Textiles ETFE foil

ETFE-foils as a fluorine-polymer material differ fundamentally from textile membrane materials in terms of their thermal-mechanical as well as building-physics behaviour. This chapter first introduces the construction forms and variants of ETFE-foil structures and provides an overview of the development of ETFE-foil constructions from an architectural perspective. Subsequently, the morphological structure of ETFE and the manufacturing process as well as the material behaviour and load-bearing characteristics of ETFE-foils are outlined. The final section discusses future development potentials and the future use of ETFE-foil constructions in structural engineering. 

Integrated sun protection elements of ETFE foil cushions with (a) aluminium lamellae and (b) textile membrane (photos L Schiemann). 

The material behaviour of ETFE-foils is extremely complex and differs fundamentally from that of textile membrane materials in regard to their thermal-mechanical as well as building-physics qualities. This section... 

Question 3 Level of knowledge on textiles (ETFE inflated foil cushions and... 

Sun protection elements (aluminium and ETFE lamellae, or mobile textile membranes, cf. Fig. 6.6) can be integrated for further building-physics improvement in the clearance of dual-chamber systems with separate layers. In variants with a curved middle layer and decoupled volumes, and different pressures, the middle layer can assume the sun protection role. For this, the outer and middle foil layers display a print of inversely arranged patterns. The translucency of the cushions is controlled by adjusting the middle layer through pressure control of the two air-chambers. 

Because of its high translucency (approximately 95% over a wide spectrum) there is a growing tendency to use ETFE (ethylene-tetrafluoro-ethylene) foil either in place of, or in combination with, coated woven textiles. Illustrations of a selection of membrane and foil materials and coatings, and a table giving an overview of properties, are presented by Pudenz (2004). 

Textile membranes are thin, low-mass structures. This means that they provide little acoustic insulation, although micro-perforated foils in combination with other membranes may provide substantial acoustic absorption (Pudenz, 2004, p. 60). The tensioning of the membrane surface means that at times of heavy rain or hail, although these are usually of short duration, skin drumming occurs. This phenomenon is even more pronounced with inflated ETFE cushions. 

Textiles used as fabric fagades are commonly a coated mesh. This allows a view out and reduces energy consumption while providing solar protection (Armijos, 2008). The most common types are PVC-coated polyester manufactured into a coated or extruded product, PTFE (poly-tetrafluoroethylene or Teflon) coated flbreglass mesh, and ETFE (ethylene-tetrafluoroethylene) foils. 

To identify ways to encourage designers to apply textiles, such as ETFE inflated foil cushions and PTFE-coated fibreglass fabric, to improve the energy efficiency of buildings in Australia. 

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