Superbtex selects Loepfe's YarnMaster ZENIT+
Superbtex, Indonesia-based expert in the manufacturing and exporting of ring spinning yarn, has selected Loepfe’s YarnMaster ZENIT+ machine. Loepfe, headquartered in Switzerland, is a leading company and a specialist for integral quality control systems. Fifty per cent of the world-wide staple fibre yarn production is monitored by Loepfe yarn clearers.
When spinning polyester, yarn clearers are used in most cases only to eliminate process related yarn faults, to monitor hairiness and imperfections, and to ensure the proper yarn count. Foreign matter detection is usually not necessary in polyester spinning, as the raw material originates from a well-controlled source – the chemical process. However, the problem of different glossiness can be solved by installing Loepfe’s yarn clearer YarnMaster ZENIT+ with the OffColor feature. The new functionality has been developed for the detection and elimination of very small colour and shade variations in mélange yarns. They can arise, when bobbins with slightly different colours are mixed up during the winding process, or the fibre blend of the differently coloured fibres change over a certain length, Loepfe said in a media statement.
As the glossiness of the different fibre qualities used in polyester spinning and winding also vary, due to the different amounts of matting agents used in their production, Loepfe came up with the idea, to test the new feature in the Superbtex spinning mill. Extensive tests have been conducted at the largest spinning mill of the group. A Savio Eco Pulsar winding machine has been equipped with the new YarnMaster ZENIT+ including the OffColor feature. The test runs have been made with Ne40 polyester yarn of two types: super-bright and semi-dull. Various settings have been tested in order to reach the optimum performance of the OffColor detection. In this particular case, the observation length has to be relatively long to ensure, that short-term effects are equalized. After triggering the set alarm limit the winding position is blocked. The winding spindle ejects the faulty bobbin once the alarm is confirmed. The operator can then remove the bobbin and the winding continue.
The utilisation of the new OffColor detection for polyester yarns has been extensively tested in the Superbtex spinning mill in Indonesia. The 100 per cent detection of wrong bobbins in the winding process can guarantee excellent results in respect of yarn with different glossiness. Thanks to the new OffColor detection feature of Loepfe’s YarnMaster ZENIT+ the labour-intensive, and therefore, expensive visual inspection of the bobbins is no longer necessary. Although customers in the past have been sceptical to use foreign matter detection in polyester spinning, the new YarnMaster ZENIT+ proves to be very advantageous in quality assurance.
The new OffColor detection uses the F-Sensor, which is an integral part of YarnMaster ZENIT+. In order to detect faults, the sensor illuminates the yarn from several sides. A special algorithm converts the signals resulting from reflection and transmission of the light into a luminosity difference. The reference thereby is the brightness of the yarn colour. Depending on the base-colour, the clearer adapts to the basic brightness of the yarn and is thereby able to detect colour and shade variations as well as glossiness differences. In the event of an objectionable luminosity fault, the clearer monitors the affected fault length and cuts only once the detection stop limit is reached. By setting various parameters the user can select the optimal tolerances. (GK)
Fibre2Fashion News Desk – India