PUR recycling - Learn How to Recycle Polyurethane Foam

What is PUR (Polyurethane Foam)?

PUR is an abbreviation of Polyurethane. PUR comes in a rigid or a flexible form.

The rigid PUR foam is very efficient as insulation material for walls and panels in industrial buildings. It is used in insulated windows, cold stores, air barrier sealants, in domestic appliances or other industrial products.

The flexible PUR foam is found in bedding, mattresses, furniture, automobiles, carpet underlay and a variety of consumer and commercial products.  

How do you recycle PUR?

One very essential question in today's global environment with the ever-increasing focus on circular plastic economy is this: Is polyurethane recyclable? 

Traditionally, PUR ended up in landfills, but it is posible to recycle the PUR foam. It can be done through reusing the ground and reprocessed material in new products, through chemical or mechanical recycling or finally the PUR foam can be used for energy recovery, as it is a raw material that can be used as a replacement for virgin fossil fuel. 

Chemical recycling of PUR is when the PUR foam is broken down or dissolved in a chemical mixture. This could be in caustic solvents. After the dissolving of the PUR foam, and processing of the chemical mixture it is possible to obtain a kind of purified polyether.  

Mechanical recycling of PUR is when the compacted and degassed foam is heated and made into new pellets that can then be used for producing new materials.

Energy recovery of used PUR is if there is no life or recycling left to do, the compacted plastic foam can then be sent to incineration to create heating and/or electricity.

Step-by-step: Using RUNI PUR recycling equipment

When talking about recycling of polyurethane foam, a very important matter is the logistics of these processes. As all plastic foams, PUR contains a great percentage of air, which makes it very hard to handle, both when considering handling, sorting, storage and transport. This is why COMPACTION is such an important matter when handling these plastic foams. Furthermore PUR foam also contains an explosive gas that can create dangers when this plastic foam is handled.

Step 1: Collect the waste

First of all the material needs to be collected and sorted, to make sure that all of the foam is PUR and that there are no nails/tape/wood pieces or other similar things together with the collected PUR foam.

One place PUR could be collected, could be in a production of PUR where offcuts or faulty production can take up quite a lot of space and focus. In this case it would make sense to gather as much of the PUR as possible, and start compacting as soon as a bit of material has been collected. It is always recommended to compact as close to the source as possible to save in both manual labor, handling, transport and logistics in general with this airy foam.

Another place where collection of used PUR could take place, could be in a recycling station. Here both private individuals and companies can drop their used PUR foams, for these to be recycled. Here it also makes sense to compact as close to the source as possible - preferably next to the collection point, as it is extremely expensive to transport the foam with the air and gas inside.

Step 2: Compaction in the RUNI Screw press

When the collection of the PUR takes place, the recommendation is to put a RUNI PUR screw compactor right next to the collection point. Depending on the quantity of material to be collected in each place, a screw compactor is designed for the compaction of the PUR foam. The RUNI screw compactor for PUR has various extraction points inside the closed system of the machine to make sure the explosive gas is extracted and handled correctly. The RUNI compactor's extraction system is then connected to the extraction system of the company or recycling station. 

When the foam is fed into the pre-crusher it is shredded into smaller pieces, and some of the gas is extracted here, but more importantly, when the smaller pieces of the PUR is falling down into the screw and pressed through the automatic jaws, creating the friction and the compaction, this is the main point for gas extraction. The PUR screw compactor has a lot of easy handling-equipment, as automatic start/stop function, control box and alarms to indicate if something needs adjusting. The process itself is continuos and as long as there is material in the machine, everything keeps working automatically, until there is no foam left to compact. The compacted PUR can then exit into endless bags, that are easy and safe to handle, and can be stacked on a pallet for transportation. This is a good solution, partially because the material can be toxic to get in close contact with, and because the foam, when compacted, turns into a kind of heavy dust, that is quite difficult to handle if not properly pushed into bags. 

The compacting assures easy handling, and the material is taking up a LOT less space. The compacted PUR foam can, in compacted form, be sold for further recycling. 
This solution, when handling PUR foam, is very environmentally friendly as it uses very little electricity and helps this material stay valuable and ready for the next step in it's life cycle. All in all, a great sustainable alternative to the traditional landfill or incineration options. 

Step 3: Pack and ship the compacted PUR for further recycling

When the compacted PUR is gathered in endless bags it helps the further handling, such as transporting it. These bags are heavy and easily stacked on a pallet, to make sure the maximum weight is achieved in the transporting truck. Both in an economic aspect as well as in a environmental one it is always better to fill up the truck and use the maximum allowed weight, than it is to transport foam, air and a half empty truck.

Take full control of PUR recycling with RUNI

What does the RUNI SK370 screw compactor for PUR offer?

• Handles up to 200 kg/hour (5 tons/day)
• Uses only 15 kw main motor (and 4 kw Heavy Duty Precrusher)
• Achieves up to 350 kg/m3 after compaction (50:1)
• High safety levels
• Is CE-approved (can be ATEX-certified)

Learn how to recycle other material waste

Do you have other types of waste, that you would like to recycle? Take a look at our other recycling guides:

Recycling of:

·        EPS

·        EPP

·        EPP

Besides our machines for compacting, we also offer solutions for dewatering of various packaging:

·         PET bottles

·         Alu cans

·         Tetra-Pak

If you need any further information, or do you have any questions about the RUNI machines, please fill out the form below. We will contact you as soon as possible.