70%). The waste straw is processed through a decorticator which enriches the fibrous portion by discarding most of the woody portion (shive) of the plant. The enriched flax straw is called tow and the material is used to make flax pulp by a modified Kraft pulping process and a mild bleaching process. Linen rags and spinning textile wastes as well as fiber waste from the processing of the raw fibers grown for textile fiber (Linen flax), is used similarly for paper making using conventional Kraft or Sulfite pulping process followed by mild bleaching. Kenaf (Hibiscus Cannabinus), an annual plant is also a non-wood fiber extensively investigated for paper making. Due to a shortage of wood fiber and to supply an agricultural product as an additional source of fibers for paper making the nonwood fibers are gaining worldwide attention, even in the fiber rich North American continent. These agricultural products also provide an alternate crop for the farmers. This paper will discuss the fiber morphology, chemical composition, pulping and bleaching methods, and pulp and paper properties of seed flax, linen flax, kenaf fibers and compare them with softwood and hardwood pulp fiber and paper properties. The unique properties of these non-wood fibers will be differentiated to provide an insight into developing technical specialty papers. The production of papers from these non-wood fibers permits multiple purpose land use, and economically benefits agriculture and the paper industry.