The Industry Business Trend Of Thread And Yarn

1. Basic requirements: to understand the position of yarn in the process of garment making and processing; to master the basic concept of yarn, the commonly used yarn classification methods and varieties; on the basis of the preliminary understanding of the spinning principle, the structural characteristics of the yarn are well known. Know the sewing thread, the type of yarn, the variety and the selection principle.

2. Key points: Master the definition, classification method and variety of yarns, and fully understand the structural traits of yarns. In particular, it is necessary to grasp the evaluation indexes of structural characteristics and their significance (impact) on clothing style.

3. Difficulties: How to understand the principle and process of yarn processing and spinning; correct understanding of the relationship, difference and physical meaning of several evaluation indexes of yarn fineness.

4. Teaching methods: classroom teaching combined with physical analysis.

Section 1 Definition of yarn for clothing

First, the status of the yarn

Yarn plays a dual role in the manufacture and processing of the garments, as the final product of the spinning mill and the raw material of the weaving mill. It can be packaged in semi-finished products or sold as finished products. Therefore, it is important to understand the basic knowledge of yarns, master the main varieties of yarns and their traits, and to properly select yarns and effectively express the appearance and surface properties of fabrics and garments. In general, the processing process of apparel fabrics is:

Fiber raw material (twisting) yarn (prepared for weaving) fabric (sewing processing) clothing

Second, the definition of yarn

The so-called "yarn" is generally referred to as the "yarn" and "line". It is defined in the material science of clothing as follows: "yarn" is a line of many short fibers or filaments arranged in an approximately parallel state and along the axial direction. Rotating twisting to form an elongated object with a certain strength and linear density; and "line" is a strand formed by twisting two or more single yarns.

Section 2 Variety of clothing yarns

There are many varieties of yarns with different properties. It can be a pure spinning yarn made of natural fibers or various chemical short fibers, a blended yarn composed of several kinds of fibers, or a filament yarn directly processed by chemical fiber spinning. . Generally, it can be classified according to the raw materials used for the yarn, the thickness of the yarn, the spinning method, the spinning system, the yarn structure, and the yarn use.

According to the yarn raw materials

  1. Pure spinning yarns Pure spinning yarns are yarns spun from a fibrous material such as cotton yarn, wool yarn, hemp yarn and crepe spinning. Such yarns are suitable for making pure textiles.

  2. Blended Yarn Blended yarn is a yarn spun from two or more types of fibers, such as a blend of polyester and cotton, a blend of wool and viscose. Such yarns are used to emphasize the advantages of both fibers.

Subdivided by yarn

  1. Coarse yarn: Coarse yarn refers to yarns of 32 tex or more (inch 18 lbs and below). Such yarns are suitable for thick fabrics such as tweed, cheesecloth, and the like.

  2. Medium special yarn: Medium special yarn refers to yarn of 21~32 special (19~28 inch in inch). Such yarns are suitable for medium thick fabrics such as medium flat cloth, gabardine, khaki and the like.

3. Fine yarn: Fine yarn refers to the yarn of 11~20 special (29~54 inch in inch). Such yarns are suitable for thin fabrics such as fine cloth, poplin and the like.

4. Extra fine yarn: The special fine yarn refers to a yarn of 10 tex or less (inch British and above). These yarns are suitable for high-grade fine fabrics, such as high-branched shirts, worsted sweaters, etc.

According to the spinning system

  1. Worsted Yarns Worsted yarns, also known as combed yarns, are yarns that are spun through a combing process, including combed cotton yarns and combed wool yarns. The fibers in the yarn have high parallel straightness, uniform and smooth strips, but the cost is higher and the yarn count is higher. Combed yarn is mainly used in the raw materials of high-grade fabrics and knitwear, such as fine spinning, gabardine, tweed, sweater and so on.

  2. Woollen yarns Woollen yarns, also known as carded or carded cotton yarns, are yarns that are carded in a general spinning system and are not spun. The wool has a large amount of short fibers, and the fibers have poor parallel straightness, loose structure, many fur, low yarn count and poor quality. Such yarns are mostly used for general fabrics and knitwear raw materials, such as woollen fabrics, medium and above cotton fabrics, and the like.

3. Waste spinning yarn Waste spinning yarn refers to yarn spun from textile waste (waste cotton) or mixed with low-grade raw materials. The yarn quality is poor, soft, uneven, dry, and poor in color. It is generally used to weave low-grade fabrics such as coarse cotton blankets, terry cloth and packaging fabrics.

According to the spinning method

  1. Ring Yarn Ring yarn refers to a yarn made by twisting on a ring spinning machine by a conventional spinning method. The inner and outer fibers of the yarn are wound and joined, and the yarn structure is compact and high in strength. However, since the twisting and winding work is performed by a mechanism at the same time, the production efficiency is limited. These yarns are versatile and can be used in a variety of fabrics, braids, and cords.

  2. Free end yarn free end yarn means that the fiber is coagulated and twisted into a yarn in a high-speed rotating rotor flow field or in an electrostatic field, and the twisting and winding of the yarn are respectively performed by different components, thereby achieving efficiency High and low cost.

(1) Airflow yarn: Airflow yarn, also called rotor spinning, uses a gas stream to coagulate and output the yarn into a spinning cup that rotates at a high speed. The yarn structure is more fluffy, wear-resistant, uniform in strip, and more vivid in dyeing than the ring yarn, but the strength is lower. Such yarns are mainly used for bulky and flat cloths in woven fabrics, flannels and knitwear with good hand feel.

(2) Electrostatic yarn: An electrostatic yarn is a yarn obtained by agglomerating and twisting fibers by an electrostatic field. The yarn structure is the same as the air flow yarn, and the use is similar to the air flow yarn.

(3) Vortex yarn: The vortex yarn is a fixed vortex spinning tube instead of the yarn spun from a high-speed rotating spinning cup. There are many bending fibers on the yarn, low strength, poor uniformity of the strip, but good dyeing and abrasion resistance. Such yarns are mostly used in pile fabrics such as fleece, sportswear and the like.

(4) Dust cage yarn: Dust cage yarn, also called friction spinning yarn, is a yarn that is agglomerated and twisted by a pair of dust cages. The yarn has a layered structure, the yarn core has a large twist, the hand feels hard, the outer layer has a small twist and the hand feels soft. These yarns are mainly used in industrial textiles, decorative fabrics, and also in outer garments (such as overalls, protective clothing).

3. Non-free end yarn: Non-free end yarn is another yarn that is spun by a new spinning method different from free end yarn. That is, in the process of twisting the fiber, both ends of the fiber strip are held, not free. end. This new type of yarn includes self-twisting, air-jet yarns and core-spun yarns.

(1) Self-twisting yarn: Self-twisting yarn is a kind of new yarn of non-free end. It is a false twist applied to the two yarns by the reciprocating roller. When the yarn is in parallel, the force of the turning back is reversed. Twisted into each other. This yarn has a non-uniform twist and a flawless section on one of the yarns, so that the yarn strength is low. It is suitable for the production of wool yarn and chemical fiber yarn, and is suitable for use on flower fabrics and suede fabrics.

(2) Air-jet yarns Air-jet yarns are yarns that are spun by twisting and kinking by applying a high-speed jet vortex generated by compressed air. The yarn structure is unique, the yarn core is almost flawless, the outer fiber is randomly wrapped, the yarn is loose, the hand feels rough, and the strength is low. These yarns can be used to process woven and knitted fabrics for men's and women's tops, shirts, sportswear and overalls.

(3) Core-spun yarn: The core-spun yarn is a kind of yarn which is spun with a filament as a core and is wrapped with short fibers, and has the advantages of both the core filament and the outer short fiber, so that the yarn-forming performance exceeds that of the single fiber. Commonly used yarn core filaments are polyester yarn, nylon yarn, spandex yarn, and outer staple fiber is commonly used for cotton, polyester/cotton, acrylic, wool, and the like. Core-spun yarns are currently mainly used as sewing threads, shirt fabrics, burnt fabrics and stretch fabrics.

By yarn structure

  1. Single yarn: Single yarn refers to a yarn that has only one bundle of fibers. The raw material may be spun into a pure spun yarn to constitute a pure woven fabric, or a blended yarn may be composed of two or more kinds of raw materials, thereby constituting a blended woven fabric.

  2. Strand: A strand is a strand of two or more single yarns twisted together. Its strength and wear resistance are better than single yarn. At the same time, the stocks can also be combined and combined in a certain way to obtain retracement lines, such as double-strand, triple-strand and multi-strand. Mainly used for sewing thread, braided thread or medium-thick sturdy fabric.

3. Monofilament: The monofilament is composed of a filament of fiber. The diameter depends on the thickness of the filaments. Generally used only for processing thin fabrics or knitted fabrics, such as nylon socks, veil and the like.

4. Textured yarn: The textured yarn is obtained by deforming the synthetic fiber filaments from straightening to curling, also known as textured or processed yarn. The textured yarn includes a high elastic yarn, a low elastic yarn, a bulked yarn, and a network yarn.

(1) High elastic wire: High elastic wire or high elastic textured yarn has high flexibility and bulkiness. Mainly used for stretch fabrics, mainly nylon high elastic yarn.

(2) Low elastic yarn: Low elastic yarn or deformed elastic yarn has moderate stretchability and bulkiness. Mostly used for knitted fabrics, with polyester low-elastic yarns.

(3) Expanded yarn: The expanded yarn has low stretchability and high bulkiness. It is mainly used for fabrics that require bulkiness such as wool, underwear or outerwear. The typical representative is acrylic expanded yarn, also known as cashmere.

(4) Network wire Network wire, also known as symmetry wire, is formed when the chemical fiber is not formed, so that some of the wires are held together. This silk is soft, bulky, and has a good hair-like effect. It is mostly used in women's styles. The popular golf in recent years is also woven with this silk.

6. Fancy Yarn: Fancy Yarn refers to a yarn that has a special appearance, feel, texture and texture by various processing methods. There are three main categories:

(1) Color line: Color line refers to the yarn which is mixed into the fiber of the base yarn in a certain proportion, so that the yarn has bright length, different size and color, such as color line, rainbow line, etc. . This type of yarn is mostly used in women's and men's jackets.

(2) Fancy line: The fancy line is a yarn having various appearance characteristics obtained by the principle of overfeeding, such as a circle line, a bamboo line, a spiral line, a knot line, and the like. The fabric woven by such yarns is fluffy, soft, warm, and has a unique appearance and strong three-dimensional effect. It can be used for both thin summer fabrics and heavy winter fabrics, both for clothing and fabrics. Make decorative materials.

(3) Special fancy line: Special fancy line mainly refers to gold and silver wire, chenille line and so on. The gold and silver wire mainly refers to a gold and silver wire obtained by sandwiching an aluminum sheet between polyester film sheets or steaming on a polyester film. It can be used on both fabrics and decorative sewing threads to make the fabric surface shiny. The chenille thread is a special fancy yarn that holds the fiber on a plied core yarn in the form of a bottle brush. It is soft to the touch and is widely used in flocking fabrics and tassel fabrics.

According to yarn use

  1. Woven yarn: Woven yarn refers to the yarn used in the processing of woven fabrics, divided into warp yarns and weft yarns. The warp yarn is used as the longitudinal yarn of the fabric, and has the characteristics of large twist, high strength and good wear resistance; the weft yarn is used as the transverse yarn of the fabric, and has the characteristics of small twist, low strength and softness.

  2. Knitting yarn: Knitting yarn is a yarn used for knitwear. The yarn quality is higher, the twist is small, and the strength is moderate.

3. Other yarns: including sewing thread, embroidery thread, knitting thread, miscellaneous thread, etc. The requirements for these yarns vary depending on the application. Among them, the sewing thread and the knitting line will be described in the fourth section below.

Section III Properties of Yarns for Clothing

First, why should we understand the spinning principle?

The yarn is an intermediate of the fabric made of fiber. The concept of yarn gives us the inspiration that the yarn consists of fibers and the fibers are tightly combined in a certain way. Then, how do fibers become yarns, which processes need to be processed, and how do the processed yarns judge their quality? The correct answer to these series of questions must be based on the basic principle of spinning, based on the basic structure of the yarn, and based on the understanding of the effect of yarn on the clothing material.

Second, the basic principle of spinning

  1. Opening and combing: The tightly packed fibers are opened, mixed, and combed to remove impurities, and the fibers are straightened in parallel and formed into slivers.

  2. Combined drafting: The prepared fiber strips are subjected to a plurality of lamination and drawing and drawing to make a roving having a desired thickness and a certain uniformity.

3. Twisting winding: On the spinning frame, the roving is further drawn while being twisted and wound on a spindle to obtain a yarn having a certain strength.

Third, the traits and effects of ordinary yarn (conventional yarn)

The properties of the yarn are determined by the fiber properties and yarn structure of the constituent yarns. The properties of the fibers have been described above, and the structural characteristics of the yarns and their taking properties are described here.

  1. Yarn twist

Twisting is one of the purposes of spinning. The amount of twisting is an important indicator of yarn performance, generally expressed in degrees (as shown). The twist refers to the number of twists per unit length of the yarn (ie, the number of turns). The unit length varies depending on the type of yarn. The unit of measurement can be expressed as “trist/10cm” or “trist/m”. The former is used for cotton and cotton type chemical fiber yarns, and the latter is used for worsted yarns. The measurement of the twist of the chemical fiber filament yarn. The twist affects the strength, rigidity, elasticity, shrinkage and other indicators of the yarn. As the yarn twist increases, its strength increases, but the twist does not exceed a certain value, otherwise its strength decreases, which is called the critical twist of the yarn. The yarns of different raw materials have different critical twists. The softness, elasticity and shrinkage of the yarn are also closely related to the twist. Generally, under the premise of meeting the strong requirements, the yarn twist is as small as possible, because the increase of the twist will make the yarn feel harder, the elasticity will decrease, and the shrinkage rate will increase. This is why the filament yarn is generally not applied as much as possible. Or less because of the blasphemy. In addition, the twist also affects the volumetric weight and diameter of the yarn, and the twisting effect increases the tightness of the yarn. Within a certain range, the volumetric weight of the yarn increases with the increase of the twist, and the diameter of the yarn decreases with the increase of the twist, thereby changing the coverage and comfort of the fabric.

In summary, yarn twist should be selected for different fabric applications. If the warp yarn needs to have higher strength, the twist should be larger; the weft yarn and the knitting yarn should be soft and the twist should be smaller; the yarn for weaving and knitting the pile fabric should be smaller, so as to facilitate the napping; The crepe fabric is required to have the characteristics of slippery, firm and cool, and the twist of the yarn should be larger.

  2. Yarn orientation

The twisted twist is directional, called the slanting direction, that is, the oblique direction of the fibers in the twisted yarn or the inclined direction of the single yarn in the twisted strand. The two directions are divided into two types: Ztrist and Strist. If the single yarn in the single yarn is twisted, the tilt direction is from bottom to top, and the right to left is called Strist, also called right hand or right hand; if the tilt direction is from the bottom On the left, from left to right, called Z trist, also known as left-handed or left-handed. As shown on the right. The direction of the representation is specified. The single yarn can be expressed as: Ztrist or Strist. In actual use, the single yarn is mostly Ztrist; the strand is the same or opposite to the single yarn because of its twist. The two directions must be expressed, so it can be written as follows: the first letter indicates the direction of the single yarn, and the second letter indicates the direction of the strand. After two twisted strands, the third letter indicates the reversal. For example, the single yarn is Z trist, the initial trist is S trist, the trist is Z trist strand, and its trist is expressed as ZSZ trist. In fact, when the strands are twisted in the opposite direction to the single yarn, the yarn is twisted.