Unplasticised polyvinyl chloride (known as uPVC or PVCu), is PVC before plasticisers have been added to make the material flexible. It is a form of plastic that is very strong and rigid.
uPVC is most commonly used for window and door frames as an alternative to wood, but is often just described as PVC. Because of its rigid, durable form it is also used increasingly for plastic pipes, both in drainage and sewage lines.
uPVC is made in the same way as PVC but without the plasticisers, by heating vinyl chloride monomer (VCM) in a catalyst containing reactor. This process is called polymerisation. VCM gas is heated to over 200°C, whereby the molecules join together to make longer molecules called polymers; in this case uPVC plastic
ADVANTAGES
DISADVANTAGES
Rigid
Durable
Safe to transport drinking water
Recyclable
Fire and weather resistant
Can be made in a variety of colours
Not flexible
Harder to work with than PVC
The most important properties of uPVC are its strength and weather resistance. As a result, uPVC is mostly used for products which are constantly exposed to the outdoor elements, such as windows and sewage pipes, which need to be strong in order to withstand impact as well as weather and corrosion resistant.
Uses
Window and door frames
The most common or well-known use for uPVC is window and door frames. Due to its durability and weather resistance, it is a suitable and less-expensive alternative to wooden frames, although some people prefer the look of wood compared with uPVC.
Water pipes
As previously mentioned, uPVC is also used for water pipes. This is mainly sewage and drainage pipes as it is strong enough and resistant enough to be exposed to constant outdoor conditions.
UPVC can be used to transport drinking water to homes, unlike PVC which contains chemicals, making it unsafe. However, uPVC is rarely used for this purpose, and instead CPVC (chlorinated polyvinyl chloride) is used.