Modeling and analysis of cage gin lint removal process

Abstract

The cage gin is a relatively new development to gin cotton fibers which is currently being commercialized. It has the advantage that the lint obtained with it is higher quality than that obtained with the saw gin or roller gin. However, it has the disadvantage that its lint turnout is lower than that of the saw gin or roller gin. A model to predict the optimum operating parameters of the cage gin was developed. The model was useful to gain understanding of the cage ginning process, to develop recommendations to improve the gin operation, and to increase lint turnout of the cage gin. Measurement of two physical properties of the cotton fibers was required because this information was not available and was required as input to the model. The two properties are fiber attachment force and friction with different materials. Exponential models to predict the frictional force as a function of the normal load and apparent contact width were determined. The model computes the nip roller normal load, torque required, the minimum tangential velocity ratio of the nip roller and the cage, and the length of the shortest fiber that can be grasped by the rollers. The values predicted by the model for the normal load and torque required at the nip roller are higher than the actual values. The minimum tangential velocity ratio obtained by the model is close to the recommended ratio obtained by experimental results of previous work. The average computed length of the shortest fiber that can be grasped between the rollers was 17.27 mm (0.68 in), however, the results of the fiber analysis showed that the lint contained fibers with a length of 12.7 mm (0.5 in) or less. The short fibers can be detached because of the interfiber friction and entanglement of the fibers. It is believed that this fiber interaction is the main cause of the over predictions in the model..