18-07-2013, 03:05 PM
WATER PROOF FABRICS
[attachment=56705]
Water proof fabrics
India is increasing total wealth and per capita income per head. The rapid spread of
satellite television is globalising the vision of the healthy lifestyle and spreading
knowledge of sports and leisure wears from country to country. Due to consumers
becoming more and more conscious for the comfort of the garments that they are
wearing. As a result new fibres and fabrics are emerging out for satisfying the
stringent needs.
The paper reviews various works done in development of waterproof, breathable
sportswear textiles. The moisture transport properties and various factors affecting it
are also discussed for sportswear fabrics using different fibres. The various branded
fibres and fabrics have been described along with their constitutional elements and
special characteristics.
Introduction
Waterproof breathable fabrics are designed for use in garments that provide protection from the environmental factors like wind, rain and loss of body heat. Waterproof fabric completely prevents the penetration and absorption of liquid water. The term breathable implies that the fabric is actively ventilated. Breathable fabrics passively allow water vapour to diffuse through them yet prevents the penetration of liquid water. High functional fabrics support active sportswear with importance placed on high functions as well as comfort. Finally, materials with heating and/or cooling property have newly attracted the interest of the market. All these materials do not pursue a single function, but different functional properties combined on a higher level.
Fabrics that can convey water vapor from body perspiration out through the material while remaining impervious to external liquids such as rainwater are widely used in sportswear and similar applications. Water-resistant and moisture-permeable materials may be divided into three main categories - high-density fabrics, resin-coated materials and film-laminated materials - which are selected by manufacturers according to the finished garment requirements in casual, athletics, ski or outdoor apparel.
Densely woven water breathable fabrics
The densely woven waterproof breathable fabrics consist of cotton or synthetic
microfilament yarns with compacted weave structure. One of the famous waterproof breathable fabrics known as VENTILE was manufactured by using long staple cotton with minimum of spaces between the fibres1. Usually combed yarns are weaved parallel to each other with no pores for water to penetrate. Usually oxford weave is used. When fabric surface is wetted by water the cotton fibres swell transversely reducing the size of pores in the fabric and requiring very high pressure to cause penetration. Therefore waterproof is provided without the application of any waterrepellent finishing treatment. Densely woven fabrics can also be produced from micro-denier synthetic filament yarns. The individual filaments in these yarns are of less than 10 micron in diameter, so that fabrics with very small pores can be engineered.
Laminated waterproof breathable fabrics.
Laminated waterproof breathable fabrics made by application of membranes into textile product. These are thin membrane made from polymeric materials. They offer high resistance to water penetration but allow water vapour at the same time. The maximum thickness of the membrane is 10 micron. They are of two types:
1) Micro porous membranes
2) Hydrophilic membranes.
The micro porous membranes have tiny holes on their surface smaller than a rain drops but larger than water vapour molecule. Some of the membranes are made from Polytetrafluoroethylene PTFE polymer , Polyvinylidene fluoride PVDF, etc2,3.
The hydrophilic membranes are thin films of chemically modified polyester or
polyurethane. These polymers are modified by the incorporation of poly. The poly (ethylene oxide)4 constitutes the hydrophilic part of the membrane by forming amorphous region in the main polymer system. This amorphous region acts as intermolecular pores allowing water vapour molecules to pass through but preventing the penetration of liquid water due to the solid nature of the membrane.
Polyester
Polyester has outstanding dimensional stability and offer excellent resistance to dirt, alkalis, decay, mold and most common organic solvents. Being durable, yet
lightweight, polyester has elasticity and a comfortable smooth feel or “soft hand”.
These are all important qualities to consumers for a wide variety outerwear and
recreational applications. Excellent heat resistance or thermal stability is also an
attribute of polyester. It is the fibre used most commonly in base fabrics for active wear because of its low moisture absorption, easy care properties and low cost.
[attachment=56705]
Water proof fabrics
India is increasing total wealth and per capita income per head. The rapid spread of
satellite television is globalising the vision of the healthy lifestyle and spreading
knowledge of sports and leisure wears from country to country. Due to consumers
becoming more and more conscious for the comfort of the garments that they are
wearing. As a result new fibres and fabrics are emerging out for satisfying the
stringent needs.
The paper reviews various works done in development of waterproof, breathable
sportswear textiles. The moisture transport properties and various factors affecting it
are also discussed for sportswear fabrics using different fibres. The various branded
fibres and fabrics have been described along with their constitutional elements and
special characteristics.
Introduction
Waterproof breathable fabrics are designed for use in garments that provide protection from the environmental factors like wind, rain and loss of body heat. Waterproof fabric completely prevents the penetration and absorption of liquid water. The term breathable implies that the fabric is actively ventilated. Breathable fabrics passively allow water vapour to diffuse through them yet prevents the penetration of liquid water. High functional fabrics support active sportswear with importance placed on high functions as well as comfort. Finally, materials with heating and/or cooling property have newly attracted the interest of the market. All these materials do not pursue a single function, but different functional properties combined on a higher level.
Fabrics that can convey water vapor from body perspiration out through the material while remaining impervious to external liquids such as rainwater are widely used in sportswear and similar applications. Water-resistant and moisture-permeable materials may be divided into three main categories - high-density fabrics, resin-coated materials and film-laminated materials - which are selected by manufacturers according to the finished garment requirements in casual, athletics, ski or outdoor apparel.
Densely woven water breathable fabrics
The densely woven waterproof breathable fabrics consist of cotton or synthetic
microfilament yarns with compacted weave structure. One of the famous waterproof breathable fabrics known as VENTILE was manufactured by using long staple cotton with minimum of spaces between the fibres1. Usually combed yarns are weaved parallel to each other with no pores for water to penetrate. Usually oxford weave is used. When fabric surface is wetted by water the cotton fibres swell transversely reducing the size of pores in the fabric and requiring very high pressure to cause penetration. Therefore waterproof is provided without the application of any waterrepellent finishing treatment. Densely woven fabrics can also be produced from micro-denier synthetic filament yarns. The individual filaments in these yarns are of less than 10 micron in diameter, so that fabrics with very small pores can be engineered.
Laminated waterproof breathable fabrics.
Laminated waterproof breathable fabrics made by application of membranes into textile product. These are thin membrane made from polymeric materials. They offer high resistance to water penetration but allow water vapour at the same time. The maximum thickness of the membrane is 10 micron. They are of two types:
1) Micro porous membranes
2) Hydrophilic membranes.
The micro porous membranes have tiny holes on their surface smaller than a rain drops but larger than water vapour molecule. Some of the membranes are made from Polytetrafluoroethylene PTFE polymer , Polyvinylidene fluoride PVDF, etc2,3.
The hydrophilic membranes are thin films of chemically modified polyester or
polyurethane. These polymers are modified by the incorporation of poly. The poly (ethylene oxide)4 constitutes the hydrophilic part of the membrane by forming amorphous region in the main polymer system. This amorphous region acts as intermolecular pores allowing water vapour molecules to pass through but preventing the penetration of liquid water due to the solid nature of the membrane.
Polyester
Polyester has outstanding dimensional stability and offer excellent resistance to dirt, alkalis, decay, mold and most common organic solvents. Being durable, yet
lightweight, polyester has elasticity and a comfortable smooth feel or “soft hand”.
These are all important qualities to consumers for a wide variety outerwear and
recreational applications. Excellent heat resistance or thermal stability is also an
attribute of polyester. It is the fibre used most commonly in base fabrics for active wear because of its low moisture absorption, easy care properties and low cost.