Rotational Moulding

The process

Rotational Moulding is a process for manufacturing hollow plastic products and has a relatively inexpensive path to market compared with other plastic manufacturing processes. Products made using rotational moulding techniques are renowned for their strength and durability. Because the moulds used in rotational moulding are comparatively cheap, both small and large production runs prove cost-effective.

How does it work?

Step 1: Plastic in powder form is poured into a mould

Step 2: The mould is heated under rotation, causing the plastic powder to melt and form a uniform layer on the inside of the mould

Step 3: The mould is cooled as it continues to rotate so that the plastic solidifies

Step 4: Once fully solidified, the new plastic product is removed from the mould. 


Inserts, undercuts, and special tooling and moulding techniques can be used to create different desired effects or reduce the need for time-consuming finishing processes. Read more about the process, or talk to us about how we can achieve this on your next plastic product. 


Polyethylene is most commonly used in rotomoulding, however, PP, PVC, and PLA are all examples of other materials that can be rotomoulded. PE’s for rotational moulding come in various densities which will have an effect on strength, stiffness, chemical resistance and impact vulnerability. The polymers that we use most commonly have been proven through years of robust use and there are many specialty polymers to assist you in fulfilling any special requirements such as brand colours, flame resistance, stability in sea water etc. Our team will recommend the most suitable product if you are unsure of the benefits of particular materials and grades. 



Product Development

Project Management

We understand that your product is your baby, that's why we treat it like our own seamlessly guiding you through the design and manufacture process. 

With 50 years experience with NZ and International companies, we have the engineering expertise and experience to constantly improve products and efficiency as well as developing new plastic product ideas. Our expert designers have a broad knowledge of materials and integrated componentry and love the challenge of creating your innovative plastic product using the most cost effective solutions.

You can be sure that we will ask the questions that you don't know to ask yourself, giving you the greatest confidence that attention has been paid to every detail. 

Mould Design & Manufacture

We can have moulds manufactured for you, or you can supply your own. There are often some minor changes that are required to be made to tool framing if you are bringing you moulds to us. We can advise you on the best way to optimise production and framing if this is the case.

By designing your mould tooling with us, using the latest CAD software, we can ensure that your product and the mould tooling is customised to your satisfaction. We will discuss mould tooling trade-offs with you in detail to ensure that you are being delivered the most cost-effective tooling solution. Following design and manufacture of your mould tooling, we would typically trial and provide 1-2 samples of your product for fine tuning to ensure an excellent quality product. 

Industries serviced

With 50 years of experience as custom moulders, there is not a question that we do not know how to provide an answer to. Gyro contract manufactures a broad range of products for the retail, point-of-sale, medical, deep water research, ocean navigation, conservation, petroleum, sports, animal feeding and waste-water industries, giving us insight into how to mould a huge range of complex product shapes and sizes.


Custom Moulding

Production Capabilities

At Gyro Plastics Ltd, as a leading new plastic product manufacturer, we run modern efficient machinery with an experienced, innovative and motivated team of people. Our multi-headed machinery can mould items from 20cm to 4m in length and weights from small to very large. The innovative design of our machines allow us to mould up to 12 products on one machine at a time giving us the greatest flexibility, capacity and variance to provide you with quality, cost-effective and efficient product runs. 

Product Manufacture

Gyro has a thorough emphasis on product quality, service to customers and on time delivery. Your product will be assigned to one of our experienced moulding staff who, supported by our design team and a supply network of dedicated and experienced suppliers with exceptionally well proven track records, will work collaboratively to ensure your business with us is seamless.

Assembling & Freighting

We are experienced in providing a full solution to our customers. This includes receiving other components from your range to assemble and complete a finished product ready to be dispatched. We can manage dispatching product direct to your end customer or hold stock in bulk for efficient freighting to you. Our extensive and long-term relationships with suppliers means we get great pricing on hardware and engineered parts, ready to be fitted to your unique product. We are proud to be able to respond to your needs with a quick, no-fuss service. 

Contact Us

If you would like to know more about your options for plastic design and moulding, contact us for a friendly discussion with one of our team. 

Fantastic tooling, and a great team to work with both in terms of design and production!

— Ben Neal, General Manager at Zeddy Ltd based in Palmerston North, New Zealand