Denis Valentinovich Manturov Minister of Industry and Trade of the Russian ...
Purpose of work: The study of methods for determining the linear density, indicators of twisting and twisting of threads and sewing thread.
Devices and materials: thickness gauge , sewing thread samples, ruler, textile magnifier, electronic scales, twist gauge, preparation needles.
Tasks: 1. To study the classification of textile threads used in the production of materials for clothing.
2. To study the characteristics of the structure of threads and sewing threads.
3. Determine the indicators of the structural characteristics of 3 types of threads.
4. Prepare samples and conduct tests to determine linear density, twist direction, number of folds, calculated and actual diameters of threads and sewing threads.
Basic information
Types of textile threads. In modern textile production, a wide assortment of yarns of various structures is used: classic yarns, complex, combined yarns and monofilaments, film yarns and yarn-like knitted, woven, braided textile products (chains, cords, ribbons, braids, etc.). Knowing their structural features, it is relatively easy to predict the properties of materials made from these threads and products.
Distinctive feature yarn is the presence of protruding fiber tips on its surface. When untwisted, the yarn eventually breaks down into individual fibers of limited length. Combed, carded, rotor and hardware yarns differ in the degree of hairiness of the surface: as a rule, combed yarns have a smoother and less hairy surface, while hardware and high-volume yarns have the greatest fluffiness and bulk.
Unlike yarn, the surface complex threads, consisting of filaments, smooth, even, and there are no protruding ends on it, unless the filaments are damaged. Surface voluminous and fluffy textured yarns, the elementary threads of which have a stable crimp, are covered with separate loops-sucrutins. Their number and sizes depend on the texturing method. Shaped yarns have in their structure periodically repeating local changes. The local structure effects found in fancy yarns are very numerous and varied (loops, knots, thickenings, curls, roving sections, lumps of fibers, etc.).
When untwisted, twisted threads are separated into constituent threads: yarn - into single yarns, complex threads - into single threads, combined - into threads of various types. The constituent threads in the structure of the twisted threads are located along helical lines and therefore their turns are noticeable on the surface. The density and inclination of the turns relative to the longitudinal axis increase as the degree of twist increases from the minimum values in the shallow twist yarns to the maximum values in the crepe twist yarns. Crepes have significant rigidity, elasticity and twist unbalance. This makes them, in a free state, wriggle and twist, forming curls.
Structural characteristics of textile yarns. The structure of a single-strand yarn is characterized by the thickness, length, shape of the fibers, as well as their number and uniformity of distribution in individual sections, relative position and intensity of twisting. The main structural characteristics of the twisted yarn are the thickness, size and direction of the twist of a single yarn; the number of additions, i.e. the number of threads forming the twisted yarn, the intensity and direction of the twist in the twisted yarn.
Thus, the structural characteristics of textile threads and sewing threads are thickness (linear density of threads), number of folds, direction and amount of twist, twist.
The use of linear dimensions of the cross-section to characterize the thickness of the threads is inconvenient for a number of reasons: its measurement is difficult irregular shape the cross section of the threads, the presence of voids and air spaces between the fibers in the yarn, the dependence of the thickness on the degree of twist and the density of the fibers in the cross section of the threads, the possibility of flattening the threads when used to determine the thickness of devices.
In this regard, the thickness of threads and sewing threads is estimated by indirect units of measurement: linear density, trade (conventional) number.
Linear density T, tex, an indirect unit for measuring the thickness of fibers or filaments, is directly proportional to their cross-sectional area, i.e. the larger the numerical value of the tex, the thicker the thread. Defined as the ratio of the thread mass T, g, to its length L, m
T = 1000 m / L(2.1)
Measurement units of linear density, except for tex in accordance with GOST 10878-70, are millitex (mtex) 1 mtex = 10 -3 tex; decitex (dtex) 1 dtex = 10 -1 tex; kilotex (ktex) = 10 3 tex.
The linear density of twisted and spun yarns is called the resulting linear densityT. R.
Linear density is distinguished by nominal, actual, calculated and conventional.
Conditioned Linear DensityT to Is the actual linear density of a single or twisted (spun) yarn, reduced to the normalized moisture content. These indicators are calculated by the formula
, (2.2)
where Wн- normalized moisture content of threads,%;
Wf - actual moisture content of the threads,%.
In terms of linear density, only the thickness of threads of the same fibrous composition and structure can be compared.
Nominal (That) are called linear density a single thread, scheduled for production in production; it is usually indicated in the technical characteristics of the thread and material (GOST 10878-71, GOST 11970.0-5-70, GOST 21750-76).
Calculated Linear Density (T p) is calculated for spliced threads, in which its individual components are not subjected to joint twisting
T p = T 1 + T 2 + ... + T n, (2.3)
where T 1 ,T 2, T n Is the nominal linear density of the individual stitched threads.
Actual Linear Density textile thread ( T f) determined experimentally and calculated by the formula (2.4)
T f = 1000 × S m / L × n,(2.4)
where S m- total mass of elementary samples, g;
L- length of a thread in an elementary sample, m;
NS- the number of elementary samples.
To characterize the thickness of sewing threads, use the symbol - trade number N, which is indicated on the labels of each product unit. The higher the trade number, the thinner the sewing thread.
The trade number shows the number of meters of yarn with a weight of 1 g
N = l / m , (2.5)
where l- thread length, m;
m- thread weight, g.
The thickness of the twisted threads (yarns) is denoted by a fraction, the numerator of which is equal to the number of threads that make up the twisted yarn, and the denominator is the number of threads included in it. The relationship between the linear density of sewing threads and their trade number is expressed by the expression:
T = 1000 / N(2.6)
An important indicator when choosing sewing threads for sewing products is the diameter of the threads. It is determined by calculation and experiment.
Estimated thread diameter, mm, determined by the formula
, (2.7)
where d is the average density of the thread, mg / mm 3 the values of which are given below.
Experimentally, the diameter of the threads is measured using projection devices or microscopes.
The direction of twisting characterizes the arrangement of the turns of the peripheral layer of the thread: at right twist(Z) the constituent threads are directed from left to top to right, with left twist(S) - from right to top to left.
Figure 2.1 - Arrangement of turns in the yarn:
a - right twist; b - left twist
For silk threads, on the other hand, the right twist is designated S, and the left twist Z. The direction of twisting of the sewing thread affects the looping process and the loss of thread strength during sewing.
The structure of the twisted yarns is characterized by number of additions- the number of threads that make it up.
Twist of threads characterized by number of torsions К, which indicates the number of turns around the axis of the thread, calculated per unit of thread length (1 m) before untwisting, and is determined on the device with a twist meter. The actual number of twists characterizes the degree of twisting of threads of the same linear density. In standard tests, two methods are used to determine the actual number of twists (actual twists): and double torsion(GOST 6611.3-73). In the first method direct unwinding the thread on the twist gauge is untwisted until the constituent threads are completely parallel. The number of twists is recorded on the counter. The readings are converted to 1 m of thread length - this is the actual twist.
Figure 2.2 shows universal steepness meter KU-500... The device consists of a body 12, a tensioner and an eyepiece, fixed on the guide 22 by brackets 4 and 18, respectively. The body 12 is a box inside which an electric motor is mounted, a clutch with a set of gear wheels for rotating the right clamp 10 and a mechanism for changing the direction of rotation of the counting device 11. The tensioning device consists of a bracket 4 with an extension scale 5 fixed on it and an oscillating system with an arrow 6, a left clamp 7, a load scale 2 with a weight 3 and a counterweight 20. To fix the arrow 6 in the zero position, a lock 21 is provided. The eyepiece consists of magnifiers 8 and screen 9 with black and white background.
Figure 2.2 - Universal steepness meter
Before threading the thread into the clamps of the twist meter, set the method for determining the number of twists, the direction of the twist of the thread and the test parameters: the number of spot samples, the clamping distance, the preload.
After determining the test parameters (distance between clamps, pretensioning values), set the required distance between clamps 7 and 10. Then, by moving the weight 3 along the load scale 2, create a corresponding pretensioning force. If the required tension force should be more than 50 cN, an additional replaceable weight is installed on the weight 3, and a counterweight 19 is screwed into the right end of the load scale. The clutch switch 13 is set to the Z or S position corresponding to the twist direction of the test thread. The package with the test thread is put on the rod 17, the end of the thread is pulled through the eyes of the thread guides 1 and 23 and fixed first in the left swinging clamp 7, and then in the right clamp 10 so that the arrow 6 points to the zero division of the elongation scale 5. When determining the number twisting by direct untwisting, the arrow 6 is fixed in the zero position by the latch 21. The toggle switch 15 is set to the Z or S position similar to the switch 13. The rotation speed of the right clamp 10 is controlled by variable resistance using the handle 16. While rotating, the right clamp unwinds the thread. The parallelism of the constituent threads is checked with a preparation needle, passing it between the threads from the left clamp to the right. If the constituent threads are close to parallelization, unwinding is completed by rotating the handle 14. Then, the readings of the counter 11 are recorded and the number of twists per meter is calculated.
When determining the number of twists of the thread double twisting method the arrow limiter 6 is set so that the arrow can deviate to the left from the zero mark of the scale by no more than two divisions. Turn on the device. The right clamp, rotating in the opposite direction to the twist direction, will first untwist the thread and then twist. When untwisted, the thread is lengthened and the arrow 6 is deflected to the left to the limiter, and when twisted, the thread is shortened and the arrow moves to the zero mark of the scale. When the pointer arrow 6 returns to the zero position, the electric motor is turned off. The counter reading is twice the number of twists for a given clamping length. The calculation of the number of twists per 1 m is carried out according to the formula (2.8), taking into account that the number of twists recorded by the counter should be divided in half before being substituted into the formula.
The number of twists is calculated by the formula
, (2.8)
where n- number of tests;
L 0- clamping length, m;
Ki - number of torsions in individual tests.
Twist coefficient, characterizing the intensity of twisting of threads of different linear density, calculated by the formula
(2.9)
Since, when twisting, the constituent threads are arranged in spiral turns, their length is shortened, or twisting.
The amount of cranking,%, determined by the formula
(2.10)
where L 1 - untwisted thread length, mm;
L o - twisted thread length, mm.
In addition to the characteristics discussed above, the structure of the yarn is evaluated hairiness or fluffiness - the presence of fiber tips on the surface. Most often, the following characteristics are used to assess hairiness: the number of villi per unit length (more often per 1m) and the average length of the villi in millimeters.
Methodology for performing work
Analysis of the structure of textile yarns. The study of the structure of various textile threads is carried out on samples obtained from packages or taken out of textile materials, and consists in unwinding and examining the samples under a magnifying glass and under a microscope at low magnification. Samples of filaments taken from materials have additional crimp, therefore, before examination under a magnifying glass or microscope, it is advisable to fix them (glue the ends) in a straightened state on a paper backing or place them between two glass slides. The prepared sample is placed on a microscope stage and viewed in reflected light.
When examining samples, the main distinctive features the structure of the thread: the appearance of its surface, the number of folds, the type and shape of the constituent fibers and threads, the nature of their arrangement in the structure, the direction of twisting, etc. To determine the direction of the twist, the thread is slightly untwisted by hand over a small area. If the top end of the thread is untwisted clockwise, the thread has a right twist (Z), if counterclockwise, it has a left twist (S).
Determination of the linear density of the threads. The linear density of textile threads is determined according to GOST 6611.1-73 “Textile threads. Thickness determination method ". The test is carried out by weighing elementary samples in the form of heaps.
The type of elementary samples (frame or segment), their length and quality are established for each type of thread in the corresponding normative and technical documentation GOST 6611.0-73. When performing the work, 10 m of threads are unwound (5 samples). After that, determine the mass of the yarn and calculate the linear density according to the formula (2.1) and the trade number according to the formula (2.5). Electronic scales are used to weigh the lengths of threads.
The device and principle of operation of electronic laboratory scalesCAS MW-150T.
Scales (Figure 2.3) are intended for weighing small weighed amounts of fibers, threads, materials with a mass of not more than 150g. accurate to 0.005g. Accuracy class (GOST 241044) - 4. Type of measurements - strain gauge. The device is equipped with automatic zero setting and gain control. Laboratory balance with liquid crystal display (1), number of indicator digits -6. Working platform with a diameter of 125mm (2) made of stainless steel.
To work on electronic scales you need:
Align the device to the level (3), which is to the left of the electronic board;
Place the transparent plastic cover on the surface of the device;
Switch on the power supply unit of the balance in electrical network;
Switch on the device with the ON / OFF button (4).
Wait until the end of the automatic testing of the device (until the electronic display shows "0.000");
Open the cap lid;
Place the material to be weighed with tweezers on the center of the weighing pan;
Close the hood lid and wait until a specific value for the weight of the material has been reached.
The balance should not be located near heating devices, as well as not be exposed to air currents.
Figure 2.3 - General view of electronic laboratory balance CAS MW-150T
Determination of the diameter of threads and sewing threads. By calculation, its diameter is determined by the formula (2.7). Experimentally, the diameter of sewing threads is determined by measuring them under a microscope or thickness gauge. To determine the diameter of the threads under a microscope, they are usually wound on a glass slide in spiral coils in one layer. To maintain a constant tension, one end of the thread is glued to a glass slide, and a load is suspended from the other. Turning the glass slide evenly, wind a thread around it.
To measure the thickness of materials, as a rule, thickness gauges of the TP (manual thickness gauge) and TH (desktop thickness gauge) are used (Figure 2.4), which may differ in the measurement range, the arc of the body, and the presence or absence of a mechanism for normalized measurement of forces. The principle of operation of the thickness gauge is reduced to measuring the vertical distance between the supporting platform, on which the material sample is located, and the measuring platform parallel to it, through which pressure is transmitted to the sample.
The device and principle of operation of the thickness gauge. The standard requirements (GOST 12023-93) are met by the indicator-type TN 40-160 thickness gauge with a normalized measuring force. Graduation 0.1mm. Measurement range 0-40mm.
Check the zero setting before working on the device. If, when the measuring surfaces touch, the pointer of the reading device does not align with the zero stroke of the scale, then turn the rim to align the zero stroke with the arrow (while loosening the screw clamp on the housing).
Figure 2.4 - General view of the table thickness gauge
1 - lever, 2 - indicator, 3 - small scale, 4 - upper table, 5 - lower table, 6 - bezel, 7 - measuring rod.
It is also necessary to check the consistency of the readings. To do this, raise the measuring rod by 2-4mm and lower it two or three times. If, with the measuring surfaces closed, the arrow takes any other position, then turn the rim to align the zero line of the scale with it.
The spot sample is placed between the lower fixed and upper movable tables. The movement of the upper stage is transmitted to the indicator, which has two scales.
To measure the diameter of sewing threads to the thickness gauge, you need a special comb device. Thread the threads between the teeth of the combs and the discs of the device. After lowering the upper disc onto the threads, the arrow on the thickness gauge scale shows the value of the thread diameter. The most accurate result is obtained after threading six or more threads at the same time. In this case, the threads are less flattened under the pressure of the discs. Conduct 10 such tests, then deduce the average value, compare the obtained actual and calculated values of the thread diameter, draw conclusions.
Determination of the direction of twist, the number of additions. To determine the direction of the twist, a short section of the thread is clamped with your fingers and, holding it vertically, slightly untwisted. If the upper end of the thread is untwisted clockwise, located in the horizontal plane, it has a Z twist (silk - S twist); when untwisting the upper end counterclockwise, the thread has an S twist (silk - Z twist).
The number of folds is determined by securing both ends of the sewing threads, and unwinding it until the strands are completely parallel, which is checked with a needle. After that, one of the strands is also untwisted and the needle is divided into threads, the number of which is recorded. The total number of additions is equal to the sum of the strands included in the strands.
Determination of the balance of the twisted yarns. When the thread is twisted, due to reversible elastic and elastic deformation, a torque is generated, usually directed in the direction opposite to twisting. This leads to the unwinding of the thread and the formation of loops - sucrutin. Such a thread is called non-equilibrium. The imbalance is especially important for sewing threads and twisted yarns. Non-equilibrium thread twists get stuck in the needle holes of sewing machines and thread guides and cause the threads to break. In addition, if the thread is unbalanced in twist, then when sewing, the loop formed can deviate from its normal position so much that it will be outside the range of the shuttle nose, as a result of this, the shuttle can pass without catching the loop. The non-equilibrium of the threads is most often determined as follows. A thread 1 m long is folded in half (Figure 2.5). A thread is considered to be in equilibrium if no more than six turns are formed on its hanging part.
Figure 2.5 - Determination of the balance of the threads during twisting
a - balanced thread, b - unbalanced thread
The results of tests and calculations are entered in table 2.1.
Table 2.1 - Linear density and indicators of the structure of threads
Control questions:
- Give a definition to the concepts of linear density: actual, resulting, nominal, conditional, normalized, calculated?
- How to determine the actual linear density of threads, and why is it needed?
- How to determine the actual diameter of sewing threads, and why is it needed?
- Method for determining twist, twist, balance and number of folds of threads?
- What is twist, twist coefficient, twist?
- What sewing thread is called non-equilibrium? Influence of imbalance of sewing threads on production processes.
- How to determine the direction of twisting of sewing threads, and why is it necessary?
- List the types of textile threads.
Laboratory work No. 3
Analysis of weaving weaves
Purpose of work: Get acquainted with the methods of analysis of weaving weaves. Acquire the skills of sketching weaving weaves.
Devices and materials: tissue samples, textile magnifier, preparation needle, colored paper.
Tasks: 1. To study the classification of weaving weaves, the principles of their mathematical designation and methods of weaving analysis.
2. Conduct a weave analysis different types fabrics.
3. Make a model of weaving
Basic information
Textile Is a textile fabric formed as a result of the interweaving of 2 or more mutually perpendicular yarn systems. The threads along the canvases are called the main threads; the threads lying across the canvases are weft. The different sequence of alternation of the main and weft overlaps creates a huge number of weaving weaves, which are one of the main structural characteristics of fabrics. Weave determines the order of mutual arrangement and connection of warp and weft threads.
The meeting point of the warp and weft is called overlap... Distinguish between: main overlap, when on the right side of the fabric, the warp thread is located on top of the weft thread, and weft overlap, when the weft thread is above the warp thread. Shift (z) shows how many threads have shifted in the weave vertically overlapping one thread relative to the overlap of another.
Finished weave pattern , are called rapport. It defines the smallest number of warp threads (R 0) and weft threads (R y) forming it. The section in which the thread passes from the front side to the wrong side and vice versa is called communication field. The area where the weft and warp threads, in contact, intersect, is called contact field... Areas where the threads do not touch - free field... The through pores formed between the threads are called lumen fields... Communication, contact and free fields can be basic and weft.
The weave pattern is presented in the form of a graph (Figure 3.1). In the graph, each horizontal row corresponds to the weft thread, each vertical column corresponds to the warp thread; warp and weft threads are conventionally assumed to be of the same thickness, there are no gaps between them. The main overlaps on the graph are shaded, the wefts are left unhatched.
Figure 3.1 - Scheme (a) and graph (b) of weaving weave
The rapport can be expressed as a fraction, the numerator of which indicates the number of basic overlaps, and the denominator is the number of weft overlaps in the rapport.
Weave fabrics are divided into 4 classes (Figure 3.2):
1. Simple (main) weaves
2. Small-patterned weaves
3. Complex weaves
4. Large-patterned (jacquard) weaves.
Figure 3.2 - Classification of weaving weaves
Plain weaves fabrics have the following features: warp rapport is always equal to weft rapport; each warp thread is interwoven with each weft thread only once. Plain, twill and satin (satin) weaves are considered simple weaves.
Plain weave has the smallest rapport: Rо = Rу = 2. Plain weave fabrics are bilateral, with a uniform smooth surface on the front and back sides (Figure 3.3). Since the threads form only the fields of connection and contact, the structure of the plain weave fabric has the greatest cohesion and, all other things being equal, greater strength and rigidity. This weave is the thinnest, lightest and least dense fabrics.
Twill weave has a rapport R ≥ 3, S = 1. It is denoted by a fraction: its numerator shows the number of main overlaps within the rapport, and the denominator shows the number of weft overlaps.
Twill are distinguished: weft 1/2,1/3, 1/4, on the front side of which weft overlaps prevail, and the main 1 / 2,1 / 3, 1/4, on the front side of which the main floors prevail. Characteristic feature twill weave fabrics is the presence on the surface of noticeably pronounced diagonal stripes formed by longer overlaps (Figure 3.4).
Figure 3.3 - Scheme and graph of plain weave
Figure 3.4 - Scheme and graph of twill weave
Most often, the direction of the diagonal is positive - to the right, less often negative - to the left. The angle of inclination of the diagonal ribs depends on the ratio of the thickness of the warp and weft threads and the density of their location. The fabrics of this weave are distinguished by greater softness, elasticity, extensibility, and drape. The main twill weave produces semi-silk fabrics. Weft twill weave produces semi-woolen fabrics, cotton warp and woolen weft.
Satin (satin) the weave is characterized by a rapport R≥5 and a shift z ≥ 2. The front side of the satin weave is formed by long main overlaps, and the satin weave - weft. The fabrics formed by these weaves have a smooth, even surface with increased sheen. Silk fabrics (satins) are most often produced with satin weave (Figure 3.5), satin - cotton sateen (Figure 3.6).
Figure 3.6 - Scheme and graph of satin weave
Small-patterned weaves are divided into two subclasses: derived main weaves and combined.
Derivatives weaves are formed by a modification of the main ones. These include derivatives of plain weave, such as matting, reps (Figure 3.7), twill - for example, reinforced twill (Figure 3.8), complex twill (Figure 3.9), reverse twill (Figure 3.10), as well as derivatives of satin (satin) - reinforced satin, reinforced satin.
Figure 3.7 - Scheme and graph of the rep weave
Figure 3.8 - Scheme and graph of weaving reinforced twill
Figure 3.9 - Scheme and graph of weaving complex twill
Derived weaves are obtained by reinforcing single main or weft overlaps. Matting weave fabrics are obtained by increasing the main and weft overlaps at the same time. In the fabrics of this weave, a checkerboard pattern is more noticeable (Figure 3.11) .
Figure 3.10 - Scheme and graph of weaving reverse twill
Matting weave fabrics are obtained by increasing the main and weft overlaps at the same time. In the fabrics of this weave, a checkerboard pattern is more noticeable. .
Figure 3.11 - Scheme and graph of weaving matting
TO combined weaves include crepe (Figure 3.12), embossed, etc. They are formed by combining different weaves.
Complex weaves include double, multilayer, pile. At least three systems of threads are involved in their formation.
Figure 3.12 - Scheme and graph of crepe weave
V double the weaves of the front and back sides are most often formed from threads of different quality or color and may have different weaves. Since the threads of the upper and lower weaves are located one above the other, double weave fabrics have a significant thickness.
Double weaves can be double-faced and double-layer. D vuhface(one and a half ply) are formed from one warp and two wefts or two warps and one weft.
Figure 3.13 - Diagram of a cut of a two-layer weave fabric with different ways links of canvases
Double layer weaves are formed by two systems of warp threads and two - weft. The connection of the canvases is carried out over the entire area of the fabric using the lower base, using the upper base or using a special clamping base (Figure 3.13).
Figure 3.14 - Scheme of the incision of the weft nap weave
Pile weaves can be weft-nap (Figure 3.14) and warp-nap (Figure 3.15). The surface of the pile weave fabrics is covered with trimmed or terry pile. In the fabrics of openwork weave, the warp threads lie in zigzags, passing from one row to another and making up a transparent pattern that resembles a hemstitch.
Figure 3.15 - Diagram of the incision of the fabric of the warp weave
Large-patterned (jacquard) weaves have a large rapport (over 24). Such weaves are produced on special jacquard machines.
Methodology for performing work
Determining the type of weave... Starting to analyze the weave, first determine the direction of the warp and weft, the front and back sides of the fabric, after which they begin to sketch the weave.
Definition of warp and weft. The warp threads always run along the edge. If there is no hem in the swatch, pull the fabric in both directions - usually the fabric pulls more along the weft. If several threads of both directions are removed from the sample with a preparation needle, the weft threads will be bent more than the warp threads (the exception is rep-type fabrics with a thin base and thick weft). The warp threads are usually more twisted than the weft threads; they are smoother and harder, the weft threads are looser and softer. More often the warp threads have a twist direction Z, weft threads - S. If in one direction of the fabric are located twisted threads, and in the other single, then the warp threads will be twisted. The main threads are located more evenly, parallel to each other, sometimes two or three threads from the teeth of the reed remain in the fabric. The density of the fabric along the weft is less uniform: there may be threads located arcuate or superimposed one on top of the other, there are often distortions of the fabric along the weft.
Determination of the front and back sides of the fabric. To recognize the front and back sides, the fabric should be placed so that both sides can be compared at the same time. In this case, the warp and weft threads in the compared sides should be located in the same direction. In some tissues, the difference between the front and seamy sides is more pronounced, in others it is hardly distinguishable. The weave pattern appears more prominently on the front surface. The front side finish is more thorough, and the fiber tips are less visible. In pile fabrics, the split pile is always located on the front side. In fabrics with a pile, the pile on the front side is thicker, better rolled up, shorter cut than on the wrong side. In printed fabrics, the design is on the front side.
In this review article, we will try to tell you how to determine the length of the thread in a skein of yarn, the label from which was lost or not at all. Also, a few words will be said about what difficulties may arise when knitting a product according to ready-made description using a different yarn.
It happens that you have yarn stale at home, and the label from it has long been lost, and it is not possible to find out how many meters there are in a skein. In this case, there is a universal method that can help you resolve this issue. Of course, you can use the most primitive method, with the help of a meter, measure the length of the thread in the skein by unwinding it. However, I want to suggest an easier way.
Take a regular student's ruler and wrap the yarn around it, placing the skeins close to each other without overlapping. Now count how many skeins fit in 2.5 cm, well, then use the table below and determine the thickness of the yarn from it.
I use this method when I buy yarn from the market. The skeins are sold there without labels or generally in hanks (that is, the yarn will need to be reeled up later). By the way, there is one effective method which can help determine your preferred knitting needle number. To do this, take the yarn from which you are going to knit and fold the thread in half, twisting it a little. Now measure the width with a ruler. Let's say you get 2.5 mm, this means that you need to take needles with a thickness of 2.5 mm.
Now let's talk a little about what to do if you liked the model from the magazine, but it is impossible to find the same yarn indicated there. First of all, it is necessary to take into account that when replacing yarn, that is, selecting an analogue, you need to pay attention to the composition of the yarn and the ratio of length and weight.
Even though if you find the perfect replacement, the knitting density indicated on the model may not match yours. This may be because the twist of the original yarn and the analog yarn is different. For example, a yarn analog has two strands, while an original has three. In this regard, in cross-section, these two threads are different, the original will have an almost circular cross-section, but the yarn of two threads is oval. The same can be the case when you fold several thin threads into one to obtain the required knitting density. Due to the fact that the folded threads are not twisted, the section also turns out to be oval, not round.
But despite all the obstacles, if you manage to choose the yarn that is as close as possible in terms of knitting density, the conceived product will turn out, and it will practically not differ from the one shown in the original.
knitweek.ru
How to calculate the "footage" of a thread, folded from two threads of different thickness .: ru_knitting
You have two strings: one 350m / 100g, the other 500m / 100g. You put them together to knit and for some reason (for example, to calculate the future consumption of yarn) you want to know how many meters per 100g. will be in a new thread.UPD. The number of meters of yarn per unit of weight (usually 100 grams) is usually called "meter". This characteristic is indicated on yarn labels.Using the law of conservation of mass and simple manipulations with fractions, I got the following formula: P1 - "footage" of the first string P2 - "footage" of the second string P - "footage" of a string folded from the first two P = (P1xP2) / (P1 + P2) In our example about 206m / 100g. Solution: From our definition it follows that "footage" = length / weight Take two pieces of our threads 1 meter long. Their total mass will be equal to the sum of the masses of the constituent threads. We can calculate the masses of these segments, since we know the length and "footage" of each. Mass = length / "footage". We get the formula: 1 / Р = 1 / Р1 + 1 / Р2 We bring to a common denominator, simplify and get the formula Р = (Р1xР2) / (Р1 + Р2). Divide the product of our values by their sum. UPD Adding from comments: olga_vadimova wrote:
I will repeat the thought again - the final universal formula makes it possible to calculate the footage of a new thread, made up of the n-th number of different threads with the footage specified at different weight ni_spb wrote: ... how can you calculate the "footage" for the n-th number of threads: 1 / P = 1 / P1 + 1 / P2 + 1 / P3 + ... -if you fold three strings or more, then nothing changes, except for the number of terms in the formula. The total mass is equal to the mass of the components. P from here it will not be difficult to calculate in each case. Regarding different threads with the "meter" indicated for different weights of balls: Suppose you have one value of 300m / 50 grams and the other 588m / 112 grams. Divide 300 by 50. And also 588 by 112. Work with these numbers (you will have these values P1 and P2). The result obtained by the formula (in this case 2.8) can be reduced to a convenient form. If you multiply it by 100, you will get the footage of a new thread in 100 grams. Multiply by 25 - respectively in 25 grams.
ru-knitting.livejournal.com
Lesson 1. Selection of threads and knitting needles
Let's talk with you today about the choice of knitting needles and yarn for knitting. The quality of the knitted product is highly dependent on the right combination the thickness of the needles and the thickness of the thread.
As a rule, with knitting needles of small diameter (No. 1-3), this is how openwork patterns and graceful things from thin threads are knitted. Consequently, thicker yarns require thicker knitting needles. How to determine what size of knitting needles we need?
If you have a yarn with a label, then you need to look at the label. On it, the manufacturer usually indicates the size of the needles recommended for a given yarn. An example in the photo - knitting with these threads requires knitting needles with a number of 2.5 to 4 mm.
How to determine the size of the knitting needles? As a rule, the number is indicated on the needles. This number is equal to the diameter of the spoke in mm. If you don't have a number on your knitting needles, it doesn't matter. It is very simple to define it. Take a thin sheet of paper and pierce it with a knitting needle. Then measure the resulting hole with a ruler, this value will be the size or number of the spoke.
But what if the recommended number of knitting needles is not indicated on the yarn or if you have threads without a label at all? Then we will use the rule: the diameter of the needles should be approximately twice the diameter of the thread. It is better to measure two strands at once, so the value will be more accurate. An example of measuring a thread and selecting knitting needles for them is in the photo below. As you can see, the diameter of the two threads is 4 mm, which means that the needles are needed No. 4, which coincides with the recommendations indicated on the label
For your first experiments, I would advise you to take knitting needles No. 4-5 and yarn in which the length of the thread in a skein is approximately 300 m in 100 g (this is also indicated on the label). It is better to take acrylic or half-woolen yarn, twisted into one thread.
A few more words about knitting needles. On sale we will be able to meet a large number of different types knitting needles. Which one is better to choose? Knitting needles are long straight, two in a set, these are used for simple straight knitting. Also, the knitting needles can be short, in a set of 5 pieces, these are used for circular knitting, such as socks. For circular knitting of large products, circular knitting needles are used, these are 2 knitting needles connected by a fishing line.
The needles can be made from a variety of materials. It can be wood, bone, plastic or metal: aluminum or steel, plated with chrome or nickel, so that each craftswoman can choose the knitting needles that will be convenient for her to work with. For starters, I would suggest choosing straight long metal knitting needles. It will be easier to knit with them, because the thread slides along them easier and they do not bend during work. Also pay attention to the ends of the needles. They should be sharp enough to easily pry on the loops, but at the same time not very sharp so as not to split the thread.
vjazem.ru
Determine the diameter of the nylon thread in the mesh by its designation in the Den and Tex standard
Determination of the diameter of the thread of nylon mesh cloth of Russian and Western manufacturers.
Many questions arise about the thickness and strength characteristics of nylon fabrics. Let's try to deal with this issue.
It is difficult to measure the thickness of the thread with simple measuring instruments. But, depending on the structure and density of the thread, its strength will vary greatly. By and large, specifying the diameter itself will not tell us anything about the strength of the thread. But, nevertheless, it is easier to operate with a diameter and compare nylon with a fishing line or monofilament, knowing exactly the diameter.
At the moment, when indicating the structure of the threads of a fishing net (net plates), two main units of measurement are accepted, Tex and Denier (Den). Moreover, in Russia, at the network factories, only the Tex unit of measurement is adopted, and foreign manufacturers have heard little about this unit and the Den unit of measurement is adopted throughout the world to designate the structure of threads. It's clean technical specifications used to determine the density of the product or the texture of the fabric, as well as knitted fabric. Well known to our women when specifying the characteristics of hosiery.
And so, 1 Den (D) is the ratio of the mass of a thread to its length, roughly this is the number of grams of a thread in 9 kilometers of its length. On the pages of the Chinese fishing store, you can find a set of sheets of foreign companies of the following designations:
- 110D / 2
- 210D / 2
- 210D / 3
- 210D / 6
The most accurate thread diameter for the Denier system can be determined by the formula:
Diameter = A * Square root (D * n / 9000), where
- A - empirical coefficient for nylon = 1.5-1.6;
- D is the density of the thread under Den;
- n - the number of primary threads in a thread
For example, let's calculate the thread diameter: 110D / 2 and 210D / 3 using the smallest factor A = 1.5:
- 1.5 * √ (110 * 2/9000) = 0.234 mm;
- 1.5 * √ (210 * 3/9000) = 0.396 mm.
In Russia, a similar, but coarser unit of measurement is used, Tex (from Latin texo - fabric) - the weight of one kilometer of thread.
- 15.6 tex * 2;
- 29 tex * 3;
- 93.5 tex * 3;
- 187 tex * 2, etc.
The diameter of the thread, the density of which is indicated in Texs, can be calculated using the same formula, but you need to divide not by 9000, but by 1000.
- 1.5 * √ (29 * 3/1000) = 0.442 mm;
- 1.5 * √ (93.5 * 3/1000) = 0.794 mm.
In the clothing industry, it is used to indicate the thickness of a thread, its number, which determines the length of one gram of thread. The thread number is 1000 / tex
kitaiki.ru
How to determine the length of the yarn and the correct knitting needles in the absence of a label
What to do if the yarn label is suddenly lost or missing altogether?
How to determine the length of the yarn and the correct knitting needles?
In the absence of identification marks on the yarn initially or if the label is lost, you can use simple method determining the required amount of yarn, as well as the required knitting needles for knitting with this yarn.
We tightly wrap a regular school ruler with a thread of yarn in an interval of 2.5 cm without overlaps and count the number of turns that fit into this interval. Next, we use the table below.
| Very thin | 18 | <2 | 32 and more | 600 and more | 2000-2500 |
| Thin | 16 | 2-3 | 27-32 | 380-550 | 1600-2000 |
| Welterweight | 14 | 3-4 | 23-26 | 240-370 | 1400-1600 |
| Average | 10-14 | 4-4.5 | 21-24 | 200-240 | 1250-1400 |
| Half fat | 12 | 4.5-6 | 16-20 | 170-200 | 1000-1250 |
| Thick | 10 | 6-8 | 12-15 | 110-160 | 900-1000 |
| Very thick | 8 | 8 and more | 6-11 | Less than 100 | 750-900 |
shimbashop.ru
Yarn thickness: hanima
In the process of knitting shawls, I studied and pondered the following questions The unit of measure for the thickness of the threads is tex. The thickness of the threads T in the tex system is determined by the amount of mass (weight) per unit of its length:
where g is the mass (weight in g); L 0 - thread length in km; L is the length of the thread in m.
The dimension of the text is g / km.
The tex system is straightforward, so the thicker and heavier the threads, the greater their numerical characteristics. The fineness of the threads is indicated by a number. This is the inverse of the tex. The fineness of the thread, indicated by the number, is the ratio of the length of the thread L to its weight g.
The number shows the length of the thread in unit of weight (meters in grams or kilometers in kilograms). Therefore, the thinner the thread, the higher its number. The relationship between text and number is expressed as follows:
The projected thickness (in tex) or thread number are called nominal. According to the nominal thickness or number, the weight of the material indicated in the price lists and GOSTs is calculated. The actual, i.e. established during laboratory testing, thickness or number of threads does not always correspond to the nominal. The deviation of indicators obtained during laboratory testing should not exceed 2% of those specified in GOST. The deviation is determined by the formulas:
where T 0 and N 0 - nominal thread thickness in tex and nominal number; TF and Nф - the actual thickness of the thread in tex and the actual number; ΔT and ΔN - deviation of the actual thickness of the thread and the number from the nominal.
The thickness (fineness) of the yarn and filaments are given in table. 1-1, 1-2.
For twisted threads, it is possible to determine the nominal-design thickness or the nominal-design number without taking into account the twist, i.e. shortening from the spiral arrangement of the twisted threads and the normal thickness (or number) taking into account the twist.
Table 1-1. Thickness (fineness) of yarn
| Fibrous composition and characteristics of raw materials | Spinning method | Thickness (fineness) of yarn in tex (N) |
| long-fiber | Combed |
|
| medium fiber | ||
| short-fiber and waste | Hardware | |
| long-fiber | Combed wet |
|
| long-fiber | Combed dry | |
| short-fiber and fleece | Carded wet | |
| short-fiber and fleece | Carded dry | |
| uniform thin and semi-thin; pure and blended with chemical staple fibers | Combed for fine wool | |
| homogeneous and heterogeneous; semi-coarse and rough; pure and blended with chemical staple fibers | Combed for coarse wool | |
| homogeneous and heterogeneous; short, thin and semi-thin; pure and blended with cotton and man-made fibers; combing waste, | Hardware for fine wool | |
| heterogeneous short; semi-coarse and rough; pure and blended with cotton and chemical staple fibers; combing waste, scrap | Hardware for coarse wool | 670-125 (1,5-8,0) |
| Natural silk: | ||
| cocooning waste, twisting and defective cocoons, combed spinning waste | Combed | |
| Combed | ||
| Hardware | ||
| Chemical staple fibers |
When twisting threads of the same thickness, the nominal calculated thickness or number is determined by the formula:
where T p is the nominal calculated thickness of the thread in tex; T 0 - nominal thickness of a single thread in tex;
N p - nominal settlement number; N 0 - the nominal number of a single thread; n is the number of twisted threads.
Table 1-2. Thickness (fineness) of filaments:
| Fibrous composition | Thread type | Thickness (fineness) of threads in tex (N) |
| Natural silk: | ||
| silkworm | Raw silk | 2,3-1,5(429-643) |
| oak silkworm | Raw silk | |
| Artificial fibers | ||
| Synthetic fibers | Complex yarns with a gentle twist | |
When twisting two threads of different thickness, the nominal calculated thickness (fineness) is determined by the formulas:
To calculate the normal thickness or fineness, the amount of twist must be determined, as a result of which a twisted thread of length L 2 is obtained from threads of length L 1.
Hence, the normal thickness T n and the fineness N H of the thread are equal:
For some calculations, it is necessary to know the size of the thread diameter. With the same thickness in tex, threads made of different fibrous materials, with different degrees of straightening and orientation of the fibers, with different intensities of twisting, compressing the fibers in the threads, have different bulk density and unequal dimensions of the apparent diameter.
Since the determination of the actual value of the thread diameter under a microscope is associated with a large investment of time, the thread diameter is usually calculated by calculation. The weight of the thread g is found by multiplying its volume by the volumetric weight β (weight referred to the volume measured along the outer contour):
Conditionally taking the thread for the correct cylinder, you can write:
Solving the equation for the diameter d, we have:
Taking:
we get the final formula for the calculated thread diameter:
Thickness is one of the most important yarn characteristics. The thickness of the yarn is estimated using various indicators: the diameter of the cross section of the fiber, the area of this section, the system of tex and the number. (True, by means of the number it is not actually the thickness that is determined, but the fineness of the yarn.)
Yarn number
A factory-made skein label often contains a fractional yarn number, such as No. 32/2. The numbers up to the line indicate the metric number of the yarn: the higher the number, the thinner the thread.
The metric number expresses the length of one gram of yarn in meters (m / g or, equivalently, km / kg). The number after the line shows how many threads the yarn is twisted.
Example. The ideal yarn for machine knitting (thin) - 32/2 in 1 kg has a length of 16 km, because it consists of two strands.
In a skein 100 g - 1600 m
in 2 additions - 1600: 2 = 800 m / 100 g;
in 3 additions - 1600: 3 = 533 m / 100 g;
in 4 additions - 1600: 4 = 400 m / 100 g;
in 5 additions - 1600: 5 = 320 m / 100 g;
in 6 additions - 1600: 6 = 267 m / 100 g, etc.
Tex
According to the international system of tex, instead of fineness, the thickness of the fibers in tex (unit of linear density) should be measured.
Tex Is the amount of mass per unit length.
1 tex is the mass of one kilometer of thread in grams.
Number and tex are reciprocal values.
The word tex comes from lat. weave.
Wraps per inch
You can determine the yarn number by taking a ruler and winding the thread tightly (or on a pencil and attaching it to the ruler), counting how many threads or turns will fit in one centimeter or inch. This method is not applicable for fine yarns such as mohair (therefore, the cells in the table below are not filled for fine and very fine yarns).
WPI= wraps per inch - the number of wraps in one inch (2.54 cm).
Thread count (Ply)
Ply Is the number of threads that make up the yarn. 2-ply yarn, for example, is twisted from two strands (twisting allows you to "balance" the thread). The yarn sold in shops is usually more than 2 strands spun.
It is clear that there is no direct relationship between the thickness of the yarn, the knitting density and the number of threads from which the yarn is spun. Say, both thin yarn (floss) and thick (wool) can be spun from 6 threads. However, by old standards, 4-ply is synonymous with fine yarn (criticism)
