Boright Rotomolding Process Summary and How to make one cooler?
Rotational Molding, also called rotomolding or rotocasting, is a thermoplastics manufacturing process for producing hollow parts by placing a powder or liquid polymer material into a hollow mold and then rotating that tool bi-axially in an oven while the material melts and coats the internal surfaces of the mold cavity. Upon completion of the cook cycle, the mold is then moved into a cooling station, where the temperature of the mold is gradually lowered until the optimum temperature is achieved to open the mold and remove the part.
Let's see what will be the rotomolding process and how to make one rotomolded cooler?
Stage 1: Material weighed
LLDPE Raw Material being weighed out for the Rotational Molding Process.A variety of materials are available for rotational molding though the most widely used is polyethylene. This outstanding material is an integral part of the rotational molding process.
The first step is loading the LLDPE in the mold. LLDPE Pulverized material in a fine powder form is loaded into the prepared mold. The mold is then secured closed and rotated to ensure no powder is able to escape.
Stage 3: Load mold on machine arm and moves into Rotomolding Oven
Mold moves into the heating chamber of the oven while rotating on two axes at a low speed. It will take around 30 minutes for heating.
Stage 4: Mold Cooling and product shaped
Mold moves into the cooling chamber and is cooled by air or water spray or a combination of both, while still rotating. It will take around 20-30 minutes.
Stage 5: Demold
Mold is unloaded revealing the molded part.Pulling part from a mold at the end of the Rotational Molding process.
Stage 6: Repair the burrs
After rotomolding finish,there will be burrs at the molds connection part, our workers will repair it.
Hollow Body of Cooler Ready
Rotomolding works end after above processes,if we make tool box,oil tank or other rotomolded products, there is only inspections and packing works need to do. But as to cooler, this process not enough..... We cut open one cooler before PU insulation injection, you can see it's hollow inside.
Stage 7: PU formed insulation
High performance thermal insulation materialPU will be injected into the hollow cooler body and formed inside.
ASSEMBLE,INSPECTION AND PACKING
After PU formed insulation,we will assemble feet, latches, seal gasket, hings and so on on cooler. And then inspection, lable or printing logo. And packing to ship.
If you want to build a customized rotomolded cooler,you should know which kind of latch you want to use first. Many USA brands(such as YETI coolers, Igloo cooler,RTIC coolers and so on) regisger their latches' patents to protect their designs. So Latch designs if the first step for your coolers customized design.