The rotomolding process allows products to be manufactured in a way that creates extremely strong, long lasting, durable parts. Rotomolded parts are resistant to deterioration from chemicals, the elements or environmental stresses. The applications of this process range from playground equipment to nuclear warhead covers, from agricultural tanks to tornado shelters, from furniture to construction materials. The rotational molding process as well as the materials used during rotomolding pair to create these extraordinary parts. What exactly is Rotomolding? Do you know what makes this very specialized process so different from other types of plastic manufacturing?

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Rotational molding, rotomolding, rotomold or rotocasting is a production process to form hollow parts of limitless size. This is a cost-effective method to produce large plastic parts. The simultaneous heating and rotation distributes and fuses the resin on the inner surfaces of the mold.

The result is a product that contains seamless parts with a uniform wall thickness with more material in corners to absorb shocks and stresses where they occur most.

In , the first polyolefin powder, a low-density polyethylene, was publicly demonstrated to the rotational molding industry. Polyetheylenes remain one of the most popular materials for rotomolding, because of the processability, broad range of properties, and low cost. Major thermoplastic raw material suppliers have investigated specially formulated powders for rotational molding, including polypropylene, nylons, polycarbonate, rigid polyvinyl chloride and others.

These powders can be foamed or reinforced with fibreglass. In addition to the raw material suppliers, many rotational molders also have used custom grinding services or have their own in-plant grinding capabilities which have also enlarged the material selection for this process. If you are intersted in getting a quote for your rotational molding project, please click here or give us a call now at Search this website. What is Rotational Molding?

Definition Rotational molding, rotomolding, rotomold or rotocasting is a production process to form hollow parts of limitless size. Materials In , the first polyolefin powder, a low-density polyethylene, was publicly demonstrated to the rotational molding industry.


Rotomolding Process

Rotational Molding BrE moulding involves a heated hollow mold which is filled with a charge or shot weight of material. It is then slowly rotated usually around two perpendicular axes , causing the softened material to disperse and stick to the walls of the mold. In order to maintain even thickness throughout the part, the mold continues to rotate at all times during the heating phase and to avoid sagging or deformation also during the cooling phase. The process was applied to plastics in the s but in the early years was little used because it was a slow process restricted to a small number of plastics. Over time, improvements in process control and developments with plastic powders have resulted in a significant increase in usage. Rotocasting also known as rotacasting , by comparison, uses self-curing resins in an unheated mould, but shares slow rotational speeds in common with rotational molding. Spin casting should not be confused with using a high-speed centrifugal casting machine to shape self-curing resins or white metal.


What is the Rotomolding Process?

Once the mould has cooled and the part solidified it can be unloaded. The rotomoulding production cycle lasts between 20 minutes and a few hours depending on the size and thickness of the part to be produced. Finishing: to control deformation, the parts are held in conformers and subjected to leak tests. Then, parts can be deburred, flamed, finished manually or by a mechanised process. Discover our know-how and method of production. There are other techniques for industrial transformation of plastics : plastic injection, blow moulding, plastic extruding, thermoforming, expansion moulding. The choice of technology will depend on the nature of the polymers and the applications for the final product.


Rotomolding vs Injection Molding

Rotomolding mainly deals with materials that are solid at room temperature, but turn liquid with a moderate degree of heat — not high enough for liquid metals though mercury and Cyberdyne Systems Model T notably excepted. Safe assumption since this IS a blog about part manufacturing. CDN Inc. To begin, a two or more part mold is assembled together with a specific amount of powdered plastic resin inside. Centrifugal force the same force that plasters you to the edge of whichever Tilt-A-Hurl ride your kids make you go on ensures the plastic evenly coats the whole interior surface before it fuses together. After enough heat, time and movement, the mold is cooled from the outside to solidify the plastic shell on the inner surface. The mold is then split apart to extract the newly made hollow plastic part before repeating the process to make more of the same.


British Plastics Federation

Rotational moulding, also known as rotomoulding, is a plastics moulding technology which is ideal for making hollow articles. It is a casting technic but unlike most other plastics processes there is no pressure involved. Moulds for the process are relatively inexpensive as they do not have to withstand pressure and therefore relatively short production runs can be made very economically. Rotomoulding is used to make a very diverse range of products. The process offers the product designer exceptional freedom as just about any shape can be produced. There is almost no limit to the size of mouldings and there are literally thousands of applications.

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