Development and evaluation of a guayule debarker

• Published in: Industrial crops and products Vol. 34; no. 2; pp. 1256 - 1261
• Main Authors: Bedane, G.M., Gupta, M.L., George, D.L.
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.09.2011
• Subjects: Bark; Crops; Debarking; Guayule; harvesting; Latex; Parthenium argentatum; prototypes; Rollers; rubber; Separation; shrubs; stems; water troughs; Guayule; Separation; Rollers; Debarking; Latex; Bark
• ISSN: 0926-6690; 1872-633X
• DOI: 10.1016/j.indcrop.2010.05.017

Guayule ( Parthenium argentatum Gray) stores its rubber primarily within the cells of its bark, which constitutes only 30% of the dry weight of the whole shrub. Debarking guayule soon after harvesting at the crop site would substantially improve the efficiency of latex extraction technology by reducing transport costs to the processing plant and increasing the processing capacity of the latex extraction plant. The objective of this study was to design, fabricate and evaluate an efficient debarking machine for guayule. The bark removal unit consists of a pair of grooved rubber rollers rotating in opposite directions at different speeds, drawing and crushing the cut stems without chipping the core. The clearance between the rollers is adjustable and can handle different stem sizes ranging from 6 to 45 mm. The speed difference between the rollers creates a shearing action, required for peeling the bark. The separation unit consists of a fan attached to metal tubing, a discrimination chamber for grading processed material and a water trough where lighter material is removed by flotation. The debarking system was tested to determine bark removal performance as well as separation of bark from other processed plant material. A debarking efficiency of up to 95% and maximum separation efficiency of 75% were found from the evaluation. The prototype debarking machine produced a throughput capacity of up to 450 kg/h which can be increased by converting it to a full-size field machine.