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We take so much care of our children and about their safety, health etc. With great care we choose their things, from their clothing to toys, and schools to hobbies. We take our children for walks, shopping and for a nice stroll in the park, and we would like to keep them always safe and protected as we introduce them to the realities of the world.
In all the public places throughout UK, we see pram shelters constructed to facilitate the public. The pram and buggies shelters are made with extra care. They are kept clean, hygienic, dry and secure. You can find such comfortable pram shelters at metros, beaches, libraries, near health centres and nurseries.
In providing these safe and secure pram shelters, the company Ace Shelters is in the forefront. Their structures provide shelter as well as blend well with the surroundings. Their pram shelters are fool proof, and keeping in mind the dangers of blockades near entrances and fire escapes, they are made with utmost care.  
Ace Shelters uses high grade aluminium extrusions pipes of BS EN 755(1-9) quality, powder coated BS EN ISO 9002, chosen RAL or BS colours which also acts as corrosion resistant, thus making the shelters maintenance free. Different configurations of shelters are available and also custom-made pram shelters with specifications from the client and requirements are given preferences.
Pram shelters are equipped with door locks, and solar lighting is provided to save energy. Exhaust pipes are fitted for rain water drainage. Wreckage resistant perforated steel sheet cover is used for withstand any human mishandling.
To match your environment or the ambience, you can choose from a wide range of available colours to highlight the structure. The expert team of designers will design the shelter according to the client’s specifications and make them more pleasing to eye as well as a safe haven for parents and toddlers. Having worked closely with schools and nurseries Ace Shelters knows what is best suited for pram shelters.
The new Canterbury pram shelter is visually pleasing and serves the purpose by providing a clean and secure pram shelter. Being in the field for nearly 60 years, Ace Shelters provides a wide range of shelters according to the needs of the clients. They have a standard product range from which one can choose from. They cater to clients requirements too.

Leeds being their headquarters, they have their installations all over UK. To see more details and the superior product range, log on to www.aceshelters.co.uk and choose the kind of pram shelter you need.

We take so much care of our children and about their safety, health etc. With great care we choose their things, from their clothing to toys, and schools to hobbies. We take our children for walks, shopping and for a nice stroll in the park, and we would like to keep them always safe and protected as we introduce them to the realities of the world.
In all the public places throughout UK, we see pram shelters constructed to facilitate the public. The pram and buggies shelters are made with extra care. They are kept clean, hygienic, dry and secure. You can find such comfortable pram shelters at metros, beaches, libraries, near health centres and nurseries.
In providing these safe and secure pram shelters, the company Ace Shelters is in the forefront. Their structures provide shelter as well as blend well with the surroundings. Their pram shelters are fool proof, and keeping in mind the dangers of blockades near entrances and fire escapes, they are made with utmost care.  
Ace Shelters uses high grade aluminium extrusions pipes of BS EN 755(1-9) quality, powder coated BS EN ISO 9002, chosen RAL or BS colours which also acts as corrosion resistant, thus making the shelters maintenance free. Different configurations of shelters are available and also custom-made pram shelters with specifications from the client and requirements are given preferences.
Pram shelters are equipped with door locks, and solar lighting is provided to save energy. Exhaust pipes are fitted for rain water drainage. Wreckage resistant perforated steel sheet cover is used for withstand any human mishandling.
To match your environment or the ambience, you can choose from a wide range of available colours to highlight the structure. The expert team of designers will design the shelter according to the client’s specifications and make them more pleasing to eye as well as a safe haven for parents and toddlers. Having worked closely with schools and nurseries Ace Shelters knows what is best suited for pram shelters.
The new Canterbury pram shelter is visually pleasing and serves the purpose by providing a clean and secure pram shelter. Being in the field for nearly 60 years, Ace Shelters provides a wide range of shelters according to the needs of the clients. They have a standard product range from which one can choose from. They cater to clients requirements too.

Normally pram shelters are found in public places like metros, bus stations, malls, shopping arcades, stadia, libraries, beaches, hospitals and other such places. The prams and buggies need to be stored in clean, hygienic dry environment. They must be made very secure too.
The Ace Shelters pram shelters are fool proof, and manufactured with utmost care. They allow valuable indoor space to be utilised well. Keeping in mind the hazards of blocked entrances and fire escapes, the pram shelters are made with high grade aluminium extrusions pipes of BS EN 755(1-9) quality, powder coated BS EN ISO 9002, chosen RAL or BS colour which gives corrosion and maintenance free finish.
Various configurations are available along with customised configuration of pram shelters. If you specify your requirements or provide drawings, then your requirements can be very easily installed in the shelter. Pram shelters are also designed according to the topography of the location too. For instance, a pram shelter in a stadium will have different designing from one in a mall or resort.
Pram shelters come with door locks, solar lighting, and rain water exhaust pipes. Glazed with polycarbonate toughened safety glass, these pram shelters can withstand any amount of rough use. It comes with wreckage resistant perforated steel sheet cover.
You can make your shelter more colourful by using any colour to match the setting. Working closely with schools and nurseries, Ace Shelters knows what is best suited for pram shelters and how it should be constructed. All their products have been CRB checked and passed CSCS health and safety exams. The new Canterbury pram shelter provides a secure, clean and dry environment for the storage of prams.
Ace Shelters has 60 years of experience in providing different types of shelters. They manufacture and install a wide variety of shelters all over the UK. Along with their standard product range, they also provide custom made services to their long standing customers.
As aluminium stock holders they bring the best of extrusion pipes and design the products to withstand the test of time. As part of British industry, Ace Shelters design and manufacture all the structures to precision, with utmost care. Lot of detailing goes into strengthening their products structure.

Based in Leeds, they provide full pram shelters installation service throughout the UK. Just log onto www.aceshelters.co.uk and check the product range that best suits your requirements.

We take so much care of our children and about their safety, health etc. With great care we choose their things, from their clothing to toys, and schools to hobbies. We take our children for walks, shopping and for a nice stroll in the park, and we would like to keep them always safe and protected as we introduce them to the realities of the world.
In all the public places throughout UK, we see pram shelters constructed to facilitate the public. The pram and buggies shelters are made with extra care. They are kept clean, hygienic, dry and secure. You can find such comfortable pram shelters at metros, beaches, libraries, near health centres and nurseries.
In providing these safe and secure pram shelters, the company Ace Shelters is in the forefront. Their structures provide shelter as well as blend well with the surroundings. Their pram shelters are fool proof, and keeping in mind the dangers of blockades near entrances and fire escapes, they are made with utmost care.  
Ace Shelters uses high grade aluminium extrusions pipes of BS EN 755(1-9) quality, powder coated BS EN ISO 9002, chosen RAL or BS colours which also acts as corrosion resistant, thus making the shelters maintenance free. Different configurations of shelters are available and also custom-made pram shelters with specifications from the client and requirements are given preferences.
Pram shelters are equipped with door locks, and solar lighting is provided to save energy. Exhaust pipes are fitted for rain water drainage. Wreckage resistant perforated steel sheet cover is used for withstand any human mishandling.
To match your environment or the ambience, you can choose from a wide range of available colours to highlight the structure. The expert team of designers will design the shelter according to the client’s specifications and make them more pleasing to eye as well as a safe haven for parents and toddlers. Having worked closely with schools and nurseries Ace Shelters knows what is best suited for pram shelters.
The new Canterbury pram shelter is visually pleasing and serves the purpose by providing a clean and secure pram shelter. Being in the field for nearly 60 years, Ace Shelters provides a wide range of shelters according to the needs of the clients. They have a standard product range from which one can choose from. They cater to clients requirements too.

Normally pram shelters are found in public places like metros, bus stations, malls, shopping arcades, stadia, libraries, beaches, hospitals and other such places. The prams and buggies need to be stored in clean, hygienic dry environment. They must be made very secure too.
The Ace Shelters pram shelters are fool proof, and manufactured with utmost care. They allow valuable indoor space to be utilised well. Keeping in mind the hazards of blocked entrances and fire escapes, the pram shelters are made with high grade aluminium extrusions pipes of BS EN 755(1-9) quality, powder coated BS EN ISO 9002, chosen RAL or BS colour which gives corrosion and maintenance free finish.
Various configurations are available along with customised configuration of pram shelters. If you specify your requirements or provide drawings, then your requirements can be very easily installed in the shelter. Pram shelters are also designed according to the topography of the location too. For instance, a pram shelter in a stadium will have different designing from one in a mall or resort.
Pram shelters come with door locks, solar lighting, and rain water exhaust pipes. Glazed with polycarbonate toughened safety glass, these pram shelters can withstand any amount of rough use. It comes with wreckage resistant perforated steel sheet cover.
You can make your shelter more colourful by using any colour to match the setting. Working closely with schools and nurseries, Ace Shelters knows what is best suited for pram shelters and how it should be constructed. All their products have been CRB checked and passed CSCS health and safety exams. The new Canterbury pram shelter provides a secure, clean and dry environment for the storage of prams.
Ace Shelters has 60 years of experience in providing different types of shelters. They manufacture and install a wide variety of shelters all over the UK. Along with their standard product range, they also provide custom made services to their long standing customers.
As aluminium stock holders they bring the best of extrusion pipes and design the products to withstand the test of time. As part of British industry, Ace Shelters design and manufacture all the structures to precision, with utmost care. Lot of detailing goes into strengthening their products structure.

Textile fiber

A unit in which many complicated textile structures are built up is said to be textile fiber.

Textile Fiber is the basic constituent (Basic raw material) required for textile industry.

Natural fibers

Main article: Natural fiber

Natural fibers include those produced by plants, animals, and geological processes. They are biodegradable over time. They can be classified according to their origin:

Vegetable fibers are generally based on arrangements of cellulose, often with lignin: examples include cotton, hemp, jute, flax, ramie, and sisal. Plant fibers are employed in the manufacture of paper and textile (cloth), and dietary fiber is an important component of human nutrition.

Wood fiber, distinguished from vegetable fiber, is from tree sources. Forms include groundwood, thermomechanical pulp (TMP) and bleached or unbleached kraft or sulfite pulps. Kraft and sulfite, also called sulphite, refer to the type of pulping process used to remove the lignin bonding the original wood structure, thus freeing the fibers for use in paper and engineered wood products such as fiberboard.

Animal fibers consist largely of particular proteins. Instances are spider silk, sinew, catgut, wool and hair such as cashmere, mohair and angora, fur such as sheepskin, rabbit, mink, fox, beaver, etc.

Mineral fibers comprise asbestos. Asbestos is the only naturally occurring long mineral fiber. Short, fiber-like minerals include wollastonite, attapulgite and halloysite.

Man-made fibers

Synthetic or man-made fibers generally come from synthetic materials such as petrochemicals. But some types of synthetic fibers are manufactured from natural cellulose, including rayon, modal, and the more recently developed Lyocell. Cellulose-based fibers are of two types, regenerated or pure cellulose such as from the cupro-ammonium process and modified cellulose such as the cellulose acetates.

Fiber classification in reinforced plastics falls into two classes: (i) short fibers, also known as discontinuous fibers, with a general aspect ratio (defined as the ratio of fiber length to diameter) between 20 to 60, and (ii) long fibers, also known as continuous fibers, the general aspect ratio is between 200 to 500.

Cellulose fibers

Cellulose fibers are a subset of man-made fibers, regenerated from natural cellulose. The cellulose comes from various sources. Modal is made from beech trees, bamboo fiber is a cellulose fiber made from bamboo, seacell is made from seaweed, etc.

Mineral fibers

Fiberglass, made from specific glass, and optical fiber, made from purified natural quartz, are also man-made fibers that come from natural raw materials.

Metallic fibers can be drawn from ductile metals such as copper, gold or silver and extruded or deposited from more brittle ones, such as nickel, aluminum or iron.

Carbon fibers are often based on carbonised polymers, but the end product is pure carbon.

Polymer fibers

Polymer fibers are a subset of man-made fibers, which are based on synthetic chemicals (often from petrochemical sources) rather than arising from natural materials by a purely physical process. These fibers are made from:

polyamide nylon,

PET or PBT polyester

phenol-formaldehyde (PF)

polyvinyl alcohol fiber (PVA)

polyvinyl chloride fiber (PVC)

polyolefins (PP and PE)

acrylic polyesters, pure polyester PAN fibers are used to make carbon fiber by roasting them in a low oxygen environment. Traditional acrylic fiber is used more often as a synthetic replacement for wool. Carbon fibers and PF fibers are noted as two resin-based fibers that are not thermoplastic, most others can be melted.

Aromatic polyamids (aramids) such as Twaron, Kevlar and Nomex thermally degrade at high temperatures and do not melt. These fibers have strong bonding between polymer chains

polyethylene (PE), eventually with extremely long chains / HMPE (e.g. Dyneema or Spectra).

Elastomers can even be used, e.g. spandex although urethane fibers are starting to replace spandex technology.

polyurethane fiber

Coextruded fibers have two distinct polymers forming the fiber, usually as a core-sheath or side-by-side. Coated fibers exist such as nickel-coated to provide static elimination, silver-coated to provide anti-bacterial properties and aluminum-coated to provide RF deflection for radar chaff. Radar chaff is actually a spool of continuous glass tow that has been aluminum coated. An aircraft-mounted high speed cutter chops it up as it spews from a moving aircraft to confuse radar signals.

Microfibers

Microfibers in textiles refer to sub-denier fiber (such as polyester drawn to 0.5 dn). Denier and Detex are two measurements of fiber yield based on weight and length. If the fiber density is known you also have a fiber diameter, otherwise it is simpler to measure diameters in micrometers. Microfibers in technical fibers refer to ultra fine fibers (glass or meltblown thermoplastics) often used in filtration. Newer fiber designs include extruding fiber that splits into multiple finer fibers. Most synthetic fibers are round in cross-section, but special designs can be hollow, oval, star-shaped or trilobal. The latter design provides more optically reflective properties. Synthetic textile fibers are often crimped to provide bulk in a woven, non woven or knitted structure. Fiber surfaces can also be dull or bright. Dull surfaces reflect more light while bright tends to transmit light and make the fiber more transparent.

Very short and/or irregular fibers have been called fibrils. Natural cellulose, such as cotton or bleached kraft, show smaller fibrils jutting out and away from the main fiber structure.

See also

Optical fiber

Fiber crop

Tensile strength

Molded pulp

Dietary fiber

Fibers in Differential Geometry

International Year of Natural Fibres

References

^ Hans-J. Koslowski. “Dictionary of Man-made fibers”. Second edition. Deutscher Fachverlag. 2009

^ Serope Kalpakjian, Steven R Schmid. “Manufacturing Engineering and Technology”. International edition. 4th Ed. Prentice Hall, Inc. 2001. ISBN 0-13-017440-8.

^ Hans-J. Koslowski. “Dictionary of Man-made fibers”. Second edition. Deutscher Fachverlag. 2009

v d e

Fibers

Natural

Animal

Alpaca  Angora  Bison Down  Camel hair  Cashmere  Catgut  Chiengora  Llama  Mohair  Pashmina  Qiviut  Rabbit  Silk  Sinew  Spider silk  Wool  Vicua  Yak

Vegetable

Abac  Bamboo  Coir  Cotton  Flax  Hemp  Jute  Kapok  Kenaf  Pia  Raffia palm  Ramie  Sisal  Wood

Mineral

Asbestos  Basalt  Mineral wool  Glass wool

Cellulose

Acetate  Art silk  Bamboo  Lyocell (Tencel)  Modal  Rayon 

Synthetic

Acrylic  Aramid (Twaron  Kevlar  Technora  Nomex)  Carbon (Tenax)  Microfiber  Modacrylic  Nylon  Olefin  Polyester  Polyethylene (Dyneema  Spectra)  Spandex  Vinalon  Zylon

v d e

Textile arts

Fundamentals:

Applique  Crochet  Dyeing  Embroidery  Fabric (textiles)  Felting  Fiber  Knitting  Lace  Nlebinding  Needlework  Patchwork  Passementerie  Plying  Quilting  Rope  Sewing  Spinning  Tapestry  Textile printing  Weaving  Yarn

History of… :

Clothing and textiles  Silk  Quilting  Textiles in the Industrial Revolution  Timeline of textile technology

Regional and ethnic:

Andean   Australian Aboriginal   Hmong   Korean   Mori

Related:

Blocking  Fiber art  Mathematics and fiber arts  Manufacturing 

Preservation  Terminology  Textile industry  Textile Museums   Units of measurement  Wearable fiber art

Categories: Fibers | Materials | TextilesHidden categories: Articles needing additional references from April 2009 | All articles needing additional references

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We take so much care of our children and about their safety, health etc. With great care we choose their things, from their clothing to toys, and schools to hobbies. We take our children for walks, shopping and for a nice stroll in the park, and we would like to keep them always safe and protected as we introduce them to the realities of the world.
In all the public places throughout UK, we see pram shelters constructed to facilitate the public. The pram and buggies shelters are made with extra care. They are kept clean, hygienic, dry and secure. You can find such comfortable pram shelters at metros, beaches, libraries, near health centres and nurseries.
In providing these safe and secure pram shelters, the company Ace Shelters is in the forefront. Their structures provide shelter as well as blend well with the surroundings. Their pram shelters are fool proof, and keeping in mind the dangers of blockades near entrances and fire escapes, they are made with utmost care.  
Ace Shelters uses high grade aluminium extrusions pipes of BS EN 755(1-9) quality, powder coated BS EN ISO 9002, chosen RAL or BS colours which also acts as corrosion resistant, thus making the shelters maintenance free. Different configurations of shelters are available and also custom-made pram shelters with specifications from the client and requirements are given preferences.
Pram shelters are equipped with door locks, and solar lighting is provided to save energy. Exhaust pipes are fitted for rain water drainage. Wreckage resistant perforated steel sheet cover is used for withstand any human mishandling.
To match your environment or the ambience, you can choose from a wide range of available colours to highlight the structure. The expert team of designers will design the shelter according to the client’s specifications and make them more pleasing to eye as well as a safe haven for parents and toddlers. Having worked closely with schools and nurseries Ace Shelters knows what is best suited for pram shelters.
The new Canterbury pram shelter is visually pleasing and serves the purpose by providing a clean and secure pram shelter. Being in the field for nearly 60 years, Ace Shelters provides a wide range of shelters according to the needs of the clients. They have a standard product range from which one can choose from. They cater to clients requirements too.

Normally pram shelters are found in public places like metros, bus stations, malls, shopping arcades, stadia, libraries, beaches, hospitals and other such places. The prams and buggies need to be stored in clean, hygienic dry environment. They must be made very secure too.
The Ace Shelters pram shelters are fool proof, and manufactured with utmost care. They allow valuable indoor space to be utilised well. Keeping in mind the hazards of blocked entrances and fire escapes, the pram shelters are made with high grade aluminium extrusions pipes of BS EN 755(1-9) quality, powder coated BS EN ISO 9002, chosen RAL or BS colour which gives corrosion and maintenance free finish.
Various configurations are available along with customised configuration of pram shelters. If you specify your requirements or provide drawings, then your requirements can be very easily installed in the shelter. Pram shelters are also designed according to the topography of the location too. For instance, a pram shelter in a stadium will have different designing from one in a mall or resort.
Pram shelters come with door locks, solar lighting, and rain water exhaust pipes. Glazed with polycarbonate toughened safety glass, these pram shelters can withstand any amount of rough use. It comes with wreckage resistant perforated steel sheet cover.
You can make your shelter more colourful by using any colour to match the setting. Working closely with schools and nurseries, Ace Shelters knows what is best suited for pram shelters and how it should be constructed. All their products have been CRB checked and passed CSCS health and safety exams. The new Canterbury pram shelter provides a secure, clean and dry environment for the storage of prams.
Ace Shelters has 60 years of experience in providing different types of shelters. They manufacture and install a wide variety of shelters all over the UK. Along with their standard product range, they also provide custom made services to their long standing customers.
As aluminium stock holders they bring the best of extrusion pipes and design the products to withstand the test of time. As part of British industry, Ace Shelters design and manufacture all the structures to precision, with utmost care. Lot of detailing goes into strengthening their products structure.

Textile fiber

A unit in which many complicated textile structures are built up is said to be textile fiber.

Textile Fiber is the basic constituent (Basic raw material) required for textile industry.

Natural fibers

Main article: Natural fiber

Natural fibers include those produced by plants, animals, and geological processes. They are biodegradable over time. They can be classified according to their origin:

Vegetable fibers are generally based on arrangements of cellulose, often with lignin: examples include cotton, hemp, jute, flax, ramie, and sisal. Plant fibers are employed in the manufacture of paper and textile (cloth), and dietary fiber is an important component of human nutrition.

Wood fiber, distinguished from vegetable fiber, is from tree sources. Forms include groundwood, thermomechanical pulp (TMP) and bleached or unbleached kraft or sulfite pulps. Kraft and sulfite, also called sulphite, refer to the type of pulping process used to remove the lignin bonding the original wood structure, thus freeing the fibers for use in paper and engineered wood products such as fiberboard.

Animal fibers consist largely of particular proteins. Instances are spider silk, sinew, catgut, wool and hair such as cashmere, mohair and angora, fur such as sheepskin, rabbit, mink, fox, beaver, etc.

Mineral fibers comprise asbestos. Asbestos is the only naturally occurring long mineral fiber. Short, fiber-like minerals include wollastonite, attapulgite and halloysite.

Man-made fibers

Synthetic or man-made fibers generally come from synthetic materials such as petrochemicals. But some types of synthetic fibers are manufactured from natural cellulose, including rayon, modal, and the more recently developed Lyocell. Cellulose-based fibers are of two types, regenerated or pure cellulose such as from the cupro-ammonium process and modified cellulose such as the cellulose acetates.

Fiber classification in reinforced plastics falls into two classes: (i) short fibers, also known as discontinuous fibers, with a general aspect ratio (defined as the ratio of fiber length to diameter) between 20 to 60, and (ii) long fibers, also known as continuous fibers, the general aspect ratio is between 200 to 500.

Cellulose fibers

Cellulose fibers are a subset of man-made fibers, regenerated from natural cellulose. The cellulose comes from various sources. Modal is made from beech trees, bamboo fiber is a cellulose fiber made from bamboo, seacell is made from seaweed, etc.

Mineral fibers

Fiberglass, made from specific glass, and optical fiber, made from purified natural quartz, are also man-made fibers that come from natural raw materials.

Metallic fibers can be drawn from ductile metals such as copper, gold or silver and extruded or deposited from more brittle ones, such as nickel, aluminum or iron.

Carbon fibers are often based on carbonised polymers, but the end product is pure carbon.

Polymer fibers

Polymer fibers are a subset of man-made fibers, which are based on synthetic chemicals (often from petrochemical sources) rather than arising from natural materials by a purely physical process. These fibers are made from:

polyamide nylon,

PET or PBT polyester

phenol-formaldehyde (PF)

polyvinyl alcohol fiber (PVA)

polyvinyl chloride fiber (PVC)

polyolefins (PP and PE)

acrylic polyesters, pure polyester PAN fibers are used to make carbon fiber by roasting them in a low oxygen environment. Traditional acrylic fiber is used more often as a synthetic replacement for wool. Carbon fibers and PF fibers are noted as two resin-based fibers that are not thermoplastic, most others can be melted.

Aromatic polyamids (aramids) such as Twaron, Kevlar and Nomex thermally degrade at high temperatures and do not melt. These fibers have strong bonding between polymer chains

polyethylene (PE), eventually with extremely long chains / HMPE (e.g. Dyneema or Spectra).

Elastomers can even be used, e.g. spandex although urethane fibers are starting to replace spandex technology.

polyurethane fiber

Coextruded fibers have two distinct polymers forming the fiber, usually as a core-sheath or side-by-side. Coated fibers exist such as nickel-coated to provide static elimination, silver-coated to provide anti-bacterial properties and aluminum-coated to provide RF deflection for radar chaff. Radar chaff is actually a spool of continuous glass tow that has been aluminum coated. An aircraft-mounted high speed cutter chops it up as it spews from a moving aircraft to confuse radar signals.

Microfibers

Microfibers in textiles refer to sub-denier fiber (such as polyester drawn to 0.5 dn). Denier and Detex are two measurements of fiber yield based on weight and length. If the fiber density is known you also have a fiber diameter, otherwise it is simpler to measure diameters in micrometers. Microfibers in technical fibers refer to ultra fine fibers (glass or meltblown thermoplastics) often used in filtration. Newer fiber designs include extruding fiber that splits into multiple finer fibers. Most synthetic fibers are round in cross-section, but special designs can be hollow, oval, star-shaped or trilobal. The latter design provides more optically reflective properties. Synthetic textile fibers are often crimped to provide bulk in a woven, non woven or knitted structure. Fiber surfaces can also be dull or bright. Dull surfaces reflect more light while bright tends to transmit light and make the fiber more transparent.

Very short and/or irregular fibers have been called fibrils. Natural cellulose, such as cotton or bleached kraft, show smaller fibrils jutting out and away from the main fiber structure.

See also

Optical fiber

Fiber crop

Tensile strength

Molded pulp

Dietary fiber

Fibers in Differential Geometry

International Year of Natural Fibres

References

^ Hans-J. Koslowski. “Dictionary of Man-made fibers”. Second edition. Deutscher Fachverlag. 2009

^ Serope Kalpakjian, Steven R Schmid. “Manufacturing Engineering and Technology”. International edition. 4th Ed. Prentice Hall, Inc. 2001. ISBN 0-13-017440-8.

^ Hans-J. Koslowski. “Dictionary of Man-made fibers”. Second edition. Deutscher Fachverlag. 2009

v d e

Fibers

Natural

Animal

Alpaca  Angora  Bison Down  Camel hair  Cashmere  Catgut  Chiengora  Llama  Mohair  Pashmina  Qiviut  Rabbit  Silk  Sinew  Spider silk  Wool  Vicua  Yak

Vegetable

Abac  Bamboo  Coir  Cotton  Flax  Hemp  Jute  Kapok  Kenaf  Pia  Raffia palm  Ramie  Sisal  Wood

Mineral

Asbestos  Basalt  Mineral wool  Glass wool

Cellulose

Acetate  Art silk  Bamboo  Lyocell (Tencel)  Modal  Rayon 

Synthetic

Acrylic  Aramid (Twaron  Kevlar  Technora  Nomex)  Carbon (Tenax)  Microfiber  Modacrylic  Nylon  Olefin  Polyester  Polyethylene (Dyneema  Spectra)  Spandex  Vinalon  Zylon

v d e

Textile arts

Fundamentals:

Applique  Crochet  Dyeing  Embroidery  Fabric (textiles)  Felting  Fiber  Knitting  Lace  Nlebinding  Needlework  Patchwork  Passementerie  Plying  Quilting  Rope  Sewing  Spinning  Tapestry  Textile printing  Weaving  Yarn

History of… :

Clothing and textiles  Silk  Quilting  Textiles in the Industrial Revolution  Timeline of textile technology

Regional and ethnic:

Andean   Australian Aboriginal   Hmong   Korean   Mori

Related:

Blocking  Fiber art  Mathematics and fiber arts  Manufacturing 

Preservation  Terminology  Textile industry  Textile Museums   Units of measurement  Wearable fiber art

Categories: Fibers | Materials | TextilesHidden categories: Articles needing additional references from April 2009 | All articles needing additional references Discovery
Imidazole was first synthesized by Heinrich Debus in 1858, but various imidazole derivatives had been discovered as early as the 1840s. His synthesis, as shown below, used glyoxal and formaldehyde in ammonia to form imidazole. This synthesis, while producing relatively low yields, is still used for creating C-substituted imidazoles.
In one microwave modification the reactants are benzil, formaldehyde and ammonia in glacial acetic acid forming 2,4,5-triphenylimidazole (Lophine).
Structure and properties
Imidazole is a 5-membered planar ring, which is soluble in water and other polar solvents. It exists in two equivalent tautomeric forms because the hydrogen atom can be located on either of the two nitrogen atoms. Imidazole is a highly polar compound, as evidenced by a calculated dipole of 3.61D, and is entirely soluble in water. The compound is classified as aromatic due to the presence of a sextet of -electrons, consisting of a pair of electrons from the protonated nitrogen atom and one from each of the remaining four atoms of the ring.
Some resonance structures of imidazole are shown below:
Amphotericity
Imidazole is amphoteric, i.e. it can function as both an acid and as a base. As an acid, the pKa of imidazole is 14.5, making it less acidic than carboxylic acids, phenols, and imides, but slightly more acidic than alcohols. The acidic proton is located on N-1. As a base, the pKa of the conjugate acid (cited above as pKBH+ to avoid confusion between the two) is approximately 7, making imidazole approximately sixty times more basic than pyridine. The basic site is N-3.
Preparation
A ball-and-stick model of imidazole, showing carbon-carbon and a carbon-nitrogen double bonds.
Imidazole can be synthesized by numerous methods besides the Debus method. Many of these syntheses can also be applied to different substituted imidazoles and imidazole derivatives simply by varying the functional groups on the reactants. In literature, these methods are commonly categorized by which and how many bonds form to make the imidazole rings. For example, the Debus method forms the (1,2), (3,4), and (1,5) bonds in imidazole, using each reactant as a fragment of the ring, and thus this method would be a three-bond-forming synthesis. A small sampling of these methods is presented below.
Formation of one bond
The (1,5) or (3,4) bond can be formed by the reaction of an imidate and an -aminoaldehyde or -aminoacetal, resulting in the cyclization of an amidine to imidazole. The example below applies to imidazole when R=R1=Hydrogen.
Formation of Two Bonds
The (1,2) and (2,3) bonds can be formed by treating a 1,2-diaminoalkane, at high temperatures, with an alcohol, aldehyde, or carboxylic acid. A dehydrogenating catalyst, such as platinum on alumina, is required.
The (1,2) and (3,4) bonds can also be formed from N-substituted -aminoketones and formamide and heat. The product will be a 1,4-disubstituted imidazole, but here since R=R1=Hydrogen, imidazole itself is the product. The yield of this reaction is moderate, but it seems to be the most effective method of making the 1,4 substitution.
Formation of Four Bonds
This is a general method which is able to give good yields for substituted imidazoles. It is essentially an adaptation of the Debus method called the Debus-Radziszewski imidazole synthesis. The starting materials are substituted glyoxal, aldehyde, amine, and ammonia or an ammonium salt.
Formation from other Heterocycles
Imidazole can be synthesized by the photolysis of 1-vinyltetrazole. This reaction will only give substantial yields if the 1-vinyltetrazole is made efficiently from an organotin compound such as 2-tributylstannyltetrazole. The reaction, shown below, produces imidazole when R=R1=R2=Hydrogen.
Imidazole can also be formed in a vapor phase reaction. The reaction occurs with formamide, ethylenediamine, and hydrogen over platinum on alumina, and it must take place between 340 and 480 C. This forms a very pure imidazole product.
Biological significance and applications
Imidazole is incorporated into many important biological molecules. The most pervasive is the amino acid histidine, which has an imidazole side chain. Histidine is present in many proteins and enzymes and plays a vital part in the structure and binding functions of hemoglobin. Histidine can be decarboxylated to histamine, which is also a common biological compound. It is a component of the toxin that causes urticaria, which is another name for allergic hives. The relationship between histidine and histamine are shown below:
One of the applications of imidazole is in the purification of His-tagged proteins in immobilised metal affinity chromatography(IMAC). Imidazole is used to elute tagged proteins bound to Ni ions attached to the surface of beads in the chromatography column. An excess of imidazole is passed through the column, which displaces the His-tag from nickel co-ordination, freeing the His-tagged proteins.
Imidazole has become an important part of many pharmaceuticals. Synthetic imidazoles are present in many fungicides and antifungal, antiprotozoal, and antihypertensive medications. Imidazole is part of the theophylline molecule, found in tea leaves and coffee beans, which stimulates the central nervous system. It is present in the anticancer medication mercaptopurine, which combats leukemia by interfering with DNA activities.
Pharmaceutical derivatives
The substituted imidazole derivatives are valuable in treatment of many systemic fungal infections.
Ketoconazole
Miconazole
Fluconazole
Itraconazole
Voriconazole
Industrial applications
Imidazole has been used extensively as a corrosion inhibitor on certain transition metals, such as copper. Preventing copper corrosion is important, especially in aqueous systems, where the conductivity of the copper decreases due to corrosion.
Many compounds of industrial and technological importance contain imidazole derivatives. The thermostable polybenzimidazole PBI contains imidazole fused to a benzene ring and linked to a benzene, and acts as a fire retardant. Imidazole can also be found in various compounds which are used for photography and electronics.
Salts of imidazole
Salts of imidazole where the imidazole ring is in the cation are known as imidazolium salts (for example, imidazolium chloride). These salts are formed from the protonation or substitution at nitrogen of imidazole. These salts have been used as ionic liquids and precursors to stable carbenes. Salts where a deprotonated imidazole is an anion are also possible; these salts are known as imidazolide salts (for example, sodium imidazolide).
Related heterocycles
Benzimidazole, an analog with a fused benzene ring.
Dihydroimidazole or benzimidazoline, an analog where 4,5-double bond is saturated.
Pyrrole, an analog with only one nitrogen atom in position 1.
Oxazole, an analog with the nitrogen atom in position 1 replaced by oxygen.
Thiazole, an analog with the nitrogen atom in position 1 replaced by sulfur.
Pyrazole, an analog with two adjacent nitrogen atoms.
References
^ Alan R. Katritzky; Rees. Comprehensive Heterocyclic Chemistry. Vol. 5, p.469-498, (1984).
^ Grimmett, M. Ross. Imidazole and Benzimidazole Synthesis. Academic Press, (1997).
^ Brown, E.G. Ring Nitrogen and Key Biomolecules. Kluwer Academic Press, (1998).
^ Pozharskii, A.F, et al. Heterocycles in Life and Society. John Wiley & Sons, (1997).
^ Heterocyclic Chemistry TL Gilchrist, The Bath press 1985 ISBN 0-582-01421-2
^ Heinrich Debus (1858). “Ueber die Einwirkung des Ammoniaks auf Glyoxal”. Annalen der Chemie und Pharmacie 107 (2): 199 208. doi:10.1002/jlac.18581070209. 
^ Microwave-Mediated Synthesis of Lophine: Developing a Mechanism To Explain a Product Crouch, R. David; Howard, Jessica L.; Zile, Jennifer L.; Barker, Kathryn H. J. Chem. Educ. 2006 83 1658
^ US6,177,575 (PDF version) (2001-01-23) A. J. Arduengo, Process for Manufacture of Imidazoles. 
^ Comprehensive Pharmacy Review, Leon Shargel, 6th edition, p930.
v d e
Antifungals (D01 and J02)
Wall/
membrane
Ergosterol
inhibitors
Azoles
(lanosterol 14
alpha-demethylase inhibitors)
Imidazoles
topical: Bifonazole, Clomidazole, Clotrimazole#, Croconazole, Econazole, Fenticonazole, Ketoconazole, Isoconazole, Miconazole#, Neticonazole, Oxiconazole, Sertaconazole, Sulconazole, Tioconazole
Triazoles
topical: (Fluconazole#, Fosfluconazole)
systemic: (Fluconazole, Itraconazole, Posaconazole, Voriconazole)
Benzimidazoles
topical: Thiabendazole
Polyene antimycotics
(ergosterol binding)
topical: (Natamycin, Nystatin#)
systemic: (Amphotericin B#)
Allylamines
(squalene monooxygenase
inhibitors)
topical: (Amorolfine, Butenafine, Naftifine, Terbinafine)
systemic: (Terbinafine)
-glucan synthase
inhibitors
echinocandins (Anidulafungin, Caspofungin, Micafungin)
Intracellular
Pyrimidine analogues/
Thymidylate synthase inhibitors
Flucytosine#
Mitotic inhibitors
Griseofulvin#
Others
Bromochlorosalicylanilide  Methylrosaniline  Tribromometacresol  Undecylenic acid  Polynoxylin  Chlorophetanol  Chlorphenesin  Ticlatone  Sulbentine  Ethyl hydroxybenzoate  Haloprogin  Salicylic acid  Selenium sulfide#  Ciclopirox  Amorolfine  Dimazole  Tolnaftate  Tolciclate  Sodium thiosulfate#  Whitfield’s ointment#  Potassium iodide#
Tea tree oil citronella oil lemon grass orange oil patchouli lemon myrtle
PCP: Pentamidine Dapsone Atovaquone
#WHO-EM. Withdrawn from market. CLINICAL TRIALS: hase III. Never to phase III
see also diseases
Categories: Imidazoles | AlkaloidsHidden categories: Chemboxes which contain changes to watched fields

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