Recycling – a new lease of life for construction foam cans
"Cradle to cradle" is the aim of modern recycling systems.
This means that, ideally, a product will be used over and over again - although perhaps in a different form. This vision is already reality for the 25 million PU foam cans used in Germany every year. A spent construction foam can is recycled to 95%; 80% of this in materials. This is made possible by the PDR industry solution.
PDR Recycling GmbH + Co KG — Products via Recycling
As early as 1993 the European manufacturers of PU foam cans set up an exemplary return and recycling solution for spent assembly foam cans in collaboration with PDR. Today, PDR is a sought-after recycling specialist for materials recycling of used products and production residues. It all started with the recycling of PU foam cans.
How PU foam cans are recycled
The only system for recycling PU foam cans in the world is located at the site in Thurnau (Upper Franconia). Both the packaging and also the fluid residual contents can be recovered here.
This recycling system chops the assembly foam cans mechanically without oxygen and the fluid residues and metal parts (aluminium and tin plate) fall into a solvent bath. Here, a washing screw removes the metal parts and washes them. This is followed by further washing and drying stages. The metal filter sorts the cleaned and dried aluminium and tinplate.
The PU solvent mix that is created runs through a filter several times to separate the PU and solvent again. The solvent is added to a cycle for reuse in the next washing stages. The propellants are suctioned off and liquefied under pressure. The plastic caps are ground into granulate and used to make plastics.
Recycling of PU foam cans explained in simple terms.
A humorous explanation of the returns and recycling system for spent PU foam cans:
New products from old construction foam cans
In this way, PDR recycles 95 percent of the returned cans. 80% of this in materials. A series of new products is created that are returned to the raw material cycle.
is the prepolymer, recovered from PU foam cans. It is reused in various polyurethane applications, such as adhesives, lacquers, filling materials and binding agents, and is also added when producing new foams - this closes the cycle.
is a blend of PREPUR® and MDI. As agreed with the customers, various mix ratios are possible depending on the specific purpose.
is the propellant, that PDR recovers from the PU foam cans. The aerosol industry uses the fluid gas mix for technical aerosol products and cleaner sprays.
The ground plastic PE/PP
is produced from the recycled caps of the spent PU foam cans. This is a colourful mix of PE/PP plastics and is used to make other plastics.
Also, there are scraps of tin plate and aluminium from the packaging material of the assembly foam cans. Both fractions are sold to the metal-working industry where they are smelted again.