The New Adjustment Tool From Loepfe: P-Matrix

Extensive tests at SLP Spinning Mills

SLP Spinning Mills Private Ltd., based in Guntur Dis­trict, India, produces high quality cotton yarns for local and export markets. The company, which has been founded in 2006, employs some 500 staff. The total capacity of 47,520 spindles is used to produce mainly combed compact cotton yarn in the range of Ne 40 to Ne 80. Contamination of the raw cotton with white and transparent polypropylene fibers is a major concern for yarn quality. Polypropyl­ene contamination, which usually originate from bale packaging, may cause many problems in subsequent processes along the production, i.e. broken needles in knitting applications, thread breakage in weaving, and visible defects in the final product after dyeing are among those.

To improve yarn clearing, SLP and Loepfe conducted extensive tests with the new P-Matrix tool, which can be used for adjusting Loepfe´s yarn clearer YarnMaster ZENIT“We use yarn clearer from Loepfe for many years now, and have always been satisfied with the results”, says Mr. Desu Suryaprakasa Rao, managing director at SLP.

Taking full control

The test runs for the new adjustment tool P-Matrix have been done as follows: In the first step, a cotton bale, where the polypropylene has been segregated manually, has been used to spin Ne 60 combed yarn. The subsequent winding has been done on a Saurer Autoconer 6. The yarn clearer eliminated 20 synthetic foreign matter faults on a length of 100 km. The clear­ing efficiency was above 80 %, and there haven´t been any complaints from the customer.

In the second step, the customer utilized the innova­tive P-Matrix to enhance the control over the clearing process. By entering the P settings the P-Matrix shows a clearing curve considering the most common factors to reach optimal and efficient clearing results. The op­erator can easily adjust settings to the individual needs by increasing or lowering the clearing curve, in order to receive optimum results. Other factors, like hairiness and yarn tension have to be taken into ac­count. The settings can be exactly adjusted to meet the requirements of the actual spun yarn. The tests have been repeated as in the first step. Due to the precise adjustment with the P-Matrix the yarn clearer eliminat­ed 42 foreign matter faults / 100 km, corresponding to an clearing efficiency of 95 %.

Rewarding results

The YarnMaster ZENIT+ combines different sensor principles in one single device. This enables the customer to effectively control the yarn quality. The P-sensor used for the synthetic foreign matter de­tection is based on the triboelectric effect. The sensor is sensitive to different materials, and is therefore able to distinguish between cotton and synthetic foreign matter, such as polypropylene, polyethylene, polyamide (nylon) etc.

The unique sensor principle in combination with the new P-Matrix improves the synthetic foreign fiber clearing substantially. The P-Matrix facilitates the perfect adjustment of the clearing. The result is not only an effective clearing of synthetic contaminations, but at the same time an optimized overall production efficiency with less waste. The set of parameters can be stored separately for all different types of yarn and desired qualities. The so-defined yarn quality can be reproduced easily just by loading the parameters back into the ZENIT+. Costly complaints from customers are minimized.

Functionality: P-Sensor

All materials become electrically charged, when they come in frictional contact with another material. In the YarnMaster ZENIT+ the yarn passes an electrode and exchanges electrons. A second electrode measures the resulting electrical charge and converts it into a voltage signal. As the effect is strongly depending on the material, the sensor can detect all synthetic foreign matters, regardless of the yarn thickness. The P-Matrix visualizes the sensor signals and enables an intuitive adjustment of the sensitivity.