Causes for Nep formation in Blow room;
*Cotton with too high or low moisture.
*Extremely fine cottons with high trash content.
*Reprocessing of laps and mixing of soft waste.
*Rough or blunt blades and bent pins on beaters.
*Narrow settings between the feed roller or pedal and beater.
*Long curved and U-bends in conveyor pipe lines.
inappropriate ratio of fan to beater speed.
*Wider setting between stripping rail and beater blade.
3. Causes for curly cotton:
*Grid bars setting too close to beater.
*Hooked or bent pins on kirschner beater.
*Too wide a setting of stripping rail.
*Long and bent conveyor ducts with low fan speed.
4. Causes for lap licking :
*Use of too much soft waste in mixing
*Too high fan speed, excessive beating.
*Weigher cotton is damp or departmental humidity is high.
* Sticky nature of material
Remedies: use of roving ends within the lap to act as a layer Separation.
Incorporation of lap felter's.
Use of antistatic spray while processing synthetic.
5. Causes for conical lap:
*Improper functioning of pedals on one side due to pedals being choked with dirt.
*Air entering at one side frcm under the grid bar of beater.
*Defective beater blade at one side.
*Uneven suction at the cages leaving to deposition of more material on one side than another.
*Lap roller racks, calander roller not exerting even pressure across the lap width. *Cages may not be properly levelled.
6. Causes for Soft lap
*Calender pressure inadequate due to wear and tear of weighting mechanism.
