The history of rotomoulding process

The first time the use of biaxial rotation and consequently rotomoulding was used was in 1855. The idea behind this was to improve consistency in wall thickness and density. Baker and Perks put this process on the next level with creation of hollow chocolate eggs in 1910. Plaster of Paris was also made using this method in 1920's. Plastic hasn't been used for rotational moulding till the early 1950's. Rotomoulding was then used for manufacturing doll heads. Mold was made from nickel copper and plastic was used in the form of PVC plastisol. Other plastic toys soon followed with the development of the rotational moulding process. Road cones, car arm sets and other products followed these improvements. Bigger machines for rotomoulding naturally followed. Indirect high speed system was developed to replace the old direct gas jets. Low density polyethylene was used to create large hollow containers, another result of developing rotational moulding. The method that was used is called the Engel process. A special cooling method was used for the first time and it consisted of turning off burners and allowing the plastic material to harden while it was still in the mold.