Rotational moulding uses bi-axial rotation and heat to form a hollow plastic product on the inside of a mold cavity. The process consists of the following steps: pulverizing the raw plastic into a powder, mixing it with the desired color and placing it in a hollow mold that is then transferred into an oven where it begins rotating on two axes. The rotation of the mold allows it to evenly coat its walls with plastic resin. After the mold has been heated and the plastic has hardened, it is cooled to allow it to cool down and take on its final shape. The process is flexible enough to enable multiple products to be molded at the same time.
The rotomolding process rotational moulding has a number of benefits over other types of plastic forming processes, such as injection molding. For example, it is possible to create a part that would not be feasible to manufacture using injection molding because of its large surface area. Rotomolding also has the advantage of producing parts with high wall thicknesses, which reduces assembly costs and helps to increase strength of the finished product. It is also possible to add ribs, inserts, kiss-offs, and foam reinforcements into a rotomolded part to strengthen it.
However, the rotomolding process does have some drawbacks. Firstly, it takes longer to produce parts than some other plastic forming techniques, which can impact the speed at which a new product can be brought to market. In addition, the rotomolding process cannot be used with all types of plastics. Only those that can be ground to a fine powder, such as Polyethylene, can be used in this way.
Another drawback is the limited design flexibility. Rotomolding can produce a wide range of shapes and sizes but the design limitations are more about how complex the finished product is, rather than the actual dimensions of the mold.
Due to the rotary motion of the mold during the manufacturing process, it is difficult to incorporate intricate features, such as internal curves. Therefore, rotomolding is best for relatively simple and cylindrical or conical-shaped plastic products. It is also a less suitable method for producing curved, spherical or multi-faceted plastic parts.
Nevertheless, despite its limitations, rotomolding is an environmentally sustainable production method. This is because it does not use harmful chemicals and produces minimal material waste and energy consumption compared to other plastic forming processes. It is also possible to recycle the rotomolded plastic and use it again.
At ASH Industries, we are experts in the rotomolding process and can help bring your bespoke product to life. We understand the complexities involved in beginning a project and can guide you through each step of the process from initial design to completion. Contact us today to find out more about how rotomolding could be the right production solution for your product.