Determining the number in spinning plays an important role in determining the quality of the yarn made. The number control enables the determination of process-related errors and the regulation of machine settings. For the number determination of yarns, standard atmospheric conditions should be 20 ºC ± 2 temperature and 65 ± 2 % relative humidity.
Sample yarns are first rested for at least 6 hours under standard atmospheric conditions to reach a constant moisture balance. If the weight loss is less than 2% in the weighing of the yarn, which is left in standard atmospheric conditions at 0,25-hour intervals, it is considered that the sample yarn has reached the test conditions, that is, it has been conditioned. A laboratory sample is taken from a ready-to-delivery yarn lot or from the machines operating in the enterprise to determine the yarn number. Experimental samples are selected from these laboratory samples. In order to determine the yarn number, laboratory samples are taken from a ready-to-deliver yarn lot or from the machines running in the enterprise and test samples are selected.
The points to be considered while taking samples are as follows;
1- The sample should be taken to represent a whole.
2-Experiments should be made with fully loaded cops.
3- There should be no substances such as dust, oil coming from the enterprise on the cops.
4- Control should be started by extracting some yarn from the cops.
5-Do not control the yarns at the ends of the cops.
