The solution for ends-down during piecing-up

The standard method of operation of the piecer carriage frequently causes ends-down with the following applications: 

1. Yarns with low twist multiplier
2. Yarns with a high percentage of short fibres
3. Yarns with poor fibre cohesion
4. Regenerated fibres.

Ends-down during piecing-up are mainly due to:

1. End-breaks due to tension peaks when the take-up roller is getting into contact, as a result of the acceleration of the take-up roller speed from zero to standard speed. This defect becomes visible by frequent lapping on the take-up shaft.
2. Yarn-breaks during the transfer of the yarn from the piercer
3. Carriage to the winding head as a result of loss of tension at the second lifting of the take-up roller. Due to the centrifugal force in the rotor, the pieced-up yarn is slightly drawn back into the rotor. The resulting thick place causes an end-break due to excessive twist. A repeated number of parallel windings on the cheese are an indication of this defect.

Such yarns cannot be spun or only with certain restrictions. Solutions up to now have been the reduction of production speed, a general change of raw material or a modification of the blending ratios.

The KAROM Piecing-up Package offers a solution to these problems.

To avoid loss of yarn tension during yarn transfer, the piercer carriage is equipped with a

This permits to eliminate the second lifting of the take-up roller and to optimize the movement of the lifter bail. Yarn tension is improved and yarn transfer to the winding head is more reliable. In addition, the take-up roller is pneumatically driven when getting into contact, so that tension peaks are avoided, which may cause end-breaks and laps on the take-up shaft. 

Depending on sliver material and delivery speed, the locking cylinder can be activated or deactivated.  The piecing-up package is available for piercer carriages type I and II.

Premium Advantages:

1. Increase in overall efficiency of machine by 3-10% (3% – 100% sure in any condition) 1% extra efficiency in turn gives one year pay back of modification cost.
2. Thread waste due to piecing failure will be reduce by 50%. Which in turn gives again payback of 4000 usd per year. (Calculated on basis of 0.15% waste reduction of 10/1 Ne Yarn)
3. Piecing Strength comes same as original yarn strength
4. Piecing Appearance will change and remain as like normal yarn, no neps and no thick places.
5. Piecing Efficiency will become 97-98%
6. Fabric Faults will reduce which caused due to piecing area yarn.
7. Elimination of Weft Bar in Denim Fabrics.