Environment: A cut above
Marsali Taylor investigates Enviroglass, a small firm with a big future.
From the outside, it doesn’t look like a firm with the UK patent for the architect’s favourite recycled floor-covering. A green agricultural shed with a smaller shed behind it; a muddy track, and what looks like a large pile of grey-green pebbles.
Inside, as Mick Clifton from the Shetland Amenity Trust told me, it’s one of the recycling world’s simplest stories: from used wine bottle to usable flooring, all in one factory.
It began with the amenity trust and the SIC looking at the feasibility of a glass recycling plant here, rather than all of the islands’ bottles going into landfill. A truck can only move four tons of bottles in one go, so sending it to a recycling plant south was just too costly. However, glass can be used as building aggregate, so a firm, Decocrete, was set up by Martin Gibbs. When the business came up for sale in 2003 there weren’t many takers, so the Shetland Amenity Trust took it back on.
“We wanted to set up a stand-alone business,” Mick said, “with any profits going back into the environment. We don’t get any public funding for Enviroglass, but the SIC pays us a “gate fee” for taking the bottles, which is less than it would cost if they were paying someone to put them into landfill. What we wanted to do was make the bottles into a product that people will buy and use.”
There are a lot of bottles and jars used in Shetland. The SIC has around 50 bottle banks, spread from Haroldswick to Fair Isle, as well as collecting bins in most of the community halls, pubs and clubs. There are three deliveries a week to Enviroglass – in all, they receive around 700 tons of glass a year. They can’t use window glass though, or car windscreens, as they break differently into potentially dangerous shards.
Enviroglass boss Chris Massie showed me around the machines used in the process. The simplest way of using glass is as aggregate, and for that it’s simply crushed. He stopped beside a machine with a conveyer belt.
“There’s the hopper from an old gritter outside this wall,” he said, “which feeds the bottles outside into this Bristol rotary crusher. The ‘Bristols’ are eight manganese steel bars. Glass is so tough that each one only lasts a month. You can gauge it to get the size of glass you want. This one’s set to 15mm – large – to get the rubbish out using this vibrating screen.”
Beside the machine is a pile of old tin lids, torn paper labels and bottle caps.
“The crushed glass lies outside for a month or two, which deteriorates the labels. You don’t need to worry about washing bottles, or even taking the lids off jars – just fire it all into the bottle-bank, and the machine will sort it out.”
The second crush machine makes a better quality of glass. It’s a “pulveriser” which rotates at 2,500rpm, and has grills like at the bottom of a fire. Next to it is a pile of crushed glass. Chris picks some up and lets it slide through his hand. “It’s safe to handle. This is builder’s aggregate, and we sell this for £11 a ton – a ton is one of these square bags. Builders use this for rough concrete foundation work, like garage floors and agricultural pens. Glass is cheaper than stone, as well as being better for the environment – we had to be competitive.”
The pile glints with different colours: green, clear, brown.
“We just can’t keep the colours separate here, there’s not enough glass,” Chris said. “On the mainland, they make their glass into more bottles, and it has to be separated for that – they can’t mix the colours when they re-smelt, they’re incompatible.” He sighed. “If only I could get enough blue glass bottles, I could sell that for £200 a ton, just crushed.”
Crushed glass can have more sophisticated uses. The next machine is the separation plant, which uses a heat process to dry and separate the glass sand. The heat of the air also removes any sugar residues on the glass. The crushed glass is dried and separated into three different sizes. The largest bits are used for garden chips, like outside the Shetland Museum; the other two bags are filled with silica sand and medium sized sand, for industrial shotblast.
“Any metal which is going to be painted has to be shot-blasted first,” Chris explained. “It’s very specialised – manufacturers even specify which size of shotblast is needed for a particular paint – which is why we make the different grades.”
“Glass is a much more environmentally friendly material to use for this, because it’s totally inert – the silica’s sealed in during the heat process of making glass.
Shotblast used to be hazardous waste, because of the copper content, and so it had to be carefully collected up and sent south for disposal, and of course you had to take all the precautions while using it. Glass is just ‘nuisance dust’, so you only need normal protective equipment, and you can hose the residue away into the voe. This sells for £70 a ton – down south you’d be paying £120. Last year, we sold 300 tons of shotblast. This isn’t the time of year for it, but in June and July we’re run off our feet.”
Enviroglass isn’t making a profit yet, but it could be, just from this side of the business, if only more folk put all their bottles in the bottle-bank.
“We ship shotblast to Orkney too, and I’ve a contact there who has contacts in the North of Scotland, so that could be another sales point. The problem is that we don’t get enough bottles. Each year, we sell more than we take in. We’ve the potential to handle 20 tons a day. Unfortunately, there’s still a lot of bottles going into black bags here in Shetland. Our 700 tons is only 50 to 60 per cent of Shetland’s used bottles.”
The firm has looked at importing bottles, perhaps from Orkney, but the economics of this would need worked out: “It would be better if we could just get all of the glass that’s being thrown out locally. Orkney also recycles its own glass, but just as aggregate, for blocks for the Churchill Barrier. They don’t use it all for that, though, so it might be possible to get some from there. This side of the business is 100 per cent automated, if only we could increase the throughput.”
Over half of Enviroglass’s business takes place in their other shed. Last year, they sold 400 tons of their UK patented glass-based concrete slabs. This is the bit of their operation which causes them most concern; the potential is huge, but their current through-put is small, because it all has to be done by hand.
Enviroglass paving slabs are now in prestigious buildings across the country, but the best example locally is in the Shetland Museum: the smooth, grey-green, flecked flooring which leads along to the boat sheds, embellished with little boats and writing.
“It started from an idea I had,” Chris said. “I wondered if you could make paving slabs, so I started fiddling about with a mould and some cement, and thought, ‘This can work.’ I went to the board with what I’d done, then borrowed a vibrating table and got some moulds. Now we’re the only organisation in the country making glass paving slabs.”
Glass paving slabs have many advantages. They’re as cheap as concrete – a palette of paving slabs is £220; they’re very strong, because glass doesn’t absorb water, as stone does, and they’re much cleaner than concrete. The vibrating table “shoogles” the mix down, so that a clean, precise shape can be made, and glass suspends itself very well in the mix. They’re also very durable: “How many people have been through the new museum?” Chris asked. They can be coloured using concrete dye mix and, as Chris and his team found, they can be decorated.
“We just had to try things out, because it had never been done before. We had two shots at the ‘boat’ design. First we made a form with a boat in serpentine and resin, but the mould stuck, so then we made the words and glued them into the mould with carpet glue. That worked really well, because you could still pull the words off the mould, but the glue was strong enough to seal them from the concrete getting underneath [i.e. on the “top” side]. The steps at the museum were poured in a oner.”
The slabs can also be chiselled. Scarborough Borough Council has ordered 400 slabs to pave a central area in the town, and they’ve been engraved with directions to different areas in the town.
The shed is filled with wooden racks, each holding a flat mould filled with concrete. Even the moulds here are made of recycled plastic, and a heating element at the back of each rack helps drying. Outside, there’s a cement mixer, wheelbarrows and spades. Everything here has to be manhandled, and because space is limited only 33 large slabs can be made at a time. These can be poured in two hours, but need two days to dry, meaning no more slabs can be made – a total of 99 large slabs a week. Last year, Enviroglass made 12,000 slabs of varying sizes.
“It’s very labour-intensive,” Chris said. “It’s completely down to the goodwill of the guys that we get so much done. These slabs are done to order. A recent one was for Southampton City College, the floor of the main end of the college, and Yell School wants at least 110 square metres, as well as steps – that’ll need a bespoke mould. The new Scalloway museum is going to use glass paving, and we’re in discussion with Shetland Arts for Mareel.”
Using recycled material in a new building is becoming increasing important. The rules dictate that any project over £1 million must use recycled material; the Environmental Agency SEPA is now telling local authorities that they expect 10 per cent of any new building to be recycled, although that’s not legally required yet. The recycling aspect is factored in by the architects, and if they can use more recycled material than the competition, then their design stands a better chance of being chosen.
As the only firm in the country doing recycled glass paving, Enviroglass should be cleaning up – but in their present set-up, they can’t.
“I had to turn down a £30,000 order the other day; we just couldn’t do it,” Chris said. “There was another from London; we couldn’t do that either. Firms really want this stuff. I even had a phone call from a London restaurant, thinking we were the Texas firm Enviroglas (with one ‘s’) – they want this stuff so much they’re ordering from America.”
He brought out a pink-coloured slab that’s polished like marble, with brown and green glass glinting through it. It’s truly beautiful, and you can imagine it in kitchens and on floors across the country. I said so, and Chris shook his head.
“This is glass ‘terrazzo’, the very top end of the market. The normal slabs retail at £20 per square metre, and I could get £40 for this. But I can’t show this one to architects, they’d just want it, and we haven’t the facilities to do it for them. What we really want is a bigger shed, with a purpose-made plant. A firm called Bristol Concrete Wet-cast has a semi-automated plant, and we’ve got planning permission for a big shed. With that machine we could make 300 slabs a day.
“The trustees are being very supportive,” Mick said. “They’re to consider our business plan this year. The capital costs would be about £300,000, but we could get most of that from European funding, and we’d also be creating more jobs here in Shetland.”
The worry is, of course, that now Enviroglass has shown the possibilities of glass paving, other firms will step in to fulfil the demand. A patent is some protection, but it can only be defended by an expensive lawsuit if another firm starts marketing a similar product. Let’s hope that Enviroglass’s new plant can be up and running before another firm south steals potential customers.
However, Chris isn’t resting on his laurels. He has other plans for extending the business.
“There’s huge potential in the thermal qualities of glass. Patrick Ross-Smith reckons that for one day’s heating, it holds two days of heat. The implications of that for house-building are enormous.”
Chris’s brother, Harold Massie, hit the headlines recently with his design for an enviro-house to be built into the hill at Weisdale. Harold enlisted his brother’s expertise, and is going to use the heat-holding properties of glass to the full.
“His internal walls are to be made of metre-blocks of recycled glass.” Chris shook his head. “Now, that’s a challenge. I don’t know how we’re going to do that yet.”
I can see, though, that it’ll most certainly be done. The new shed may need an extension for another “UK first” idea before it’s even been put up.
Mick Clifton currently works for Shetland Islands Council, not Shetland Amenity Trust.