What is PU? PVC? PVB? rPET?
What is Polyurethane (PU)?
- in technical terms, polyurethane (PU) is a polymer. It is prepared using fossil-fuel raw materials, most commonly petrol-based or oil-based. Hence at the early stage of life PU is created with non-renewable and non-biodegradable materials and emits high levels of GHG in its production
- a polymer is the raw material (resin) that is combined with other ingredients to be shaped into final form PU plastic. There are varying types of PU plastic - flexible or solid - and used in a wide variety of applications to create many consumer and industrial products, including fashion clothing and accessories, building insulation, car parts, and more
- PU material used as faux or vegan leather is then produced by mixing the PU polymer with 2 chemicals. The chemical reaction of combining the PU polymer with those chemicals delivers the PU plastic which is then attached to a textile backing beit polyester, cotton, nylon or whatever
- in technical terms, the 2 chemicals used are 'di-isocyanate (TDI)' (which is a form of 'isocyanates') and 'polyols'
- isocyanate chemicals used in the production process are toxic and hazardous to workers. Regulators and organisations around the globe have focussed on the exposure of workers to isocyanate chemicals in manufacturing
What is polyvinyl chloride (PVC)
- polyvinyl chloride ( PVC) is also, like PU above, a synthetic polymer of plastic
- PVC is made from fossil fuels including natural gas
- it is the world's 3rd most produced plastic polymer and considered to be most versatile because it is lightweight, durable, low cost, easy processing
- PVC polymer resin is combined with additives to create the PVC textile required - rigid (window frames and sills, doors, rigid pipe), semi-rigid (vinyl flooring, flexible pipe, thin films like stretch wrap, advertising banners), flexible (wire and cable insulation, flexible pipe), very flexible (boots and clothing, inflatables, toys), extremely flexible
- it is widely used in the building and construction industry, also used in the making of fashion products - faux or vegan leather - and in the making of children's toys
- it is the additive chemical 'phthalate' (pronounced (THAL-ates) aka plasticizers in the production process which give PVC its adaptable rigidity and flexibility. For added flexibility and softness, more phthalate is added in the production process
- in the case of 'very flexible' PVC for boots, clothing, inflatables, toys it is estimated that 44% of the PVC textile is comprised of phthalate
- phthalates are not chemically bound to the plastic they are used in and they leech or migrate out over time and contaminate indoor dust and air
- health impacts of exposure to chemical phthalates are being identified with higher impact for reproductive health and developmental problems
- phthalates aren’t a single chemical and particular additives are included to get a particular result eg Bis(2-ethylhexyl) phthalate (DEHP) has been the most widely-added phthalate to PVC to make products flexible.
- it has been discovered from research that DEHP has increased environmental and health risks and stated that its use is generally being phased out. DEHP use in children's toys has received regulatory responses around the globe eg it was permanently banned for use in children's products in the US in 2008 by US Congress
- in addition to more calls for Government regulatory actions regarding PVC, here are calls for business and consumers to take action to get phthalates out of use everywhere. Such as businesses to take action not to purchase products made with PVC containing phthalates, consumers rejecting purchases made with or containing phthalates
What is polyvinyl butyral (PVB) and Recycled PVB?
- similar to PU and PVC, PVB is a type of plastic polymer resin and is similarly created with the use of petroleum-based fossil fuels
- PVB is made by chemical reaction of polyvinyl alcohol with butyraldehyde
- PVB is mostly used for applications that require strong binding, optical clarity, adhesion to many surfaces, toughness and flexibility
- major application is laminated safety glass for car windshields where PVB is used in between two panes of glass to bond them together to increase strength and safety to the glass
- PVB sheets for glass lamination usually include a plasticizer additive of about 20–25% and it is not always known whether the plasticizer is one of the phthalates family
- Recycled PVB (RPVB) is a plastic resin made by recycling windshields from abandoned cars. The resin is made by separating non-pvb materials - such as the glass it bonded - and cleaning the PVB film from glass and mess for turning into recycled PVB pellets and coating resins.
- post-consumer or recycled PVB leather is the re-incarnation of the PVB plastic resin and can be similarly used for applications requiring strong binding, optical clarity, adhesion to many surfaces, toughness and flexibility - such as upholstery, packaging
- also could be over time used for car windshields instead of the traditional PVB laminated glass windshields which is more eco-friendly: if required to make RVPB the use of fossil fuel raw materials would be greatly reduced from traditional PVB and cheaper
- there are claims that RPVB is being used to create a synthetic vegan leather textile and is being used to make handbags
- there is also a claim that handbags made with RPVB are made with 100% RPVB
- research has shown that RPVB can theoretically be used as a textile coating, however, its use as such is far from developed and questionable that it could be described as '100% RPVB'