Humidity effect on coefficient of static friction of rosemary and lavender by friction - electric meter

Background & Aim: Increasing economic role of medicinal herbs in recent society and complexity of modern technologies in production (planting and harvesting), transportation, storage, processing, quality evaluation, distribution, marketing and consumption of these products require a thorough understanding of their physical properties. Coefficient of friction of plant on the various surfaces is needed in designing of silos, storage of agricultural products and handling equipment, such as conveyors, and design of other equipment used in post harvest processing. Experimental: In this study, static coefficient of friction for two values of water content (wet basis) 58% and 53% for rosemary and, 65% and 63% for lavender on three surfaces, galvanized steel, glass and wood was investigate. For this purpose an apparatus made that includes an electrical motor and an optical sensor for precise measurement of the slipping moment of the product and its coefficient of friction. Results & discussion: Average values of maximum and minimum of static coefficient of friction that obtained for rosemary at 58 percent of water content were 0.87 on the wood surface and 0.46 on the glass, respectively. While at 53 percent water content, the maximum and minimum average values of coefficient of static friction obtained for rosemary were on wood, 0.66 and glass 0.38, respectively. The minimum average value of coefficient of friction for the lavender at 65 percent water content was 0.66 and on the glass however after the reduction of water content, at 63 percent water content, obtained 0.56 on the glass, too. Industrial and practical recommendations: The understanding of the engineering properties of herbal drugs for creating appropriate industrial procreation methods is of great importance.