**4. Suitable raw material for engineered fabrics**

Various natural fibers have enough potential to become the part of engineered fabrics. The major natural fibers have been used as basic material in engineered fabrics is cotton, flax, jute and sisal. These fiber are used to manufacture various heavy engineered fabrics like canvas, needle punched nonwoven fabrics for geo applications, ropes, belts and other multilayer fabrics, etc. [12]. However, some limitations of these fibers restricted the growth in engineered fabrics in which higher rigidity, prone to fungal and microbial attack; poor water resistance and lower flame retardancy are remarkable. Jute is cheaply available fiber which has ample potential to be used in engineered fabrics in gray and treated form. Sisal fiber is suitable material for ropes, nets and twines manufacturing [13].

Wool is another natural option with merits of higher limiting oxygen index value, thermal insulation but its limited availability and versatility has restricted its applications in engineered fabrics [14]. Silk fiber is another rare option for engineered fabrics due to its low availability and higher cost [15].

#### **4.1. Regenerated fibers**

First commercially manufactured manmade fiber developed 1905–1910, is still suitable material for manufacturing engineered fabrics like tyre cords, preforms for conveyer belts and hoses, etc. Some other regenerated fibers like acetate rayon and cuprammonium rayon also have found its place in engineered fabrics [16].

ceramic fibers have found limited applications in engineered structures due its high cost and

Introductory Chapter: Engineered Fabrics http://dx.doi.org/10.5772/intechopen.82717 5

Successful polyamide-imide fiber was produced by Rhone-Poulenc Inc. with a trade name of Kermel. The limiting oxygen index (LOI) of Kermel fiber is 32. It remains safe without any degradation up to 250°C for a exposure of 500 h to heat. This fiber does not have melting temperature Tm but is carbonize. Kermel fiber can be blend successfully with other commercial fibers like viscose and polyester. A wide variety of engineered fabrics with Kermel fiber can

The PBI fiber was invented by Celanese Inc. This fiber is highly stable at 300–350°C. Its limiting oxygen index (LOI) value is 41, which is quite safe and higher than threshold value 25. This fiber offer equal heat protection to asbestos with half density. It has moisture regain. The PBI fiber based engineered fabrics are used as reinforcing material to produce fire protection in aircraft seats, firefighter suits and racing-car driver suits. It found its smart applications in in rocket motors and boosters to provide safety against ignition [22]. The engineered fabrics

Phenolic or novoloid fibers fiber is manufactured by spinning and postcuring of phenol formaldehyde resin precondensate. Kynol is a well-established novoloid heat-resistant fiber of GUN EI chemical industry. Kynol fiber is golden in color, soft feel with moisture regain of 6%. It slowly carbonized at very high temperature without any smoke. It has poor strength and abrasion resistance which suppresses it application in apparel sector. It can be easily blended with aramid fibers like nomex to make it suitable for flame retardant apparel applications. Philene is another important fiber member of this group with moisture regain of 7.3% and LOI 39% [23].

The modacrylic fiber still has first choice of manufacturers to engineer flame-retardant fabrics. Modacrylic fibers are produced under various commercial names, such as SEF (Solutia Inc.), Velicren FR (Montefibre, Italy), Elura (Monsanto Fibers), Dynel (Union Carbide) and Verel (Tennessee Eastman). Modacrylic fiber and is a copolymer of acrylonitrile, vinyl chloride or vinylidene chloride in the ratio of 60:40 (w/w) along with a sulfonated vinyl monomer. Modacrylic fiber has LOI in the range of 26–31%. Kaneka Corporation has also developed Kanecaron, an FR modacrylic with an LOI value in the range of 30–35%. Fabrics from Kanecaron with commercial name of Protex M has LOI 33% blended with cotton, while main-

taining the softness and comfort similar to cotton fabric.

made of PBI fibers offer excellent resistant to puncturing, tearing and ripping.

be produced for air forces, army, navy and firefighter dresses [21].

poor bending performance.

*4.2.5. High performance fibers*

*4.2.5.1. Poly(amide-imide) fibers*

*4.2.5.2. Polybenzimidazole (PBI) fibers*

*4.2.5.3. Phenolic or novoloid fibers*

*4.2.5.4. Modacrylic*

#### **4.2. Synthetic fibers**

### *4.2.1. Polyolefins*

Polyethylene (PE) and polypropylene (PP) are two major fibers of this group which have registered its valuable presence in the manufacturing of engineered fabrics. Low density, easy manufacturing techniques, high moisture and abrasion resistance have secured its rapid growth in engineered fabrics. The major engineered fabrics made of these fibers are used to manufacture bags, carpet bases, furniture linings, sacks, nets and other marine textiles. PP Fiber has good wicking with poor moisture absorption potential and this characteristic make this fiber appropriate for use in engineering of high performance diapers. The PP fiber has low spinning temperature (210–220°C) have proved ideally suited material for meltblowing and spun bonding techniques to manufacture engineered nonwoven structures quickly [17].

#### *4.2.2. Polyamide*

Polyamide fiber group containing various nylon fibers like nylon 6, nylon 66, nylon 6.10, etc. have good abrasion resistance, high strength, remarkable elasticity and excellent impact absorbing potential proved very useful in manufacturing various engineered items like parachute fabrics, spinnaker sails, reinforced tyres and geofabrics for high performance road construction. Western Europe and North America are more strongly inclined towards nylon 66 while Asia and Eastern Europe produce predominantly nylon 6 [18].

#### *4.2.3. Polyester*

Polyester is low cost fiber with plenty of merits like high abrasion resistance, high strength, low moisture regain and excellent uniformity. Recycled polyester fiber is another cost effective alternative fiber for manufacturing of engineered fabrics like spun bonded structures, needle punched structures, etc. [19]. A modified polyester fiber is used widely in manufacturing of flame retardant fabrics, waterproof breathable fabrics and canvas fabrics.

#### *4.2.4. Glass and ceramics*

Glass fiber was very difficult handle for many years, been one of the most underutilized fibers. This fiber is used in various engineered nonwoven structures to be considered as a cheap insulating material and reinforcement preforms for relatively low performance composites like fiber glass and heat-resistant materials. The applications of glass fiber increasing day by day in the form of engineered structures for sealing materials, rubber reinforcement, as well as filtration, protective clothing, packaging metal body parts and components [20]. Some ceramic fibers have found limited applications in engineered structures due its high cost and poor bending performance.

#### *4.2.5. High performance fibers*

**4.1. Regenerated fibers**

4 Engineered Fabrics

**4.2. Synthetic fibers**

*4.2.1. Polyolefins*

*4.2.2. Polyamide*

*4.2.3. Polyester*

*4.2.4. Glass and ceramics*

have found its place in engineered fabrics [16].

First commercially manufactured manmade fiber developed 1905–1910, is still suitable material for manufacturing engineered fabrics like tyre cords, preforms for conveyer belts and hoses, etc. Some other regenerated fibers like acetate rayon and cuprammonium rayon also

Polyethylene (PE) and polypropylene (PP) are two major fibers of this group which have registered its valuable presence in the manufacturing of engineered fabrics. Low density, easy manufacturing techniques, high moisture and abrasion resistance have secured its rapid growth in engineered fabrics. The major engineered fabrics made of these fibers are used to manufacture bags, carpet bases, furniture linings, sacks, nets and other marine textiles. PP Fiber has good wicking with poor moisture absorption potential and this characteristic make this fiber appropriate for use in engineering of high performance diapers. The PP fiber has low spinning temperature (210–220°C) have proved ideally suited material for meltblowing and spun bonding techniques to manufacture engineered nonwoven structures quickly [17].

Polyamide fiber group containing various nylon fibers like nylon 6, nylon 66, nylon 6.10, etc. have good abrasion resistance, high strength, remarkable elasticity and excellent impact absorbing potential proved very useful in manufacturing various engineered items like parachute fabrics, spinnaker sails, reinforced tyres and geofabrics for high performance road construction. Western Europe and North America are more strongly inclined towards nylon

Polyester is low cost fiber with plenty of merits like high abrasion resistance, high strength, low moisture regain and excellent uniformity. Recycled polyester fiber is another cost effective alternative fiber for manufacturing of engineered fabrics like spun bonded structures, needle punched structures, etc. [19]. A modified polyester fiber is used widely in manufactur-

Glass fiber was very difficult handle for many years, been one of the most underutilized fibers. This fiber is used in various engineered nonwoven structures to be considered as a cheap insulating material and reinforcement preforms for relatively low performance composites like fiber glass and heat-resistant materials. The applications of glass fiber increasing day by day in the form of engineered structures for sealing materials, rubber reinforcement, as well as filtration, protective clothing, packaging metal body parts and components [20]. Some

66 while Asia and Eastern Europe produce predominantly nylon 6 [18].

ing of flame retardant fabrics, waterproof breathable fabrics and canvas fabrics.

#### *4.2.5.1. Poly(amide-imide) fibers*

Successful polyamide-imide fiber was produced by Rhone-Poulenc Inc. with a trade name of Kermel. The limiting oxygen index (LOI) of Kermel fiber is 32. It remains safe without any degradation up to 250°C for a exposure of 500 h to heat. This fiber does not have melting temperature Tm but is carbonize. Kermel fiber can be blend successfully with other commercial fibers like viscose and polyester. A wide variety of engineered fabrics with Kermel fiber can be produced for air forces, army, navy and firefighter dresses [21].

### *4.2.5.2. Polybenzimidazole (PBI) fibers*

The PBI fiber was invented by Celanese Inc. This fiber is highly stable at 300–350°C. Its limiting oxygen index (LOI) value is 41, which is quite safe and higher than threshold value 25. This fiber offer equal heat protection to asbestos with half density. It has moisture regain. The PBI fiber based engineered fabrics are used as reinforcing material to produce fire protection in aircraft seats, firefighter suits and racing-car driver suits. It found its smart applications in in rocket motors and boosters to provide safety against ignition [22]. The engineered fabrics made of PBI fibers offer excellent resistant to puncturing, tearing and ripping.

#### *4.2.5.3. Phenolic or novoloid fibers*

Phenolic or novoloid fibers fiber is manufactured by spinning and postcuring of phenol formaldehyde resin precondensate. Kynol is a well-established novoloid heat-resistant fiber of GUN EI chemical industry. Kynol fiber is golden in color, soft feel with moisture regain of 6%. It slowly carbonized at very high temperature without any smoke. It has poor strength and abrasion resistance which suppresses it application in apparel sector. It can be easily blended with aramid fibers like nomex to make it suitable for flame retardant apparel applications. Philene is another important fiber member of this group with moisture regain of 7.3% and LOI 39% [23].

#### *4.2.5.4. Modacrylic*

The modacrylic fiber still has first choice of manufacturers to engineer flame-retardant fabrics. Modacrylic fibers are produced under various commercial names, such as SEF (Solutia Inc.), Velicren FR (Montefibre, Italy), Elura (Monsanto Fibers), Dynel (Union Carbide) and Verel (Tennessee Eastman). Modacrylic fiber and is a copolymer of acrylonitrile, vinyl chloride or vinylidene chloride in the ratio of 60:40 (w/w) along with a sulfonated vinyl monomer. Modacrylic fiber has LOI in the range of 26–31%. Kaneka Corporation has also developed Kanecaron, an FR modacrylic with an LOI value in the range of 30–35%. Fabrics from Kanecaron with commercial name of Protex M has LOI 33% blended with cotton, while maintaining the softness and comfort similar to cotton fabric.
