The answer is none. In our country uPVC changed it’s name to PVCu in the late 1980’s to fall in line with other European countries. They were all calling it PVC-U because European languages mostly place the noun (being PVC in this case) before the adjective (U).
So what is PVCu?
The ‘PVC’ part of it stands for Polyvinyl Chloride. The ‘U’ stands for Un-plasticised, often wrongly called Un-modified.
Poly Vinyl Chloride, which we know as every day ‘PVC’ is modified, i.e. softened and can then be used in the manufacture of products such as hand bags, sport bags, shoes and fake leather. It is the use of this material, which has made us familiar with the abbreviation ‘PVC’.
Pure PVC-U is not quite suitable for window and door profiles. A small amount of stabilisers and additives are required, the mix of which may vary slightly between different manufacturers of profiles for window and door systems, and is necessary to provide longevity, high weather and UV resistance, and also to achieve a brilliant white colour.
The basic material properties of PVCu make it ideal for window and door application, including:
Does not rot or biologically decompose.
Resistant to weathering with low maintenance requirements.
Is tough on impact.
Retains its shape within normal climatic temperatures.
Can be reshaped at very high temperature and can therefore be recycled.