Essay On Rotor Piecing

CHAPTER - 2

LITERATURE REVIEW

2.1 Mechanism of Auto - Piecing in other spinning methods:
2.1.1 Rotor Spinning: Rotor spinning is based on the principle of open end spinning where the fibre continuity between the feed and the twisting is broken. The opened fibres are condensed to the required linear density and given true twist. Rotor spinning production rate is 4-8 times that of ring spinning. The rotor yarn is regular with fewer imperfections. Due to the breaking of the yarn during spinning normal piecing operation happens. The process involves:
Rotor, rotor brake and a feed roll feeding fibre sliver to an opening roll, comprising braking the rotor prior to yarn joining while the feed roll is rotated for some short period of time

This new starting end is to be pieced together with an end of a thread already spun. The normal piecing process in air jet spinning involves the following steps:
First the pair of apron rollers is stopped.
Then the pair of delivery rollers are stopped.
The pair of delivery rollers are opened.
Then the apron rollers are driven in such a way that pulls back the starting end of the fibre.
The piecing portion of the fibre is fed backwards from the air jet assembly.
The delivery rollers are run at slow speeds which move the piecing portion of the fibre to the selected position.
Then the pair of apron rollers piece together the piecing portion of the fibre and the starting end of the fibre. The auto piecing consists of
An activated suction device which assists feeding backwards the piecing portion of the fibre.
Accelerating to a normal operating speed the pairs of delivery rollers and apron roller.
Then compressed air is provided to assist joining the piecing portion of the fibre and the starting end of the