LOW-COST PLASTIC FOAM MOLDS FOR LAMINATED PLASTICS,

Low-cost rigid plastic foam molds are used at the Pacific Missile Range for prototype or minimumproduction runs of radomes, nose cones, spheres, cylinders, etc., that are to be made of glass-reinforced epoxy or polyester where the hand-layup or vacuum-bag method is used. The method used in fabricating rigid plastic foam molds is presented, but is intended as a guide only. Fabrication of rigid plastic foam molds suitable for prototype and limited production of laminated plastic objects is simple and economical. The equipment required for fabrication does not exceed that normally used in fabricating wooden or plaster molds. The plastic molds are light and are therefore easy to handle. Longer runs may be possible by using high density foam for the molds. The foam used at PMR had a density of 2 pounds per cubic foot, but it is available in densities up to 44 pounds per cubic foot. Author