Seminar on Architectural Constructional Textiles Ravindra Kumbhar Introduction

Seminar on Architectural & Constructional Textiles -Ravindra Kumbhar

Introduction •

Introduction What made this possible? ? ? q Synthetic fibres allowed development of high performance fabrics (High tenacity Polyester, Aramid, Kevlar, Glass, Carbon fibres etc) - High Strength & High Modulus fabrics - Hydrophobicity - Rot and fungi Resistance q New material with Composites (cross linking resins) • High strength to weight • High stiffness to weight • Extreme flexibility q Development of new & Improved Polymer Coatings - increases the properties and performances of the fabric

Introduction Coated fabrics as “Envelopes” for • Airports • Stadiums • Sports halls • Exhibitions and Display halls • Storage bases – Industrial & Military Supplies Coated Fabric resists extremes of - Sunlight - Temperature - Biological attack - Wind, rain & snow

Area of interest

Products used in Architectural & Construction Textiles Architectural Membranes

Products used in Architectural & Construction Textiles Hoardings & Signages

Products used in Architectural & Construction Textiles Scaffolding Nets Material : HDPE filament

Products used in Architectural & Construction Textiles Awnings & Canopies - vinyl-laminated polyester - vinyl-coated polyester - acrylic-coated polyester - vinyl-coated polyester/cotton - solution-dyed acrylic - painted polyester/cotton - solution-dyed modacrylic

Products used in Architectural & Construction Textiles Tarpaulins - HDPE Tarpaulin Fabric - Laminated PVC tarpaulins - Polyester mesh fabrics

Products used in Architectural & Construction Textiles Floor & Wall Coverings

PROPERTIES OF ARCHITECTURAL AND CONSTRUCTION TEXTILES Why to use Architectural Textiles? • Material Properties • • • High Strength to weight ratio High Stiffness to weight ratio Light Translucency Fabric UV resistance Flame retardancy Water repellency Resistance to sunlight & temperature Resistance to rot & biological attack Resistance to Wind, Rain and Snow • Durability & Sustainability – the service life of fabric membrane structure: 15 to 30 years with PVC, PTFE, PVDC & ETFE textiles – The typical life expectancy of a semi permanent PVC structure is 15 -20 years plus

PROPERTIES OF ARCHITECTURAL AND CONSTRUCTION TEXTILES Why to use Architectural Textiles? • Design Creativity & Efficiency - Unlimited range of forms & shapes • Solar Protection - Specialty textiles offer a range of UV & solar protection options for both humans & buildings

PROPERTIES OF ARCHITECTURAL AND CONSTRUCTION TEXTILES Why to use Architectural Textiles? • Energy Efficiency In comparison to traditional building materials, textiles are more energy efficient in terms of: - The textile production process - Fabrication & installation of membrane systems - The ability to use natural lighting instead of artificial lighting, with the use of translucent fabrics • Cost Efficiency -Fabric structures offer a number of cost efficiencies in terms of: - Economy & efficiency of materials used - Speed of installation -Re-deployability of fabric structures

PROPERTIES OF ARCHITECTURAL AND CONSTRUCTION TEXTILES Why to use Architectural Textiles? • Fire Safety - Architectural textiles range from non-combustible (PTFE) to low combustible (PVC/PVDF) • Recyclability - PVC textiles are now fully recyclable with major textile manufacturers - At the end of a fabric structures life, deconstruction is far simpler than more traditional structures. - The deconstruction process is also much simpler & more conducive to the re-use & recycling of building components.

MEMBRANE STRUCTURES IN ARCHITECTURAL & CONSTRUCTION INDUSTRY There are three types of membrane structures Films: Films are transparent polymers in sheet form without coating or lamination. Films are less expensive and durable than textiles. e. g. Clear vinyl, polyester or polypropylene Meshes: Meshes are porous fabrics, such as woven polyester, that are lightly coated with vinyl. Knitted meshes are made of high density polyethylene, polypropylene, or acrylic yarns. Meshes are used as shelters from wind and Sun, however they cannot provide adequate protection from rain. Fabrics: Fabric structures are by far most widely used membrane structures. Fabrics are typically coated or laminated with synthetic materials to improve strength and environmental resistance

FABRICS FOR ARCHITECTURE AND CONSTRUCTION Fabrics must be - Resistant to deformation and extension under tension Resistant to wind and water Waterproof Impermeable to air and wind Resistant to abrasion and mechanical damage Resistant to degradation (long term exposure to sunlight & acid rain) Base Fabrics: • • • Base fabrics are usually made of synthetic fibres and form the carrier layer which provides the necessary strength to the structure. Aramid and Carbon fibres have excellent properties but expensive to use in construction extensively High-tenacity Polyester, Fiberglass and Nylon are most widely used

FABRICS FOR ARCHITECTURE AND CONSTRUCTION q Polyester fabric - High strength, low stretch, durable, least expensive q Nylon fabric - More durable than polyester, more stretch and higher cost than polyester q Glass fabric – Resist stretching, reflects a high percentage of the Sun’s heat and keep the interior of the structure cool. Do not burn or smoke. - Continuous filament yarns are preferred over staple fibre yarns due to inherent strength and elongation resistance Base fabric can be; q Woven q Knitted q Non-woven Woven structures are usually the design of choice for fabric rigidity and dimensional stability for many applications. Generally simple weave patterns such as plain weave and low harness twills are used

COATING AND LAMINATING • Laminating: Vinyl films over woven or knitted polyester or nylon meshes ü Most economical ü Good tear resistance • Coating: Plastic material or synthetic rubber Polyester fabric is tensioned before and during the coating ü ü ü ü Waterproofness Protects the base fabric from sunlight and weathering degradation Coating claims to improve dimensional stability Higher tensile strength Higher flex resistance Higher abrasion resistance Longer life • Double Coating - Water and chemical resistance

COATING AND LAMINATING • Common polymer coatings are - PVC (polyvinyl chlofide) PVDC (polyvinylidene chloride) PTFE (polytetrafluoroethylene) - PVDF (polyvinyledene fluoride) • Polyester fabrics are usually coated or laminated with PVC films • Fibreglass fabrics are usually coated with PTFE for durability

COATING AND LAMINATING • Importance of Top Finish • Without the top finish the PVC coated fabric begin to attract dirt and lose its aesthetic benefit • Pyurethane topcoating for - “self cleaning” • PVDF (polyvinylidene fluoride) - applied as a thin liquid to the surface of the PVC coated fabric. PVDF polymer has better UV resistance

PROPERTIES OF COATED FABRICS FOR ARCHITECTURE AND CONSTRUCTION ü ü ü ü High tensile strength Adequate elongation High melting point Waterproofness Toughness Resistance to rot and fungi Resistance to weathering effects and aging Wet and dry dimensional stability Resistance of coating to high and low temperatures Flame resistance Abrasion and tear resistance Low weight Flexibility Good adhesion of the backing fibres to coating

PROPERTIES OF COATED FABRICS FOR ARCHITECTURE AND CONSTRUCTION • For constructional and architectural coated fabrics resistance to fatigue and time related fatigue becomes very important. • One of the most important properties of coated fabrics for buildings is the residual strength THICKNESS BREAKING LOAD WARP BREAKING ELONGATION WEFT TEAR STRENGTH 0 10 20 30 40 50 60 70 80 90 100 Fig: Residual properties of PVC coated Polyester fabric after eight years of use in air structure

APPLICATIONS OF COATED FABRICS IN BUILDING STRUCTURES • Membrane structures can be divided into four categories; – – Tents Clear-span structures Air structures Tensile structures (Membranes can also be categorized as temporary or permanent) Tents: • Pole tents: Fabric is draped or hung rather than tensioned

APPLICATIONS OF COATED FABRICS IN BUILDING STRUCTURES • Tension Tents: Tension tents include various tensile structures • Tensile Tents: Tensile tents have tensioned fabric that provides clear span and do not require guys

APPLICATIONS OF COATED FABRICS IN BUILDING STRUCTURES • Clear-Span Structures - Clear space beneath the fabric Free of poles and other supporting elements Can accommodate doors, flooring, insulation, electricity More permanent than Tents & Less permanent than air or Tensile Structures

APPLICATIONS OF COATED FABRICS IN BUILDING STRUCTURES Tension Structures • metal pylons • tensioning cable • wooden or metal frameworks are used to support the fabric. - Fabric carries most of the load relatively minimal rigid support system is required

APPLICATIONS OF COATED FABRICS IN BUILDING STRUCTURES Air Structures Air-supported structures can be built in two ways q Air pressure inside the Envelope - Provides tensioning - Maintains Required configuration & stability q Air-inflated ribs (air beams) supports the structure

FIBRE REINFORCED CONCRETE AND CEMENT § Cement based matrix Ø Inherently brittle Ø Failure under impact loading § Fibre Reinforcement Ø Increases the toughness or tensile properties of basic matrix Ø Decreases cracking of concrete Fibres with moduli lower than the cement matrix - Cellulose, Nylon, Polypropylene Fibres with moduli higher than the cement matrix - Glass, Carbon, Kevlar High modulus short fibres may require bonding to avoid pull-out

TEXTILES FOR ACOUSTIC AND HEAT INSULATION Absorbant textile materials : carpets, textile wall coverings and curtains • • • To improve audibility To preserve the natural quality of sound To prevent transmission of undesired sound • Teflon fiberglass composite materials are used for noise reduction • Housewrap materials for thermal insulation - reduce thes flow of air into and out of the house, cutting heating and cooling energy costs.

Case study

Properties