Properties of fabrics
1. Mechanical properties of fabrics
2. Physical properties of fabrics
3. Optical properties of fabrics, color, pattern and dyeing of fabrics
4. Technological properties of fabrics
1. Mechanical properties of fabrics
During use, the main wear of clothing occurs as a result of repeated exposure to tensile load, compression, bending, and friction. Therefore, the ability of the fabric to withstand various mechanical influences, i.e. its mechanical properties, is of great importance for preserving the appearance and shape of clothing and increasing the period of its wear.
The mechanical properties of fabrics include: strength, elongation, wear resistance, wrinkleability, rigidity, drape, etc.
The tensile strength of a fabric is one of the most important indicators characterizing its quality. .
Fabric tensile strength refers to the fabric's ability to withstand stress.
The minimum load required to break a strip of fabric of a certain size is called the breaking load. The breaking load is determined by tearing strips of fabric on a tensile testing machine (Fig. 31). Sample 7 is secured in clamps 8 and 6. The lower one is
Fig.31. Universal tensile testing machine
press 8 moves up and down from the electric motor,the upper clamp 6 is connected to the load lever 5.
When the lower clamp is lowered, the sample, stretching, moves down the upper clamp, which turns the load lever 5, which causes the pendulum force meter 4 with a load 9 to deflect. load scale 2 the magnitude of the load acting on the sample.
Under the influence of tensile force, the sample elongates and the distance between the clamps increases. The elongation value is indicated on the elongation scale 3 by an arrow. 10.
For testing, three strips of fabric are cut along the warp and four along the weft so that one is not a continuation of the other. It is important that the width of the strip exactly matches the established dimensions, and that the longitudinal threads are intact. The width of the strips is 50 mm. The distance between the clamps of the machine is taken to be 100 mm for woolen fabrics, and 200 mm for fabrics made from all other fibers. Strips are cut 100 - 150 mm longer than the clamping length. In order to save fabric, a small strip method has been developed, in which a strip 25 mm wide is tested with a clamping length of 50 mm.
The breaking load is calculated separately for the warp and weft. The breaking load of a sample on a warp or weft is considered to be the arithmetic mean value of the test results of all warp or all weft strips.
When evaluating fabric in laboratories, the breaking load is determined and compared with the standards. For example, the strength of cotton dress fabrics is 313 - 343 N for the warp, 186 - 235 N for the weft, 687 - 803 N for cotton suiting fabrics, 322 - 680 N for the weft, 322 - 588 N for wool suiting fabrics, per weft 294 - 490 N. Despite the fact that cotton suiting fabrics have greater tensile strength than woolen ones, they wear out faster during use. This is explained by the fact that woolen fabrics have higher elongation and elasticity.
The tensile strength of a fabric depends on the fibrous composition of the fabric, the thickness of the thread (yarn), density, weave, and the nature of the fabric finishing. Fabrics made from synthetic fibers have the greatest strength. Increasing the thread thickness and fabric density increases the strength of the fabric. The use of weaves with short overlaps also helps to increase the strength of the fabric, therefore, all things being equal, plain weave imparts the greatest strength to fabrics. Finishing operations such as rolling, finishing, and decating increase the strength of the fabric. Bleaching and dyeing lead to some loss of strength.
Simultaneously with the strength of the fabric, the elongation of the fabric is determined using a tensile testing machine. The increase in sample length at the moment of rupture - elongation at break - can be determined in millimeters (absolute elongation) or expressed as a percentage of the original length of the sample (relative elongation).
where /1 is the original length of the sample; /2 is the length of the sample at the moment of rupture. For example, the breaking elongation of calico at warp is 8-10%, at weft 10-15%; boumazei on the warp 4-5%, on the weft 12 - 15%; linen for warp 4 - 5%, for weft 6 - 7%; fabrics made of natural silk, warp 11%, weft 14%; staple fabric 10% for warp, 15% for weft.
Modern tensile testing machines are equipped with diagramming devices that record load-elongation curves.
The breaking load is displayed vertically, and the breaking elongation in millimeters or percentage is displayed horizontally. Elongation curves provide insight into how a material deforms under increasing load. This allows, for example, to judge how the fabric will behave in sewing production processes under loads significantly lower than tensile loads.
Linen fabric, for example, has greater strength than woolen fabric, but due to its low elongation, less energy is spent on breaking it than woolen fabric, which has less strength but greater elongation.
The quality of the fabric is largely determined by the ratio of the proportion of elastic, elastic and plastic elongation of the fabric. If the fabric has a large proportion of elastic elongation, it wrinkles little, and wrinkles that appear on the fabric during use quickly disappear. Elastic fabrics are more difficult to handle with moisture and heat, but they retain the shape of the product well during wear. If a larger percentage of the total elongation of the fabric is elastic elongation, then wrinkles that occur when wearing clothes gradually disappear - the clothes have the ability to "sag". If a large proportion of the total elongation is plastic elongation, then the fabrics become strongly wrinkled, clothing quickly loses its shape, and wrinkles appear on the elbows and knees. "bubbles". Such products need to be ironed frequently.
The amount of total elongation of the fabric and the proportion of elastic, elastic and plastic elongations in the composition of the total elongation depend on the fiber composition, structure and finishing of the fabric.
Synthetic and pure wool fabrics made from twisted yarn, fabrics made from textured threads, and dense fabrics made from wool with lavsan have the greatest elasticity. Fabrics made from natural fibers of animal origin (wool, silk) have significant elastic elongation, so they wrinkle little and gradually restore their original shape. Linen, cotton, viscose fabrics, i.e. fabrics made from plant fibers, have a large plastic elongation, so they wrinkle heavily and do not restore their original shape on their own (without wet-heat treatment). Linen has the greatest amount of plastic deformation, which is why linen fabrics wrinkle more than others.
The composition of the mixtures and the percentage of fibers of different origins in them affect the elasticity of the fabric. For example, adding staple viscose fiber to wool reduces the elasticity of the fabric; adding staple lavsan or nylon, on the contrary, increases elasticity. To increase elasticity, up to 67% lavsan is added to linen fabrics in the form of staple fiber or filament threads. The use of elastic or spandex threads in the warp and weft fabric systems makes it possible to obtain materials with a three-dimensional structure that have high stretchability. For example, for sports trousers, fabric with an elastic base is produced, which ensures good stretchability of the fabric during exercise and maintains the appearance and shape of the product after repeated training. The use of elastic as weft in fabrics for swimsuits makes it possible to obtain products that tightly fit the figure and do not restrict movement when swimming. High-quality corsetry products are made from spandex threads.
With a uniform fibrous composition, the elasticity of the fabric will depend on its structure, i.e., on the thickness and twist of the threads (yarn) and the density of the fabric. An increase in these indicators increases the elasticity of the tissue.
The ratio of disappearing and remaining elongations depends on the magnitude and duration of the tensile force. With increasing load and its duration, the proportion of remaining elongations increases. With prolonged wear, repeated loads lead to the accumulation of irreversible deformation, as a result of which the product increasingly loses its shape.
Fabric elongation affects all stages of sewing production. When creating a model and developing a product design, it is necessary to take into account the percentage of elongation and the ratio of disappearing and remaining elongations. In models made from fabrics that do not have elasticity, tapered sleeves, tight skirts and trousers, etc. should be avoided.
When laying elastic fabrics, the sheets should be laid without tension. The stretching of the fabric in the flooring leads to a decrease in the size of the parts. Fabrics stretch especially strongly along an oblique thread, i.e. at an angle of 45° and close to 45°. Therefore, when laying, it is necessary to ensure that there is no distortion of the fabric, displacement or sliding of the canvases in the flooring. When the fabric is distorted and the canvases are displaced, the shape of the cut details is distorted. When sewing oblique cuts, the fabric is greatly stretched, the direction of the stitching is distorted, which spoils the appearance of the product. Stretching of the upper and lower panels and displacement of parts may occur. During wet-heat treatment, the product is given a certain shape by forcibly stretching the fabric (pulling). At the same time, unwanted stretching of parts may occur, which leads to damage to the product.
To reduce the stretching of the fabric, low-stretch linen tape (edge) or low-stretch fabric with an adhesive coating (adhesive edge) is laid along the edges of the sides of outerwear. The edge is laid in the armholes of the sleeves, along the waistline and in other parts of men's and women's suits. To maintain the shape of the pockets, strips of cotton fabric (lobes) are laid.
Wrinkleability - This is the ability of a fabric to form wrinkles and folds when bent and under pressure, which can only be eliminated by wet-heat treatment. The cause of creasing is plastic deformation that occurs in the fabric under the influence of bending and compression. Fibers that have a significant proportion of elastic and elastic elongation, after bending and compression deformation, more or less quickly straighten and return to their original position, so wrinkles disappear.
Creaseability depends on the fiber composition of the fabric, the thickness and twist of the threads, the weave, density and finish of the fabric. Fabrics made from elastic fibers wrinkle less: wool, natural silk, many synthetic fibers. Fabrics made from cotton, viscose fiber and especially linen are very wrinkled. Increasing the thickness and twist of threads reduces the wrinkling of fabrics. The gradual disappearance of wrinkles in wool, natural silk and synthetic fabrics is explained by the manifestation of the elastic properties of the fibers, due to which the fibers return to their original position after bending. Increasing the density prevents the threads in the fabric from shifting when it bends, so dense fabrics wrinkle less.
Big influence finishing affects fabric wrinkleability. To reduce the creasing of cotton, staple, and viscose fabrics, anti-crease finishes are used. In the sewing industry, to impart wrinkle resistance and ensure the shape of the product, processing forniz.
Reducing wrinkles can be achieved by changing the structure of the fabric and using different types of twisted threads. The creation of fabrics with three-dimensional structures with the widespread use of textured threads makes it possible to produce a large number of different wrinkle-resistant and elastic silk fabrics.
Shine, coloring and pattern of fabric can emphasize or visually reduce wrinkles. Wrinkles and folds are most noticeable on light, shiny skin. thin fabrics satin and twill weaves, for example on lining fabrics. It seems that light, plain-dyed fabrics wrinkle more than the same variegated fabrics or fabrics with a printed pattern. The pattern does not reduce the wrinkleability of the fabric, but makes it less noticeable.
Wrinkling of fabrics spoils the appearance of clothes and complicates the sewing process. Easily wrinkled fabrics wear out faster, as they experience greater friction in places of bends and folds, and also lose strength with frequently repeated wet-heat treatments.
The creasing properties of tissues can be determined organoleptically by squeezing tissues in the hands and in the laboratory using special devices. There are instruments for determining oriented and non-oriented crumpling (the “artificial arm” device IR-1, which is used to study the deformability of textile materials in the elbow area of sleeves under repeated stretching and compression; a device for determining the bending resistance of fabrics, designed to determine the bending angle of the fabric in degrees after load equal to 124 bends per minute).
When testing a fabric sample for creasing, depending on the degree of creasing, it is given the following rating: strongly crumpled, crumpled, weakly crumpled, non-crumpled.
Drapability - the ability of the fabric to form soft round folds. Drapability depends on the weight, stiffness and flexibility of the fabric. Stiffness is the ability of a fabric to resist changes in shape. The inverse of stiffness is flexibility - the ability of a fabric to easily change shape.
The stiffness and flexibility of a fabric depend on the size and type of fiber, thickness, twist and structure of the thread, structure and finishing of the fabric. Low-density fabrics made from thin flexible fibers and lightly twisted yarn are characterized by significant softness and flexibility. Flexible fabrics have good drapability, but require attention when laying and stitching, as they warp easily.
The bending rigidity of household fabrics is determined using a PT-2 device by measuring the amount of deflection of a strip of fabric under the influence of its own weight. There are special instruments for determining stiffness and elasticity artificial leather and film materials.
Artificial leather and suede, fabrics made from complex nylon threads and monocapron, wool with lavsan, dense fabrics made from twisted yarn and fabrics with a large number of metal threads have significant rigidity. Weaves with short ones. Overlapping and finishing increase the stiffness of the fabric. Rigid fabrics do not drape well - they form gentle folds with sharp corners. Rigid fabrics lay well, do not warp when sewing, but at the same time they have great resistance to cutting and are difficult to wet-heat treatment.
The requirements for fabric drapability depend on its purpose and product model. To create models of dresses and blouses of a loose silhouette with soft lines, gathers, flounces, soft folds, fabrics with good drape ability are required. Models with a strictly straight silhouette and widened downwards should be made from stiffer fabrics with less drape. Fabrics for men's suits and coats may have less drape than dress ones, as they are used for products with a straight silhouette.
Fabrics made from natural silk, woolen fabrics with crepe weaves and soft woolen coat fabrics have good drapability. Fabrics made from plant fibers have less drape than wool and silk fabrics.
D = (200 - A) 1 00/200.
To determine the drapability of fabric in all directions, the disk method is used (Fig. 32). From the fabric you-
cut the sample in the shape of a circle and place it on a disk of smaller diameter. The drapability of the fabric is determined depending on the number and shape of the folds formed and on the projection area that the fabric gives when the disk is illuminated from above.
Drapability coefficient is the ratio of the difference
Rice. 32. Determination of fabric drapability using the disc method: / - fabric; 2 - projection
area of the sample and its projection to the area of the sample.Drapability coefficient Kd, %, is calculated by the formula
Kd=(So - SQ) 100/ So,
where So is the sample area, mm2; SQ - projection area
sample, mm2.
The drapability of artificial fur is determined using the loop method using the DM-1 device.
According to the Central Research Institute of Shipping, fabric drapability is considered good if the following coefficient values are obtained as a result of testing. For woolen suiting, coat and cotton fabrics, drape is more than 65%. And for woolen dress fabrics - more than 80%, for silk dress fabrics - more than 85%.
Wear resistance tissues is their ability to withstand a number of destructive factors. clothing fabric is exposed to light, sun, friction, bending, compression, moisture, sweat, washing, etc.
A complex set of mechanical, physicochemical and bacteriological influences leads to a gradual weakening and then destruction of the tissue.
The nature of the impacts experienced by the fabric during use depends on the purpose of the product and operating conditions. For example, linen wears out from repeated washing, window curtains and curtains lose strength from the action of light and sun; wear of outer clothing occurs mainly from friction. IN initial stage Pilling is observed on many textile materials.
Pilling is the process of formation of lumps of rolling fibers on the surface of textile products - pills, which appear in areas experiencing the most intense friction and spoil the appearance of the product.
Textile materials can be pilled during the manufacture of garments, their use, washing, and dry cleaning. The pattern of the appearance and disappearance of pills is as follows: the tips of the fibers emerge on the surface of the materials, the formation of moss; formation of pills; separation of pills from the surface of materials.
Fabrics, knitwear, and non-woven materials containing short fibers, especially synthetic ones, have the greatest pilling ability. Of the staple fibers, polyester fibers produce the greatest pilling. Fabrics with cotton weft produce more pilling than fabrics with viscose weft.
Pill resistance is especially important for lining materials. Determination of pilling in textile materials is carried out using devices of various designs called pilling testers. Depending on the number of pills on an area of 10 cm, materials are divided into non-pilling, low-pilling (1 - 2 pills), medium-pilling (3 - 4 pills) and high-pilling (5 - 6 pills).
Under the influence of friction, the destruction of fabric begins with abrasion of the bends of threads protruding onto the surface of the fabric, forming the so-called supporting surface of the fabric. Therefore, the abrasion resistance of a fabric can be improved by increasing the supporting surface of the fabric. This is achieved by using weaves with elongated overlaps. All other things being equal, fabrics of satin and satin weaves have the greatest resistance to abrasion. Therefore, most lining fabrics are made with satin and satin weaves.
When cutting, it is necessary to take into account that the destruction of the fabric occurs more slowly if the abrasion is directed along the threads that form the front covering.
During use of the products, the fabric is rubbed along the bottom of the sleeves and trousers, on the elbows, knees, and collar. To increase the wear life of products, it is recommended to sew a nylon tape with a side at the bottom of the trousers, which prevents abrasion of the fabric. In women's garments, a braid can be sewn along the hem line, the collar flap and the bottom of the sleeves, which serves as decoration and at the same time prevents wear. In products sporty style and in work clothes they make elbow and knee pads, which increase the durability of the products.
Nylon fabrics and fabrics containing synthetic fibers are the most resistant to abrasion. Therefore, to increase abrasion resistance, staple synthetic fibers are added to wool fabrics. Thus, investing 10% staple nylon fibers into wool fabric increases its abrasion resistance three times.
It should be remembered that violation of the regime of wet-heat treatment of fabrics - excessive heating and duration of treatment - leads to a decrease in the wear resistance of fabrics. In areas of woolen fabric that have a barely noticeable opal, the strength and wear resistance of the fabric are reduced by 50%.
Under the influence of repeated stretching, compression, and torsion, the structure of the fabric and threads becomes loose. Plastic deformations accumulate in the product, fabrics stretch, and products lose their shape. The fibers gradually fall out, the thickness and density of the fabric decrease; the tissue is destroyed.
The resistance of fabric to repeated mechanical stress is called endurance. Each tissue has an endurance limit, after which irreversible changes occur and accumulate in the tissue.
Durability of the product increases if, during the operation of the fabric, the load on it does not exceed its endurance limit.
Due to the fact that clothing wear occurs as a result of a complex set of environmental influences and depends on operating conditions, a unified method for determining wear resistance has not yet been established. The wear resistance of new sewing materials can be determined by experimental wear. A batch of products is sewn from the tested materials and handed over to a certain group of people for trial wear. After a set period of time, the products are examined in organizations that conduct experimental wear, the reasons leading to wear are analyzed, and the question of the advisability of introducing new materials into mass production is decided.
In laboratory conditions, individual factors or complexes of factors leading to fabric wear are determined: resistance to abrasion, washing and dry cleaning, resistance to repeated stretching and bending, resistance to light weather.
For a comprehensive study of materials for tension, relaxation (size restoration) in various environments and at different temperatures, an electronic device - a strograph - is used.
The abrasion resistance of fabrics and knitted fabrics can be determined using devices of various designs. But the principle of operation of the devices is the same - the material is subjected to friction against notched metal surfaces, sanding blocks, fabric, etc. The device counts the number of revolutions of the abrasive surface when the test material is abraded to holes, or after a certain number of strokes of the device, a decrease in the strength of the material is determined. An acoustic method has been developed for testing materials without destroying them, based on the dependence of ultrasonic attenuation on material wear.
Plan.
1. General mechanical properties of fabrics
2. Drapability
3. Physical properties of fabrics
4. Optical properties of fabrics
5. Technological properties of fabrics
6. List of used literature
1. General mechanical properties of fabrics.
During use, the main wear of clothing occurs as a result of repeated exposure to tensile load, compression, bending, and friction. Therefore, the ability of the fabric to withstand various mechanical influences, i.e. its mechanical properties, is of great importance for preserving the appearance and shape of clothing and increasing the period of its wear.
The mechanical properties of fabrics include: strength, elongation, wear resistance, wrinkleability, rigidity, drape, etc. .
Strength fabric when stretched is one of the most important indicators characterizing its quality. Fabric tensile strength refers to the fabric's ability to withstand stress.
The minimum load required to break a strip of fabric of a certain size is called the breaking load. The breaking load is determined by tearing strips of fabric on a tensile testing machine.
The tensile strength of a fabric depends on the fibrous composition of the fabric, the thickness of the yarn or thread, density, weave, and the nature of the fabric finishing. Fabrics made from synthetic fibers have the greatest strength. Increasing the thickness of the threads and the density of the fabric increases the strength of the fabrics. The use of weaves with short overlaps also increases the strength of the fabric. Therefore, under all equal conditions, plain weave imparts the greatest strength to fabrics. Finishing operations such as rolling, finishing, and decating increase the strength of the fabric. Bleaching and dyeing lead to some loss of strength.
Wear resistance tissues is their ability to withstand a number of destructive factors. In the process of using clothing, the fabric experiences the effects of light, sun, friction, repeated stretching, bending, compression, moisture, sweat, washing, dry cleaning, temperature, etc.
The nature of the impacts experienced by the fabric during use depends on the purpose of the product and operating conditions. For example, linen wears out from repeated washing ; when boiling in solutions detergents under the influence of atmospheric oxygen, cellulose oxidizes and the strength of the fibers decreases; mechanical stress on the fabric during the washing process, as well as the action of a heated metal surface during ironing, also lead to weakening of the fabric. Window curtains and curtains lose their strength from the action of light and sun.
Wear of outerwear occurs mainly from friction. In the initial stage of abrasion, pilling is observed on many textile materials.
Pilling called the process of formation on the surface textile products lumps of rolling fibers - pills, which appear in areas experiencing the most intense friction and spoil the appearance of the product.
Wear is greatly influenced by the action of light and repeated bending, stretching, and compression. During use of the products, the fabric is rubbed at the bottom of the sleeves and trousers, on the elbows, knees, and jacket collar.
To increase the wear life of products, it is recommended to sew nylon tape with a side at the bottom of trousers and sleeves, which prevents abrasion of the fabric.
It should be remembered that violation of the regime of wet-heat treatment of fabrics - excessive heating and duration of treatment - leads to a decrease in the wear resistance of fabrics. In areas of woolen fabric that have a barely noticeable opal, the strength and wear resistance of the fabric are reduced by 50 %.
Under the influence of repeated stretching, compression, and torsion, the structure of the fabric and threads becomes loose. Plastic deformations accumulate in the product, fabrics stretch, and products lose their shape. The fibers gradually fall out, the thickness and density of the fabric decrease; the tissue is destroyed.
2. Drapability
D rapability- the ability of the fabric to form soft, round folds. Drapability depends on the weight, stiffness and softness of the fabric. Rigidity is the ability of a fabric to resist changing shape. The reciprocal of stiffness is g and b k - the ability of a fabric to easily change shape.
The stiffness and flexibility of a fabric depends on the size and type of fiber, the thickness, twist and structure of the yarn, the structure and finishing of the fabric.
Artificial leather and suede, fabrics made from complex nylon threads and monocapron, wool with lavsan, dense fabrics made from twisted yarn and fabrics with a large number of metal threads have significant rigidity.
Fabrics made from natural silk, woolen fabrics with crepe weaves and soft woolen coat fabrics have good drapability. Fabrics made from plant fibers - cotton and especially linen - have less drape than wool and silk.
3.Physical properties of fabrics
The physical (hygienic) properties of fabric include hygroscopicity, breathability, vapor permeability, waterproofness, wetness, dust holding capacity, electrification, etc.
Hygroscopicity characterizes the ability of fabric to absorb moisture from the environment (air).
Breathability- ability to pass air - depends on the fiber composition, density and finish of the fabric. Low-density fabrics have good breathability.
Vapor permeability- the ability of fabric to transmit water vapor released by the human body. Vapor penetration occurs through the pores of the fabric, as well as due to the hygroscopicity of the material, which absorbs moisture from the air under clothes and transfers it to the environment. Wool fabrics evaporate water vapor slowly and are better than others at regulating air temperature.
Thermal properties are especially important for winter fabrics. These properties depend on the fiber composition, thickness, density and finishing of the fabric. Wool fibers are the “warmest”, flax fibers are “cold”.
Water resistance is the ability of a fabric to resist water seepage. Water resistance is especially important for special-purpose fabrics (tarpaulins, tents, canvas), raincoat fabrics, woolen coats and suiting fabrics.
Dust capacity- this is the ability of tissues to become dirty. Dust holding capacity depends on the fibrous composition, density, finishing and nature of the front surface of the fabric. Loose fleece fabrics with fleece have the greatest dust holding capacity.
Electrification is the ability of materials to accumulate static electricity on their surface. During contact and friction, which are inevitable during the production and use of textile materials, electrical charges continuously accumulate and dissipate on their surface.
4 Optical properties of fabrics
The choice of model, development of designs, visual perception of creasing, volume, size, proportions of the product depend on optical properties tissues, i.e., on their ability to quantitatively and qualitatively change the light flux.
Depending on the reflection, absorption, scattering, and transmission of the light flux, such properties of materials as color, gloss, transparency, and whiteness appear.
If the material completely reflects or absorbs the light flux, then a sensation of achromatic color (from white to black) appears: with complete reflection - White color, with complete absorption - black, with uniform incomplete absorption - grey colour various shades.
Shine fabric depends on the degree of specular reflection of the light flux and, therefore, on the nature of the surface of the fabric, the structure of the threads, the type of weave, etc. The use of weaves with elongated overlaps (satin, satin, basic twill), pressing, calendering, giving a polished, silvery finishing, “varnish” increase the shine of fabrics.
Transparency is associated with the sensation of light flow passing through the thickness of the fabric and depends on the fibrous composition and structure of the fabric. Thin, low-density fabrics made from synthetic fibers and natural silk have the greatest transparency.
Color- this is the ratio of all colors involved in the color of the fabric. By combining colors of different tones, saturation, and lightness, you can give fabrics a joyful or gloomy flavor.
Plot are called drawings that can be talked about (portraits, paintings, etc.). Thematic designs may include anniversary scarves, tapestries, tablecloths, some fabrics, etc.
Thematic are called drawings that can be characterized by some concept (peas, stripes, checks, etc.). Abstract drawings are called non-objective. In fabrics these are various color spots or. undefined contours.
5. Technological properties of fabrics
Technological properties tissues are properties that can appear at different stages clothing production- in the process of cutting, grinding and wet-heat treatment of products.
The technological properties of fabrics include: cutting resistance, slip, frayability, cutability, shrinkage, the ability of fabrics to be molded during wet-heat treatment, and the spreadability of threads in seams.
Shrinkage- This is a reduction in the size of the fabric due to heat and moisture. Shrinkage occurs during washing, soaking, wet-heat treatment of products during ironing and pressing. Shrinkage of fabrics can lead to a decrease in the size of the product and distortion of the shape of its parts. If the fabrics of the top, lining and lining shrink differently when wet dry cleaned or ironed, wrinkles and creases may appear on the product.
After washing, some fabrics shrink along the base and increase slightly in width, getting the so-called attraction.
Attraction may appear, for example, in fabrics with a cotton warp and unspun viscose weft .
There are concepts “ index», « property" And " parameter». Index– a numerical or letter designation that makes it possible to judge the state or development of an object or process. Property– quality, a sign that constitutes a distinctive feature of an object. Parameter– a quantity that quantitatively characterizes an indicator or property of an object. For textile materials, parameters and properties are measured and assessed.
Properties of fabrics. The properties of fabrics depend on their fibrous composition, type of weave and finishing features. In turn, the purpose, properties and performance of fabric products depend on the properties of the fabric. The following classification of fabric properties according to mechanical, physical and technological properties is known.
Mechanical properties determine the relationship of the material to the action of various external forces. Under the influence of these forces, the material is deformed: its size and shape change. Mechanical properties include: strength, wear resistance, creasing, drapability, pillability, extensibility.
Ø Strength – the ability of a fabric to withstand external influences (tear, abrasion, etc.), one of the important properties affecting the quality of the fabric.
Ø Wrinkleability - the ability of a fabric to maintain a fold at the bend.
Ø Drapability – the ability of the fabric to form beautiful rounded stable folds.
Ø Extensibility – an increase in the length of the sample when a tensile load is applied to it.
Ø Pillability - the ability of a fabric, during its use or during processing, to form small balls on the surface from rolled ends and individual sections of fibers.
Ø Wear resistance - the ability of a fabric to withstand the effects of friction, stretching, bending, compression, moisture, light, sun, temperature and sweat.
Physical (hygienic) properties– these are properties aimed at preserving human health. TO physical properties fabrics include: heat-shielding properties, dust holding capacity, hygroscopicity, air, steam, water permeability, water absorption, thermal conductivity, etc.
Ø Heat-protective properties - the ability of fabric to retain heat generated by the human body.
Ø Dust holding capacity – the ability of a fabric to hold dust and other contaminants.
Ø Air permeability – the ability of a fabric to allow air to pass through.
Ø Hygroscopicity - the ability of a fabric to absorb moisture from the air.
Ø Water absorption – the ability to absorb water when a tissue sample is directly immersed.
Ø Vapor permeability - the ability of a fabric to pass water vapor from an environment with high air humidity to an environment with lower humidity.
Ø Water permeability - the ability of a fabric to pass water under a certain pressure.
Ø Thermal conductivity - the ability of a fabric to transmit heat to one degree or another.
Technological properties- these are the properties that the fabric exhibits during the manufacturing process of the product, from cutting to the final wet-heat treatment. The technological properties of fabrics include: slip, thread spreading, rigidity, formability, shape stability, fraying, shrinkage.
Ø Sliding is the mobility of one layer of tissue relative to another.
Ø Formability – the ability to create a spatial shape under the influence of temperature and moisture.
Ø Shape stability – the ability to maintain a spatial shape under the influence of external influences.
Ø Stiffness – elastic resistance of fabric to change in shape.
Ø Shedding – displacement and loss of threads from open sections of tissue.
Ø Shrinkage – reduction in the size of the fabric after wet-heat treatment in the direction of the weft and warp.
Ø Separation of threads – characterizes the degree of fastening of one system of threads relative to another.
In state standards, the mechanical, physical and technological properties of fabric vary and are standardized depending on the raw material composition and purpose of the fabric. Technological properties of the fabric that are not specified in GOST and required in the manufacture of garments are formally classified by the customer of the fabric as “Customer-specific tests” and are taken into account when designing the fabric.
Fabric quality indicators. Repeated attempts to develop a methodology for designing the performance of threads and fabrics led to the creation of a holistic scientific direction for assessing and managing the quality of textile materials. The complexity of the product quality management mechanism lies in the diversity and multidimensionality of the connections between the technological and economic elements that make up a quality product.
The quality of produced fabrics is one of the conditions for competitiveness. According to, a quality indicator is a quantitative characteristic of product properties that determine quality, considered in relation to certain conditions of its creation and operation. According to S. Siro, quality is a set of characteristic properties, form, appearance and conditions of use that goods must have to meet their intended purpose. A.N. Soloviev and S.M. Kiryukhin believe that the quality of a material is the compliance of its properties with the requirements of the consumer, which determines the suitability of the material for processing and intended use. In work, the quality of a fabric is determined by a set of physical, mechanical, hygienic, aesthetic and other properties that depend on the structure of the fabric and the technological process of its formation.
If we consider the quality of a product (fabric) as a set of its properties that determine the product’s ability to satisfy certain needs in accordance with its purpose, that is, the quality of a fabric can be defined as the degree to which it satisfies the requirements of consumers, then fabric design is partly a mechanism for managing this quality.
The nomenclature of indicators used in assessing the quality of fabrics for household use has been determined state standards:
Ø GOST 4.3–78 – for cotton fabrics;
Ø GOST 4.6–85 – for silk fabrics.
Distinguish general and additional indicators. General indicators , that is, mandatory for all fabrics of this type, these include:
Ø fibrous composition of the fabric;
Ø linear density of yarn;
Ø fabric density, number of threads per 10 cm;
Ø surface density of the fabric;
Ø tensile load of a strip of fabric when stretched to the point of rupture;
Ø change in the linear dimensions of the fabric after wet treatments;
Ø whiteness or color fastness.
Additional (specialized) tissue indicators include properties that vary depending on the intended purpose of the fabric.
Indicators of fabric quality are usually grouped according to certain characteristics, depending primarily on the goals and objectives set. To assess the quality level of any product, including fabrics, the following classification of indicators has been established:
· Destination indicators characterize the beneficial effect of using the product for its intended purpose and determine the scope of its application (for example, the fibrous composition of fabrics; surface density; dimensions for piece products; indicators of certain mechanical properties that determine the degree of suitability of the material for certain purposes, etc.).
· Reliability indicators characterize the properties of reliability and durability of products under specific operating conditions (for example, color fastness to wet treatments, the ability of a material to withstand abrasive influences during operation, etc.).
Manufacturability indicators characterize the effectiveness of technical and technological solutions to ensure high labor productivity in the manufacture and repair of products.
