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