Friction properties of reed stalks

One of the most important phenomena accompanying numerous processes biomass materials undergo is friction. The identification of the friction processes for plant materials is necessary for the correct design of many technological processes during which they are transported, chopped, or stored. Most research on friction uses the simple Coulomb model. To determine the coefficient of friction, an adjustable tilt plate is used, on which the material under study is placed. The coefficient of static friction was taken as the tangent of the angle of the inclined plate at which the material begins to slide. Friction can be determined by moving biomass against horizontal surfaces of different materials. Common materials for friction pairs with biomass were steel plates, wood, glass and rubber. Common reed (Phragmites australis) is a grass which has spread nearly all over the globe. Considering that the reed stalk is a natural tube, it can be used to make cocktail straws. However, there is a much wider range of uses, such as toy components, room decors etc. Such applications require that the reed stem is not flattened after cutting. Likewise, the end of the stem must be free of sharp edges and smooth. In previous studies, non-destructive cutting of reeds using abrasive discs was evaluated. In order to create a device for non-destructive cutting of reeds, it is necessary to know the coefficient of friction of the reed stalk. This paper analyses friction parameters of reed stalks of different diameters. As a result of the research, the values of friction coefficients for reed against various plastics, metals and rubber were obtained. The coefficient of friction of reeds against hard materials (both metals and plastics) ranges from 0.12 to 0.37. A significant difference depending on the diameter of the reed is not observed. The highest values of the coefficient of friction are between reeds and rubber, from 0.81 (transverse direction) to 1.02 (longitudinal direction).