Theoretical Studies of Design Parameters of Machine Elements for Surface Planting of Rice

The paper presents the definition of the main parameters and operating modes of spreading centrifugal devices of technical means when using them in the surface planting technology. It has been determined analytically and experimentally that under the existing operating modes of centrifugal apparatus, in order to reduce reflection, grooved blades should be used, the upper planes of which are tilted from the horizontal position by an angle of 5-10 °, the angle of the blades should be ≤15 °. According to the results of theoretical and experimental studies, a prototype was made, the productivity of which when sowing rice in comparison with serial machines increased by 1.5 times with an uneven distribution over the working width not exceeding 15%.

Flame Retardant Polyethylene Terephthalate Fibers Added with Melamine Based FR Additive

Polyethylene terephtalate (PET) was modified with a melamine derivative additive in order to obtain flame resistance of fiber products. The effect of flame retardant (FR) agent was determined by measuring rheological and combustion properties of PET linear polyester. The solubility of additive was investigated using a torque-rheometer. In course of the rheological investigation, the rate of solution was determined. The effect of FR additive on the melt rheology could well be traced by using a torque-rheometer and its evaluation method. After preparation of polyethylene terephtalat and melamine mixture melt, fibers were made by coextrusion centrifugal apparatus. The flame retardancy of fibers were determined by standard combustion tests. These tests were performed in order to determine the oxygen index of fiber products. It was proven that a favourable degree of combustibility of PET can be obtained under the influece of adding melamine-derivative additive.