Measurements of Grain Kernel Friction Coefficients Using a Reciprocating-Pin Tribometer

Abstract

Highlights A tribometer was used to measure the friction coefficients of corn and wheat kernels. Both static and dynamic friction coefficients were measured for particle-wall interaction. Data analysis processes were developed to calculate dynamic friction coefficients for inter-particle interaction. Abstract. Various devices have been developed to measure the coefficient of friction (COF) of grain kernels; however, the majority of these tests measure the particle-wall COF at a bulk level. A method that can accurately measure both particle-wall and inter-particle COFs at a single-particle level remains to be developed. The objective of this study was to explore the feasibility of using a reciprocating-pin tribometer to measure static and dynamic COFs between grain kernels and between grain kernels and wall materials. In this study, the methodology of the test was developed, and representative data from the particle-wall and inter-particle friction tests were reported. It was found that the static COFs of corn-steel, corn-acrylic, wheat-steel, and wheat-acrylic are 0.24 ±0.05, 0.22 ±0.03, 0.32 ±0.02, and 0.29 ±0.03, respectively. The dynamic COFs of corn-steel, corn-acrylic, corn-corn, wheat-steel, wheat-acrylic, and wheat-wheat are 0.22 ±0.06, 0.16 ±0.01, 0.09 ±0.02, 0.30 ±0.02, 0.20 ±0.02, and 0.18 ±0.04, respectively. The current study demonstrates that the reciprocating-pin tribometer is suitable for measuring the particle-wall and inter-particle COFs of grain kernels. Keywords: Coefficient of friction, Grain kernel, Reciprocating-pin tribometer