Slub distance

The slub distance is measured between the end of a previous slub to the start of the subsequent slub. All slub distances plus all slub lengths together will add up to the overall test length. If two or more populations are defined, the slub distance is defined within the same population. If required, the mean slub distance between consecutive slubs can be evaluated.

Mass decrease

Mass decreases before and after a slub can lead to severe weak places in the yarn. They are often related to the settings of the slub yarn device used and / or the spinning machine. Therefore, this parameter is an important quality characteristic of a slub yarn as it can lead to severe problems in the further processing of the yarn. For this evaluation, only mass decreases within a distance of three centimeters and a mass decrease of -30% before or after a slub are evaluated. The starting points of this distance are at the ends and the beginning of the slubs.

Percentage slub length / slub distance / mass increase

This value is equivalent to the percentage of the slub lengths and slub distances compared to the overall length of the measured yarn or the mass increases of the slubs compared to the overall mass of the yarn.

Count of slub / base yarn

Usually, the nominal count of a slub yarn consists of a mean value of the overall mass per unit length. With the USTER� FANCY YARN PROFILE, it is possible to separate the count of the slubs from the count of the base yarn, in order to describe the yarn more accurately.

Fancy Yarn Configuration

This is the overall definition, how a slub yarn should be evaluated regarding the reference level, the setting of a limit to separate slubs from random thick places (boundary) and the definition of populations. This configuration is done in the settings of the USTER� TESTER 5 by the operator depending on the appearance of the slub yarn and the aim of the evaluation. In the Fancy Yarn Configuration dialog it is possible to adjust the reference line if required, to define boundaries, to mark populations, to save and to change configurations and apply them to a tested sample.


These are slubs that are located above the defined boundary, but do not belong to any population, if populations are defined. If no populations are defined, no outliers can be analyzed.

4 Measurement of slub yarns

Slub yarns can be measured reproducible on the USTER� TESTER 5 with a speed up to 800 m/min in the Fancy Yarn mode. For the slub yarn evaluation the sensor CS is used. The optical sensors like the sensor OH for the hairiness measurement, the sensor OM for the optical evaluation of a yarn, the sensor OI for the evaluation of the trash and dust as well as the foreign matter sensor can be used at the same time for other evaluations of the yarn. As slubs can be distributed randomly a test length of 1000 m is recommended.