Rotational moulding is ideal technology for the production of objects with complex shapes and large dimensions.
RIMA-TEAM designs and manufactures various types of machines for rotational molding, which can be chosen by the customer based on the available installation space and production needs.
Efficiency in the rotational molding process, and thus optimal energy usage, also depends on reducing cycle times. This involves optimizing the material loading, heating, rotation, and cooling phases to achieve a faster production cycle.
The ability to accurately program the molding parameters, thanks to the SCADA solution developed by RIMA-TEAM technicians, helps reduce waste and maximize the utilization of raw materials.
RIMA-TEAM’s R&D department is constantly working on solutions to improve burner efficiency, heat distribution within the oven, thermal sealing of doors, along with various other innovations to facilitate maintenance and increase the longevity of both static and moving parts of the machine.
Rotational molding machines were conceived in 1955 by R. Peters, a british inventor, who developed the rotational molding process for the production of plastic objects.
This manufacturing method involves heating of plastics material inside a mold, which is then rotated to evenly distribute the molten material inside the mold. Once the plastic has solidified, the final shape of the product is extracted.
The rotational molding process is widely used for the production of large-sized objects such as tanks, containers, toys, and components for the automotive industry.
The maintenance of a rotational molding machine is a process aimed at keeping the machine in optimal operating conditions, preventing failures, and extending its lifespan.
In addition to regular machine maintenance, which includes cleaning the mold, rotating arm, and other machine parts to remove any plastic residues, dust, or dirt that may accumulate, it is important to follow the manufacturer’s instructions regarding checks on fastenings, types of lubricants to use, and lubrication frequency.
To ensure efficiency and reduce the possibility of medium-term failures, RIMA-TEAM provides its customers with instructions for scheduled maintenance and replacement kits for parts subject to wear.
The main technical features to consider when evaluating a rotational molding machine are:
Regarding the production process, in injection molding, the plastic material is melted and injected into a high-pressure mold. The plastic rapidly solidifies inside the mold and is then extracted as the finished product.
In rotational molding machines, the plastic (either in particles or dust form) is poured into an empty mold, which is then rotated on multiple axes to evenly distribute the plastic material on the inner surface of the mold. The plastic is melted and solidified during the rotation process, and the final shape of the product is then extracted.
Injection molding is typically used to produce small or medium-sized objects, such as electronic components, containers, automotive parts and much more.
Rotational molding is more suitable for large-sized and complex-shaped objects, such as tanks, children’s toys, garden furniture, and heavy vehicle components.
In injection molding, molds are generally expensive to design and manufacture because they require high precision and strength to withstand the high injection pressures.
Molds used in rotational molding machines are generally less expensive, as they can be made from less robust materials since they do not need to withstand high pressures.
Rotational molding is therefore ideal for the production of objects with complex shapes, thanks to its ability to evenly distribute the plastic material on the entire inner surface of the rotating mold.
Rotational molding is also particularly advantageous for the production of large-sized objects. Rotational molding machines can handle significant mold sizes, enabling the production of tanks, industrial containers, and parts for the naval industry. This capability to work with larger sizes provides an advantage over injection molding, which is more suitable for small-sized objects.