Aramid Fiber Uses

• Flame-resistant clothing

• Heat protective clothing and helmets

• Body armor, competing with PE based fiber products such as Dyneema and Spectra

• Composite materials

• Asbestos replacement (e.g. braking pads)

• Hot air filtration fabrics

• Tires, newly as Sulfron (sulfur modified Twaron)

• Mechanical rubber goods reinforcement

• Ropes and cables

• Wicks for fire dancing

Aramid fiber characteristics

• Good resistance to abrasion

• Good resistance to organic solvents

• Nonconductive

• No melting point, degradation starts from 500°C

• Low flammability

• Good fabric integrity at elevated temperatures

• Sensitive to acids and salts

• Sensitive to ultraviolet radiation

• Prone to static build-up unless finished

overview of Aramid Fiber

Aramid fibers are a class of heat-resistant and strong synthetic fibers. They are used in aerospace and military applications, for ballistic rated body armor fabric, and as an asbestos substitute. The name is a shortened form of "aromatic polyamide". They are fibers in which the chain molecules are highly oriented along the fiber axis, so the strength of the chemical bond can be exploited.

Appearances of Aramid Fiber Characteristics

Fiber,Chopped fiber,Powder, Pulp

Acrylic Fiber Uses

Apparel: Sweaters, socks, fleece wear, circular knit apparel, sportswear and childrens wear 

 

Home Furnishings: Blankets, area rugs, upholstery, pile; luggage, awnings, outdoor furniture 

 

Other Uses: Craft yarns, sail cover cloth, wipe cloths 

 

Industrial Uses: Asbestos replacement; concrete and stucco reinforcement

Acrylic Fiber Characteristics

• Outstanding wickability & quick drying to move moisture from body surface

• Flexible aesthetics for wool-like, cotton-like, or blended appearance

• Easily washed, retains shape

• Resistant to moths, oil, and chemicals

• Dyeable to bright shades with excellent fastness

• Superior resistance to sunlight degradation

Basic Principles of Acrylic Fiber Production

Acrylic fibers are produced from acrylonitrile, a petrochemical. The acrylonitrile is usually combined with small amounts of other chemicals to improve the ability of the resulting fiber to absorb dyes. Some acrylic fibers are dry spun and others are wet spun. Acrylic fibers are used in staple or tow form.

Spandex Fiber Characteristics

• Can be stretched repeatedly and still recover to very near its original length and shape

• Generally, can be stretched more than 500% without breaking

• Stronger, more durable and higher retractive force than rubber

• Lightweight, soft, smooth, supple

• In garments, provides a combination of comfort and fit, prevents bagging and sagging

• Heat-settable - facilitates transforming puckered fabrics into flat fabrics, or flat fabrics into permanent rounded shapes

• Dyeable

Major spandex fiber uses

Apparel and clothing articles where stretch is desired, generally for comfort and fit, such as:

athletic, aerobic, and exercise apparel

wetsuitss

wimsuits/bathing suits

competitive swimwear

netball bodysuits

brassiere straps and bra side panels

ski pants

disco jeanss

lacks

hosiery

leggings

socks

diapers

skinny jeans

belts

underwear

dance belts worn by male ballet dancers and others

Compression garments such as:

surgical hose

support hose

cycling shorts

wrestling singlet

one piece rowing suits

foundation garments

motion capture suits

Shaped garments such as

bra cups

Home furnishings, such as microbead pillows

Spandex Fiber Production

Spandex-or elastane-is a synthetic fiber known for its exceptional elasticity. It is stronger and more durable than rubber, its major non-synthetic competitor. It was invented in 1959 by DuPont chemist Joseph Shivers. When first introduced, it revolutionized many areas of the clothing industry.

"Spandex" is a generic name and not derived from the chemical name of the fiber, as are most manufactured fibers, but an extension of the word expand. "Spandex" is the preferred name in North America; elsewhere it is referred to as "elastane".

Spandex fiber production

Spandex fibers are produced in four different ways, including melt extrusion, reaction spinning, solution dry spinning, and solution wet spinning. All of these methods include the initial step of reacting monomers to produce a prepolymer. Once the prepolymer is formed, it is reacted further in various ways and drawn out to produce a long fiber. The solution dry spinning method is used to produce over 90% of the world's spandex fibers.

 

Solution dry spinning

Step 1: The first step is to produce the prepolymer. This is done by mixing a macroglycol with a diisocyanate monomer. The two compounds are mixed together in a reaction vessel to produce a prepolymer. A typical ratio of glycol to diisocyanate is 1:2.

 

Step 2: The prepolymer is further reacted with an equal amount of diamine. This reaction is known as chain extension reaction. The resulting solution is diluted with a solvent to produce the spinning solution. The solvent helps make the solution thinner and more easily handled, and then it can be pumped into the fiber production cell.

 

Step 3: The spinning solution is pumped into a cylindrical spinning cell where it is cured and converted into fibers. In this cell, the polymer solution is forced through a metal plate called a spinneret. This causes the solution to be aligned in strands of liquid polymer. As the strands pass through the cell, they are heated in the presence of a nitrogen and solvent gas. This process causes the liquid polymer to react chemically and form solid strands. 

 

Step 4: As the fibers exit the cell, an amount of solid strands are bundled together to produce the desired thickness. Each fiber of spandex is made up of many smaller individual fibers that adhere to one another due to the natural stickiness of their surface.

 

Step 5: The resulting fibers are then treated with a finishing agent which can be magnesium stearate or another polymer. This treatment prevents the fibers' sticking together and aids in textile manufacture. The fibers are then transferred through a series of rollers onto a spool.

 

Step 6: When the spools are filled with fiber, they are put into final packaging and shipped to textile manufacturers

Characteristics of Nylon

Variation of luster: nylon has the ability to be very lustrous, semilustrous or dull.
* Durability: its high tenacity fibers are used for seatbelts, tire cords, ballistic cloth and other uses.
* High elongation
* Excellent abrasion resistance
* Highly resilient (nylon fabrics are heat-set)
* Paved the way for easy-care garments
* High resistance to: insects, fungi and animals,molds, mildew, rot,many chemicals
* Used in carpets and nylon stockings
* Melts instead of burning
* Used in many military applications

Overview of Nylon Fiber

Nylon is a generic designation for a family of synthetic polymers known generically as polyamides and first produced on February 28, 1935 by Wallace Carothers at DuPont. Nylon is one of the most commonly used polymers

Density - 1.15g/cm³
Electrical conductivity (σ) - 10-12S/m
Thermal conductivity 0.25W/(m·K), 463 K-624 K
Melting point 190°C-350°C or 374°F-663°F

Nylon is a thermoplastic silky material, first used commercially in a nylon-bristled toothbrush (1938), followed more famously by women's stockings ("nylons"; 1940). It is made of repeating units linked by peptide bonds (another name for amide bonds) and is frequently referred to as polyamide (PA). Nylon was the first commercially successful synthetic polymer. There are two common methods of making nylon for fiber applications. In one approach, molecules with an acid (COOH) group on each end are reacted with molecules containing amine (NH2) groups on each end. The resulting nylon is named on the basis of the number of carbon atoms separating the two acid groups and the two amines. These are formed into monomers of intermediate molecular weight, which are then reacted to form long polymer chains.

was intended to be a synthetic replacement for silk and substituted for it in many different products after silk became scarce during World War II. It replaced silk in military applications such as parachutes and flak vests, and was used in many types of vehicle tires.

Nylon fibers are used in many applications, including fabrics, bridal veils, carpets, musical strings, and rope.

Solid nylon is used for mechanical parts such as machine screws, gears and other low- to medium-stress components previously cast in metal. Engineering-grade nylon is processed by extrusion, casting, and injection molding. Solid nylon is used in hair combs. Type 6/6 Nylon 101 is the most common commercial grade of nylon, and Nylon 6 is the most common commercial grade of molded nylon. Nylon is available in glass-filled variants which increase structural and impact strength and rigidity, and molybdenum sulfide-filled variants which increase lubricity.

Nylon Fiber production

The first approach:

* combining molecules with an acid (COOH) group on each end are reacted with two chemicals that contain amine (NH2) groups on each end.

This process creates nylon 6,6, made of hexamethylene diamine with six carbon atoms and acidipic acid, as well as six carbon atoms.

The second approach:

* a compound has an acid at one end and an amine at the other and is polymerized to form a chain with repeating units of (-NH-[CH2]n-CO-)x.
* In other words, nylon 6 is made from a single six-carbon substance called caprolactam.
* In this equation, if n=5, then nylon 6 is the assigned name. (may also be referred to as polymer)

Nylon 6,6

* Pleats and creases can be heat-set at higher temperatures
* Nylon 6 is very easy to dye, but Nylon 6,6 is not

Nylon 6

* Better dye Affinity
* Softer Hand