PVC-U: A natural construction principle
PVC-U windows open up unique possibilities for architecture. They owe their performance and versatility not least to the material PVC-U. The polymer is one of the first plastics ever to be used, and its favourable properties mean that it is still very much in demand - even among building owners. This is because windows and doors made of PVC-U profiles are comparatively inexpensive, notwithstanding their outstanding energy efficiency and design options. The almost complete recyclability is an additional plus point.
Windows and doors made of PVC-U have been undisputed favourites on the market for many years: around 57% of all installed elements in Germany have frame and sash profiles made of polyvinyl chloride, or PVC-U for short. This high demand is largely due to the special properties of the polymer material. Only they enable the extrusion of multi-chamber profiles with a highly developed geometry that combines stability and excellent insulation values. The fact that easy-care vinyl windows retain their attractive appearance for decades is also ultimately due to PVC-U.
As a polymer, PVC-U uses a construction principle that can also be found in nature. Biological polymers such as cellulose - used in the form of wood, paper or cotton - or natural rubber are created by linking thousands and thousands of identical basic building blocks. This gives the resulting material completely new chemical and physical properties. This is also the case with PVC-U: The gaseous and extremely reactive monomer vinyl chloride gives rise to a polymer solid that proves to be robust in every respect. Its advantages as a material were first recognized in 1912, some 80 years after it was first produced, and it still impresses today. After polyethylene (PE) and polypropylene (PP), polyvinyl chloride is one of the plastics most in demand worldwide.
PVC-U
A versatile material
PVC-U is used in two varieties: While soft PVC is used for medical products, among other things, rigid PVC is found in products for the construction sector and many other industries.
Tailor-made properties: from pellet to compound
Today, a technical distinction is made between two types of PVC: Soft PVC or PVC-P (plasticized) with a very high content of plasticizers and rigid PVC or PVC-U (unplasticized). ROSCOM quality profiles are made of rigid PVC and therefore do not contain plasticizers. In order to further optimize the already advantageous properties of the polymer, small quantities of other additives are mixed into the PVC pellets supplied in accordance with a recipe developed by ROSCOM.
Only from this compound are the ROSCOM profiles with their strong walls extruded in class A quality. In addition to their high mechanical strength, stiffness and hardness, they are impact-resistant and notch-resistant, abrasion-resistant and, last but not least, physiologically harmless. Essential for precise production according to planning specifications is the good weldability, while the high resistance to UV radiation, moisture, chemical air pollutants and other environmental influences ensures a permanently high-quality appearance.
KRONOS - the experts company
The KRONOS group is one of theworld‘s leading manufacturers of titanium dioxide (TiO2) and has been operating as an international company for more than 100 years. The group owes its signicant market position to the quality of its products, innovation, technical experience and reliable customer service around the world. The company‘s international representation is supported by an effective distribution system. KRONOS manufacturing sites are located in FIVE countries on two continents, with European sites at Leverkusen and Nordenham/Germany, Fredrikstad/ Norway and Ghent/Belgium, and North American sites at Lake Charles, Louisiana/USA, and Varennes, Quebec/Canada. The current annual production capacity is approximately 550,000 metric tonnes TiO2. The company has its own ilmenite mine in Hauge i Dalane/Norway, a key raw material in the sulphate process. KRONOS is certified to DIN EN ISO 9001, DIN EN ISO 14001, DIN EN ISO 50001 and FSSC 22000. There are two processes for manufacturing TiO2 pigments, one uses sulphuric acid for digestion (sulphate process), while the other uses chlorine (chloride process). KRONOS plants employ both methods.
As a result of the raw material used, both processes also produce iron salts, which are used in water treatment and purication, in the production of iron oxide pigments, chromate reduction in cement and in agriculture. The sulphuric acid occurring in the sulphate process at KRONOS is either concentrated and returned to the process or neutralised. The chlorine from the chloride process is recovered.
OMYA
A new functional Calcium Carbonate
for PVC Window Profiles
Calcium Carbonate is well known in extrusion processes. It is also prone to cause difficult processing conditions as the lubrication system had to be adapted in order to control the shear. Also a decrease of the gloss level was discovered as loadings of Calcium Carbonate have increased. Hydrocarb® XP is a tailor-made Calcium Carbonate designed specifically to meet the requirements of the PVC window profile market. Unlike traditional Calcium Carbonates, Hydroca®rb XP allows for an increase in mineral loadings without negatively influencing other properties and overcomes the influences on the shear and processing behavior at high loadings. These effects are possible due to improved dispersion properties of Omya’s Hydrocarb XP Calcium Carbonate in PVC.
The result, of the improved dispersion produces a better gloss and superior surface finish which challenges the conventional opinion that gloss decreases with higher loadings of Calcium Carbonate. In addition, the fine ground Hydrocarb ® XP exhibits higher notched impact resistance compared to the industry standard, more coarsely ground grade – Hydrocarb ® 95T. This allows processors the possibility to improve their formulations while easily meeting the RAL GZ 716/1 standard.
PARALOID™ Impact Modifier Improving the gloss of extruded PVC products
The gloss of extruded PVC products is controlled by the melt strength of the formulation. Melt strength refers to the stress at fracture of extruded melt and it varies according to melt temperature and degree of gelation. It also depends on the type of acrylic processing aid and impact modifier used in the formulation. Glossy surfaces are characterized by a smooth finish which reflects images distinctly. The more direct light is reflected, the more obvious the impression of gloss. The surface structure of a matte surface versus a glossy one is shown in the electron micrographs presented below, which clearly point out the differences between a surface that scatters light in many directions (rough surface) and a surface where the light is specular scattered (smoother surface).
KANE ACE® PA-40 ACRYLIC PROCESSING AID Product Description Kane Ace® PA-40 is a high molecular weight acrylic polymer that enhances the processing of PVC based formulations. Kane Ace® PA-40 is an excellent high efficiency processing aid that promotes a wide processing window, providing the flexibility to limit the number of processing aids for various applications. General Benefits Kane Ace® PA-40 has excellent powder properties with typically larger particle size, more spherical particle shape and tighter particle size distribution as compared to many competitive processing aids. This results in greater efficiency in processing, ease of handling, effective weighing and a less dusty work environment. Typical Applications and Benefits • Extruded Profiles- Kane Ace® PA-40 can contribute to an improved processing window and enhanced impact through proper fusion control for vinyl window profiles and fencing applications. Melt elasticity, melt strength and sizing can be improved through the use of PA-40. •
Vinyl Siding- The use of Kane Ace® PA-40 processing aid can contribute to enhanced impact properties thought the proper control of fusion and impact modifier dispersion.
Melt elasticity, melt strength and sizing can be improved through the use of PA-40. •