Textile Technology :: "Open End Spinning"

Passage of Material Through Rotor Spinning M/c.

• •Sliver is slowly drawn into the m/c by a feed roller ,operating in conjunction with a spring-loaded feed pedal.
• •The rapidly rotating opening roller , which may be pinned or covered with metallic card clothing ,combs out the leading ends of fibres untill they are released ,
• •When it carries them forward virtually as individual fibres.
• •Provision may be made for trash to escape through an aperture in the beater casing while the fibres are sucked through the transit tube & onto the inner ,grooved, periferal surface of the rotor.
• •The transit tube may tapered so as to create an accelerating air-stream, which it is hoped will tend to straighten the fibres in flight.
• •In order to achive ideal fibre flux i.E. Unity {fibre flux =number of fibres in cross section},in the transport tube , the air speed in the tube would have to be as high as 75m/s for fine yarns & 600 m/s for coarse yarns. {Generally flux = 7-8}.

  •Some straightening of fibres occur as they enter the rotor , since the surface speed of the rotor is greater than the air-speed.

  •Centrifugal force flings the fibres outwards & presses them onto the collecting surface of the rotor ,where a ring consisting of many layers of fibres forms.

  •To start spinning ,an existing seed yarn is introduced through the exit tube . since the rotor & the air contained in it are rotating , the yarn tail is also caused to rotate.

  •Centrifugal force throws it against the inner peripheral surface of the rotor ,where it makes contact with the ring of fibres.As soon as this occurs , the seed yarn is withdrawn , and yarn production begins.

  •Each revolution of the yarn arm puts a turn of twist into the yarn in the exit tube, &, since there is little to stop it , some of this twist leaks back along the yarn arm to the rotor surface,which thus causes the tip of the seed yarn to become entangled with the ring of fibres , which can then be progressively peeled off the surface of the rotor to form a yarn.

  •The yarn produced is simply wound onto a large package, usually a cheese.