Key Facts about the Milton KeynesMaterials Recycling Facility

Community Waste bring in recyclables from all over the countryand generate profits from sorting and selling the recoveredmaterials.

The MRF is state-of the-art and has one of the largestcapacities for handling recycling in the UK.It can process up to93,000 tonnes a year or 20 tonnes per hour,more thanenough to handle the extra recycling which will be generatedas Milton Keynes grows!

The original MRF was built in 1993 and cost £5.7 million.In2006 the MRF was re-equipped with the latest equipmentafter a major fire destroyed the original machines.

The majority of the sorting process is automated; operativescan control or isolate each conveyor or machine, using a hand-held remote control.They monitor the machines via acomputer and can detect blockages or faults anywhere in thefactory, from their central control room.

Situated on 1.88 ha with an additional 0.4ha of storage space.The building has 4,300-square metres of processing area. It issituated on a heavy industrial estate, with good transportconnections to the M1 and the grid roads of Milton Keynes.

The materials are compressed using high pressure balers inorder to form regular shaped bales, which are easy to stackand transport.The average bale weights for:– Newspapers and magazines = 1000kg– Plastics = 550kg– Steel Cans = 1000kg– Aluminium Cans = 500kg

Tipping at the glass bays Quality control in the picking cabin

Sorted, squashed and ready to go…Sorted paper on its way to the baling machines

Tipping Floor(commercial)

Tipping Floor(domestic)

Storage area

Storage area

Shop

EducationRoom

(upstairs)

Bale feeder

De-clumperDe-baler

Loose cans & plastics in

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Our MRF Processing Floor

Weighbridge

Glass bays

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Factory plan descriptions1.Weighbridges All vehicles are weighed to establish the type andweight of material in kilograms, before tipping. Lorriesare weighed again after tipping and payment formaterials is made on the basis of weight.

2. Glass baysColoured mixed glass from households is tipped intothe large glass bays. There are several smaller, separatebays for the brown, clear and green glass, collectedfrom the recycling banks.

The MRF has three separate inputs for loose,baled and bagged materials (3, 4 and 5 below):

3.Tipping floor &input for loosecans/plasticsVehicles tip loose cansand plastics here, fromthe recycling banks inMilton Keynes andbeyond.A digger truckwith a bucket pushes the cans and plastic onto aconveyor belt sunken into the factory floor.

4. Input for baledcans/plastics – de-clumperBaled cans and mixedplastics are fed into the‘de-clumper’ whichbreaks the bale apartusing a large steel

rotating ‘corkscrew’ called an ‘auger’.

5. Input for Co-mingled Recycling SacksRecycling sacks, from Milton Keynes households andbeyond, are split open by a mechanical bag splitter.Thesharp teeth of the bag splitter can rip open 12 tonnesof sacks per hour.

6. Metering DrumThe recycling is ‘metered’ to supply the rest of thefactory with an even flow of materials. The meteringdrum slows down the incoming materials, stopping toomuch of the recycling from entering the machines atone time, and causing blockages.

7. Ballistic SeparatorsFor an illustration of how thismachines work please see backpage. This screen sorts by sizeand weight.The small pieces ofrubbish such as bottle tops andshredded paper fall through theholes and drop onto a residueconveyor, travelling to acompactor bin.The flat/light itemssuch as paper and film carry onover the screen dropping onto aconveyor, which travels to thepaper cabin. The heavier papers,cardboard, cans and plastic itemsfall backwards onto the screenbelow. On this level the rest ofthe paper and cardboard travels over the screen onto aconveyor to the paper cabin. Again the cans andplastics roll backwards falling onto the container linebelow and are sent to the magnet, eddy current andplastic sorting line, the last of the paper and cardtravels up and over to a third conveyor travelling to thepaper cabin.

8. Material SplitterWhen the material enters the factory it is split into two lines.The material drops from one large conveyor to two smallerconveyors underneath. These conveyors run in oppositedirections to each other, which has the effect of splitting thematerials onto two conveyors travelling to the ballisticseparators.

9. Film SuctionThe film (pink sacks) travels with the paper to the picking cabin.The film is then manually picked from the newspapers and sentthrough a vacuum/suction system to the bunker underneath toawait baling.

10. Over band magnetThis large magnet rotates, attracting the steel cans off theconveyor belt and dropping them off into a bunker underneathto await baling.

11. Eddy current machineThis machine uses repulsion toseparate aluminium cans.Anelectromagnetic field creates asmall electric current in the canscausing them to be negativelycharged.A rotating drum with anopposing magnetic field that isalso negatively charged, causes the cans to be repelled sendingthem flying off into a bunker.

12. Bottle flattener - perforatorThis machine is an essential part of the plastic bottle sortingprocess. It squashes the bottles so they don’t roll about whilebeing scanned by the Auto-sort machines; It sieves out any

remaining bottles tops, whichcontaminate the plastic; andmost importantly, it puncturesthe bottles so that they formregular cubes during the finalbaling process. Square bales arevery important, as misshapenbales are hard to stack, fallover, hard to load onto lorries,and tend to fall apart.

13.Vibrating PlateThis vibrates the plastics and cans to send a level flow ofmaterial over the eddy current machine.

14. Rubbish conveyorThis transports the non-recyclables and contamination, whichhave fallen through the screen, to the rubbish compactor.

15.Auto-sort PETThere are four auto-sort machines that separate the differenttypes/colours of plastics.A fast-scanning spectrometer analysesthe moving objects using reflected near-infrared light (NIR).Thescanned bottles are blasted off the conveyor using compressedair. Plastic contamination such as yoghurt pots remains on theconveyor belt. In simple terms, the machine takes a photograph

of each individual bottle using a scanning device andmatches it to information held in the computer software.It can determine the position of the bottle, its’ size, type,shape and colour. The PET auto-sort separates all of thePET bottles from the rest of the waste stream. PET canbe clear or colour-tinted, it is strong and used for fizzydrink, shampoo, squash and mineral water bottles.

16.Auto-sort PET – clear and colouredThis machine further sorts the PET into clear andcoloured bottles.The coloured bottles fall onto oneconveyor and the remaining clear bottles onto anotherand travel to separate storage bunkers to await baling.

17.Autosort HDPEThis machine automatically removes all of the HDPE fromthe remaining plastics. HDPE bottles are either opaque orcoloured and are normally milk or detergent bottles.

18.Autosort HDPE – natural and jazzThis automatically separates the 2 types of HDPE.‘Natural’ is the name given to opaque bottles such as milkbottles, whilst ‘jazz’ is the name given to all the mixedcoloured non-transparent bottles such as detergentbottles.

19. Plastic sorting cabinThe machines can mistake some light colours for clearplastics. So we use this cabin to manually check and sortthe few items that the machines have missed.

20. Paper sorting cabinThe cabin has three conveyors running through it. Twoconveyors are used for newspapers and magazines andone conveyor for mixed newspapers and cardboard (seeinformation on ballistic separators for explanation). Thestaff in the paper cabin ‘negatively sort’ the recycling bypicking out the small items i.e. any contamination andallowing the rest of the materials to travel to the bunkersor baling machines.The items removed here are plasticfilm, some cardboard, and any small items missed by theballistic separators.The bunkers for storing the sortedmaterials are located underneath the paper cabin.

21. Baler for paperand cardboardSome paper andcardboard and paperis compressed intobales andautomatically tiedwith wire. This makestransportation to thepaper mill easier. Each bale of paper weighs approximately1000kg.

22. Baler for plastics/cansSeparated materials are baled here.They are then readyto be sold and transported to other factories where theywill be recycled. Each bale can weigh between 200-500Kg’s depending on material.

23. Storage of BalesBales are stored outside intwo areas awaitingtransportation to otherfactories where they will berecycled.

24. Rubbish compactorA small amount of the material that comes into thefactory is contaminationand cannot be recycled(around 5%). This isstored in a rubbishcompactor before beingsent to landfill or to an‘energy from waste’factory to be used asfuel.

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Bag splitter

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Baler 1

AutosortHDPE

AutosortPET

Ballistic Separators

Metering drum

Plastic sorting cabin

Control room

Colour sortPET

Colour sortHDPE

Vibrating plate

Eddy current separator

Plastic sorting cabin

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BUNKERS:A NewspapersB Mixed papersC ResidueD CardboardE Film/LDPEF Aluminium cansG HDPE colourH HDPE clear/naturalI PET clearJ PET colourKL Steel cans

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Film suction

Bottle flattener

BALLISTIC SEPARATORS

Paper, cans, plastic, pink sacks in Light material (newspapers/film)– to picking cabin

Mixed papers (newspapers/cardboard) – to picking cabin

Mixed papers (newspapers/cardboard) – to picking cabin

Fines/residue to compactors

Cans and plastics to container line

Heavy material – some paper,cans, plastic

Heavy material – some paper,cans, plastic

Heavy material – cans, plastic

Recyclables from Milton Keynes sacks are sorted, squashed andsold, but this is just the first stage on their journey oftransformation. From here they go to reprocessing factories inthe UK or are loaded onto shipping containers where they awaittransportation to manufacturing based economies in the Far Eastand Asia;The materials are sold wherever the demand is high andthey will fetch the best price. Many of the materials will nevercome back to the UK; they are used to make plastic, metal andpaper products in countries such as China where boomingeconomies have created new found wealth, and demand forconsumer goods.

Paper Products made from newspapers and magazines include: telephonedirectories, newspapers, building insulation, egg boxes and animalbedding.The majority of newspapers collected in Milton Keynesare recycled back into newspapers.

CardboardProducts made from cardboard: allcardboard collected in Milton Keynes isrecycled into new cardboard boxes withthe majority being used to produce thecorrugated inserts you see in the middlelayer of a cardboard box.

Steel / tin cansProducts made from Steel cans include: new steel cans, cars, oilfilters, bicycles, paper clips, steel beams and other steel products.

Aluminium cans (drinks cans) Products made from aluminium include: newcans, window frames etc. Most aluminium cansare recycled into new aluminium cans.Producing new cans from recycled aluminiumsaves 95% of the energy and emits 97% less airand water pollution than producing cans from ore,known as bauxite.All Milton Keynes aluminium cans are sent to Al can - the UK’s largest aluminium recycler.

Glass Bottles and JarsProducts made from glass include: newglass bottles, aggregate for highwayconstruction.All the glass containersfrom Milton Keynes are recycled intonew glass bottles/jars. Because theglass is so clean from Milton Keynes itis recycled into new glass bottles. Inother areas the glass is contaminated andhas to be used for aggregate in the constructionof roads.

Plastic Bottles• PET (Polyethylene Terephthalate) – fizzy drinks/water

bottlesProducts made from PET include: new bottles, carpet fibres,drainage pipes, clothing, fleece, luggage and artificial woodenfencing/benching.

• HDPE (High density polyethylene) - milkbottles/shampoo bottlesProducts made from HDPE include: new bottles (notfood/beverage bottles), traffic cones, toys, flower pots, recyclingboxes and drainage pipes.

Pink SacksLDPE (Low density Polyethylene) Products made from LDPE include: new bags, flexible films such asdry cleaned garment bags, flexible lids and bottles, insulation forelectrical wire due to its stable electrical properties.

What happens to our recyclables?

* A note about material qualityThe factory is an essential stage in the recycling process, as wellas sorting the materials we remove items, which ‘contaminate’ aload. ‘Contamination’ is any item mixed with the originalmaterial that will cause a problem either at the MRF or later inthe recycling process at the destination factories. It is essentialthat good quality, clean materials are presented to the recyclingindustry. Contaminated materials could result in the materialbeing ‘rejected’, and therefore needing to be re-sorted.

Examples of contamination:• Pyrex• Crockery• Drinking glasses & sheet glass• Saucepans and other metal objects besides cans• Plastic bags• Drinks cartons• Yogurt pots