The arcuate shape of the trough bottom results in an effect similar to an airfoil effect, whereby the aspirated air is accelerated with the consequent beneficial effect on {HEAD ~ the gathering} of {TAIL ~ the fibre fleece} to the shape of a fibre sliver 
of
The arcuate shape of the trough bottom results in an effect similar to an airfoil effect , whereby the aspirated air is accelerated with the consequent beneficial effect on { HEAD ~ the gathering } of { TAIL ~ the fibre fleece } to the shape of a fibre sliver
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH