the same within each horizontal row the distribution of hole sizes may obviously be varied within each row in any desired manner in order to produce the desired form or pattern of fiber distribution in the manufacture of glass fibers the specific gravity of molten glass allows it to be delivered to a rotating disc with only minor concern about retaining it in the disc prior to being centrifugally forced through the holes in the disc sidewall thus molten glass is delivered in a stream to a convenient location on the bottom wall of a disc and it flows relatively smoothly toward the sidewall because the specific gravity of molten polymer material is significantly lower as pointed out above molten polymer may tend to be randomly distributed against the sidewall 40 and bounce out of the rotating disc this results from the fact that air currents generated in the process tend to move the molten stream as it is delivered to the disc and the spinning disc itself tends to pull the stream in the direction of rotation in addition relatively high viscosity molten polymer does not flow easily toward the sidewall of the disc and at times tends to be flung about in gobs in order to combat these tendencies of the molten material to behave in a manner contrary to the behavior of molten glass in a rotary fiberization process it is been found necessary to deliver the material to the disc through the transfer hose delivery nozzle 22 by positioning the nozzle close to the bottom wall and sidewall of the disc the length of the molten polymer.