Abstract: An elongated, flexible protective urethane member is bonded and firmly affixed to the leading edge of a glass fiber reinforced polyester skin fan blade for large diameter industrial water cooling tower fans. The polyester blade without such protective member would be subject to leading edge abrasion and deterioration during use. The flexible protective member is applied to the blade prior to curing of the chemically thickened polyester skin. Firm bonding and adherence of the protective member to the leading edge of the blade skin is obtained by curing of the skin with the protective member in place over the leading edge of the blade.

Abstract: A molded, composite, airfoil-defining, synthetic resin blade for large diameter cooling tower fans is disclosed wherein a moderately dense synthetic resin foam core is first formed that is generally of the same size and shape as the final desired blade. A shank embedded in the foam core extends outwardly from the end of the blade that is adapted to be fastened to the fan hub. A skin of fiberglass reinforced synthetic resin material is placed over the foam core with the thickness of the skin being greatest at the hub end of the blade and especially around the shank. The foam core with the skin thereon is molded into the final desired configuration thereof under pressure and temperature conditions such that the core is compressed and the thickness reduced to an extent correlated with the thickness of the synthetic resin skin on opposite faces thereof.