Molded Fiberglass Grating

Molded fiberglass grating is cast in full panel sizes. Liquid resin and continuous fiberglass roving are manually woven into a mold that resembles an oversized waffle iron. Layer after layer of roving is wetted out and placed in the mold in a systematic pattern to achieve maximum strength along with the desired thickness and panel size. These panels are then allowed to cure in the mold before the part is ejected and the process is repeated. This one piece construction has several benefits. The first is that it can be cut in any direction and can be riddled with access holes without weakening the overall structure. These glued joints can work loose in heavy traffic or around unsupported edges and access holes.The second benefit of the molded type is a high percentage of resin to glass fibers (65%). The resin in the main component that provides corrosion resistance so in general, the higher the resin content, the better the chemical resistance. On the other hand, the higher the glass content, the stiffer the grating. Therefore, the deflection of a pultruded panel is usually less than for the molded of the same thickness. A third reason customers often choose the molded type is the non-skid surface. Grit can be applied to the surface to provide maximum slip resistance or it may be left with a concave (meniscus-shaped) surface. The meniscus surface provides good skid resistance so stringy by-products to not easily get hung up and the surface is non-porous to help eliminate bacterial breeding areas in food applications. DEFLECTION CHARTThe deflection data presented in these tables is a result of extensive testing. Please note that the flexural modulus of fiberglass is much less than steel or aluminum. Allowable deflection is therefore usually the limiting factor. A deflection of no more than 1/2" is recommended for walking platforms.U = Uniform load in pounds C = Concentrated load in pounds D = Deflection in inches Clean Span Load Type 24" U 100 200 300 400 500 600 650 850 D .03 .05 .09 .14 .18 .22 .24 .32 C 100 200 300 400 500 600 700 800 D .03 .06 .09 .12 .16 .18 .21 .24 36" U 50 75 100 125 150 175 200 350 D .08 .13 .18 .22 .27 .32 .38 .67 C 50 75 100 150 200 250 300 350 D .04 .07 .10 .15 .20 .24 .30 .35 48" U 40 50 50 60 65 70 75 100 D .20 .26 .29 .32 .36 .39 .42 .55 C 50 60 70 80 90 100 200 250 D .10 .12 .15 .18 .20 .23 .41 .50