Apparatus for forming glass fibers

In an apparatus for forming glass fibers strands comprising a first level having therein a bushing having bushing tips through which filaments are attenuated, means for providing an air stream across the bushing, means for applying a binder and/or size to the filaments, means for gathering the filaments into a unified strand and a back shield member behind said means for applying the binder and/or size and said means for gathering the filaments, a second level having therein a means for collecting said strand and a floor separating said first level and said second level, said floor having an opening provided therein through which a majority of said air stream is aspirated downwardly with said filaments and said strand through said opening, the improvement wherein said back shield includes an opening therein extending upwardly from said floor, said opening being of a sufficient height to vent the portion of said air stream which strikes the floor of said first level and thus does not pass through said opening downwardly with said strand and to allow said portion of said air stream to be aspirated back into said air stream to thereby prevent return of said portion of said air stream to the region directly below the bushing and thereby prevent turbulent air flow below the bushing.