In 1912, Fritz Klatte discovered the basic principles for the industrial production of PVC-U/vinyl, a process which can be summarised in five steps:

 

	1.	Electrolysis of salt produces chlorine.
	2.	Ethylene is obtained after refining the oil and cracking naphtha.
	3.	Chemical synthesis of these two elements produces the 'monomer', vinylchloride, in gaseous form.
	4.	Polymerisation of this monomer structure produces the polymer, poly-vinylchloride, or PVC-U; an inert powder.
	5.	The PVC-U resin is mixed (compounded) with various additives in order to form variations with different properties. The result is a fairly fine powder or granules.

Characteristics PVC-U

- Excellent weatherability.
Weather has no effect on PVC-U building materials. Problems like rotting, rust, etc. just don't apply. Even in special conditions like coast areas (salt, storm, sun, ....) PVC-U is more applicable.

- Self extinguishing.
PVC-U burns when subjected to flame, but does not burn by itself: The product extinguishes immediately when the external flame source is removed.

- Resistance to most chemical products.
The list of chemical products that PVC-U is able to resist is very long indeed and can be obtained on request.

- Anti fungi properties.
No bacteriological development on PVC-U => hospitals, food industry, ..

- Easy to clean = low maintenance.
Its closed, smooth surface means that PVC-U is extremely easy to clean using a gentle household detergent dissolved in water. This also means that the product is virtually dirt resistant because

there are no pores which can be filled with dirt.

- Thermal insulator.
Like wood, PVC-U is a good insulator. Its coefficient of heat conductivity is actually slightly lower than wood at 0.17 W/mC, compared with 0.23 W/mC. The equivalent coefficient for aluminum is 

approximately 210 W/mC.

- Acoustic insulator
The PVC-U window system and the performing seals are developed in this way that the sound source is shielded from the room.

- Easy to work with.
Practically any automated or manual processing is possible.

- Weldable.
Its ability to be welded means that this material offers window manufacturers the opportunity to install high productivity automated manufacturing systems with no need to cope with materials. 

A whole window can be welded together in just a few minutes. The fusion temperature of the weld is approximately 260 Degree Centesimal. The sawn joints are heated locally to this temperature.

- Bondable.
Additional plastic components, such as end cap can easily be bonded to PVC-U.                       

- Good value for money.
Notwithstanding high price increases in the PVC-U raw material, the price of the end product remains very competitive in view of the many advantages it delivers. PVC-U takes more and more 

market share from other materials in its applications.

• Only 4% of the world's gas and oil reserves are used in plastic production, and only 1% of these are used for PVC. 40% of all gas and oil reserves in the world are used in heating and providing energy to buildings.
• The main component of PVC is chlorine obtained from rock salt, and crude oil accounts for only 43% of the material.
• PVC windows are at the top of their class in eco-balance and eco-efficiency analysis.
• New PVC windows offer a service life of over 50 years.
• PVC producers have certain commitments regarding environmental issues, ecological and sustainable production processes.
• The PVC content of the windows is recycled to produce PVC granules and can be used in the construction of windows at least seven more times.