Development of a machine for combing seed capsules from flax straw at a flax mill

Abstract

Modern combing must meet agrotechnical requirements by ensuring complete separation of flax capsules, preventing stem entanglement, and minimizing damage to flax stems. However, existing designs do not fully satisfy these requirements, as the penetration of comb teeth into the flax ribbon causes excessive entanglement and stem damage. (Research purpose) The purpose of the research was to develop a stem-combing device for flax-processing enterprises and to substantiate the rational design parameters and operating modes of the machine. (Materials and methods) A stationary experimental setup equipped with a conveyor for feeding flax ribbons into the combing zone was designed and manufactured. The setup made it possible to simulate the separation of seed capsules from fiber flax stems during the combing process. Fiber flax of the Visit variety was used as the initial plant material in the experiments. Combs with different tooth profiles were tested. (Results and discussion) The experiments were conducted using the methodology of mathematical design of multifactor experiments based on a second-order Box–Behnken design. Among the tested variants, the comb with a circular profile proved to be the most effective. (Conclusions) A combing purity of at least 98.5% for fiber flax ribbons was achieved when using a comb with a circular tooth cross-section, a flax ribbon conveyor speed of 1.25 meters per second, and a comb rotational frequency of 2.8 meter per second. The obtained results can be used in the manufacture of serial combing units for flax processing lines. The proposed unit is suitable for integration into domestic production lines for both long and short flax fiber.