Yarn deflection guide with thermal control - has separate adjustments made to set yarn temp. at the deflection point

摘要

At the deflection point for a travelling yarn in a yarn guide, the yarn temp. is maintained within given limits independently of the yarn processing parameters. The temp. at the yarn deflection point is affected by altering at least one of the deflection parameters, independently of the overall yarn processing parameters. Pref. the yarn temp. at the deflection point is affected by altering at least the friction coefficient between the yarn and the deflection surface and/or the speed difference between the yarn and the deflection surface and/or increasing the deflection angle above the min. required for the process and/or the heat flow between the yarn and the ambient environment and/or the heat flow between the yarn and the yarn guide surface. The friction between the yarn and the guide surface is altered by at least the guide surface material and/or the composition of the yarn guide material and/or pressure forces against normal forces and/or a lubricant. The speed difference between the yarn and the guide surface is altered by changing the guide surface speed. The deflection angle is modified by the position of the deflector in relation to the yarn and/or by locating a number of deflectors in relation to each other. The heat flow between the yarn and the environment is set by the medium and temp. of the ambient environment and/or heat transfer between the yarn and environment and/or relative speed between yarn and guide surface and/or a contact surface between the yarn and the environment. The heat flow between the yarn and the guide surface is varied by the material of the guide surface and/or the thermal capacity or conductivity of the yarn guide and/or the heat transfer between the yarn guide and the environment and/or wetting parameters and/or a contact surface between the yarn and the yarn deflection parameters. The deflection point provides at least one process function to the yarn in addition to altering its path of travel, such as heating or cooling the yarn or acting as an applicator to deliver a dye, adhesion aid or a magnetic additive. ADVANTAGE - The heat generated by the deflection of the yarn at the guide is freely selected, adjustable and/or continuously regulated to set the yarn temp. before and after deflection according to the nature of the yarn material and its behaviour when heated.