Purpose of Cop Control It is done to determine whether the yarn on the cop is wound in the specified standards. Sample yarns are taken from the spinning machine. The yarns are brought to the laboratory by the car with the yarn stand.
Apparatus and devices used for testing;
Digital caliper and precision balance are used in cop control.
Causes of Cops Winding Errors
1-Abnormally rough cop,
2-Worn cop,
3-The cop is not seated tightly on the spindle,
4-Low thread tension
5-Incorrect selection of traveler number,
6-Low spindle speed,
7-Winding speed not working normally,
8-Incorrectly wound upper and lower tapered bobbin,
9-Frequent thread breaks
10Frequent winding on rollers in the drafting area,
11Thick windings in places,
12climatic conditions,
13The quality of the fiber causes faulty winding.
To prevent such errors, the thread number should be checked, the tooth gear settings and the winding speed settings should be checked.
In the spinning mill;
>>> Raw material selection,
>>> Appropriate speed and setting,
>>> If attention is paid to the general cleaning and maintenance of all machines, yarn faults will be minimized.
Determining the Amount of Thread on the Bobbin
1-The bottom of the cop is measured first with a digital caliper.
2-The cop head is measured.
3-The taper height is then measured.
4-The middle part of the cop (ring diameter) is measured with a digital caliper, the values on the caliper are recorded in the cop diameter tracking form.
5-The full state of the bobbin is weighed on a precision balance.
6-To tare the bobbin, the empty bobbin is weighed.
7-Then the amount of thread on the bobbin is calculated.
Example: For Ne10/1 yarn;
Yarn weight after weighing; 191.77 g
Empty core weight; 52 g
Formula
Plain thread weight = Total full bobbin - Empty Bobbin Plain thread weight =191.77-52 Plain thread weight =139.71 Thread amount in cop=139.71x10/1x1.693 Thread amount in cop=2365.2903m.
lessontextile 
