Article

Developing potato plates

Potatopak (now re-branded as earthpac) make and sell potato plates. Find out more about the research and development needed to take biodegradable potato plates from the initial concept to the final product.

Potatopak machine with eight moulds.

Potato plate machine

The Potatopak machine above has incorporated eight moulds.

Rights: The University of Waikato Te Whare Wānanga o Waikato

Richard Williams started the Potatopak business in New Zealand producing a range of plates made from potato starch. Before deciding on shapes and sizes, he first researched existing disposable products on the market.

Checking out the competition

Potatopak chose shapes for the plates that had a point of difference from existing plastic varieties. Potato plates need to have this point of difference because they are more expensive to produce than their plastic counterparts, so the retail price is slightly higher. If consumers are motivated by cost more than the environmental impact of the product, they are likely to choose the cheaper alternative. When choosing the plate sizes, Potatopak had to consider the usual size of food portions.

Designing the machines and moulds

As well as the function of the item and consumer preferences, Richard has to consider the constraints of manufacture. He has to make a mould for each different shape and size of item and determine the weight of mixture that will produce the required thickness and strength to make a quality product.

Potato plate research and development

Developing the products requires a lot of research and trialling to produce successful products. How does Potatopak do this?

Rights: The University of Waikato

Richard drew on his engineering background and knowledge to design, build and maintain the machines that make the products and optimise their performance.

Potatopak’s first machine was installed in 1999, but it was not up to commercial use. It could not withstand long hours of continuous operation and needed an operator present constantly to keep producing.

Potatopak’s second machine incorporated eight moulds rather than four and didn’t need an operator present all the time. This machine has a larger hopper, which feeds all eight moulds at once rather than one at time, and it does not need to be topped up with ingredients so frequently. Now both machines operate continuously throughout the day.

Potatopak recently built a third, more sophisticated machine to make new and more complicated products.

Solving manufacturing problems

Richard is constantly thinking about how to redesign or modify his machines to achieve greater efficiency and ease of use, and make different and stronger products. For example, the hot potato starch stuck to the original mould materials so new moulds were coated with Teflon. Adding wax to the potato starch mixture also helped solve this problem, but the wax can discolour the plates, which sometimes leads to rejects.

Red tomatoes on a biodegradable potato plate.

Tomatoes on a potato plate

The potato plates are used for the packaging of fresh produce.

Rights: The University of Waikato Te Whare Wānanga o Waikato

Potatopak’s range of products

Initial research and development focused on making plates (used for takeaway food) and trays (used for packaging foods like vine tomatoes and sweetcorn cobs, and holding sets of wooden disposable cutlery that Potatopak sells along with their plates).

Other products include trays used in hospitals for patient meals or to hold surgical instruments in operating theatres, a lidded container for serving takeaway salads and a possum bait station.

Biodegradable possum bait station product.

Possum bait station

The final biodegradable possum bait station product incorporated three compartments for the bait.

Rights: The University of Waikato Te Whare Wānanga o Waikato

Development is also underway for a tray for inflight meals. With the potential of the new machine to produce more complicated shapes, many more product ideas are now possible.

Potatopak product labels

The Potatopak product labels have to attract consumers and promote the ‘environmentally friendly’ aspect, so the company invited feedback to help decide on images, shape and colours – they found that colours held strong associations for many people.

Packaged set of Potatopak plates with the Potatopak branding.

The potato plate product

A packaged set of Potatopak plates with the Potatopak branding.

Rights: The University of Waikato Te Whare Wānanga o Waikato
Published: 05 December 2008