Twine, baler

Sisal fiber finds use in a variety of items such as in the manufacture of binder twine and baler twine, mattings, rugs, marine ropes, padding material for cars, upholstery, etc. 

Fibers are readily baled with wire or into paper or plastic bags. Refined wood and straw fiber for hydromulch, shredded recycled paper for insulation or mulch, and RDF are commercially extruded with piston balers at 50 to 100 psi (0.4-0.7 MPa) producing 16 to 18 Lb/CF (256-288 Kg/m3). Cotton motes, linters and flax fiber are baled at similar pressures into wire- or twine-bound bales. Under certain conditions fibers can be cubed. 

Photo-biodegradable polyethylene using the above system was developed commercially for use in agriculture by D. Gilead of Plastopil Hazorea in Israel in collaboration with the author and is now widely used as Plastor in mulching films in Europe and Plastigone in the USA. It is also used in polypropylene baler twines as Cleanfields by AMBRACO in the USA, and in controlled release fertilisers as Nutri-cote by Chisso-Asahi Fertilizer Company in Japan. The biodegradation mechanism will be discussed below. 

Coarse products suitable for the manufacture of baler twines, ropes and hawsers are made by flat film extrusion, water-bath quenching, air-oven stretching and optionally annealing thick film strips. The oriented strips are twisted and coarse fibrillation then occurs spontaneously. These polypropylene twines and ropes are stronger than ropes of sisal or manilla... 

In the USA photo-biodegradable polypropylene baler twines based on SG oxo-biodegradable PP have been used for 15 years and substantially replaced conventional PP slit films in hay wrapping and crop-protection netting. These are given a useful life of one year and this is followed by rapid disintegration and bioassimilation. 

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