Frequently Asked Questions

Your common questions, answered.

What is co-mingled recycling?

Co-mingled recycling is where recyclables including plastics, cardboard, paper, metal cans (and sometimes glass) are all collected together in the same recycling bin or container. These materials must be mechanically and manually separated before the individual waste streams can be recycled. Monoworld operates sophisticated modern equipment that uses Infrared and colour-sorting technology to automatically sort the majority of these materials. Manual fine tuning and quality control ensures the highest quality plastic feed-stocks are created for subsequent recycling processes.

What plastics can you clean and recycle?

At Monoworld Group, we predominantly wash and granulate High-Density Polyethylene (HDPE) Plastic Bottles and Polypropylene (PP) Pots, Tubs and Trays. However, it is possible to wash most single-stream rigid plastics where required.

Larger items such as plastic wheelie bins, plastic oil tanks, crates, pallet boxes, dolavs, etc. that require pre-shredding before being granulated. Monoworld Group has the ability to dry shred and granulate heavy-duty plastics first and then wash the regrind as a separate process.

Monoworld Group offers a total recycling solution so we have a flexible approach that can handle many different plastics in all shapes and sizes.

Why do you need to separate different plastic types?

Different plastic types need to be separated to ensure each can be effectively recycled to produce a quality recycled plastic raw material. Each different polymer or plastic type has a different chemical makeup and a different set of physical properties and attributes. Many plastic types are not compatible with each other.  For example, when you try to mix water and oil the oil will float to the top. A similar thing happens when non-compatible plastics are recycled together

Why do you need to sort different colours of plastics?

The principal reason for sorting different plastic colours is to increase the value of the recovered plastic. Uncoloured (natural or clear) plastics have more value in the recycling market because they then have more potential use.

As an analogy using water colour paints, when you went for art classes at school, each time you want to change the paint colour, you would dip your brush into the water pot. After repeatedly dipping the brush into the water pot using different colours the water became murky.

In an ideal world we would use the technology available to separate each different colour of plastic BUT the reality is, it is not cost effective. Hence, we separate coloured from non-coloured plastics and sometimes black plastics are removed too.

Can dirty plastics be recycled?

Yes of course. As the name “wash / granulation” implies, Monoworld Recycling can take dirty, contaminated plastics and wash them to produce high quality plastic raw materials that can be manufactured into new products.

Washing individual bottles or trays would be difficult. Each item would need to be individually scrubbed or shaken to get it clean. Hence, washing and granulation tasks occur together.

Simultaneously the size of the plastic waste is reduced to manageable pieces of 10-12mm diameter through regrinding and washing the same. The regrind can then be agitated (stirred) in the water and detergent mix to ensure a thorough clean.

Do plastics need to be rinsed at home?

Ideally yes. Monoworld Recycling would always recommend households to rinse their plastic recyclables at home before putting them into the recycling bin. This reduces the risk of cross-contaminating clean plastics from dirty plastics.

Heavy contamination in the recycling bin will leak onto other recyclables and could mean they have to go to landfills instead of being recycled. Food contamination will also attract flies in the warmer months which can cause problems at the recycling centers and surrounding neighbourhoods.

Monoworld has taken great efforts over recent years to improve facilities on-site to minimize issues caused by flies but the best way to tackle the problem at source.

A quick rinse in your leftover washing up water before you discard it is enough to remove the worst of the contamination from your recyclables. Any further residual contamination will be dealt with by our wash/granulation line.

What is the output from wash or granulation?

What goes into the Monoworld wash / granulation line are dirty/contaminated plastic products such as buckets, trays, pots, bottles, etc. This is mostly plastic packaging waste from commercial and domestic applications.

When those items have been cleaned and granulated the resulting product is a clean, dry plastic regrind which can be used directly into some moulding applications. Alternatively, the plastic flakes can be melted down and compounded with additives and colourants (masterbatches). This produces a more homogenous, valuable plastic pellet that can compete with virgin plastic feedstocks.

How are metal cans recycled?

The first stage of recycling is to extract the different metals from the co-mingled waste streams to create single streams of Aluminium and Steel.

The important thing to know, is that Steel is magnetic (ferrous) and Aluminium is not (non-ferrous).

Ferrous cans can be extracted from the waste stream using magnets. Non-ferrous metals can be extracted using something called an eddy current separator. Once separated into different waste streams Monoworld compact the metals into bales. These baled materials can then be shipped to UK metal recycling and processing foundries where they can be melted down and turned into re-useable raw materials.

Interesting Facts about Metal Can Recycling

  • Aluminium is infinitely recyclable (its physical properties do not degrade with each recycling cycle).
  • Both Steel and Aluminium are easy to recycle AND use far less energy in the recycling process than in the extraction and processing of the raw materials from the Metal Ores.
  • Recycling just 1 kg of Aluminium saves 6 kgs of Bauxite (Aluminium ore) from being mined, 4 kgs of chemical processing materials and 14 kw/h of electricity.


What is single stream plastic waste?

Single stream essentially means it is all the same plastic type. Although Monoworld sorts domestic plastic packaging waste into “single streams” when we talk about single stream rigid plastics, we are generally referring to large format plastic waste derived from industrial sources where disposal is more controlled rather than domestic from applications which more usually end up as Mixed Rigid Plastics.

Single streams of plastic waste can come from a variety of sources such as:

  • Manufacturing Waste
  • Defects or Rejections
  • End of Life Products
  • Transit Packaging (crates, trays, pallets, pallet boxes, dolavs, IBC’s etc)
  • Waste Collection Services (all sizes of wheel bins – domestic and commercial)
  • Utility Companies (water pipes, gas pipes, drainage pipes)


How do you recycle single-stream rigid plastics?

Many of the items received from such waste streams are quite large and with several components, they are relatively easy to dis-assemble and recycle.

Washing and Granulating Plastics

The next stage of recycling plastics is size reduction and cleaning. To complete the recycling process, plastics need to be melted down. The melting process requires the plastics to be fed into a machine called a compounder (aka. extruder) that will melt the plastic and convert the molten polymer into pellets.

It is not easy to feed whole bottles, trays or ice cream tubs into such equipment so we need to granulate the plastic (chop it up) into more manageable sized pieces (typically 10-12mm diameter). This process is called granulation and produces what is known as plastic regrind.

We also need to remove any residual contamination from food, grease, shampoo etc. Unfortunately, not everyone washes their waste before putting it in the recycling bin and so we use a “wet granulation” process that removes the worst of the contamination and then a further “hot wash” to remove more stubborn contaminants such as grease or oil.

Why Does Plastic Need to be Clean to Recycle It?

Plastic needs to be clean to be recycled for several reasons. Firstly, if it is not clean the food or grease will cause the plastic regrind pieces to stick to each other (known as agglomeration) and then it will not feed into the compounder properly.

Secondly, the temperatures and process used to process plastic will not burn off the contaminants like it would in say metal or glass recycling and so the contaminants would remain encapsulated in the final recycled plastic pellets. This would reduce their quality and value significantly.

How to Recycle a Wheelie Bin?

Both the body and lid of a standard domestic wheelie bin are made from HDPE. So to recycle wheelie bins we simply have to remove the wheels (plastic and rubber) and axles (metal). This has usually been done for us so the bins can be stacked for collection.

The bin is then reduced in size and fed into the shredder where it is ripped into more manageable sized pieces.

Do Monoworld recycle mixed rigid plastics?

Yes! At our Sharnbrook site in Bedford, Monoworld handles a wide variety of different plastic grades including:

  • Mixed Rigid Plastics (MRP)
  • Expanded Polystyrene (EPS)
  • PP Big Bags (aka FIBC’s or Bulk Bags)
  • Plastics from Waste Electrical and Electronic Equipment (WEEE)
  • Construction Grade Films

…and many others.

Do Monoworld recycle other materials?

Yes. Monoworld operates integrated waste sorting and recycling facilities for co-mingled household packaging waste which includes:

  • Recycling of Mixed Metal Cans
  • Recycling of Cardboard and Paper Grades
  • Recycling of Single Stream Rigid Plastics


Contact us

Monoworld Recycling Ltd.

Sanders Lodge Industrial Estate
Northamptonshire NN10 6BQ
United Kingdom

+44 (0) 1933 412 333

Monoworld Ltd.

Monoworld Business Park
Rushden Road
Bedfordshire MK44 1NB
United Kingdom

+44 (0) 1234 782 702