The material is usually a coated fabric composed of two parts, the fabric and the coating. The fabric is basically made of high strength polyester or glass fibers, woven in two different ways. For the coating, mainly PTFE or PVC coatings are used, that enhances the performance and durability of the membrane material and add qualities such as self-cleaning and UV reduction etc.
Membrane materials are made of different components and can be divided into three categories, according to their chemical composition as follows:
PVC Membrane Materials
PVC is Poly Vinyl Chloride. In general PVC membrane materials are composed of high-strength polyester fibers with both sides coating of PVC. In order to protect the PVC coating’s chemical stability under the sun, a relatively stable Polyvinylidene (PVDF) top layer is applied, thereby improving the durability as well as the self-cleaning of the PVC membrane material. The life span of PVC membrane material is more than 20 years. It has certain self-cleaning properties, B1 fire resistance level, and a tensile strength between 2500/2200 N/5cm and 10000/8000 N/5cm depending on the material’s thickness (0.5-1.14 mm). The transparency reaches from 5.5% to 12% . The transparency of the inner membrane material can reach more than 50%.
PTFE Membrane Materials
PTFE is Poly Tetra Fluoride Ethylene. In general, PTFE membrane materials are made of high strength glass fiber fabric with a PTFE coating on both sides. PTFE itself has good chemical stabilities and therefore does not need any other surface protection. The life span of PTFE membrane materials is more than 30 years, it has good self cleaning properties, A1 fire-resistance level and a tensile strength ranging form 4800/3300 N/5cm to 11000/9000 N/5cm depending on material thickness (0.37-1.00 mm). The transparency of the material is 10%-22%.
ETFE Type Membrane Materials
ETFE is Ethylene Tetra Fluoride Ethylene. ETFE membrane materials do not have a fabric core and just consist of a film of ETFE. The material has a good chemical stability and therefore does not need any other surface protection. The material life of ETFE is 30 years and above, it has good self-cleaning properties, an A1 fire- resistance level, a tensile strength of 45-60 N/mm2 depending on material thickness (0.012-0.5mm) and a transparency of 95%.
SAFS Email: safs139@safsteelstructure.com
