Friday, 31 October 2008

Warp Knitting | New Rot-O-Tense yarn tensioner with motor drive from KARL MAYER

Rot-O-Tense, the yarn tensioner with a special feature – motor-driven – operation 

The new yarn tensioner Rot-O-Tense
Right from the early stages of the production process, textiles for use in special applications have to be produced on machines having very specific features.
Special warp preparation technology is needed to produce warps from high-strength technical yarns, such as glass or aramid, for example, and these must be able to guarantee high tension levels, gentle handling of the materials, maximum efficiency and top quality.
The Rot-O-Tense from KARL MAYER can make an effective contribution here.
The new yarn tensioner, which has been developed by this successful, traditional manufacturer, is both accurate and reliable and is extremely flexible to use.
It autonomously controls the yarn tension that has been set by the operator at the creel as an independent unit. Each yarn tensioner autonomously monitors the actual value and adjusts it to suit the desired value that has been set – and this is done in real time, independently and steplessly over a wide yarn tension range. This enables each take-off point to have its own yarn tension value, e.g. if different yarns are needed in the warp.
The operating range of the Rot-O-Tense theoretically begins at a yarn tension of 0 cN and goes up to 330 cN. The system can achieve variable yarn running speeds of 0 to 1,200 m/min, regardless of the yarn tension. This opens up completely new opportunities for the customer.
Operating principles
The new Rot-O-Tense yarn tensioner owes its exceptional performance to the use of high-quality control electronics, which are located in each yarn tensioner and process the information on the yarn tension obtained by the measurement sensor. If the actual and desired values correlate with each other, the status is maintained.
If there are any deviations, the yarn tension is automatically adjusted in real time. The required adjustment is carried out by a motor-driven AccuGrip wheel, which is either made to actively rotate or braked, depending on the type of adjustment needed. To produce the desired, low tension, the yarn has to be removed and driven from the package. If a higher yarn tension is required, the motor acts as a brake. This is an ingenious technique and its well-thought-out principles open up new opportunities for yarn handling. The design features of the AccuGrip wheel with its profiled discs ensure that the yarn is delivered very gently, without any sliding friction and without any of the associated abrasion. If required, the grip-wheel can be replaced by a yarn guiding device or used in conjunction with a yarn guiding device. With all its special features, the Rot-O-Tense is ideal for processing polyester, polyamide and polypropylene, as well as glass, aramid and carbon or acetate, rayon, wool and cotton. The new yarn tensioner can handle virtually every type of yarn in practically any count.
Even though the yarns are handled gently, yarn breakages may still occur, and packages may also run out, in which case the system automatically detects the missing or loose yarn and stops the machine
Communication principles:
Depending on the machine being used, which stands in front of the creel, any yarn breakages are transmitted by a bus system and analyzed. Their occurrence can be displayed using X-Y coordinates for the row and level, either at the touchscreen or at a separate display. Information on the nature of the disruption can also be requested.
To ensure that the number of warp yarns on the final beam corresponds exactly to the specifications of the production job, missing yarns are displayed and yarns that have been incorporated inadvertently are also recorded. In this case, the machine is stopped.
A wide range of information is available at the request of the customer. The Creel Boy, which was developed a few years ago, can be used to help with creeling of the bobbins, and even with selecting the colors. The light-emitting diodes that are attached to the yarn tensioner can be used in this case.