Features of the production of knitwear. The technical process of making knitwear

01.10.2019

Knitwear production technology

Knitwear is a textile fabric or a product obtained by knitting, therefore any knitted material is a system of loops connected in the longitudinal and transverse directions.

Knitted fabric consists of two perpendicularly intersecting yarn systems. The longitudinal threads are called the warp, and the transverse threads are called the weft. The primary element of the knit fabric is the buttonhole. It is a spatial curve, the shape of which affects the properties of the canvas. The shape of the loops is varied: round, wide, narrowed, elongated.
In height, loops of normal size, reduced and enlarged, are distinguished. The higher the loop and the more straightened the thread, the brighter the canvas appears as a result of directional light reflection.

The loops, connecting with each other horizontally, form looped rows, vertically looped columns. The distance between the centers or points of the same name of two adjacent loops along the line of the stitch row is called the loop step.
Knitwear is divided into warp knitting and jersey knitting. In warp knitting, each thread forms one loop in the stitch row and goes to the next row. In kulirny jersey, each thread sequentially forms loops of one stitch row. One thread is enough to form one stitch row of knitted fabric.
To form a stitch row in warp knitwear, as a rule, as many threads are required as there are loops in the stitch row.
Knitting and warp jersey can be either single or double. Single jersey is produced on machines with one bed, and double jersey is made on machines with two bed.

According to the classification, all knitted weaves are divided into main (weaves having the simplest structure) and derivatives (a combination of several identical main weaves, mutually knitted so that looped posts of another of the same weave are placed between the looped posts of one weave). On the basis of each of the classes of these groups, it is possible to form patterned and combined weaves (weaves, which consist of weaves of several classes).

To obtain fabric in the simplest case, two systems of threads (warp and weft) are required. Knitwear can be knitted entirely from one thread. And also jerseys can be made in the following ways:

Cutting
Semi-regular
Regular

The cutting method consists in the fact that the knitted fabric is cut out, i.e. cut out parts of products from it according to patterns and connect them on a sewing machine, giving the products the desired shape. This method is used to make linen and tops, as well as most of the glove products. This method of manufacturing products is characterized by significant waste of knitted fabric, reaching 18-23% when cutting linen products and up to 25-28% when cutting upper products. This technology is used for inexpensive mass-produced garments and underwear knitwear. The positive for this method is the ability to manufacture products of various models and high productivity of knitting machines.

The semi-regular method differs from the previous one in that the knitted fabric is knitted on a circular knitting machine in the form of tubular coupons. The coupons are separated from one another by means of a dividing stitch row so that the bottom edge of the coupon has a one-piece non-opening stitch row that does not require sewing processing. The consumption of knitted fabric for a product with a semi-regular manufacturing method is 3-5% less than with a cutting method due to the absence of side seams and allowances for the hem of the bottom of the product; in addition, less time for cutting and sewing processing by 8-10%.

The semi-regular method is most common in the manufacture of outer knitwear, and can also be used for the manufacture of women's underwear if the necessary knitting equipment is available. Products made in this manner have the great advantage of achieving the best fit and fit for the product.

A regular way of making a product is that the products are knitted entirely without seams, or individual parts are knitted along the contour, and then sewn with a chain stitch. This method is characterized by the most economical use of raw materials. However, knitting parts of a product requires more labor than knitting in a semi-regular way. This method is used when knitting upper garments made of expensive materials.

The last two technologies are most applicable in exclusive small-scale production, since they make it possible to achieve high quality products, a maximum range of products and quick change of models.

Raw materials used in the production process. Requirements for its quality.

Raw materials are one of the main factors that shape the quality of knitwear. Currently, knitwear enterprises process practically all types and varieties of fibers and yarns obtained from them.
Filaments are composed of short or long filaments of various natures. They are divided in the transverse direction into their constituent parts - fibers by untwisting.

By the type of raw materials used, knitted fabrics and products are divided into three groups:
· From yarn - this is a thread consisting of short fibers formed as a result of twisting;
· From threads, consisting, as a rule, of long monofilaments and having different twists;
· From various combinations of yarns and threads.

At present, knitwear is used to process all types of raw materials, including yarn from natural silk fleece and from flax fibers mixed with synthetic ones; use threads of various thicknesses and degrees of twist. Mainly, yarns and threads of mixed fibrous composition are used, which ensures good hygienic properties of fabrics, less shrinkage and wrinkling, and good wear resistance.

Linen fabrics are produced mainly from cotton, cotton-lavsan, cotton-polinose, cotton-viscose yarns, as well as from viscose, acetate and polyamide complex yarns. A number of canvases are produced from half-woolen and pure-woolen yarns. Cloths for knitted outerwear are made from all types of raw materials; hosiery - mainly from polyamide threads, cotton and wool blend yarns.

Depending on the purpose of the canvases, threads of different structures are selected: yarn of various spinning methods and degrees of twisting, complex yarns from chemical raw materials, single and twisted, shaped twists, textured yarns, and in different combinations - twisted yarn with complex yarns, textured yarns with yarn etc.
Thin and smooth threads from chemical raw materials are used for fabrics with increased surface smoothness (front and back), which should easily slide over the surface of leather and outerwear. These are linen, blouse and forties. The shiny surface of the threads emphasizes the effect of shiny and matte stripes and shades. From threads of increased bulk - textured - webs are obtained with a relief surface, increased thickness with a small mass of 1 m2. Thick, loose yarns are used for combing fabrics for warm linen or sportswear.

The yarns and threads of increased twist give the fabric stiffness; the loop structure of such knitwear is uneven due to the increased tension of the thread when bending into loops, the curling of the edges of the fabric increases, but its surface is less loose, more wear-resistant. Twisted yarns and threads are pretreated (steamed, stabilized, oiled) in order to balance their structure and relieve stress.

The yarn with the best properties cannot be considered satisfactory if it does not meet the requirements of the manufactured product or is not prepared for processing on equipment in modern production conditions.
Incomplete readiness of raw materials for processing adversely affects not only the quality and grade of products, but also the performance of the enterprise and the use of technology.

The wide range of requirements for raw materials for knitwear is explained by the very wide variety of products themselves. For example, requirements for the structure of the thread are imposed, starting from nylon monofilaments for thin stockings and ending with loose woolen and synthetic yarns for pullovers and jackets.

The properties of the yarn for knitting production are determined by studying the structure of the loops, the deformation of this structure, i.e. considering, first of all, the mechanical functions of the thread in the knit loop.
If we imagine schematically a thread that is round in cross-section, then with an increase in the diameter of the thread, its resistance to bending will increase significantly. We are interested in increasing the diameter of the thread without increasing the number of fibers in the cross section. This is quite possible if the threads are betrayed by a loose structure. The loose structure of the yarn has many advantages, the main ones of which are: 1) an increase in elastic resistance to bending and the ability to better restore the shape of the loop during deformations; 2) high stiffness, which allows the use of threads of lower linear density (by 10-15%) without increasing the knitting density (reducing the length of the thread in the loop) and therefore without reducing the productivity of knitting machines; 3) lightening the weight of the product and giving it a pleasant softness to the touch; 4) increasing the thermal insulation properties of products; 5) improvement of the yarn processing ability on knitting machines.

The thread (yarn) of a loose structure is especially necessary for the manufacture of outer knitwear. For underwear that should fit the body well, you need not a rigid thread, but a very flexible one, consisting of thin fibers, but a loose structure that can maintain the shape of a loop. For winter hosiery, a thread of a loose structure is needed, and for most other hosiery, a thread that is denser, twisted is desirable. For women's stockings, the thickest thread is preferable, such as monofilament, with minimal stippling so that the stocking looks thinner.

The loose structure of the yarn is achieved due to the reduced twist, which is associated with a decrease in the strength of the yarn. If for fabric strength is the main property of the thread, then for knitwear this property is of secondary importance.
For knitwear, yarn evenness in thickness and twist is more important than for fabrics.
The structure of the knitted loops is such that a short piece of thread bends several times, intertwining with itself and forming loops located next to each other. The thread in each loop seems to fold in half, which is why its unevenness becomes pronounced. A group of loops is formed from a thickened or thinned section of the thread, which is easily distinguishable from adjacent ones. With periodic unevenness of the thread, a defect is obtained, known as zebrism.

Thus, the requirements for raw materials for the evenness of the thread are based on the structural features of the knitwear loops.
Among the most important requirements for raw materials, one cannot fail to point out the resistance of the thread to friction. The elasticity of knitted fabric loops during deformation is associated with the friction of the threads against the thread (when the shape of the loop changes) and the friction of the fibers between themselves (when the thread is bent). Friction resistance in this case plays a very significant role. It can be reduced by reducing the coefficient of friction and improving the condition of the thread surface, which is achieved by waxing or emulsifying the thread, which reduces the coefficient of friction of the thread on the thread and on the thread guiding organs of knitting machines.

The smoothness of the thread surface, its purity, the absence of impurities, bumps, knots are necessary not only for the normal course of the thread processing process, but also to give the knitwear elasticity, dimensional stability, and good appearance. Some knitwear specialists argue that the finishing of knitwear is designed to improve the properties of the raw materials or to correct their deficiencies. It is not right. A knitted fabric is formed from the thread, and the properties of the knitted fabric primarily depend on the initial properties of the thread. For the production of good products, finishers must receive harsh knitwear of full-fledged properties.
The considered requirements are common for all types of yarns intended for the production of knitwear.

However, they do not exhaust all the requirements for raw materials. For example: yarn that does not meet the requirements of knitwear production includes: underwired cobs, which lack yarn for more than 30% of the forging weight, yarn on broken containers, frayed, mixed numbers, covered with mold, soiled, oily, of different shades.
External defects of yarn on skeins include: tangled and torn threads, foreign and oily threads, loose ends, large knots, thickening and thinning of the thread, bumps, shades of color.

Determination of external defects of raw materials is carried out by visual inspection of the surface of the packages (bobbins, skeins) or by winding the yarn on a screen board. The variability of the yarn is determined by counting the number of defects at a certain length in comparison with the standards established in the corresponding GOSTs. The procedure for checking all types of raw materials is carried out in accordance with GOST 6611-55 “Yarn and textile threads. Test methods ".

All types of threads and yarns are checked for the following basic physical and mechanical properties: thickness, strength, twist (number of twists per 1 m), moisture (% to absolutely dry weight). The physical and mechanical properties of raw materials should be checked under certain conditions of humidity and temperature of the room in which the test is carried out. In GOST 10681-63, these conditions are defined: temperature -20 + 8 0С, relative humidity -65 2%.

According to the current GOSTs, the following winding density indicators are established: for viscose silk within the range of 0.7-0.8 g / cm3. The density of the winding of cotton, woolen and semi-woolen yarn is not regulated by GOSTs.
Yarn that does not meet the requirements of this standard can be used for other industries, provided that the requirements established for this industry are met.

The work contains: 25 pages, 3 tables, 1 block diagram.

Key words: technological process, thread, cloth, knitting, cutting, detail, sewing, product, quality.

The aim of the work is to study the main processes carried out in the process of knitwear production.

The technology of knitwear production has been studied and described. It also provides information about the equipment used in the manufacture of products, and notes the main requirements for the quality of finished products.

Introduction 3

1. Description of the theoretical foundations of the technological process of manufacturing knitwear. 4

2. Raw materials used in the production process.

Requirements for its quality. 6

3. Technology for the production of knitwear. ten

4. Information about the equipment used in the process

production of knitwear. 15

4.1. Equipment used in the process

knitting fabric. 15

4.2. Equipment used in the process

sewing products. 16

4.3. Ancillary equipment. 17

5. Requirements for the quality of the finished

products and methods of its control. eighteen

6. Standards for the rules of acceptance, testing, storage

and the operation of the product. 21

Conclusion. 24

List of used literature. 25

Introduction

For the production of clothing, various materials are used, which are divided into the main components of the top and lining; applied, used to create a frame, a rigid form, strengthen parts; heat insulating; connecting; fittings and finishing.

The main materials used are fabrics, knitted fabrics, woven, film and layered materials of various fibrous composition and structure, artificial furs and leather. The industry mainly manufactures clothing from fabrics and knitted fabrics. According to the raw material composition, they are divided into cotton, woolen, silk, linen, according to their intended purpose, into coats, suits, dresses, shirts, underwear and lining. Different requirements are imposed on the appearance, hygienic properties of these materials, resistance to various influences. So, the materials used for the details of the top of the coat must have a beautiful appearance, sufficient resistance to abrasion and crushing loads; lining - good abrasion resistance, hygroscopicity, vapor and air tightness.

Knitted items include products obtained from threads (yarns) by machine or hand knitting.

Some jerseys are completely knitted on machines (stockings, socks, scarves, mittens, etc.), others - linen, most outer knitwear, gloves - are sewn from knitted fabric made (knitted) on machines.

According to the purpose of the manufactured products, the knitwear industry is subdivided into the following types of production: knitted underwear and underwear, hosiery, glove, technical cloth and medical products.

The knitted product is characterized by great stretch and plasticity, which makes it possible to achieve a feeling of lightness and comfort.

1. Description of the theoretical foundations of the technological process of manufacturing knitwear.

Knitwear is a textile fabric or a product obtained by knitting, therefore any knitted material is a system of loops connected in the longitudinal and transverse directions.

In height, loops of normal size, reduced and enlarged, are distinguished. The higher the loop and the more straightened the thread, the brighter the canvas appears as a result of directional light reflection.

Knitwear is divided into warp knitting and jersey knitting. In warp knitting, each thread forms one loop in the stitch row and goes to the next row. In kulirny jersey, each thread sequentially forms loops of one stitch row. One thread is enough to form one stitch row of knitted fabric. To form a stitch row in warp knitwear, as a rule, as many threads are required as there are loops in the stitch row.

Knitting and warp jersey can be either single or double. Single jersey is produced on machines with one bed, and double jersey is made on machines with two bed.

To obtain fabric in the simplest case, two systems of threads (warp and weft) are required. Knitwear can be knitted entirely from one thread. And also jerseys can be made in the following ways:

Cutting

Semi-regular

Regular

2. Raw materials used in the production process. Requirements for its quality.

Raw materials are one of the main factors that shape the quality of knitwear. Currently, knitwear enterprises process practically all types and varieties of fibers and yarns obtained from them.

Filaments are composed of short or long filaments of various natures. They are divided in the transverse direction into their constituent parts - fibers by untwisting.

By the type of raw materials used, knitted fabrics and products are divided into three groups:

· From yarn - this is a thread consisting of short fibers formed as a result of twisting;

· From threads, consisting, as a rule, of long monofilaments and having different twists;

· From various combinations of yarns and threads.

Technological process "Production of knitwear"

Because there are many types of knitwear and each type has its own characteristics in manufacturing, we will consider the manufacture of knitwear using the example of linen knitwear.

In the manufacture of linen knitwear, the following technological transitions are envisaged: quality control of raw materials, packaging of raw materials, knitting of the fabric, preparation of the fabric for cutting, overlapping the flooring, cutting the fabric, completing cut parts, sewing knitwear, technical control.

Quality control of raw materials. Raw materials received at the warehouse of a knitwear enterprise are evaluated by their appearance. Samples of raw materials are tested in a laboratory to determine physical and mechanical parameters. The methods of testing raw materials and the types of their defects must comply with those specified in the current regulatory and technical documentation.

Packing of raw materials. After laboratory tests, raw materials are delivered in batches to workshop warehouses in boxes, boxes or other containers. In the workshop warehouse, raw materials are unpacked and packaged. The packaged raw materials are fed to knitting machines. Reels with defective winding found during packaging are set aside for rewinding.

Knitting fabric. Before knitting, the threads should be kept in storage for at least 10 hours under normal climatic conditions. The fabric is knitted by machines in accordance with the filling data. The knitting density is measured on the machine in the free state of the fabric. Pieces of fabric from threads of the same linear density are knitted of the same weight (10-12 kg) with deviations not exceeding 5%.

The quality of the fabric in the knitting process throughout the shift is monitored by the knitter and the assistant to the master. The knitter is obliged to keep the machine clean - clean it every shift.

Preparation of the canvas for cutting. After finishing, the knitted fabric is sent to the departments for preparing the fabric for cutting, in which they carry out: reception of the fabric and applied materials; grading of the canvas, i.e. the canvas is viewed on the machine from both sides to determine its quality and identify defects; storage (tracking) of the canvas; selection of fabrics according to articles and widths; completing canvases for flooring; stencil preparation; preparation of applied materials and their issuance for cutting; calculation of the cutting plan for each flooring.

The canvas is supplied to the preparation department in batches, i.e. according to articles, colors and calculated widths. The pieces of fabric selected for the flooring are fed to the cutting shop along with the cutting map and the prepared stencil.

Decking of the flooring. Chamfering of the upper layer of the flooring, or drawing the contours of the cut parts on the upper layer of the flooring, is performed in two ways: by patterns and by a stencil.

When overlapping along the patterns on the upper layer of the flooring, in accordance with the sketch of the layout, lay out the patterns in such a way that the area of the canvas is used most efficiently.

When using a stencil, the patterns laid out on it are traced along the contours, on which through holes are then applied. Stenciling consists in the fact that a stencil is applied to the top layer of the flooring and the holes of the contours of the patterns are powdered with powder - chalk or talcum powder.

Cut the canvases. The cutting of the canvas is preceded by the operation of laying the canvas and cutting it into sections.

Warp-knitted fabric is laid in a turn or fold. Laying folds are used when cutting products in small batches. Reversal laying provides a more economical use of the canvas in comparison with fold laying due to the rational arrangement of product patterns over a large width of the canvas; in addition, this method facilitates the control of the web.

The web is laid by machine and manually. The flooring of the canvas is cut by mobile cutting machines with straight and circular knives and stationary draw frames.

During this operation, the following requirements must be met:

§ Cloths of fabrics in the flooring should be located freely, without tension and distortions, but also without slack and wrinkles, otherwise the cut details may be deformed;
§ The pattern in all canvases of the flooring must be the same in length and width, otherwise the symmetry of the pattern in the finished product is disturbed;
§ The direction of the pile in all sheets of the flooring must be the same so that in all parts of the finished product the pile is directed in one direction.

Cutting the web is a complex and responsible operation. It is possible to ensure high quality of cutting when cutting the flooring only if the following requirements are met:

§ High accuracy of cutting: deviation from the contours of parts should not exceed cm;
§ Contours of parts should not be skewed;
§ Good cut quality, i.e. the frequency of the edges of the cut parts.

The quality control of the cut is carried out according to the control patterns by combining with them cut out parts from the flooring. Usually check the top, bottom and one or two parts from the middle of the pack.

Acquisition of cut parts. After inspection and sorting, the cut parts are assembled into bundles. At the same time, they are examined, disassembled by colors and shades, trimmed in those places where they cannot be cut by machines in the flooring, and inaccuracies in mechanical cutting are corrected.

The end product of the cutting shop is a set, i.e. a pack of details selected according to the article of the canvas, color, shade and pattern.

The complete packs are stacked in such a way that all small parts of products and applied materials are collected in dozens and neatly tied. The bundles are sent to sewing machines.

Knitwear sewing. Sewing processes cover a whole range of operations, which are mainly divided into the following: sewing, wet-heat and auxiliary.

Sewing operations include not only operations on joining parts of products with stitches to give them a certain shape, provided by the design, but also operations on sewing buttonholes, sewing on buttons, stitching braids and laces, embroidery, etc.

Sewing operations are performed on various types of sewing machines.

In the sewing workshops of linen production, such an organization system is used as a line one. It is characterized by the following main features:

§ The technological process of manufacturing products is divided into separate technologically indivisible operations, performed, if necessary, on various equipment;
§ Each performer is assigned a so-called organizational operation, which includes one or several technologically indivisible operations;
§ Workplaces and equipment are located along the technological process of sewing the product;
§ The processed product or pack of products is transferred to each subsequent operation after the end of this operation;
§ Operations are performed synchronously at all workstations of the flow in accordance with the established rhythm of the movement of products.

The flow system of organization, depending on the degree of rhythm of work, in turn, is subdivided into discontinuous flow and continuous flow.

With a discontinuous flow system, products follow from one workplace to another as several products are processed by performers; the sewing conveyor belt serves only for the delivery of products from one workplace to another, or is not used at all.

In a continuous-flow system, each product enters the next operation immediately after the end of the previous one; the speed of the belt is linked to the duration of operations at each workplace, and the belt itself serves not only to deliver products from one workplace to another, but also to maintain a uniform rhythm of the entire conveyor process.

Wet-heat treatment of linen is carried out using presses, steam-air dummies, and irons. It includes such operations as: ironing (seam allowances are smoothed on two sides) and ironing (seam allowances are smoothed on one side), steaming (processing the surface of the product with steam to remove shiny areas of the fabric), ironing.

One of the requirements for the manufacture of clothing is the accuracy and high quality of wet-heat treatment, which guarantees the absence of wrinkles, creases and opals of the product.

Ancillary operations include sewing on labels, sorting products, cleaning finished products from thread ends, and packaging products.

Technical control. It is performed at all technological transitions in the manufacture of products from linen and coupons. The tasks of technical control are checking the compliance of the indicators of raw materials and materials supplied to the enterprise with the indicators of current standards and technical conditions, checking the quality of technological operations and the quality of linen and coupons in the production process.

The production of knitwear includes a number of sequential operations: design of knitwear; preparation of yarn and threads for knitting, knitting of a knitted fabric or product, cutting, joining of knitted products, wet heat treatment and finishing.

Design of knitwear consists of modeling and design operations. However, when designing knitwear, the elongation of the knitted fabric must be considered. In terms of extensibility, the canvases are divided into four groups: canvases with extensibility up to 40%, from 40 to 70, over 70 and over 100%. Taking into account the group of extensibility of the canvases, the issue of allowances is being resolved. So, for the first group, allowances for free fitting should be positive, and for the fourth - negative. In addition, it should be borne in mind that when stretched, the knitted fabrics become shorter in the direction of the buttonhole posts. For example, the narrowing of the back and front for a sweater made from fabrics of the third group should not be more than 4 cm. The inter-height difference in knitted clothes depends on the type of product.

Preparation of yarns and threads for knitting consists in checking their quality, rewinding, moistening, emulsifying and para-finishing. Natural fiber yarn is waxed to make it smooth. Blended yarns and filaments are emulsified to give them softness and flexibility. Moistened yarns have higher knitting properties, reduce breakage and reduce needle breakage. The yarn used for the production of warp knitted fabric is warp knitted. For this purpose, it is wound on separate coils, which are then installed on a common shaft, forming a beam.

Straight and niches used for the manufacture of knitwear, differ in fiber composition, structure, spinning method, thickness, structure and finish. Yarns and yarns made by different methods can vary in twist, count, appearance and properties.

All types of textile yarns and threads are used for the production of knitwear.

The structure of the yarn can be single-strand, twisted, woven, textured, shaped. Monofilament yarns are made up of monofilaments that do not split longitudinally without breaking. Twisted yarns and threads are composed of two or more twisted threads. Spun yarns and threads are composed of two or more folded threads.

According to the spinning method, cotton yarn is divided into combed, carded, and hardware. Woolen yarn can be combed and made from hardware. Blended yarn is widely used for knitting knitwear. The yarn of various fibrous composition gives the knitted products a variety of consumer properties: softness, silkiness, strength, abrasion resistance.

By the type of finish, the yarn is harsh, dyed, bleached, mottled (consisting of fibers dyed in different colors), multicolor, wigone, pile, mercerized, sour, etc.

For yarn and threads used in knitting production, certain requirements are imposed on uniformity

Chapter 4

Jerseys

thickness and twist, strength, color. The yarn and thread must be soft, flexible, stretchable and free from defects.

Knitting of knitted fabrics and products carried out on knitting machines. The productivity of knitting machines is several times higher than that of weaving machines, the labor and costs of knitting are lower, and the working conditions are much better due to the low noise level. Therefore, the production of knitted fabrics has better technical and economic indicators than weaving.

Knitted machines are classified according to the principle of knitwear production, the shape of the needle beds, the number of needle beds, the type of knitting needles, design features, purpose, etc.

According to the principle of obtaining knitwear, machines are divided into cross-knitting (kulirny) and warp knitting. According to the number of needle beds, machines are available with one needle bed (single-circuit) and two beds (double-circuit).

The design of the working bodies depends on the type of web or product and the looping process. Hook and tongue needles are most common in knitting machines.

According to the shape of the needle beds, the machines are flat knitting and circle knitting. Flat knitting machines are used to produce met-razhnaya fabrics and product details. On circular knitting machines, the needle beds are in the shape of a cylinder, they knit fabrics in the form of a tube, hosiery, etc.

The distance from the geometric center of the needle to the center of the next needle is indicated as needle step knitting machine.

The number of needles per unit length of the needle bar is called knitting machine class. The higher the class, the more needles per unit of length, the thinner the needles should be, the thinner the fabric produced.

The properties of knitwear are determined by two main factors: the properties of the threads from which the knitwear is formed, and the structure of the knitwear. The shape and length of the thread in the loop, the relative position of the loops depend on the conditions of their formation on the knitting machine. There is a wide variety of types of knitwear. But the looping processes are based on a single

principle. To form a loop, it is necessary to create a position of the two threads in which one of the threads (new thread) is pulled through the loop formed earlier from the other thread.

Finishing of knitted fabrics. Cloths taken from knitted machines, as well as finished products, individual parts and coupons are finished to improve their appearance and give them a set of necessary properties. Before finishing operations, the fabric is darned, if necessary. The sequence and types of finishing operations used depend on the purpose, the fibrous composition, the structure of the threads, the structure of the canvases.

The complete finishing cycle consists of the following operations: soaking, washing, boiling, bleaching, stabilizing, dyeing, printing, dressing, widening, decating, as well as forming finished products.

The finishing processes in the knitwear industry are similar to the finishing of fabrics. However, the specific properties of knitwear, which are a consequence of its loop structure (increased extensibility, dissipation, etc.), also determine the peculiarities of finishing processes. Finishing operations are carried out with minimum tension on the knitted fabric. Cloths are not treated with a tourniquet, but in a straightened form to prevent creases and wrinkles. The inner surface of the finishing equipment must be smooth so that no puffs, breaks and loops occur.

During preliminary finishing of knitwear - boiling (linen) or rinsing (variegated fabrics, fabrics for upper garments), oily and paraffinic compounds are removed from the surface of the threads, and relaxation processes take place in the materials. As a result of finishing, the threads in the loops come to an equilibrium state, the loop structure of the fabric is aligned and shrinks.

Synthetic knitted fabrics are stabilized. To do this, they are exposed to hot air or saturated steam under pressure at temperatures close to the melting point of the polymer. With this processing, thanks to

Chapter 4

Jerseys

The thermoplasticity of the fibers fixes the shape of the loops and the linear dimensions of the fabric, removes the internal stresses of the fibers, reduces the wrinkle of the knitted fabric and increases its ability to dye.

Finishing pile fabrics, in addition to bleaching, dyeing, printing, drying, teasing, includes such operations as cutting to equalize the length of the pile, polishing the surface of the pile layer, and straightening it. When polishing, the pile cover of the canvas acquires shine, bulk, orientation in a certain direction.

Cloths of textured threads are finished to give them high bulk, elasticity, dimensional stability, and crease resistance. For this purpose, they are steamed, which gives them bulk, washed, dried, stabilized, and then painted. To give high resistance to washing and dry cleaning, the fabrics are finished and antistatic treatment is carried out.

Fabrics used for outerwear, as well as for protection from atmospheric moisture, are subjected to a water-repellent finish.

Features of cutting knitwear. Before cutting, knitted fabrics are kept in a straightened state (lying) under normal conditions (at a temperature of 20 ° C and a relative humidity of 65%). The maturation period depends on the thickness of the knitted fabrics: thick fabrics withstand 48 hours, and thin fabrics - 24 hours. During this time, natural shrinkage occurs in the knitted fabric and the structure of the fabric stabilizes.

Increased extensibility, curling of the edges and other features cause certain difficulties in performing the operations of the cutting process. Canvases made on flat machines are laid in a turn, and canvases from round machines are folded in the form of a sleeve. When laying and cutting, special clamps are used along the edges of the flooring.

Operations of joining parts of knitted products. Thread seams are used to join knitted items. The glue method is used when hemming the edges of products, attaching appliqués.

The seams in knitwear should have a beautiful appearance, be strong and elastic, correspond to the strength and extensibility of the knitted fabric, and should not be unraveled at the cuts. This is best matched by seams with buttonhole stitches.

Buttonhole stitches are characterized by a significant amount of thread in the stitching, this ensures the stretch of the seams. By purpose and appearance, loop stitches are divided into three groups: chain stitches, flat stitches and overcasting.

The most common chain stitches - single-strand and double-strand. One-thread stitch is used on areas of products that are not subjected to significant stretching during wear (for example, a sweatshirt bar), as well as for embroidery. Double thread stitch is used to join the details of regular products, gloves and mittens, for embroidery. Zigzag chain stitches are used for making loops, finishing strapping the edge of the product with air loops (two-thread stitch).

Flat stitches get on machines with two, three, four needles. These stitches are characterized by sufficient strength, good elongation, beautiful appearance, good styling (multi-thread stitches). They are used when performing flat seams (butt, overlap, fold with an open cut) and as finishing seams.

Overcasting stitches the most common. They are used for stitching knitted items with simultaneous overcasting of their cuts. Overcasting stitches have good stretch, elasticity and provide sufficient seam strength. Distinguish between overlock and overlock stitches.

Stitching stitches are mainly used for joining regular knitwear. Overlock two-thread stitches are used to sew parts of regular products when a large overlap of the seams is not required, and also hem the edges of the product. Overlock three- and multi-thread stitches are used to join knitted items with cut and crumbling

Chapter 4

Jerseys

slices. With these stitches, seams with covered edges are obtained. The overlay seams on the seamy side have a thickening (scar). For thinning and at the same time for strengthening, a flat two-needle three-line stitching is applied to the overlock seam.

Kettle stitches They are used to join parts with a loop-to-loop seam (connection with a product of collars, cuffs, beeks, etc.), toe-knit the toes of hosiery, produced on round stocking machines. The joints are stretchable, strong, without thickening.

The edges of the linen are finished with shell stitch, which gives them a beautiful appearance.

Shuttle stitches and stitches in knitwear, they are used mainly for processing parts and knots that are not subject to stretching in the sock (processing strips, collars, woven belts, sewing on zippers, etc.).

The types of seams used in the manufacture of knitwear are almost the same as those used in the sewing industry.

Wet heat treatment of knitwear requires special attention. So, due to the peculiarities of the structure and elastic properties, it is impossible to process knitted products with a high pressure of the ironing surfaces, otherwise the fabric will lose its relief structure and splendor.

The operations of ironing seams, pulling or pressing the edges of parts are performed using irons. Uncomplicated jerseys (T-shirts, women's shirts, combinations, etc.) are ironed on calenders.

For pressing parts of regular and semi-regular products, coupons, finished outerwear and underwear, presses of various designs are used. The cycle of processing products includes moistening them with steam, pressing and cooling. For forming, wire frame forms are used, on which the product is put on before pressing.

Forming and final WTO of finished products is carried out in steam chambers and on dummies. Processing of products in steamed

chambers include heating, steaming and drying. The plant can process several products at the same time. Frame forms can be interchangeable depending on the styles, sizes and heights of products.

Knitted products include clothing made of knitted fabric or knitting threads. The main methods for the production of knitwear include: cutting, semi-regular, regular and all-knitted.

Cutting method consists in knitting a flat knitted fabric on flat knitting machines or tubular - on circular knitting machines, from which parts of a certain size and configuration are cut according to the model (similar to cutting fabric products). The advantage of the method is that models of any complexity can be obtained, the disadvantage is waste when cutting up to 18-25% of knitted fabric.

Semi-regular way involves the manufacture of products from a coupon knitted fabric of tubular or flat form, obtained from flat and circular knitting machines.

The width of the coupon is equal to the width of the part, or the part is stacked an integer number of times in the coupon (Fig. 14).

Figure 14. Form of coupons and details for the manufacture of knitwear in a semi-regular way

Coupons in the canvas are separated from each other by a dividing loop row. The length of the coupon is determined by the overall dimensions of the product parts, and its lower edge does not open and does not require sewing processing. Details of knitwear, obtained in a semi-regular way, have a shape close to a curved one, and require additional cutting along the lines of the neckline, armhole and sleeve ridge. They are connected into a product on a stitching and overcasting buttonhole machine.

Regularly a knitted product is obtained by means of knitting parts with a complete contour of structural lines. Details are completely knitted on specialized machines or automatic machines (Fig. 15).

Figure 15. Details for the manufacture of knitwear in a regular way

The bottom edge of them, as a rule, is earned at the beginning of knitting, and the remaining contours are formed by changing the number of needles, that is, deductions and increases in loops in the process of knitting. Details do not require additional cutting operations and are joined without overcasting on chainstitch sewing machines.

Small parts (pockets, collars, flaps, inlays, belts, etc.) used in the manufacture of cut jerseys are obtained in a regular way.

Regular and semi-regular products have important advantages over cut, they are more economical and reduce or simplify the technological process of cutting and sewing (for example, due to the absence of side seams). However, at present, up to 60% of jerseys are produced by the cut method. This is due to the relative simplicity of their manufacture, as well as the possibility of expanding the range by designing products for an unlimited number of models of a wide variety of shapes.

Recently, new technologies for producing knitwear have appeared.

Solid knitted products are called, the shape of which is achieved when knitting products in automatic mode. The manufacture of such products requires a minimum number of sewing operations (seamless technology).

This technology is the most complex, requiring the use of the latest generation flat-fang electronic knitting machines equipped with thread trimming and gripping systems.

Properties of knitted fabrics. An important role in solving the problems of modeling and designing knitwear is played by the properties of knitwear. The main properties include: extensibility, elasticity, shrinkage, thickness, width of the web, curl of its edges, blooming, etc.

Extensibility- this is the ability of a knitted fabric to deform or change its size under the influence of various kinds of loads, and after their removal, it can be partially or completely restored. Stretching of the knitted fabric can occur in three directions - length, width and diagonal.

Figure 16. View of jerseys obtained by cutting,

semi-regular and regular way

All knitted fabrics are divided into three groups depending on the degree of stretching across the width under the action of the same dynamic loads (600 g):

The canvases of the 1st group have low elongation - from 0 to 40%;

The canvases of the 2nd group have an average elongation - from 40 to 100%;

The canvases of the 3rd group have a high elongation - over 100%.

For each of the groups, the values of technical and general increases are established.

The extensibility of the knitted fabric leads to the expansion of the part in the transverse direction and a decrease in its length. In this regard, when designing knitted garments, the length of the parts is increased by 1% in the 1st group of canvases, by 2-2.5% - in the 2nd parts by 1% - in the 1st group of canvases,

A characteristic feature of knitted fabrics is a high proportion of elastic deformation, especially in width, regardless of the degree of their elongation. The elasticity of the fabric depends on the weave and the yarn. The introduction of modern elastomeric yarns into the fabric makes it possible to obtain a knitted fabric with an elongation of up to 500%. Also, the use of weaving a full or partial eraser allows you to increase the elasticity of the fabric.

Thickness knitted fabric more than 3 mm requires an increase in the width of the product, equal to three times the thickness (5), i.e. P you = 3 - 5, otherwise the product will be narrowed.

Curl of knit edges- one of its negative properties. The amount of twist depends on the type of weave, knitting density and the type of fiber. The highest curl of the edges is observed in single weaves of satin stitch, chain, tights, satin, 2nd and 3rd groups of extensibility. Therefore, along the free edges of the parts (sides, collar departure, etc.), several rows are knitted with another more stable weave or additional strips and braid are sewn.

Dissolving knitted fabrics occurs when the loop is broken or cut. The satin weave has the greatest dissipation. Warp-knitted weaves are practically not unraveled. In products made from highly loose fabrics, before cutting, it is necessary to lay a chain stitch along the contour of the part. The model should have a minimum of partitions.

Shaping of knitted garments. In the production of knitted clothes, along with traditional methods of shaping, original ones are also used, due to the properties of the yarn, weaving, etc.

A constructive method, involving cutting the fabric into parts of a certain size and configuration, is used when designing clothes from knitted fabrics of the 1st stretch group. In the production of one-piece knitted products, a given configuration of the contour of a part is obtained by changing the number of stitches at a certain distance from the edge of the part or by knitting incomplete stitch rows. But the constructive method does not always take into account the peculiarities of the structure and properties of knitwear, in particular, its forming ability.

Shaping using the physical and mechanical properties of knitted fabrics is used in the manufacture of knitted products obtained by regular and semi-regular methods.

For example, as a result of alternating weaves with a full and an incomplete eraser, a stable fit (or reduction) of the part is achieved in a given area (Fig. 17).

Figure 17. Shaping of a knitted product by changing weaves

Loop step press, openwork, etc. weaves, changing their knitting density allow you to achieve an expanding effect (Fig. 18).

Shaping is possible by changing the length of the thread in the loops, their thickness, or the introduction of elastic or spandex threads.

Knitting techniques also make it possible to solve the problem of forming parts and surface plastics.

For example, a clear bend of a fold or detail along the bead line can be ensured by disabling the needle from work when knitting on flat-fanged machines. This technique allows you to achieve a kind of effect, which consists in the fact that along the entire length of the idle needle, the knitted fabric seems to break. An exact bend is tight across the part can be achieved by knitting along the bend line of one loop of a lower density or a thread of lesser thickness.

The alternation of knit and purl knit along or across the fabric creates the impression of longitudinal or transverse tubular folds, etc. (Figure 19).

The high elasticity of the fabrics of the 2nd and 3rd groups of extensibility allows you to reduce the solution of the dart and distribute it between several areas (neck, shoulder cut, armholes, etc.) and exclude the shoulder dart on the back and chest dart on the shelf.

Figure 18. Shaping of a knitted product due to a change in the knitting density of press or openwork weaves

Areas for placing darts solutions should be secured with an edge, tape or glue pad along the cuts.

The physicochemical method of shaping has found application in the production of clothing from tubular fabrics made of highly elastic fibers. Shaping is carried out in the heat treatment process.

Features of the calculation and construction of drawings for details of cut clothing from knitted fabric. Methods for constructing drawings of details of knitted garments depend on the extensibility of the fabric and the method of production of knitted garments.

The book discusses methods of constructing drawings for a cutting method for producing clothes from knitted fabrics of the 1st and 2nd groups of extensibility. In the literature, for these purposes, it is proposed to use computational and graphic methods. One of the best ones that allows you to build drawings for standard and individual figures is the method developed by Ros-ZITLP.

Figure 19. Shaping of a knitted product by combining various weaves

The implementation of the basic design (BC) of a knitted product, as well as clothes made of fabrics, includes the construction of a basic grid of the drawing and drawing on it the contours of the main parts.

When constructing drawings of clothing parts from canvases of the 1st group of extensibility, the Ros-ZITLP method can be used without changes and additions. When designing clothes from canvases of the 2nd group of extensibility, the construction is carried out, as in the first case. The increments are chosen equal to 2-5 cm.In the finished drawing, the shoulder dart on the back is divided into three parts, which are distributed between the neck of the back (0.5-0.75 cm), the shoulder cut (1 - 1.5 cm) and the armhole of the back ( 1-1.5 cm). Landing of the material in the indicated areas is fixed with an edge.

On the shelf in swinging products, the chest dart is distributed in the following proportions along the side lines - up to 15% solution of the chest dart, along the neckline - up to 10%, along the armhole - up to 25-30%, along the side cut - up to 40-50% solution of the dart ... The landing of the canvas in these areas is fixed with an edge.

A feature of constructing a structure of a tight-fitting jersey made of fabric of the 3rd group of extensibility is the calculation of the structure, taking into account the percentage of narrowing (Fig. 21).

First, a drawing of the basic structure is built with a total increase along the chest line P o6sh = 0. Then the chest dart is distributed into the fit along the side cut and the cut of the armhole, as discussed above.

The next step is to select the percentage of narrowing, depending on the type of weave, density, threading and machine class. The following approximate values of the percentage of narrowing are recommended: for weaving eraser 2: 2 - 30-40%, 3: 3 - up to 50%, 4: 4 - more than 50%. Depending on the volume along the shoulder girdle, the part of the structure above the armhole is calculated according to the main percentage of narrowing or 5% less than the main one.

Figure 20. Redistribution of the bust dart in the jersey

Figure 21. Drawing of the basic structure of a knitted product from a fabric of the 3rd stretch group

The main percentage of narrowing of the sleeve is 5-10% less than the main percentage of narrowing of the product. The sleeve ridge is calculated 5% less than the main percentage of sleeve tapering. Next, the most characteristic design points in the drawing are recalculated taking into account the selected percentage of narrowing. For the final construction of the jersey design, taking into account the percentage of narrowing, the following adjustments are made to the resulting drawing: the end of the shoulder cut on the back and front is raised by 1.0-2.0 cm, as a result of this, to maintain the length of the armhole, its depth is raised accordingly by the same amount.

Bibliographic list

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