| Abstrakt: |
The objective of this study was to investigate the technical feasibility of manufacturing new composite products (particleboards) from agricultural residues (non-useful parts of industrial cannabis stalks). The use of such a material may benefit both the socioeconomic and environment development since these are left on the field to decay and therefore, they are generally considered as waste material of no industrial value. After the receiving hemp residue material, the outer part of the cannabis plant stem was separated from the inner part by a special defibrillating machine, next the evaluation of the physical and chemical properties of the material (percentage of moisture, density, extracts, pH, determination of the percentage of pith, woody part and fibres, percentage of moisture absorption, shrinkage, swelling) was conducted. The internal woody part was cut down appropriately to be used in the manufacture for wood-based panels, next the fractional analysis to control the shape and dimensions of the wood chips was conducted. The evaluation of these results allowed to determine the most suitable way of crushing with the ultimate goal of using the appropriate fractions to manufacture particleboards. Eight types of particleboards, with different parameters, were prepared in which the wood chips from hemp stems (hemp fibres and woody part of hemp) were used in various mixing ratios with the industrially produced wood chips (wood to hemp percentages of 75:25, 50:50, 25:75 and 0:100). Phenol-formaldehyde and urea-formaldehyde resins were used as the reference adhesives. Mechanical properties (internal bond strength, modulus of rupture and modulus of elasticity) and physical properties (thickness swelling, water absorption) were also determined. The production of particleboards seems to be the most ideal way of utilizing hemp residues since the product is widely consumed worldwide, it is cheap and the raw material requires little energy expenditure to reach the final production form. The main advantage of these new products is the lower cost and weight. Overall, an economy in the use of new raw materials is achieved and agricultural waste finds use in value added applications. [ABSTRACT FROM AUTHOR] |
