GB733838A - Improvements relating to the separation of fibers from bast-fiber stalks - Google Patents

Abstract

733,838. Decorticating apparatus. BOBKOWICZ, E. July 28, 1953, No. 20937/53. Class 120(1). Fibre is separated from bast stalks by splitting the stalks longitudinally, laying the split portions side by side with the bark all facing in one direction, flexing the split portions and, while flexed, cutting the wood core transversely at intervals without cutting the bark, and subsequently picking the wood pieces from the bark. As shown, a vibrator unit B pushes stalks into compartments of a divider unit C, each compartment forming a narrowing chute which delivers one stalk at a time onto a conveyor belt 34 whence the stalks are fed side-byside to a cutting unit D. In unit D, driven rollers 45, 46 feed each stalk between channels in the surfaces of co-operating rollers 60, 65, a knife 61 mounted in the middle of the channel of roller 60 splitting the stalk longitudinally. The stalk then passes between further mating rollers 70, 75, 70a, 75a and 70b, 75b of a flattening unit E ; rollers 70, 70a, 70b have wedge surfaces of increasing bluntness which turn the halves of the split stalk until they are disposed with the bark downwards and wood upwards. In this condition the stalks are flexed around a drum 90 of a cutting and stripping unit F where the wood core is cut at intervals by the chisel edges 92 of a rotary cutter 91, the edges of the blades being spaced from the drum surface so as not to cut the bark. The cut wood is picked off by plates 101 on a rotary cylinder 105 and by a chisel-edged roller 109a, and is removed by a screw conveyer 107. The bark then passes around a knurled drum 411 of a scrubbing unit H where spiked or scraper-edge rollers 419, 423, 427 and 431 scrape the gummy material from the bark and liberate the fibres which are then scrubbed by brushing rollers 445, 449, 453, 457 and 461. Each scraping or brushing roller comprises scraping or brushing elements running axially of the roller, and, located between such elements, axial perforated pipes through which water is projected onto the bark. The solids detached by the scraping rollers are removed by a screw conveyer 500. The scrubbed fibre is discharged in web form between belts 475, 477.