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Construction of Membrane Material |
| The membrane material generally consists of woven fiber cloth and coating material. Several fiber materials are available for structural cloth of architectural membrane. Synthetic fiber such as polyester or fiber glass is the most commonly used material for base cloth. The coating material is either PVC or Teflon (PTFE). Additional top coating, such as PVDF, Tedlar or TiO2, can be applied on the surface of coating material depending upon the design requirements. The membrane materials are 1 to 4m wide and rolled in 50 to 200m length when shipped from the factory. As the membrane is woven material, mechanical properties in warp and fill direction is different each other. |
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| The constructional membrane material is divided into four grades in Taiwan, the classification is mainly based on the durability, fire safety performance and fouling performance of the membrane material. |
| PTFE membrane |
It is known as PTFE membrane (Poly tetra fluoro ethylene). The composition of PTFE membrane is a fiber glass cloth coated with PTFE (Teflon). Both fiber cloth and coating material are non-combustible materials. Therefore, PTFE can be used to most projects that should demand strict fire safety requirements, such as closed gymnasiums, courtyards or other major facilities. |
| ETFE membrane |
The ETFE membrane is the latest unique membrane technology. The material is a modified copolymer composed of ethylene and tetrafluoroethylene (referred to as ETFE). ETFE was first applied in the aerospace applications. ETFE provides excellent weather protection, very high translucency, self-cleaning property and over 35 years of durability. ETFE also translates ultra-violet rays required for growing plants. Eden Project in UK and the Beijing Water Cube Swimming Pool are the most famous projects with ETFE roof. |
TiO2 /PVC
membrane |
TiO2 is the advanced coating technology which is applied to PVC membrane surface. TiO2 will provide excellent self-cleaning property which PVDF coating could not accomplish. TiO2 will remove particles on surface by chemical reaction caused by combination of sunshine and rain water. It is very efficient for locations with polluted air such as big cities in Asia. TiO2 coated PVC membrane should fulfill the gap between PTFE and conventional PVC membrane with reasonable economy and high performance on self-cleaning. |
| PVDF/PVC membrane |
PVDF coated PVC membrane is the most common membrane material, and is commonly known as PVDF/PVC membrane. The fiber is composed of polyester fabric coated with PVC. It is a combustible material. It is seldom used in the major buildings in Japan, and the self-cleaning property is poor in Taiwan. |
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