Encyclopedia of fiber properties

The properties of a fiber determine its quality characteristics and its suitability for specific application conditions. Standard tests and laboratory tests are generally used to measure and compare fiber properties.

1. Abrasion fastness

Abrasion fastness refers to the ability to resist wearing friction, which helps to improve the durability of fabrics. Garments made from fibers with high breaking strength and good abrasion fastness can last for a long time and show no signs of wear after a long period of time.

Nylon is widely used in sports jackets, such as ski jackets and football shirts. This is because its strength and abrasion fastness are exceptionally good. Acetate is often used in the lining of outerwear and jackets due to its excellent drape and low cost. However, due to the poor abrasion resistance of acetate, the lining tends to fray or form holes before the outer fabric of the jacket wears accordingly.

2. Water absorption

Water absorption is the ability to absorb moisture, which is usually expressed by moisture regain. The water absorption of fibers refers to the percentage of moisture absorbed by dry fibers in air at standard conditions of 70°F (equivalent to 21°C) and 65% relative humidity.

Fibers that absorb water easily are called hydrophilic fibers. All natural plant and animal fibers and two man-made fibers - viscose and acetate are hydrophilic fibers. Those fibers that have difficulty absorbing water or can only absorb a small amount of water are called hydrophobic fibers. With the exception of viscose, Lyocell and acetate, all man-made fibers are hydrophobic. Glass fibers don't absorb water at all, and other fibers typically have a moisture regain of 4% or less.

The water absorption of fibers affects many applications, including:

● Skin comfort: Due to poor water absorption, the flow of sweat can cause a cold and wet feeling.

● Static: Clothes sticking and sparking problems occur with hydrophobic fibers, because there is almost no moisture to help disperse the charged particles accumulated on the surface of the fibers, and dust is also brought to the fibers due to static electricity and adheres to them.

● Dimensional stability after washing: After washing, the shrinkage of hydrophobic fibers is smaller than that of hydrophilic fibers, and the fibers rarely swell, which is one of the reasons for fabric shrinkage.

● Stain removal: It is easy to remove stains from hydrophilic fibers, because the fibers will absorb the detergent and water at the same time.

● Water repellency: Hydrophilic fibers usually require more water-repellent and durable post-treatment, because this chemical treatment can make these fibers more water-repellent.

● Wrinkle recovery: Hydrophobic fibers generally have better wrinkle recovery, especially after laundering, because they do not absorb water, swell, and dry in a wrinkled state.

Three chemical effects

Fibers typically come into contact with chemicals during textile processing (eg, dyeing, finishing) and home/professional care or cleaning (eg, with soap, bleach, and dry cleaning solvents, etc.). The type of chemical, the intensity of action and the duration of action determine the degree of effect on the fiber. It is important to understand the effect of chemicals on different fibers as it directly relates to the care required in cleaning.

Fibers react differently to chemicals. For example, cotton fibers are relatively low in acid resistance, while alkali resistance is very good. In addition, cotton fabrics will lose a little strength after chemical resin non-iron finishing.

Four Coverage

Coverage refers to the ability to fill a range. Coarse or crimped fibers provide better coverage than fine, straight fibers. The fabrics are warm, feel full and require fewer fibers to weave.

Wool is a widely used fiber in winter clothing because its curl provides excellent coverage to the fabric and creates a large amount of still air in the fabric, which is relatively insulated from the cold outside. The effectiveness of fiber covering depends on its cross-sectional shape, longitudinal configuration and weight.

Five flexibility

Elasticity refers to the ability to increase in length under tension (extension) and return to a rocky state (recovery) after releasing an external force. Elongation when external forces act on the fibers or fabrics can make clothing more comfortable and cause less stress on the seams. There is also a tendency to increase the breaking strength. Complete recovery can help prevent fabric sagging at elbows or knees, thereby preventing loose deformation of the garment.

Fibers that can stretch at least 100% are called elastic fibers. Spandex fiber (Spandex is also called Lycra, our country is called spandex) and rubber fiber belong to this type of fiber. After elongation, these elastic fibers can almost forcefully return to their original length.

Six environmental conditions

Environmental conditions have different effects on fibers. How the fibers and final fabrics respond to exposure, storage, etc. is very important. Here are some examples:

● Wool garments need to be protected from moths during storage because they are easily eaten by wool moths.

● Nylon and silk will lose their strength when exposed to sunlight for a long time, so they are not usually used to make curtains and doors and windows.

● Cotton fiber is prone to mold, so it cannot be stored in a humid environment for a long time.

7. Flammability

Flammability is the ability of an object to ignite or burn. This is an important feature because people's lives are always surrounded by a variety of textiles. We know that clothing or interior furniture, due to its flammability, can cause serious injury to consumers and cause significant material damage.

Fibers are usually classified into flammable, non-flammable, and flame-retardant:

● Flammable fibers are fibers that are easily ignited and continue to burn.

● Non-flammable fibers refer to fibers that have a relatively high burning point and a relatively slow burning speed, and will self-extinguish after evacuating the burning source.

● Flame retardant fibers are fibers that will not burn.

Flammable fibers can be made into flame-retardant fibers by finishing or changing fiber parameters. For example, regular polyester is flammable, but Trevira polyester is treated to be flame retardant.

Eight softness

Softness refers to the ability of fibers to be easily bent repeatedly without breaking. Soft fibers such as acetate can support fabrics and garments with good drape. Rigid fibers such as glass fibers cannot be used to make clothing, but can be used in decorative fabrics that need to be relatively stiff. Generally, the finer the fibers, the better the drapability. Softness also affects the feel of the fabric.

Although fabrics with good drape are often required, stiffer fabrics are sometimes required. For example, on garments with capes (clothes that hang over the shoulders and turn out), use a stiffer fabric to achieve the desired shape.

Nine feel

Hand is the feeling when you touch fibers, yarns or fabrics. The fiber's hand feels the influence of its shape, surface features and structure. The shape of the fibers is different, and can be round, flat, multi-lobal and so on. Fiber surfaces also vary, such as smooth, jagged or scaly. The shape of the fibers is either curly or straight. Yarn type, fabric structure and finishing process can also affect the feel of the fabric. Terms such as soft, smooth, dry, silky, stiff, rough or rough are often used to describe the hand of a fabric.

Ten glosses

Gloss refers to the reflection of light on the surface of the fiber. Different properties of fibers affect their gloss. A glossy surface, less curvature, a flat cross-sectional shape, and a longer fiber length enhance light reflection. The drawing process in fiber manufacturing increases its luster by making its surface smoother. Adding a matting agent will destroy the reflection of light and reduce the gloss. In this way, the amount of added matting agent can be controlled, and optical fibers, semi-matting fibers and non-optical fibers can be manufactured. Fabric gloss is also affected by yarn type, weave and all finishes. Gloss requirements will depend on fashion trends and customer needs.

Eleven Pilling

Pilling refers to the entanglement of some short and broken fibers on the surface of the fabric into small balls. Poms form when the ends of fibers break from the surface of the fabric, usually caused by wearing. Pilling is undesirable because it makes fabrics such as bed sheets old, unsightly, and uncomfortable. Poms are created in areas that are frequently rubbed, such as collars, under-sleeves, and cuff edges.

Hydrophobic fibers are more prone to pilling than hydrophilic fibers, because hydrophobic fibers are more likely to attract static electricity to each other and are less likely to fall off the surface of the fabric. Pompoms are rarely seen on 100% cotton shirts, but are quite common on similar shirts in polyester-cotton blends that have been worn for a while. While wool is hydrophilic, pom-poms are created because of its scaly surface. The fibers twist and twist around each other, forming a pom-pom. The strong fibers easily hold the pom-poms on the fabric surface. Easy-to-break low-strength fibers that do not pill easily because the pom-poms fall easily.

Twelve resilience

Resilience refers to the ability of a material to elastically recover after being folded, twisted, and twisted. It is closely related to wrinkle recovery ability. Fabrics with better resilience are less prone to wrinkling and, therefore, tend to maintain their good shape. Thicker fiber has better resilience because it has more mass to absorb strain. At the same time, the shape of the fiber also affects the resilience of the fiber. Round fibers have better resilience than flat fibers.

The nature of the fiber is also a factor. Polyester fibers have excellent resilience, but cotton fibers have poor resilience. It's no surprise then that these two fibers are often mixed in products such as men's shirts, women's baggy tops and bed sheets.

If you need to form obvious wrinkles on the clothing, the rebounded fibers can be a little troublesome. Creases are easy to form on cotton or denim fabrics, but not so easy on dry wool fabrics. Wool fibres resist bending and wrinkling, and straighten afterward.

13 Relative Density

The relative density refers to the ratio of the fiber mass to the water mass of the same volume at 4°C. Lightweight fibers keep the fabric warm without being bulky, potentially creating a thick, voluminous fabric but still maintaining a low weight. A good example is acrylic, which is much lighter than wool but has wool-like properties, making it widely used in fabrics that are light and warm in blankets, scarves, thick socks, and other winter items.

Fourteen static electricity

Static electricity is the electrical charge produced by the friction of two dissimilar materials against each other. When electrical charge is generated and builds up on the fabric surface, it will be the garment that clings to the wearer or the lint that sticks to the fabric. When the surface of the fabric comes into contact with the foreign body, an electric spark or electric shock is produced, which is a rapid discharge process. When the static electricity on the fiber surface is generated at the same speed of electrostatic transfer, the static electricity phenomenon can be eliminated.

The moisture contained in the fibers acts as a conductor to remove electrical charges and prevents the aforementioned electrostatic effects. Hydrophobic fibers, because they contain very little water, have a tendency to generate static electricity. Static electricity is also created in natural fibers, but only when very dry does it become hydrophobic. Glass fibers are the exception to hydrophobic fibers, because of their chemical composition, static charges cannot be generated on their surfaces.

Fabrics containing Ebitrobic fibers (fibers that conduct electricity) are free of static electricity and contain carbon or metals that allow the fibers to transfer accumulated static charges. Because there is often a problem with static electricity on carpets, nylons such as Monsanto Ultron are used on carpets. Trobic fiber eliminates electric shock, fabric fit and dust pickup. Because of the danger of static electricity in special working environments, it is very important to use low-static fibers to make subways in areas near hospitals, computers, and work areas near flammable and explosive liquids or gases.

Fifteen Strength

Strength is the ability of a fiber to resist stress. Fiber strength is the force required to break a fiber and is expressed in grams per denier or centinewtons per tex (a legal unit of measurement).

Sixteen thermoplastic

The ability of fiber to resist heat is an important factor affecting its application performance. Often, this is also an important factor to consider in fiber processing, since fibers are subjected to heat during many fabric forming processes, such as dyeing, ironing, and heat setting. In addition to this, heating is often employed to care and update clothing and interior furniture.

Some thermal effects are only temporary and obvious during the course of action. For example, in dyeing, the properties of the fibers can change during heating, but return to normal after cooling. But some thermal effects can be permanent, as the fibers themselves degrade due to molecular rearrangement after heat. Heat setting, on the other hand, changes the molecular arrangement, making the fabric more stable (minimal shrinkage) and more wrinkle-resistant, but without significant degradation. However, prolonged exposure to elevated temperatures may cause degradation such as loss of strength, fiber shrinkage and discoloration. Many consumers have experienced severe degradation of fabrics and even damage to garments caused by ironing at excessively high temperatures.

When heated, thermoplastic fibers become soft and melt into a liquid state at higher temperatures. Many man-made fibers are thermoplastic. By applying heat to a fabric containing thermoplastic fibers to form creases and folds without melting the fibers, long-lasting creases and folds can be made when the temperature is lowered. Thermoplastic fibers can be molded into shape when heated (softened) and retained when cooled (care must be taken when ironing garments made from rayon to avoid softening or melting. When softening or melting, The fabric will start to stick to the iron) and the creases will be permanent unless a higher temperature removes the original heat set effect. The shape of the garment can also be formed by this method, and the thermoplastic fabric has good dimensional stability.

17. Wicking effect

Wicking is the ability of fibers to transfer moisture from one place to another. Normally, moisture is transported along the surface of the fibers, but liquids can also pass through the fibers when absorbed by the fibers. The wicking tendency of fibers often depends on the chemical and physical composition of the outer surface. A smooth surface reduces the effect of wicking.