These profiles used in UPVC windows are produced by forcing molten PVC through a precision die , the material is cooled almost immediately before being cut to length. The flatness , squareness , and straightness of the profile is maintained by the design characteristics of the profile and the tooling.
The windows are then fabricated from pieces of profile that have been cut to the correct size. These pieces of profiles are joined together using either heat-fusion welding or T-joint connectors. Steel or aluminium reinforcement sections are fixed inside the UPVC profiles to provide additional strength , where required.
Additives and Stabilizers
UPVC is based on the polyvinyl chloride polymer , however , in order to make the material suitable for use as a window , a number of different additives and stabilizers are used. These special heat and UV stabilizer additives are an essential part of any PVC formulations destined for the manufacture of PVC-U windows.
The choice of stabilizer will largely depend on the particular end-application , and there are good technical reasons why certain stabilizer types are used for specific applications. Stabilizers often comprise a metallic component together with various organic compounds - the simple elemental form of a metal is never used. There are several types of metal salts and soaps used to stabilize PVC for window applications.
UPVC Windows Maintenance and Repair
One of the main features of PVC windows is low maintenance but this is often interpreted as no maintenance.
There are two main categories of repairs:
a) Surface repairs
These kind of repairs are done in case of cosmetic damages like scratches and minor damage to the appearance of the window and structural damages like holes , chips , knocks etc.
For surface repairs (scratches , indentations etc.) there are very well designed kits available. These contain everything needed to effect a good cosmetic repair – soft wax and hard wax to fill the damage - but also tools , including a tool to melt the hard wax and lacquers and touch up pens to give a finish indistinguishable from the original. The waxes can be mixed to match any particular wood effect PVC. All components are designed to weather at the same rate as the PVC and to move in harmony with the substrate.
Areas where large sections of profile have been removed can also be repaired. The process is to build the levels with the paste , sanding using wet and dry paper , spraying with white lacquer , and polishing the area. Resins and lacquers can generally be colour matched.
b) Functional repairs
Usually associated with the hardware such as damaged handles , locks or hinges. It is possible to get replacement parts for most type of hardware fitted to PVC windows/doors. Locking mechanisms can breakdown especially if they have been abused and the gearbox can then break. Fortunately replacing a locking mechanism on a window/door is relatively easy. Repair screws may be necessary if the existing holes are too large.
Hinges are usually accessible and straightforward to remove. PVC window systems are designed for ease of fabrication and with that comes ease of replacement. Hinges can be replaced with larger sizes should they need to be. Limitations can arise on side hung stays where typically only two sizes are used. It is also possible to pop rivet them back into place as a last resort.
Keeps do not usually go wrong but again these are straight forward to replace should it be necessary. Replacement parts are also available for door locks and tilt and turn furniture.