The operation of high speed drawing frame(FA311) is stable and reliable and suitable for a wide variety of fibres length ranging form 20mm to 75mm.When the fibres length is 61mm to 75mm,take away the third roller,and then the drafting system becomes the three over three types,twin drafting zones with guiding roller and pressure bars.The max delivery speed is 400m/min.

DRAFTING
The drafting system is the four over type,twin drafting zones with guiding roller and pressure bars.Positions of the pressure bars can be adjusted to suit fibres of different kinds and different lengths and enhance the evenness and quality of sliver.

Being made of acrylonitrile-butadiene rubber,the roller is vulcanized directly so that deformation will not happen.It is durable and has a well anti-reeling feature.The diameters of all rollers are 34mm, thus resulting in a well exchangeability and convenient management.Both the top and bottom rollers are mounted on needle bearings which enable a smooth operation under high speed.The bearings are furnished with oil cups which can be filled up pe-riodically and last a long time before maintenance.

The draft zones are pressed ty swing bridges under the actions of springs which have been treated with a special processing method,therefore the quality reliable.