1. Overview of textiles
(1) The meaning of textiles
Textiles refer to single yarns, strands, woolen yarns, twisted yarns, ropes, woven fabrics, knitted fabrics, braided fabrics, various textile reproduction products, felts, non-woven fabrics, etc., which can be used directly or further processing.
(2) Ecological textiles
1. Meaning: Eco-textiles refer to those Textile products made from raw materials that are harmless or less harmful to the surrounding environment and are harmless to human health. Such textiles have been toxicologically tested and have corresponding marks, that is, manufacturers, distributors and textile associations and their member organizations, according to “Oeko-Tex
Standard 100》 system and requirements for specific certification. Those that meet the requirements will be issued a specific certificate and a specific label. The certificate is valid for one year.
2. Conditions: production ecology, consumption Ecology, processing ecology, and supervision of the entire process
2. Textile fibers
(1) Concept and features
Fiber is a natural or synthetic filament-like substance, and textile fiber refers to the fiber used to process textile cloth.
Textile fiber characteristics: Textile fibers have certain Length, fineness, elasticity, strength and other good physical properties. It also has good chemical stability. For example, natural fibers such as cotton, wool, silk, and line are ideal textile fibers.
(2) Classification and identification
①Category
②Identification
Identification of different types of textile fibers can be done through sensory methods, combustion methods, microscopy methods, dissolution methods, and pharmaceutical methods Coloring method and infrared spectroscopy are used for identification. Identification often requires analysis from both qualitative and quantitative aspects. Usually, the following steps are used for identification:
First use Combustion method or sensory method to initially determine what kind of fiber it is (natural fiber or chemical fiber)
If it is a natural fiber, microscopic observation can be used to identify whether it is a plant fiber or an animal fiber. If it is a chemical fiber, the differences in melting point, specific gravity, refractive index, solubility properties, etc. of the combined fiber can be distinguished one by one.
When identifying mixed fibers and blended yarns Generally, microscopic observation can be used to confirm that it contains several types of fibers, and then appropriate methods can be used to identify them one by one.
For dyed or finished fibers, generally Dyeing and stripping or other appropriate pretreatment must be carried out first to ensure reliable identification results.
3. Textile yarn
(1) Main technical indicators of yarn
Yarn quality depends on the quality of raw materials and process quality. The quality of yarn directly affects the beauty and use value of the fabric. The main indicators for measuring yarn quality are the fineness and uniformity of the yarn., strength and elongation, twist and twist direction, etc.
①Yarn thickness and uniformity
Yarns are divided into thicknesses, which means the relationship between the quality of the yarn and its length. Usually expressed by fixed weight system and fixed length system. Fixed weight refers to the length of yarn with a specified weight, while fixed length refers to the weight of yarn with a specified length.
Yarn count, an indicator of yarn thickness , often used to measure the thickness of yarn spun from short fibers. It is divided into metric system (metric system) and imperial system system (imperial system).
Metric count (Nm): 1 gram The length of yarn (silk) in meters. Formula: Nm＝L/G
Inch support Number (Ne): The number of 840 yards of yarn in 1 pound (453.6 grams). Formula: Ne=L/ (G×840)
The yarn count is represented by a number. The larger the number, the longer the length of the yarn and the thinner it is; conversely, the thicker the yarn. In addition, the yarn count is represented by two sets of numbers. The first set of numbers indicates the count of single yarn, and the second set of numbers indicates the number of plies. For example, 16S/1 means sixteen orders
Yarn; 32S/2 means thirty-two double-ply yarn. Generally speaking, the finer the yarn and the uniform thickness, the thinner and smoother the fabric will be after weaving and processing, and the weight of the garment will be lighter, and vice versa.
②Strength and elongation
The tensile capacity of the yarn is called strength. Under other conditions being equal, the greater the strength of the yarn, the stronger and more durable the fabric will be. The single yarn strength is measured on a single yarn strength testing machine. The strength of the yarn is expressed in grams or kilograms of the load that breaks the yarn. When the yarn is stretched by an external force, elongation deformation occurs. The percentage of the stretched length of the yarn to the original length under a certain load is called the elongation of the yarn. The yarn should have appropriate stretch to make the yarn elastic and flexible. Too much elongation will cause the yarn to relax and reduce its strength; too little elongation will increase the strength of the yarn but make the fabric harder.
③Twist and twist direction of yarn (omitted)
(2) Common indicators of textile yarn quality
Judgement of textile yarn quality can be based on relevant national standards. Usually, it can also be visually judged from the appearance of yarn thickness uniformity, defects (such as impurities, neps), etc.
①The number of neps. Refers to the number of spherical knots formed on 1 gram of cotton yarn fibers. Neps are harmful yarn defects.
②Tree dry. It is the uniformity of thickness (or quality) along the length of the yarn, also known as evenness. Evenness is an important indicator of yarn quality. Good evenness, uniform yarn thickness, and good quality; otherwise, poor quality.
③Hairiness. Mainly for short fiber yarns. Because the fiber is short, after it is spun into yarn, the head end of the fiber is exposed outside the yarn, forming plush on the surface of the yarn. Hairiness is also a harmful defect in yarn and is usually removed by singeing.
④Thick sections. Thick places are segments of yarn that are thicker than normal yarn along the length direction. They are divided into short thick places (below 15mm) and long thick places.
⑤Details. Contrary to slugs, minutiae are segments along the length of the yarn that are thinner than normal. Detail is a point in the yarn that affects the strength of the fabric.
⑥Twist. Twist is the number of twists within a specified length of yarn. Twist is usually used for short fiber yarns and has two expression methods, namely the number of twists per 10cm and the number of twists per inch (plied yarn is also expressed in this way). Wool yarn and filament are expressed by the number of twists within lm.
⑦Intensity. It is the force required to break a unit yarn. Strength is a term that reflects whether the yarn is strong and strong.
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⑦Intensity. It is the force required to break a unit yarn. Strength is a term that reflects whether the yarn is strong and strong.
