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Rotomolded Tanks

A reliable source for Rotationally Molded Plastic information and leading Rotationally Molded Plastic Companies & Suppliers.

Rotomolded tanks are hollow containers that may hold and store a wide range of contents. They are made of thermoplastic materials. They are renowned for their great tensile strength, impact resistance, and broad design range. Plastic tanks are the most often used object that can be produced using rotational molding, which is a low-cost method that uses rotation, heat, and a mold.Read More…

Rotomolded Tanks Rotomolded tanks are hollow vessels that are fabricated from thermoplastic materials to contain and store a wide variety of materials.
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Leading Manufacturers

Orange, CA  |  877-768-6585

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 services, check out our website, or submit a request for quote to see how we can serve you!

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Roto Dynamics Inc. $$$

Pearland, TX  |  281-648-0909

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.

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Sherman Roto Tank $$$

Elberfeld, IN  |  800-304-4600

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!

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Fibertech Plastics $$$

Madera, CA  |  559-673-4764

IRM uses the highest quality, environmentally friendly polymers for the customer’s application including products requiring FDA and UL approval. Constant electronic monitoring of the manufacturing process assures consistency of all products. The finished goods are inspected by highly trained factory technicians resulting in the highest quality products available.

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Innovative Rotational Molding $$$

Middletown, OH  |  866-510-9701

The Granger Plastics Company specializes in large and more complex mold products and components. Our rotational molding services provide products with competitive pricing, design flexibility and uniform construction. We provide a variety of complex inserts, threaded fittings, roto-molded heavy walled intricate parts, as well as custom molds for to fit the changing needs of all customers.

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Granger Plastics Company $$$

Carle Place, NY  |  516-334-2300

Formed Plastics specializes in the custom fabrication of vacuum formed plastics and rotomolding. We also offer plastic thermoforming and pressure forming, as well as line bending. Formed Plastics also has a lighting products line. We serve industries such as medical, dental, machinery and more.

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Formed Plastics, Inc. $$$
placeholder image Roto Dynamics Inc. Sherman Roto Tank Fibertech Plastics Innovative Rotational Molding Granger Plastics Company Formed Plastics, Inc.

Rotomolding Process of Tanks

In the process of rotomolding a tank, a heated hollow is filled with a charge or shot weight of material. Additionally, it is often slowly rotated across the two parallel heat axes, allowing the softened material to disseminate and adhere to the mold walls. The mold rotates continuously during the heating phase to prevent drooping or distortion and during the cooling phase to maintain the thickness throughout the portion.

rotomolded tanks

The mold is mounted in the oven, which has natural gas burners heating it, and bolted at the dividing line. At 4 to 12 rpm, it is hydraulically rotated. Polyethylene is added layer by thin layer as the plastic melts. When the plastic has fully formed and hardened, it adopts the shape of the mold, which is then taken out of the oven. Once the tank has cooled, the mold is removed to reveal the finished item. In a rotomolding setup, expert manual labor is required. For instance, special workers are required to open and close the molds during the rotomolding process. The die's opening and closing require strenuous manual labor.

rotomolding process

Materials Used to Make Rotomolded Tanks

Rotationally-molded tanks can be created using a variety of thermoplastic substances, such as polyethylene, polypropylene, Halar, and polyvinylidene fluoride, all of which are high-purity plastics. Depending on the application of the product, additive materials are frequently added to the plastic resin to improve attributes including strength, moisture, chemical, and temperature resistance, color, and flame retardancy.

Plastic tanks are among the largest goods made using rotational molding. As a result, producers use the biggest rotomolders to make them. They need a lot of room, a place where intense heat can be generated, and a place to cool things off. If necessary, the rotational molding machine will need room to turn around two separate axes in each of these locations.

The polymer resin is usually in fine-powder form when making the tanks so it is easier to get into all the nooks and crannies of the tank-shaped mold. Even distribution of the plastic can be a difficulty because the process is conducted at low speeds and low pressure. However, sophisticated designs like two-compartment tanks are feasible if the plastic granules are fine enough. Rotomolded tanks can store anything from a few gallons to several thousand gallons and are made to be either horizontal or vertical in configuration.

/horizontal rotomolded tanks

Advantages of Rotomolding

  • Low operating pressures enable the creation of rotomold tooling from inexpensive metals like aluminum.
  • Wall thickness is constant thanks to the mold's continuous rotation during the heating and cooling cycles.
  • Complex double-walled open containers can be made using the double-wall construction method without further processing.
  • High durability: pieces are molded as a single, solid piece, avoiding the necessity for weakening connection methods like welding and joint fabrication.
  • High stability: Since the molding material is not subjected to external pressure, it is more stable and there is less chance that the finished item will have flaws.
  • Strength: Rotomolding produces thicker corners, lowering the likelihood that they may fail at certain stress-concentration places.
  • Aesthetics: Surface finishes like fine-detail textures, logos, emblems, and letters are easily accommodated by the soft metal utilized for the rotomold tooling.

Disadvantages of Rotomolding

  • High cycle times: rotomolding can take up to three hours to complete one part at eight rotations per minute.
  • Limited material choices: Poly-based resins are the only materials that can be utilized for rotomolding since they can easily be transformed from granules to a fine powder and have great thermal stability.
  • High cost of raw materials: The cost of adding the necessary additives, the expense of grinding the material into a powder, and the high criteria for thermal stability all contribute to high material costs.
  • Low repeatability: Due to a lack of repeatability, the rotomold tooling's soft metal must be repaired or replaced after 3,000 cycles and may result in quality problems.
  • High labor costs: rotomolding requires more labor intensity than equivalent production because mechanization and automation have not yet been implemented.

Rotomolded Tanks Informational Video

 
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