PMI foam core moulds are made of expandable and shrinka […]
PMI foam core moulds are made of expandable and shrinkable rubber bags using high quality rubber, which are vulcanized from high quality rubber and fiber reinforced layers like water plugging airbags, and can be used to form cavities in concrete members for precast concrete prestressed hollow slabs casting process. The early PMI foam core moulds were cold glued process, which was later replaced by hot vulcanization one-shot process, with the advantages of low cost, high heat resistance and reusable many times.
How to use PMI foam core mold: Place the bridge inflatable core mold into the reinforcement cage and make the longitudinal joints face upward, inflate to the specified pressure and close the valve. Avoid floating when pounding concrete, must be fixed according to the construction process on the top, bottom, left and right, with the formwork pulling screw pressure to overcome the floating; pouring concrete using high-frequency insertion vibrator, from both sides at the same time pounding, to prevent the bridge inflatable core mold left and right displacement, the vibrator end can not touch the bridge inflatable core mold, so as not to penetrate the air leakage; wait for the first concrete set can be pulled out PMI foam core mold, demoulding.
PMI foam is a new type of polymer structure foam with the best overall performance, featuring light weight, high strength and high/low temperature resistance, etc. PMI structure foam is a closed cell, rigid rigid foam obtained by foaming methacrylic acid and methacrylonitrile copolymer. At the foaming temperature of 180-230℃, the pre-built blowing agent in the copolymer is vaporized to produce PMI foam sheets.