1. INTRODUCTION

The TYSON range has been developed by Rotational Plastics as a tough, durable, rust-proof and rot-proof alternative to steel toolboxes and trailers. Most steel trailer and toolboxes cannot take the rough knocks over time and have to be at least repaired, if not rebuilt. The simple fact is that wood rots and steel rust.

TYSON Storage Boxes and Trailers are proudly made in New Zealand and are available to the public through our distributor network.

TYSON Storage Boxes are the number one New Zealand range.  This is not surprising as they have been designed and manufactured by kiwi's for our conditions.

The extremely innovative TYSON Trailer range has been developed to take the knocks as well. They have strong rust and rot proof trays, making them virtually indestructible. TYSON Trailers are truly tomorrow's trailer today combining the benefits of steel frame with a strong plastic tray.

Because they are manufactured using polyethylene, TYSON Toolboxes and Trailers are relatively light. This means they are easy to manoeuvre, easy to empty and easy to tow.

TYSON Storage / Tool Boxes and Trailers come in a range of sizes with many optional add-ons to suit your needs. The most innovative TYSON Trailers is a 5'x4' lidded trailer. This lidded option always generates a lot of interest as it creates a large water proof and lockable area. This trailer is very useful for tradesmen locking away tools on site and for active outdoors people.

2. ROTATIONAL PLASTICS LTD

Rotational Plastics Ltd is one of New Zealand's prominent manufacturers of high quality rotational moulding products. We have specialised in the design and manufacture of rotationally moulded plastic products for over 25 years and have manufacturing facilities in Auckland and Hamilton. A New Zealand owned and operated company we have built a reputation for reliability and service for which we are proud.

Further company details are available on our websites www.rotationalplastics.co.nz

3. THE ROTATIONAL MOULDING PROCESS

Some of the benefits of the process and the polyethylene used are:

  • Environmentally friendly, all scrap is recycled and products can also be recycled or made from recycled plastic.
  • UV stabilized polyethylene is used to protect against the sun.
  • Products moulded in one piece for added strength making them strong, durable and lightweight.
  • The process does not force the plastic into a shape so the resulting product is virtually stress free adding to the strength.
  • Plastic will not rot or rust.
  • Available in a variety of colours.
  • Thicker corners than other plastic processes leading to longer service life.
  • Lighter products than if made in steel or wood reducing stress and accidents.
  • Graphics can easily be incorporated into the products.
  • Easy to keep clean.

The Roto-moulding process consists of melting raw material inside the interior of a sealed hollow mould. The mould is then rotated for a calculated period about two perpendicular axes, distributing the melted material into the required shape and size. When heat is turned off for a cooling phase, the mould, with raw material inside, is allowed to continue to rotate for a specific time. Once the set time has elapsed for cooling, the product is ready to be released from the mould. The diagram below depicts the process stages.

The Rotational moulding process is ideal for many applications. The polyethylene we use is now one of the most common manufacturing materials, proven to be tough, durable and also UV stable.

Charging Charging
A pre-determined amount of  powder is placed in the mould. With the powder loaded, the mould is closed, locked and loaded into the oven. 
cooling Heating & Fusion
Once inside the oven, the mould is rotated around two axes, tumbling the powder – the process is not a centrifugal one. The speed of rotation is relatively slow, less than 20 rev/min. The ovens are heated by convection, conduction and, in some cases, radiation. As the mould becomes hotter the powder begins to melt and stick to the inner walls of the mould. As the powder melts, it gradually builds up an even coating over the entire surface.
heating Cooling
When the melt has been consolidated to the desired level, the mould is cooled either by air, water or a combination of both. The polymer solidifies to the desired shape.
de moulding De-moulding
When the polymer has cooled sufficiently to retain its shape and be easily handled, the mould is opened and the product removed. At this point powder can once again be placed in the mould and the cycle repeated.