RESEARCH AND IMPROVEMENT OF A STAKING MACHINE FOR PROCESSING ELASTIC-VISCOUS FIBROUS MATERIALS

An improved design of a technological machine was developed for staking various elastic-viscous fibrous materials, such as leather, leather fabrics, fur skins, and other materials. A machine for staking elastic-viscous fibrous materials consists of a frame, on a shaft of which a cast-iron drum with flat steel knives on radial grooves is installed using bearings; the knives are arranged in a semi-circular contour. In operating a technological machine, first, the skin is installed on a support belt and is put behind the working knives. Then the pedal is pressed and using the lever the skin is lifted on the table belt. The material being processed is in contact with the knife blades in turn, and the operator pulls the skin and stakes it. In this manner, the operator repeats the procedure and the entire area of the skin is staked. When the pedal is released, the elastic belt lowers to its original position due to the gravity and pressing force of springs. The elastic conveyor belt is periodically moved and fixed with a stopper with two bolts. When one blade of the knife is worn out, the rotation of the drum is stopped and two bolts of the knife clamp are unscrewed, and then the blade is turned over and the worn-out end of the blade is inserted into the drum, tightened with two bolts and the knife is fixed. By making elastic movable support in the form of a conveyor belt, its service life can be highly increased and the replacement time reduced. This improves the quality of leather staking and increases the yield area, and processing productivity. The technical and economic result of the use of an improved machine is an increase in the productivity and quality of leather processing, skin yield in terms of usable area, and an increase in the service life of the elastic movable support and working knives. The authors developed designs for working knives with wavy blades. Working knives are made with alternating waves on the blade, for example with two and three waves. Theoretically, a 1.1 times increase in the stress values between the processed material and wavy working knives was determined. Preliminary experiments were performed using wave-shaped knives. It was determined that due to the use of wavy knives, additional bending and stretching of the leather fabric of the skin occurs. This led to additional delamination between the fibers of the skin's leather fabric. Consequently, an increase of more than 5.7 percent in the plasticity of the treated inner side of the skin fabric was achieved.