Please contact Excelsior using the details below:
Hartshead Works
Deal Street
Bury
Lancashire
BL9 7PU
Tel: 0161 765 2010 / 2014
One of the UK's leading Rotational Moulders
CONTACT INFORMATION
The Rotational Moulding Process
Nowadays more and more companies are choosing roto moulding as their preferred method of producing moulded plastic parts. Historically, roto moulding has been somewhat overshadowed by Injection moulding, however there is now industry wide recognition that roto moulding is in many cases a far more cost effective, flexible process for medium sized batch runs.
Roto moulding has distinct advantages over both injection and blow moulding because start up costs are significantly lower in terms of tooling – a roto moulded tool costs a fraction of the price of an injection or blow moulding tool. Furthermore, roto moulded products offer a uniform wall thickness of between 3-5mm, in some cases far more – greatly superior to other processes and just one of the reasons why roto moulded products are so suitable for such a wide range of modern day applications.
The practical uses of roto moulded products are far ranging, their use includes everything from garden and street furniture to tractor parts and kayak’s. As with the products, the machinery used is also diverse and ranges from open flame machines to large computer programmed gas ovens with multiple arms.
- How does rotational moulding actually work?
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Roto moulding is a very simple process – polymer powder is measured out by the operative and placed into a sheet steel or cast aluminium tool which is then clamped shut and moved into an oven chamber.
The tool is heated up to temperatures typically between 220°C and 400°C, while rotating on two axes at low speed. As the rotating tool heats up, the powder melts and begins to adhere to the inner surface of the tool, progressively building up a layer over the surface.
Once the plastic is completely fused to the surface, the mould is then withdrawn automatically from the oven and is cooled. The plastic product is then removed from the tool by the operative and allowed to cool. For products of a more technical nature we would normally always use jigs which help to maintain critical features.
- Advantages
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Relatively low start up costs – sheet steel and cast aluminium tools are very cost effective ways of bringing a new product to market as cheaply and quickly as possible. Simple sheet steel tools start from as little as £3000.
Extremely flexible process – roto moulded products can be run for one off’s if necessary, making the process ideal for small to medium sized batch runs. Injection moulders will not consider any runs of less than several hundred products.
Multiple tools of differing sizes can be run at the same time – this effectively means that the average cycle time of 1 hour is greatly reduced depending on the number of tools running. For certain best selling products we would look to run 3 or 4 tools together on 1 machine to maximise efficiencies.
Wall thicknesses – generally between 3-5mm, but can be taken up to 8/9mm if required and depending on the application.
Surface textures - Different surface textures can be achieved within the same product in so much that a shoot peen (rough texture) finish can be applied to a tool that can be masked off to leave certain areas of the tool smooth. It is also possible to apply coatings to the tooling which remove the need for release agents and enhance the general surface finish of the finished product.
New product development
Equestrian Range (494)
Custom Moulding