PVC is a homopolymer featuring molecular chains with few branches; it has a molar mass of between 40,000 and 150,000.
PVC-U (unplastifiated or rigid PVC) is widely used in industrial applications.
Chemically, PVC has a structure which is similar to that of PE but instead of several hydrogen atoms it has chlorine atoms, which are attached to the molecular chains at the side in a random manner (atactically). The large chlorine atoms prevent parallel alignment of the main chains so crystallisation from the melt is impossible. This explains the amorphous molecular structure. As a result, semi-finished products made from uncoloured, unmodified PVC are transparent.
In the case of PVC-U a distinction is also made between impact resistance properties:
- PVC-NI (normal impact): this is the most common PVC-U type (SIMONA® PVC-CAW) with a notched impact strength of <5 kJ/m2 and excellent chemical resistance.
- PVC-RI (raised impact): this is a PVC-U type:
Those PVC types have notched impact strength of between 5 kJ/m2 and 20kJ/m2 and good tension crack resistance.
Generally speaking, up to 12% modifier is used. Owing to the high proportion of modifiers, limitations with regard to chemical resistance and thermal resistance have to be taken into account.
Special types of PVC
PVC-T: UV-stabilised, especially for door production, matt or gloss
PVC-T is a special type of material developed within the area of door production. PVC-T features very good thermal forming properties, allows sophisticated door designs, is very easy to process and has a long service life. In addition, PVC-T is classified as a material with low flammability (DIN 4102 B1). PVC-T can be made in various shades of white to suit customers' requirements. PVC-T is UV-stabilised and weather resistant.
PVC-TF: increased impact strength, UV-stabilised, for extreme thermoforming requirements
- PVC-TF is a special type of material developed for the thermoforming sector and is suitable for extreme stretch conditions. PVC-TF guarantees highly uniform wall thickness distribution and perfect surfaces. Additional key benefits are increased impact strength, versatility in terms of processing and high chemical resistance.
- Excellent forming properties
- Suitable for extreme thermoforming requirements
- Chemically resistant
- UV-stabilised and weather resistant
- Increased impact resistance
- PVC-GLAS: Rigid PVC, normal impact strength, transparent, permeable to light
- PVC-GLAS opal: Rigid PVC, translucent, opal
- PVC-GLAS-SX: Rigid PVC, increased impact strength, transparent, permeable to light, easy to die-cut
- Extremely permeable to light (up to 88%)
- UV and weather resistant
- Low flammability in accordance with DIN 4102 B1
- Chemical resistance
Available upon request:
PVC-GLAS highly transparent: Rigid PVC, high transparency
PVC-GLAS-LZ: Rigid PVC, normal impact strength, transparent, permeable to light, suitable for contact with foodstuffs
They are also others currents types of PVC
PVC plasticized: contains more than 20% plasticizer. At room temperature plasticized PVC displays characteristics similar to those of an elastomer, i.e. it is tough and very flexible. The main fields of application are cable sheathing, films, sheets (to make flat joints: see Mipolanâ) and above all:
- Strips in PVC transparent and plastifized : 200, 300, 400 mm width and respectively 2, 3, 4 mm thick, on roll to close large opening for passage of truck and lift trucks.