Method and device for twisting linear products having no shape memory

Abstract

The subject of the application is a method of twisting linear products without shape memory, especially polypropylene raffia, which consists in introducing the twisted product with a forced linear movement through one of the transverse feeding channels into the vortex chamber (6) driven by oscillating movement, and then directing it to a forming slot subjected to cycloidal movement, shaped between the outer surface of a cylindrical armature (11) mounted on a conical spindle and the inner surface of the vortex chamber (6).Then, the product, with the help of a loop-shaped passage (23), moving in a cycloidal motion, is formed into the shape of several turns forming a conical spiral with the desired direction of rotation, each with a different angular velocity during its progressive circular motion around the conical spindle and mandrel (16), delivering the last turn having an angular velocity equal to the revolutions of the main shaft to the outlet of the swirl chamber (6), located in the loop-shaped passage (23), where, as a result of the action of the torsional moment at the point of contact of the product with the receiving blocks, it receives a given twist. The application also concerns a device for twisting linear products without shape memory, which in the body of the twisting assembly comprises a swirl chamber (6) with at least one transverse input channel located in its cylindrical wall.Furthermore, inside the vortex chamber (6), on a conical spindle, a cylindrical armature (11) is freely and rotatably mounted. Its cylindrical surface, together with the inner cylindrical surface of the vortex chamber (6), forms a forming slot, which is set in cycloidal motion. A mandrel is located in the vortex chamber (6), the longitudinal axis of which is aligned with the main shaft. It is mounted in the front wall (20) of the vortex chamber, with the other free end moving in a recess located in the front wall of the conical spindle. Furthermore, a loop-shaped passage (23) is located in the front wall of the vortex chamber (6) along its geometrical axis, constituting the outlet from the vortex chamber (6), which is set in cycloidal motion.