Rieter

Yarn waxing device

Index

In the production of knitted goods in particular, where the yarn is bent sharply around the needles, rough yarns can cause disturbances, broken threads, and a high degree of wear. In order to improve running performance, knitting yarns have always been waxed. The rotor spinning machine enables this to be done directly at the spinning position.

Mill results have shown that a maximum reduction of the coefficient of friction of between 40 and 50% is achieved by means of the usual wax application of between 0.5 and 3 g/kg of yarn. Type and quality of the wax are decisive for optimum waxing application. Wax differs in hardness, melting point and penetration and needs to be selected according to raw material, yarn type and knitting requirements. Waxing devices also differ in the size of the wax blocks used. In addition to longer running times, larger wax blocks entail significantly reduced effort for replacing the wax blocks. In this connection, it should be noted that over-application is just as detrimental as under-lubrication, since both result in a high coefficient of friction.
The waxing device (see Fig. 37) is arranged between the take-off rollers and the package so that small particles of lubricant can settle on the yarn as it passes over a body of wax. These particles are rubbed off as the yarn is sharply bent at the needles of the knitting machine, and they then ensure good running properties. The wax block is pushed automatically by a spring into an optimum position to counteract wear. The rotating wax block is stopped in the event of ends down.
The waxing device always requires yarn compensation devices such as compensation bows or yarn tension bars. Different kinds of covers at or below the waxing device prevent loose wax particles from falling into the spinning cans and thus contaminating the sliver.

Fig. 37 – Waxing device with large wax blocks