In one preferred embodiment, an air blast is directed through {HEAD ~ the porosity} created by tensioning {TAIL ~ the fabric} to impinge upon the underlying layer of fabric 
created by tensioning
In one preferred embodiment , an air blast is directed through { HEAD ~ the porosity } created by tensioning { TAIL ~ the fabric } to impinge upon the underlying layer of fabric
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD REL REL REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH