What is Rotomolding?


You may have heard about the process of rotomolding. This technology has become more popular in the last 20 years and has revolutionized the manufacturing process of many common items. But what exactly is rotomolding?

Rotomolding, short for rotational molding, is a thermoplastic manufacturing process used to create seamless one-piece items using a unique plastic molding. It is most suitable for large and hollow one-piece parts, and double-walled items such as rotomolded cases. This technology is also used for canoes, toys, industrial equipment, garbage bins, plastic planters and much more.

Here is more information about rotomolding and its use in the packaging industry.

How is rotomolding done?

Most other plastic processes use high pressure, but rotomolding is quite a long process using low pressure and high heat. This makes it more complicated than it seems because the material cannot be handled the same way. It is also more likely to be affected by factors such as temperature, polymer quality, and more. Despite this, it is a worthwhile process since it results in a very high-quality product.

The rotomolding process involves four main steps:

1. Filling the mold

The hollow mold must first be filled with the quantity of polymer needed. This polymer is usually in powder form and mainly made of polyethylene. Once the mold is filled, it can be secured.

2.  Heating the mold

The mold is then heated at a high temperature so the polymer can melt and fill the inside of the mold. During this entire process, the mold slowly rotates by-axially so the plastic can properly form to the mold’s shape.

3. Cooling

The cooling process then begins while the mold continues to slowly rotate. The cooling process must be carefully measured so the manufactured part does not get warped. This is usually done with air and sometimes with a fine mist of water.

4. Dismantling

The cooling process is done when the item can be handled and the polymer holds its shape. At this point, the rotation is stopped and the part can be removed from the mold. The item is ready and the mold can be reused to make an identical part.

Why use rotomolding in the packaging industry?

Rotomolding can be used to easily make stackable containers, pallets and tanks. It is often used in the packaging industry for its many benefits.

Perhaps the most appreciated benefit by manufacturers is its cost-efficiency. Molds are inexpensive and do not require large quantity purchases for them to be worth your money.

Additionally, items require no assembly. Since they are a uniform product, they are a lot more durable and resistant to deterioration caused by chemicals or environmental factors.

Rotomolding is also highly customizable with endless design possibilities. It always offers smooth and uniform wall thickness, even when the mold shape is more complex. The corners also tend to be thicker, which contributes to their increased strength and integrity.

Finally, rotomolding produces little waste since the exact weight of plastic required is used.

Industries that can benefit from rotomolded packaging

Rotomolding can be used for packaging in a variety of industries such as marine, security, oil and gas, aerospace, and more.

Food industry

Rotomolded packaging can be used in the food industry to transport and store temperature-sensitive food products or dry ice pellets and blocks.

For example, this can be done with our polar insulated container. Rotomolded with FDA-approved polyethylene with foam insulation, it is ideal for food distribution, fish and wine industries.

Military industry

The military industry requires the use of quality cases to transport their heavy-duty equipment. Rotomolded packaging and cases are perfect for handling materials where delicate equipment needs to be transported or stored safely.

Medical industry

The medical industry involves transporting fragile devices and storing chemicals. Medical and pharmaceutical packaging must also comply with strict standards and regulations.

At Creopack, we understand that packaging for fragile products of the medical industry must have maximum protection, so quality is our top priority.

No matter your industry, your business is sure to benefit from rotomolded packaging.

One of many packaging options

In conclusion, rotomolding is a manufacturing process that produces sturdy thermoplastic items using high heat and low pressure. It offers many benefits that can be useful in different industries. However, obtaining rotomolded items may require the help of professionals such as Creopack.

Trying to decide if rotomolding is the best packaging option for your needs? Contact us to know more about your different options!