GumDrop: Recycling Chewing Gum


We’ve all trodden in a sticky patch of chewing gum at some time or other. It’s messy, annoying, hard to get rid of – and everywhere on our pavements. One enterprising UK designer has decided to attack the problem not with a clean up, but by recycling. By Jeremy Torr.

London, 22 May 2019. When design student Anna Bullus was studying at the University of Brighton, UK, she specialised in plastics and material experimentation, which led to her to develop an interest in recycling. As part of her research, she soon realised that one common material, chewing gum, was not only not being recycled, but was also a real nuisance on our streets.

And there was lots of it: one study in 2000 estimated that the world market for chewing gum back then was around 374 billion pieces sold every year, making up about 560,000 tonnes of waste. That will likely have increased significantly by today.

Worse still, that’s over US$25 billion spent on something that is just thrown away, and that never gets recycled. And the most irritating aspect is that it messes up the environment, permanently. The base material, a synthetic rubber called Poly-isobutein, sticks to pavements (and under restaurant tables) and never goes away. As Bullus says, once here, it’s here forever.

“The biggest problem is chewing gum doesn’t biodegrade. Can you imagine, if dinosaurs were able to blow bubble gum, we would be able to dig those bubbles up still, today!” she says. And it’s an expensive problem too; local street maintenance crews can spend up to $2 cleaning a blob worth 4 cent off the pavement.

Universities, airports and tourist destinations have all fitted Gumdrop bins with positive results. Courtesy GumDrop.

Universities, airports and tourist destinations have all fitted Gumdrop bins with positive results. Courtesy GumDrop.

Bullus realised that there was a simple answer: recycle all that gum. But would people stop throwing it in bins, or onto to ground, and start putting it into recycle bins instead? She thought they might, if the bins had something special to mark them out as chewing gum receptacles.

“One of the things I wanted to do was to create a bin that people would want to put their (used) chewing gum into,” she explains. She started looking at what a bin like that should look like, to help stop all those dirty spots of gum on the pavements.

So she got to work on a design that resembled a giant pink gum bubble, one that could be mounted on lamp-posts or stuck to walls in high pedestrian traffic areas and would hold enough used gum to be worth collecting.

Then, and this was her Eureka moment, she wondered if it was possible to use the used gum itself to make the bubble-shaped bins. “We thought, why can’t we use all this discarded bubblegum that’s on our streets (as the raw material) to make the bins from?”

Working with a group of plastics experts and moulders from the Polymers Department at the London Metropolitan University, Bullus spent three years developing a recycled chewing gum material she calls Gum-tec. Gum-tec can be used in any existing plastics manufacturing process such as injection and blow moulding.

The process takes used bubblegum, cleans and purifies it, then mixes it with other recycled plastics to make a strong, durable and recyclable material.

“We use a clever process to separate off the gum from the other litter,” says Bullus. “When it’s mixed with other recycled plastics it forms this really durable material that is perfect for making our GumDrop bins. From one full Gumdrop bin, we can make three new bins! So it’s a completely sustainable process.” And one that helps produce cheeky-looking, giant pink bubble bins that reduce street litter..

GumDrop bins can be fixed to poles or stuck to walls anywhere. Courtesy GumDrop.

GumDrop bins can be fixed to poles or stuck to walls anywhere. Courtesy GumDrop.

So the overall effect is that the process can collect yet more otherwise wasted gum, to be used to make even more collection bins, that can collect even more gum. A virtuous recycling cycle, in fact.

But once the recycled gum process was mastered, Bullus started to realise the full potential of her ex-chewed plastic.

“Then we thought, hey, we can use the recycled gum to make other things like Americano mugs, pencils, shoe soles and things,” she says. This really opened up new possibilities for the ex-gum compound. “It means we have the opportunity now to make a huge difference in terms of things we can recycle and make,” she adds.

Her company, GumDrop, has already been supported by big names like  Legoland, Heathrow Airport, Westfield Shopping Centres and more as a way to cut gum cleaning costs. Initial results have seen the company’s GumDrop bins, placed strategically around public areas, reduce chewing gum litter by an average of up to 46% in the first 12 weeks of their use.

And her product is blowing bubbles into the plastics moulding industry too. The uniquely bright pink Gum-tec is now being used to make other products like dog bowls, rulers, wellington boots and sports cones.

Keyring sized GumDrop on the go. Courtesy GumDrop.

Keyring sized GumDrop on the go. Courtesy GumDrop.

And for places where GumDrop bins are hard to find, keen gum-recyclers can now use Bullus’s new Gumdrop On-the-go. This is a portable mini bin that hygienically stores waste gum. Each comes with its own key ring tag, so users can clip it to their keys, belt or whatever.

Once full of used gum they can be popped into a big Gumdrop bin, or mailed to Gumdrop Ltd by post

“Chewing gum is an incredibly useful material, but it is just ending up on our streets. We want to change that,” says Bullus.