Abstract: A method of producing a synthetic yarn, wherein a yarn is spun and wound in a continuous process. For monitoring the quality, several process parameters are continuously measured. From measured data variations of the process parameters that occur within a predetermined period of time, a quality value is determined that is a measure for the regularity of the production process.

Abstract: A method of winding a continuously advancing yarn to form a package, and so as to define an initial winding time T and a normal winding time. During the normal winding time a contact roll is positioned to lie against the surface of the package being formed, and the winding spindle speed is controlled by the contact roll. During the initial winding time T, however, the rotational speed of the winding spindle is controlled by a speed change function, which associates in the course of the winding cycle a certain winding spindle speed to each package diameter, while maintaining a constant yarn speed during the winding.

Abstract: A method for winding a yarn in a random wind at a rated traversing frequency in a predetermined course, and so as to produce a ribbon free randomly wound package. For avoiding ribbon formations, a critical range characteristic of a ribbon is traversed at a changed traversing frequency. In particular, the traversing frequency is slowed down constantly or in steps upon entry into the critical range, and it is increased suddenly in the further course within the critical range to a value above the rated traversing frequency. After increasing the traversing frequency, same is slowed down constantly or in steps, so that upon exit from the critical range the traversing frequency assumes the value of the rated traversing frequency.

Abstract: A method and apparatus for continuously producing an endless thermoplastic material, such as yarn or tape, and winding the material into a package. A physical parameter of the package, such as its diameter or weight, is monitored, and a control signal is generated which is a function of the monitored physical parameter. The control signal is then compared to a predetermined reference signal, and an output signal is generated when the difference between the control signal and the reference signal exceeds a predetermined deviation. The output signal thus represents the quality of the material in the package, and it may be used to permit classification of the final product or to control the operating conditions of the apparatus so as to maintain a desired quality level.