The History of Rotomolding

Do you know the history of rotomolding? This process is actually quite fascinating, and so is the history.
The first documented use of the rotational molding system was in 1855. R. Peters used biazial rotation and heat to create metal artillery shells and hollow vessels. The rotational pull of the process make the walls of each shape uniformly thick and dense. In 1905, the rotational molding process was used to hollow wax objects, and eventually, chocolate eggs in 1910. By the 1920s, the process was used to mold plaster of Paris.
It was not until the 1950s that the process of rotomolding was used to manufacture plastic products. The first use of the process was to manufacture hollow doll’s heads. The first kind of plastic used in roto molding was PVC plastisol. To cool the mold, the entire mold was placed into cold water. After the success with doll’s heads, many other toys were manufactured using the same tools and process. The process has also been used to make traffic cones, car armrests, and even marine buoys. In the 1960s, a new form of heating using indirect high velocity air was introduced. This make it possible to make bigger shapes from low-density polyethylene. Now the cooling process consisted of letting the plastic harden naturaly inside the mold.
From this point, manufacturers were able to figure out how to rotomold other plastics, including polyester, nylon, and polycarbonate. In the modern world, there is nearly no end to what can be molded using this process, including fuel tanks, industrial parts, and more.