Leading Rotomolding Manufacturers

Rotational molding, sometimes referred to as rotomolding, rotomolded, or roto-casting, is an industrial technique for producing hollow parts of any size. The best options for rotational molding are large, single-piece hollow components and double-walled open containers. This is an economical way to make big plastic pieces. A heated, gently rotating mold is filled with resin and rotated vertically and horizontally. Simultaneously heating and rotating, the resin is dispersed and fused on the inside surfaces of the mold. Read More…

Rotomolding Rotomolding, also known as rotational moulding, rotomoulding, and plastic rotational molding, is a plastic formation process in which a mold is used to shape raw plastic material into a useable product.

As a full-service rotational molding company, Roto Dynamics is your source for high quality, custom rotomolded products. Since our inception, we have continued to earn success by closely working with our customers, developing innovative and tailored solutions. We are with you every step of the way, from design and development to production and assembly. For a complete view of our capabilities and ...

Roto Dynamics Inc. $$$

We are a custom manufacturer of rotationally molded products. Our state of the art technology creates precise, cost effective and dependable products. Whether your order is large or small, we want to be sure you are satisfied.

Sherman Roto Tank $$$

Western Industries Plastic Products, LLC, specializes in large-part plastic blow molding. We provide expertise and services in product design, process improvement, and product assemblies. We offer our customers comprehensive services and turnkey opportunities to achieve their specific project goals. We can assist with: R&D, product design, product improvement, and secondary-fixture design. For...

Western Industries Plastic Products LLC $$$

We provide outstanding custom plastic rotational molding. Our teams offer short lead times and we will assist you from concept to production. All of our materials and designs are FDA approved and we can handle the most complex projects. We are your one stop shop for all of your rotational molding needs. Give us a call today to learn more information!

Fibertech Plastics $$$

At Horizon Manufacturing Group LLC, we pride ourselves on being pioneers in the realm of rotational molding. We leverage cutting-edge technology to craft a diverse array of products that cater to a multitude of industries. Our core competency lies in the art and science of rotational molding, a process through which we transform raw materials into seamlessly designed, durable products. We excel...

Horizon Manufacturing Group, LLC $$$

Agri-Plastics Custom Rotomolding produces quality, rotomolded parts with only the highest quality aluminum metal molds. At our facility, we develop and test our products through hands-on experience. Our mission is to offer the best quality plastic products by designing solutions that meet our customers’ expectations, while establishing a worldwide reputation for reliability and durability.

Agri-Plastics Custom Rotomolding $$$
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rotomolding process

Rotomolding Process

Hollow object production is done via rotational molding. A preweighted amount of polymer, either in liquid or powder form, is first added to one-half of a cold mold to start the process. Next, the mold is sealed and put inside an oven biaxially rotated. At first, the polymer rotates inside the mold as it spins. Most of the polymer mass remains at the bottom of the mold, forming a pool because of the low rotational speed, which ranges from 2 to 20 rpm.

The polymer starts to melt, or react in the case of thermosets, as soon as the inside surface of the mold reaches a sufficient temperature, coating the mold. As the mold turns, additional polymer layers cover the mold's inner surface until the entire polymer pool disappears. The mold is moved into a chilly area, and the molding is removed once it has cooled to the proper temperature so that a fresh batch of polymer can be charged to start the next cycle.

Rotomolding Products

The industrial potential for items made using rotational molding is practically infinite. The transformation of products composed of less resilient materials into rotomolded products is an increasing trend in manufacturing. Because of the method and the properties of the materials, rotomolding offers a wide range of advantages. Some examples of rotomolding product conversions include pallets, agricultural tanks, drainage piping, laundry carts, Department of Defense items, air cargo containers, burial urns, cemetery products, and even tornado shelters.

rotomolding products

Types of Rotomolding Machines

  • Rock and roll machine
  • Clamshell producer
  • Up and over rotational machine
  • Material jetting machine
  • Shuttle machine
  • Swing arm machine
  • Carousel machine

The rock and roll machine mostly produces long, narrow pieces. The clamshell machine occupies less area than the shuttle and swing arm machines while still heating and cooling in the same chambers. Due to their modest heating and cooling chambers, vertical rotational machines are small-to-medium in size and energy-efficient compared to the other rotomolding machines.

In addition, although there is a single-arm shuttle machine, most shuttle machines have two arms that alternate the molds between the cooling station and the heating chamber. The arms revolve the molds in a biaxial motion and are independent of one another. Finally, the swing-arm machine is advantageous for businesses with extensive cooling cycles or significant demolding durations. It has a biaxial movement and up to four arms.

rotomolding machine

Areas Where Rotomolding Can Be Used

Food Sector

Temperature-sensitive food items or dry ice pellets and blocks can be transported and stored in the food business using rotomolded packaging. This is possible, for instance, with an insulated polar container. Rotomolded using foam insulation and FDA-approved polyethylene, polar containers are perfect for the food distribution, fish, and wine industries.

Military Sector

The military sector needs to use high-quality cases to transport its robust equipment. Rotomolded packaging and cases are ideal for handling materials where delicate equipment needs to be transported or stored safely.

Medical Sector

In the medical industry, it is typical to transport and store fragile equipment. Therefore, packaging for medical and pharmaceutical products must adhere to strict standards and rules that often require rotomolded cases.

Advantages of Rotomolding

  • Rotational molding has several benefits, including homogeneous wall thickness, minimal tooling costs, and design flexibility. Molds can be made in a wide variety of sizes and shapes. Additionally, there are several choices for textures, colors, and materials using rotomolding. They are economical and environmentally friendly because extra material is frequently reused.
  • Rotational molding is superior to other molding techniques in terms of design. With the right design, items that are put together from numerous pieces can be molded as one part, reducing the need for expensive fabrication.
  • Other inherent design advantages of rotomolding include constant wall thickness and robust exterior corners that are almost stress-free. Reinforcing ribs can be built into the part to increase strength. These ribs can either be introduced or designed into the component.

Drawbacks of rotomolding

  • Slower production time
  • Rotomolding uses more plastic, so products are heavier
  • The process has a low thermal efficiency, resulting in longer cycles

Choosing the Proper Rotomolding Company

To make sure you have the most productive outcome when selecting a rotomolding company, it is important to compare at least 5 companies using our rotomolding directory. Each rotomolding company has a business profile page that highlights their areas of experience and capabilities and a contact form to directly communicate with the company for more information or request a quote. Review each rotomolding company website using our patented website previewer to get an idea of what each company specializes in, and then use our simple RFQ form to contact multiple rotomolding companies with the same form.

Rotomolding Informational Video

 

Rotational Molding Power Pages

Rotational Molding

Blow Molding

Rotational molding, commonly referred to as "rotomolding", is a plastic casting technique used to produce large hollow, seamless, and double-walled parts. It is a three-stage process that involves a mold on a rotating frame, a heating chamber, and a cooling chamber. Molds for the rotomolding process are specially designed....

Blow Molding

Blow Molding

Blow molding is a type of plastic forming process for creating hollow plastic products made from thermoplastic materials. The process involves heating and inflating a plastic tube known as a parison or preform. The parison is placed between two dies that contain the desired shape of the product...

Compression Molding

Compression Molding

Molding is a manufacturing process that uses a mold - the latter being a solid container used to give shape to a piece of material. It is a forming process. The form is transferred from the mold to the material by...

Plastic Coating

Plastic Coating

Plastic coating is the application of liquid polymers or plastic on the surface of a workpiece by dipping or immersion. The result is a thick plastic finish for protective and decorative purposes. This gives the material additional resistance against...

Fiberglass Molding

Fiberglass Molding

Fiberglass molding is a method for forming complex and intricate parts using fiberglass resin. Though there are several reasons for producing parts and components from fiberglass, the most pressing reasons are the...

Polyurethane Molding

Polyurethane Molding

Polyurethane molding is the process of fabricating or manufacturing plastic parts by introducing a urethane polymer system into a tool or mold and allowing it to cure. Like any other type of plastic, the excellent processability...

Plastic Injection Molding

Plastic Injection Molding

Plastic injection molding, or commonly referred to as injection molding, is a manufacturing process used in the mass fabrication of plastic parts. It involves an injection of molten plastic material into the mold where it cools and...

Rubber Molding

Rubber Molding

Rubber molding is a process of transforming uncured rubber or an elastomer into a usable product by transferring, compressing, or injecting raw rubber material into a metal mold cavity...

Rubber Injection Molding

Rubber Injection Molding

Rubber injection molding is when uncured rubber is transformed into a usable product by injecting raw rubber material into a mold cavity made of metal. The applied pressure produces a chemical reaction like...

Plastic Molding Processes
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