Consumerium's information on materials, their production, use and recycling.
Materials have many properties which effect which material is most suitable for which use.
w:Materials science is the design and discovery of new materials, particularly solids.
Recycling biodegradable waste
There are various ways in which biodegradable waste can be recycled
- w:Composting yields viable w:humus
- w:Anaerobic digestion yields w:biofuel
- w:Incineration yields energy
Running an private biodegradable waste recycling facility or compost as it's called you might have noticed some things like citrus fruit peels compost quite slowly compared to say some other fruit leftovers.
In centralized biodegradable waste management this might not be such an big issue due to the longer time horizon of the activity. Drying biodegradable waste before you put it into the recycling bin helps you avoid fungus growth allowing you to take it out less frequently and also makes the job of the collector nicer
Carton and cardboard
Effective recycling of glass (mostly bottles currently) relies on a refund system where a small refund is paid for the return of the package to the producer for reuse after it has been cleaned and checked to be in a functional condition.
Also recycling glass containers without using them again is useful though if the glass is broken and crushed in the process to just create more raw material. Though this consues much more energy as the glass is melted once again
Again here there are many resolution levels. Not knowing about the technology in this area I'm not very equipped to write anything about this. Different metals have different prices and different raw material extraction costs so that could be used as guideline.
- How does plastic, rubber or paper that is attached to some metal surface affect the usability of the metal?
Paper is made from w:pulp that can be made from trees or recycled paper.
There are many different classes of papers in high resolution recycling. Office paper (print outs) are different from magazine papers and so on. This further separation of paper into different bins is done somewhere and somewhere it's not, but we should work to make it more available as all recycling
- Small metals such as magazine or tabloid binders are not a big problem since they can be detected and removed by machines in the processing.
- Plastic and glues from envelopes are more of a problem in the recycling process. Someone with more knowledge on this could helpfully write something here.
w:Plastics are made from petroleum or recycled plastic.
Information about plastics on Wikipedia
Advanced countries have deposit-refund systems for efficient plastic (and aluminum) recovery.
- Most types of plastic can be recycled to make plastic. PVC, marked with code '03' is not welcome in the plastic recycling bin.
What plastics should be recycled?
In Finland the following rules of thumb have been given: You should put the plastic into a recycling bin if the three following conditions are met: 
- If the packaging (visually inspected) contains more that 50% plastic
- If the packaging does not contain dangerous substances and
- If the packaging is not made of PVC (marked with sign '03')
- As of 2018 in Finland the demand for recycled plastic exceeds the amount being recycled.
Links to information about recycling plastics
w:Polyethylene terephthalate (PET or PETE) is the most common type of plastic.
- w:PET bottle recycling
- Polyester terephalate recycling industry in the Wikipedia article on Polyethylene terephthalate
- PET Container Recycling Europe, commonly known as w:Petcore, is a Brussels-based non-profit European trade association.
w:High-density polyethylene (HDPE)
w:Polyvinyl chloride (PVC) is not accepted in normal consumer plastics recycling bins. But industrial PVC waste may be reprocessed.
Wikipedia on sustainability of PVC states that recycled PVC is broken down into small chips, impurities removed, and the product refined to make pure white PVC. It can be recycled roughly seven times and has a lifespan of around 140 years.
Another method is the w:VinyLoop, a proprietary physical plastic recycling process for polyvinyl chloride (PVC). It is based on dissolution in order to separate PVC from other materials or impurities. The solvent is in a closed loop, hence the name.
w:Low-density polyethylene (LDPE) is the material that most w:plastic bags are made of. The Wikipedia article on plastic bags, section "Environmental issues" states that many recycling plants don't process LDPE.
w:Polypropylene (PP) can be recycled.
Wikipedia on Polystyrene recycling states that it is generally not accepted in w:curbside collection due to the lack of recycling companies incentives to invest in compactors. An exception is Germany where PS is collected due to the packaging law (Verpackungsverordnung) that requires manufacturers to take responsibility for recycling or disposing of any packaging material they sell.