Open-end spinning has the advantage of high production output. As winding is not necessary, a yarn clearer is often not applied. On the other hand, periodic yarn faults can have a huge impact on the final product – the so-called Moiré effect.

Loepfe, the leading manufacturer of sensors and monitoring equipment for yarn spinning and fabric weaving processes, has developed yarn clearers of type 3N1 and 1N1 to offer a fast and safe possibility to detect these faults during open-end spinning process, resulting in a higher quality of the produced yarn.

Quality defects

Periodical occurring faults in open-end spun yarns can cause quality defects in the woven end product. Due to the periodicity, even small variations in yarn thickness are visible in the woven fabric – the so-called Moiré effect.

The solution to avoid this effect is the installation of optical yarn clearers in open-end spinning machines, the manufacturer reports. The yarn clearers 3N1 and 1N1 from Loepfe utilize an optical sensing technology and are able to detect yarn faults in a very reliable way, according to the company.

Optical yarn clearers

Loepfe´s optical yarn clearers cover open-end yarn counts from Nec 3 to Nec 60 at a maximum spinning speed up to 400 m/min with one sensing head. The type 3N1, compared to type 1N1, offers an additional detector for foreign matter and a triboelectric sensor for detection of synthetic foreign matter.

The optical sensing technology is non-sensitive against changing humidity, which can occur quite often in spinning mills, the company reports. Other environmental conditions like changing temperatures are also said to show no effect on the sensor.

Quality control

The central unit provides and analyses all quality and production related data on its large touch screen. Periodical faults, which could result in Moiré effect and which cannot be detected during subsequent laboratory quality control, are visualized as well.

In general, the use of a yarn clearer is said to eliminate the need for laboratory quality controls of the spun yarn. The user has the advantage of 100% quality control and the possibility of fast reaction times, according to the manufacturer.

www.loepfe.com