FAQ - Frequently
Asked Questions

About Rotational Molding

Rotational molding, also known as rotomolding, is a process for making hollow plastic products. It has some advantages in terms of low levels of residual stress and cheap molds, being best known for making water tanks or tanks, but it can also be used to make complex medical products, toys, kayaks, decorative pieces, among many other possibilities.


Rotoline produces some models and sizes of rotational molding machines.

The Shuttle model has a special relation between productivity and economy, as well as easy access to change
molds and the option of working with one or two stations. This model is more suitable to manufacture
a variety of products, since it is possible to use different molds at the same time, producing with different time
settings and recipes in each station, since the cooling step is independent for each cart.

Rotoline Carrossel machines, on the other hand, are more suitable for producing parts in large quantities and in sequence, since they have 5 stations, which allows each of the 3 or 4 carts to work in a single step individually, and can present up to 20% more productivity than other machine models.

Rotoline Open-Flame machines can produce cylindrical parts in a more economical and viable way in relation to gas consumption.

For universities and laboratories, LAB machine is recommended.

Rotoline helps you choose the most suitable equipment for your process.

Contact us and we will be ready to help you.

Parts can be manufactured without the need to join or weld them;
The final product has low levels of residual stress;
The molds are relatively cheap and their manufacture does not have a long waiting period compared to other polymer transformation processes;
There are practically no material losses in the process;
Different types of products can be rotated on the same machine;
It is possible to manufacture multilayer products;
It is possible to use inserts that are easy to rotomould;
The process can be easily monitored through the technology applied by Rotoline in their machines.

The most widely used material in the world is polyethylene, being used by around 95% of rotomolders. There are several materials that can be used and new technologies appear every day aimed at this in the application of rotational molding.

Rotoline rotomolding machines allow the use of both natural gas
and liquefied petroleum gas, LPG.

In terms of cycle times, there are many variables to consider, such as the number of molds, mold opening and closing time, amount of material processed and wall thickness of the mold and the final product, oven and cooling time.

Rotoline rotomolding machines require, in addition to the space to be installed, electricity, gas, water and compressed air.
On top of that, you only need your product molds and you are ready to be a part
of one of the most prosperous industries in the world.

Having the machine and a defined product, it is necessary to adjust your process to have the highest possible performance. Rotoline recommends testing recipes and monitoring the results until a balance is reached between cooking/ cooling time and part molding.

Depending on the machine, the assembly can be done in 5 to 8 days.



The RWTC (Rotoline Wireless Temperature Control) is a wireless temperature controller that was developed by Rotoline to optimize the cycle by controlling the cycle according to the simulated mold internal temperature.
This optimizes the process, as when the RWTC reaches a certain temperature set by the operator, the intelligent control of the machine ends the cycle and sends the cart to the next rotational molding step. This also eliminates possible variations in ambient temperature, increasing
the repeatability rate of the parts. The RWTC can also be used to control the temperature in the cooling station, as long as the operator configures it to do so.

Burner access platform
Full protection fence
Mold support
Weighing and feeding system
Cooling fans
RWTC
Work platforms

See what components are available for your machine or your needs.