Reinforced threads (LL, LH). Chemical properties of LH threads

I don’t know how it is in other cities and countries, but in my city the assortment of sewing threads on store shelves is represented by 10% threads from domestic manufacturers and 90% threads from foreign manufacturers.

A large number of threads come to Russia from China, Taiwan, India under the trademarks: “DOR TAK”, “DON HIEAN”, “NEW STAR”, “NEW ERA”, “WONDER THREAD”, “SILVER THREAD”, “WINTER BIND” , "DC", "BUTTERFLY", "Routsher", etc.

Moreover, most of the imported threads are represented not by the manufacturers themselves, but by intermediaries. At the same time, the threads are supplied in modified packaging and under a different name, which creates certain problems for buyers, that is, you and me.

For example, sewing threads under the trademarks “MAX BASIC”, “MAX AG” and “Ideal” are registered on the Russian market by the company “MAG”, which distributes sewing accessories. The well-known company "Gamma" offers polyester threads of "own production" under the trademarks "Nitka" and "Gamma". Who is the real manufacturer of these threads? Not known.

However, we, ordinary consumers, are of little interest in the name of the manufacturer. Much worse is that the packages of threads do not indicate the characteristics of the thread, in particular there is no thread number. When asked about the thread number, sellers shrug and answer: polyester. That's all they can say. 🙂

Let's try to figure out together what it is polyester threads, and how they correlate by number with cotton threads, so familiar to the older generation, which have almost disappeared from sale and are present in all.

Cotton threads have almost disappeared, replaced by durable reinforced threads made from synthetic fibers.

A little theory.

Reinforced threads are produced by connecting a core of polyester filament yarn and a braid of cotton (LC), polyester (LL) or siblon (LS) fiber.

Some information from the conditional O designations of threads made in Russia

L— lavsan X - cotton WITH - siblon

If there are two letters LL, LH or LS in the thread marking, these are reinforced threads

The first letter indicates the type of core thread.

The second letter indicates the type of braid fiber

Cotton lavsan reinforced threads LH are distinguished by their ability to withstand high temperatures (up to 200°C).

Polyester reinforced threads LL are considered universal and provide high strength of the connection of parts, good appearance and elasticity of the stitching. They are used for stitching parts, sewing cuts and making finishing stitches.

But, let's return to imported polyester threads.

Polyester(aka polyester) is the trade name for polyester threads, an analogue of lavsan. Those. polyester threads are lavsan threads produced in Russia under the LL marking.

How to compare the size of reinforced LL or LH threads with cotton threads?

Reinforced threads 45LL or 44 LH (photo below) are similar in thickness to cotton threads No. 40, recommended for sewing items from suit and coat fabrics.

Polyester threads “DOR TAK”, “DON HIEAN”, “NEW STAR”, “Ideal” and others like that (next photo) are a little thinner and can be considered substitutes for cotton threads No. 50.

They correspond to Russian-made threads marked 36ЛХ and 35ЛЛ. Recommended for sewing items from thin and medium fabrics, as well as knitted fabrics.

For sewing products made from denim materials, leather and leather substitutes, threads marked 65LH, 70LL, 80LL are used.

If you are interested in more detailed information on threads, I recommend downloading and studying the Handbook “Assortment of sewing threads, the most famous manufacturers, selection and determination of sewing thread consumption for a product.” It contains a lot of valuable and useful information :)

My blog is found using the following phrases

Sewing thread - this is an extended, thin, evenly twisted yarn or thread with special properties that allow it to be used for sewing. Sewing threads are the main material for fastening clothing parts made of fabrics, knitted and non-woven fabrics, fur, leather, etc.
When working the thread is subjected to repeated stretching and bending, friction and abrasion (for example, against the eye of a needle and the material being joined, etc.). These effects partially disrupt the integrity of the thread and reduce its strength.

When using the finished product the thread in the seam is also subject to various influences - insignificant in magnitude, but repeated stretching and bending; friction; exposure to detergents during washing and chemicals during dry cleaning; high temperatures and pressure during ironing. These impacts also destroy the threads in the seams.
In other words, the features of sewing technology and operating conditions of finished products dictate certain quality requirements for the sewing threads selected for sewing.

Particularly strict requirements are imposed on their strength, which depends on the quality of the original yarn, the fibrous composition of the threads, their additional finishing, etc. (see below" Properties and structure of sewing threads ").
The quality of sewing threads is regulated by standards that indicate performance standards for the most important characteristics.

Requirements for the quality of sewing threads

Sewing threads must have:
- high tensile strength and sufficient elasticity (to reduce breakage on sewing machines and ensure the necessary seam strength during product use);
- be uniform in thickness (also for uniform tension in the sewing machine and the formation of a high-quality seam);
- have high color fastness to the effects of light weather, dry cleaning, washing;
- be heat-resistant (to prevent breakage from melting of synthetic threads or overheating of natural and artificial threads, etc.).

The properties and structure of sewing threads are determined by:

Fibrous composition;
. number of additions;
. direction of twist;
. thick;
. final finishing.

Let's take a closer look...

By fiber composition sewing threads are divided into natural (cotton, silk, linen); chemical (polyester, polyamide, viscose); combined from various fibers (see section below " ").

According to the number of folds, threads can be single-twisted in 2 or 3 folds and double-twisted in 4, 6, 9 or 12 folds.
- Single-twist threads are produced by twisting 2 or 3 original individual threads. Hence their name - single-twist in 2 or 3 additions (see below Figure 1 " Sewing thread structure ").

To obtain two-twist threads, the original threads are pre-twisted into 2 or 3 folds. Then the resulting single-twist semi-finished products are twisted together once again completely. Depending on the number of initial components in the first and second stages of twisting, these threads are called double-twist in 4, 6, 9 or 12 folds.

Important!

For sewing, the use of double-twist threads is more preferable, since, thanks to the additional fastening of the fibers when twisted, they acquire greater strength, better resist abrasion, and this reduces thread breakage when sewing a product, and the stitching is smoother. Increasing the number of plies also increases the strength of the threads.

Picture 1. The structure of sewing threads.

In the direction of twist threads come in right (Z) and left (S) final twist. It is preferable to use right-twist threads, since they have less breakage in sewing machines than left-hand twist threads.

Important!

The direction of twisting the threads can be determined in this way: untwist a piece of thread with your right hand between the thumb and forefinger clockwise. If the thread is additionally twisted, then it has a twist (S), and if it unwinds, it has a twist (Z)

By thickness Sewing threads are also very diverse. The thickness of sewing threads is characterized by a trade (conventional) number or linear density (tex). Threads of different fibrous compositions have their own trade numbering. For example, cotton threads have trade numbers 10, 20, 30, 40 and so on; natural silk threads - 18, 33, 65; lavsan threads - 22 L, 33 L, 55 L, etc.; nylon threads - 50 K.

It is important to know: for threads made of natural fibers (cotton, natural silk), the higher the number, the thinner they are. With synthetic threads, on the contrary, thinner threads have lower numbers.
And one more thing: If the thickness of the threads is the same, it is recommended to pay attention to the number of folds - the more threads are twisted, the better the quality of the threads.

By type of finish threads can be gray, matte, glossy, white, colored, black. Bleaching and dyeing reduce the strength of threads. Glossy threads are stronger than matte threads.

Recommendations for using sewing threads
1. Regardless of whether you sew by hand or on a machine, different threads are used for each type of work (for basting, for sewing stitches, for finishing a product with decorative seams, etc.). In each case, they must be selected individually, taking into account the required strength of the seams and their purpose. General recommendations for using various sewing threads are given in Table 2" Purpose of sewing threads " (see below).
2. To obtain high-quality stitches when sewing products, it is necessary to choose the right threads, take into account their fibrous composition and thickness.
The correct choice of thread depends, first of all, on the fabric - its thickness and composition. For example, when sewing thick materials, thicker threads are used, when sewing thin materials, thinner threads are used. The raw material composition of the threads must also be similar or similar to the composition of the fabric, since the care requirements for the selected threads and the fabric itself must match. The thickness of the sewing thread, in turn, serves as the basis for choosing a sewing needle of the required diameter: the thicker the thread, the larger the needle should be.
And further:
- Threads used for sewing products must match the color of the material or be combined with it.
- The threads on the spool always look darker than on the fabric. Therefore, in order to correctly determine their color, it is recommended to choose threads slightly darker than the color of the fabric.
- Instead of cotton threads, it is allowed to use chemical threads and fibers of similar thickness.

Recommendations for the interchangeability of sewing threads of different compositions are given in Table 3 " Interchangeability of sewing threads " (see below). The basis for compliance is their thickness (linear density).

Table 2 "Purpose of sewing threads"

Table 3 "Interchangeability of sewing threads"

Characteristics of sewing threads by raw material composition
When sewing, there should be a lot of threads - in a large assortment and with a wide selection of colors. When choosing threads, you should pay attention to their thickness and composition.

Important!

For each type of work, and also depending on the characteristics of the material, threads must be selected individually - there are no “UNIVERSAL” sewing threads. As a rule, the basis for the correct choice of threads is, first of all, their raw material composition. And one more thing: threads of different composition with the same numbers will not be the same in thickness, which must be taken into account when choosing threads.

Raw material composition of threads
Sewing threads are made from natural and chemical fibers and threads.

Cotton threads (Cotton)
They are used in the manufacture of almost any type of garment, and natural raw materials make these threads indispensable in the production of clothing for children.

Depending on the finishing method, cotton threads are available in matte and glossy versions, harsh and treated with special compounds, and different colors. The most expensive option today is mercerized cotton threads.

Depending on the thickness, sewing threads are assigned trade numbers. The trade number is the conventional number of the threads, characterizing their thickness. As a rule, the higher the number, the thinner the thread.

Cotton threads are produced in the following trade numbers: 10, 20, 30, 40, 50, 60, 80, 100.

The use of threads depends on their thickness. For example, threads No. 80 and No. 100 are the thinnest, so they are used for sewing products from the thinnest fabrics, and threads No. 30 and No. 40, respectively, are suitable for products made from denser and thicker fabrics (see Table 1 from the section " Tools and accessories for manual work. Hand sewing needles ").

When performing manual work (for example, basting parts), it is recommended to use thin (No. 60-80) cotton threads.

Based on their strength, cotton threads are divided into the following brands: “Prima”, “Extra”, “Special”, “Especially strong”. Prima brand threads are the least durable. Threads of the “Especially Durable” trademark are used for the manufacture of workwear.

Silk threads (sewing silk)

Due to insufficient strength, the range of silk threads is currently quite limited (replaced by chemical analogues). Silk threads are used mainly for finishing work and machine embroidery.

By thickness, natural silk is divided into

thin No. 65,

average No. 33,

thickened No. 13, No. 18.

Thread No. 65 is used for joining and sewing parts made of thin fabrics (for example, organza, chiffon, etc.);

for finishing stitches on medium-thick fabrics, No. 33 is suitable; No. 18

and 13 - for machine sewing buttonholes, sewing on buttons and for performing finishing stitches on woolen fabrics.

Linen threads

Intended for the manufacture of products for technical purposes and household consumption, for example, tarpaulin products; sewing shoes (in saddlery), making lace.

Viscose threads

In appearance they are similar to threads made from natural silk. A feature of viscose threads is their reduced strength when wet. Therefore, in the sewing industry they are used in limited quantities, mainly for embroidery.

Synthetic threads

Synthetic threads are produced from polyester (lavsan) and polyamide (nylon) fibers and threads, both in pure form and in mixtures. Such threads have increased strength and low shrinkage.

Important!

For synthetic threads, their conventional numbers are commensurate with their linear density (thickness).

According to production method synthetic threads are divided into complex, reinforced (combined), textured (voluminous, elastic), monofilament, etc.

Complex synthetic threads in appearance they resemble threads made of natural silk.
. Complex nylon threads They have high strength and are superior in abrasion resistance to all other threads, so they are widely used for sewing buttonholes, as well as in the manufacture of clothes from durable, non-shrinkable materials. They have a commercial designation of 50K.

The heat resistance of threads is low, so wet-heat treatment of products made using nylon threads should be carried out through a moistened ironing iron at a temperature of 160-165 ° C and for no more than 30 s.

. Complex lavsan threads also non-shrinking, but inferior to nylon in strength and abrasion resistance, but superior to them in heat resistance. Trade numbers: 22L, ZZL, 55L, 90L. Thin threads 22L, ZZL are used for the manufacture of linen, shirts and suits and dresses, and thick threads 55L, 90L are used for embossed finishing stitching.
Lavsan and nylon threads can withstand short-term heating to a temperature of 240-270°C.

Important!

Sewing threads made from filament threads are characterized by their low thickness with a significant breaking load. Therefore, you can use complex threads with a thickness equal to the thickness of commonly used cotton threads, but get a much stronger seam.

Textured sewing thread (elastic)

Currently, the most widely used polyester textured threads (PT) are bulky threads with loops on the surface.

Textured sewing threads are used for overcasting sections of parts, as well as in the manufacture of garments from elastic knitted fabrics. They provide strong, stretchable seams with good coverage, which is also important when processing items made from easily frayed fabrics. Thread designation - 18 LT, 24 LT, 37 LT, etc.

Reinforced sewing threads

They are produced by connecting a core of polyester (lavsan) filament thread and a braid of cotton (LC), polyester (LL) or siblon (LS) fiber.

Due to their combined properties, reinforced threads are universal; they are used in the sewing, knitting, footwear, and leather goods industries for stitching parts, overcasting edges, and performing finishing stitches.

.
. Reinforced cotton lavsan sewing threads 36 LH, 36 LH-1, 35 LL are suitable for sewing products from thin and medium-thick fabrics and knitted fabrics; 44 LH, 44 LH-1 and 65LH, 65 LH-1 are recommended to be used instead of cotton threads of trade numbers No. 30 and 40. Threads have high strength, heat resistance, elasticity and wear resistance, as well as slight shrinkage. They are resistant to dry cleaning and washing.
.Reinforced lavsan threads with braided lavsan fibers also provide thread seams with the required strength and wear resistance. Threads with number 35LL are used for sewing products from thinner fabrics and knitwear; 45 LL, 70 LL, etc., respectively, are suitable for denser and heavier fabrics.

Monofilament

The range of transparent threads is interesting and promising. They can be colorless for processing light-colored materials and pigmented (tinted gray, brown) for dark tones.

The starting raw material for their production is polyamide (nylon or nylon), which has high elastic properties, great abrasion resistance and transparency.

Treated with special optical preparations, they are able to acquire the color of the material being processed. Therefore, when sewing fabrics of different colors, the need for frequent refilling of sewing machines is eliminated. They are produced under the numbers 7KMP, 13KMP and 20KMP. Transparent threads are recommended for sewing shirts made of polyamide fabric, women's blouses and knitted dresses in medium and light colors.

Staple synthetic threads (LS)

In structure and appearance they are close to cotton, but they are distinguished by greater strength and less shrinkage. They are softer than complex ones and more resistant to high temperatures.

The staple thread is universal in use: 27 LSh - used for sewing thin linen, dress, silk and shirt fabrics; 40 LSh - fabrics of medium surface density; 80 LSH - leather goods.

All of the above types of threads are not a complete list of threads used in sewing production today; their range is much richer and more diverse.

Polyester bag stitching thread made from staple lavsan. Made from 100% polyester staple fiber. They have the property of resisting repeated dynamic tension, ensuring the strength and elasticity of seams during longitudinal transverse stretching of the seam line.

Bag stitching threads

Designed for sewing bags made of polypropylene, burlap, paper, as well as sewing products from tarpaulin and awning fabrics.

The material of the container thread has high strength, resistance to moisture, low temperatures and high dynamic loads. LS thread does not require special lubrication, and its soft texture increases the service life of the parts of bag sewing machines in contact with it.

LH thread, LL thread, reinforced cotton-lavsan, reinforced polyester. They are made from polyester filament yarn and braided cotton (LC) or polyester (PL) fiber. Polyester reinforced threads LL are considered universal and provide high strength of the connection of parts and good appearance
and stitch elasticity. These threads are used for overcasting sections, stitching parts and making finishing stitches.

In the production of products from thick and dense materials, for sewing shoes, leather goods, car covers, awnings and tents, technical products, upholstered furniture.

On this page we will get acquainted with the main characteristics of sewing threads.
Sewing thread- this is an extended, thin, evenly twisted yarn or thread with special properties that allow it to be used for sewing. Sewing threads are the main material for fastening clothing parts made of fabrics, knitted and non-woven fabrics, fur, leather, etc.
When working the thread is subjected to repeated stretching and bending, friction and abrasion (for example, against the eye of a needle and the material being joined, etc.). These effects partially disrupt the integrity of the thread and reduce its strength.
When using the finished product the thread in the seam is also subject to various influences - insignificant in magnitude, but repeated stretching and bending; friction; exposure to detergents during washing and chemicals during dry cleaning; high temperatures and pressure during ironing. These impacts also destroy the threads in the seams.
In other words, the features of sewing technology and operating conditions of finished products dictate certain quality requirements for the sewing threads selected for sewing. Particularly strict requirements are imposed on their strength, which depends on the quality of the original yarn, the fibrous composition of the threads, their additional finishing, etc. (see below "Properties and structure of sewing threads").
The quality of sewing threads is regulated by standards that indicate performance standards for the most important characteristics.

Requirements for the quality of sewing threads
Sewing threads must have:
- high tensile strength and sufficient elasticity (to reduce breakage on sewing machines and ensure the necessary seam strength during product use);
- be uniform in thickness (also for uniform tension in the sewing machine and the formation of a high-quality seam);
- have high color fastness to the effects of light weather, dry cleaning, washing;
- be heat-resistant (to prevent breakage from melting of synthetic threads or overheating of natural and artificial threads, etc.).

The properties and structure of sewing threads are determined by:
fibrous composition;
number of additions;
direction of twist;
thick;
final finishing.

Let's take a closer look...

By fiber composition sewing threads are divided into natural (cotton, silk, linen); chemical (polyester, polyamide, viscose); combined from different fibers (see section below "Characteristics of sewing threads by raw material composition").
By number of additions threads can be single-twisted in 2 or 3 folds and double-twisted in 4, 6, 9 or 12 folds.
- Single-twist threads are produced by twisting 2 or 3 original individual threads. Hence their name - single-twist in 2 or 3 additions (see below Figure 1 "Structure of sewing threads").
- To obtain two-twist threads, the original threads are first twisted into 2 or 3 folds. Then the resulting single-twist semi-finished products are twisted together once again completely. Depending on the number of initial components in the first and second stages of twisting, these threads are called double-twist in 4, 6, 9 or 12 folds.

Important! For sewing, the use of double-twist threads is more preferable, since, thanks to the additional fastening of the fibers when twisted, they acquire greater strength, better resist abrasion, and this reduces thread breakage when sewing a product, and the stitching is smoother. Increasing the number of plies also increases the strength of the threads.

Picture 1. Sewing thread structure.

In the direction of twist threads come in right (Z) and left (S) final twist. It is preferable to use right-twist threads, since they have less breakage in sewing machines than left-hand twist threads.

Important! The direction of twisting the threads can be determined in this way: untwist a piece of thread with your right hand between the thumb and forefinger clockwise. If the thread is additionally twisted, then it has a twist (S), and if it unwinds, it has a twist (Z)

By thickness Sewing threads are also very diverse. The thickness of sewing threads is characterized by a trade (conventional) number or linear density (tex). Threads of different fibrous compositions have their own trade numbering. For example, cotton threads have trade numbers 10, 20, 30, 40 and so on; natural silk threads - 18, 33, 65; lavsan threads - 22 L, 33 L, 55 L, etc.; nylon threads - 50 K.

It is important to know: for threads made of natural fibers (cotton, natural silk), the higher the number, the thinner they are. With synthetic threads, on the contrary, thinner threads have lower numbers.
And one more thing: If the thickness of the threads is the same, it is recommended to pay attention to the number of folds - the more threads are twisted, the better the quality of the threads.

By type of finish threads can be gray, matte, glossy, white, colored, black. Bleaching and dyeing reduce the strength of threads. Glossy threads are stronger than matte threads.

Recommendations for using sewing threads
1. Regardless of whether you sew by hand or on a machine, different threads are used for each type of work (for basting, for sewing stitches, for finishing a product with decorative seams, etc.). In each case, they must be selected individually, taking into account the required strength of the seams and their purpose. General recommendations for using various sewing threads are given in Table 2 "Purpose of sewing threads"(see below).
2. To obtain high-quality stitches when sewing products, it is necessary to choose the right threads, take into account their fibrous composition and thickness.
The correct choice of thread depends, first of all, on the fabric - its thickness and composition. For example, when sewing thick materials, thicker threads are used, when sewing thin materials, thinner threads are used. The raw material composition of the threads must also be similar or similar to the composition of the fabric, since the care requirements for the selected threads and the fabric itself must match. The thickness of the sewing thread, in turn, serves as the basis for choosing a sewing needle of the required diameter: the thicker the thread, the larger the needle should be.
And further:
- Threads used for sewing products must match the color of the material or be combined with it.
- The threads on the spool always look darker than on the fabric. Therefore, in order to correctly determine their color, it is recommended to choose threads slightly darker than the color of the fabric.
- Instead of cotton threads, it is allowed to use chemical threads and fibers of similar thickness.
Recommendations for the interchangeability of sewing threads of different compositions are given in Table 3 (see below). The basis for compliance is their thickness (linear density).

table 2 "Purpose of sewing threads"

Table 3 "Interchangeability of sewing threads"

Characteristics of sewing threads by raw material composition
When sewing, there should be a lot of threads - in a large assortment and with a wide selection of colors. When choosing threads, you should pay attention to their thickness and composition.

Important! For each type of work, and also depending on the characteristics of the material, threads must be selected individually - there are no “UNIVERSAL” sewing threads. As a rule, the basis for the correct choice of threads is, first of all, their raw material composition. And one more thing: threads of different composition with the same numbers will not be the same in thickness, which must be taken into account when choosing threads.

Raw material composition of threads
Sewing threads are made from natural and chemical fibers and threads.

Cotton threads (Cotton)
They are used in the manufacture of almost any type of garment, and natural raw materials make these threads indispensable in the production of clothing for children.
Depending on the finishing method, cotton threads are available in matte and glossy versions, harsh and treated with special compounds, and different colors. The most expensive option today is mercerized cotton threads.
Depending on the thickness, sewing threads are assigned trade numbers. The trade number is the conventional number of the threads, characterizing their thickness. As a rule, the higher the number, the thinner the thread.
Cotton threads are produced in the following trade numbers: 10, 20, 30, 40, 50, 60, 80, 100.
The use of threads depends on their thickness. For example, threads No. 80 and No. 100 are the thinnest, so they are used for sewing products from the thinnest fabrics, and threads No. 30 and No. 40, respectively, are suitable for products made from denser and thicker fabrics (see Table 1 from the section "Tools and accessories for manual work. Hand sewing needles").
When performing manual work (for example, basting parts), it is recommended to use thin (No. 60-80) cotton threads.
Based on their strength, cotton threads are divided into the following brands: “Prima”, “Extra”, “Special”, “Especially strong”. Prima brand threads are the least durable. Threads of the “Especially Durable” trademark are used for the manufacture of workwear.

Silk threads (sewing silk)
Due to insufficient strength, the range of silk threads is currently quite limited (replaced by chemical analogues). Silk threads are used mainly for finishing work and machine embroidery.
According to thickness, natural silk is divided into thin No. 65, medium No. 33, thick No. 13, No. 18. Thread No. 65 is used for joining and sewing parts made of thin fabrics (for example, organza, chiffon, etc.); for finishing stitches on medium-thick fabrics, No. 33 is suitable; No. 18 and 13 - for machine sewing buttonholes, sewing on buttons and for finishing stitches on woolen fabrics.

Linen threads
Intended for the manufacture of products for technical purposes and household consumption, for example, tarpaulin products; sewing shoes (in saddlery), making lace.

Viscose threads
In appearance they are similar to threads made from natural silk. A feature of viscose threads is their reduced strength when wet. Therefore, in the sewing industry they are used in limited quantities, mainly for embroidery.

Synthetic threads
Synthetic threads are produced from polyester (lavsan) and polyamide (nylon) fibers and threads, both in pure form and in mixtures. Such threads have increased strength and low shrinkage.

Important! For synthetic threads, their conventional numbers are commensurate with their linear density (thickness).

According to production method synthetic threads are divided into complex, reinforced (combined), textured (voluminous, elastic), monofilament, etc.
Complex synthetic threads in appearance they resemble threads made of natural silk.
Complex nylon threads have high strength and are superior in abrasion resistance to all other threads, so they are widely used for sewing buttonholes, as well as in the manufacture of clothes from durable, non-shrinkable materials. They have a commercial designation of 50K. The heat resistance of threads is low, so wet-heat treatment of products made using nylon threads should be carried out through a moistened ironing iron at a temperature of 160-165 ° C and for no more than 30 s.
Complex lavsan threads are also non-shrinking, but inferior to nylon threads in strength and abrasion resistance, but superior to them in heat resistance. Trade numbers: 22L, ZZL, 55L, 90L. Thin threads 22L, ZZL are used for the manufacture of linen, shirts and suits and dresses, and thick threads 55L, 90L are used for embossed finishing stitching.
Lavsan and nylon threads can withstand short-term heating to a temperature of 240-270°C.

Important! Sewing threads made from filament threads are characterized by their low thickness with a significant breaking load. Therefore, you can use complex threads with a thickness equal to the thickness of commonly used cotton threads, but get a much stronger seam.

Textured sewing thread (elastic)
Currently, the most widely used polyester textured threads (PT) are bulky threads with loops on the surface. Textured sewing threads are used for overcasting sections of parts, as well as in the manufacture of garments from elastic knitted fabrics. They provide strong, stretchable seams with good coverage, which is also important when processing items made from easily frayed fabrics. Thread designation - 18 LT, 24 LT, 37 LT, etc.

Reinforced sewing threads
They are produced by connecting a core of polyester (lavsan) filament thread and a braid of cotton (LC), polyester (LL) or siblon (LS) fiber. Due to their combined properties, reinforced threads are universal; they are used in the sewing, knitting, footwear, and leather goods industries for stitching parts, overcasting cuts, and performing finishing stitches.
Reinforced cotton lavsan sewing threads 36 LH, 36 LH-1, 35 LL are suitable for sewing products from thin and medium-thick fabrics and knitted fabrics; 44 LH, 44 LH-1 and 65LH, 65 LH-1 are recommended to be used instead of cotton threads of trade numbers No. 30 and 40. Threads have high strength, heat resistance, elasticity and wear resistance, as well as slight shrinkage. They are resistant to dry cleaning and washing.
Reinforced Mylar threads with a braid of Mylar fibers also provide thread seams with the required strength and wear resistance. Threads with number 35LL are used for sewing products from thinner fabrics and knitwear; 45 LL, 70 LL, etc., respectively, are suitable for denser and heavier fabrics.

Monofilament
The range of transparent threads is interesting and promising. They can be colorless for processing light-colored materials and pigmented (tinted gray, brown) for dark tones. The starting raw material for their production is polyamide (nylon or nylon), which has high elastic properties, great abrasion resistance and transparency. Treated with special optical preparations, they are able to acquire the color of the material being processed. Therefore, when sewing fabrics of different colors, the need for frequent refilling of sewing machines is eliminated. They are produced under the numbers 7KMP, 13KMP and 20KMP. Transparent threads are recommended for sewing shirts made of polyamide fabric, women's blouses and knitted dresses in medium and light colors.

Staple synthetic threads (LS)
In structure and appearance they are close to cotton, but they are distinguished by greater strength and less shrinkage. They are softer than complex ones and more resistant to high temperatures. The staple thread is universal in use: 27 LSh - used for sewing thin linen, dress, silk and shirt fabrics; 40 LSh - fabrics of medium surface density; 80 LSH - leather goods.

All of the above types of threads are not a complete list of threads used in sewing production today; their range is much richer and more diverse.

Reinforced threads- These are threads with a braid of polyester or cotton fiber and a continuous polyester filament thread. This combination gives maximum tensile strength, which ensures the use of these threads on high-speed sewing machines. Such threads are also characterized by high resistance to stretching and friction, which makes it possible to create a very strong and durable seam. Reinforced threads are used for sewing high-quality products, where delicate stitching, high strength and the absence of seam gathering are essential.

Reinforced threads with polyester braid (LL)

The marking LL (lavsan, lavsan) means that the thread consists of a lavsan core and a lavsan braid.

Composition of LL threads: 100% lavsan (polyester, polyester)

Reinforced threads (RL) are made from Polish, German complex polyester thread and Korean staple polyester fiber and lavsan.

They have a right direction of final twist.

The high strength of the threads is ensured by a core made of polyester filament thread. Braided polyester staple fiber provides good sewing properties and reduces the risk of the seam pulling effect during the sewing process.

During the rewinding process on the Jacoba machine, final finishing by immersion in a liquid composition with an organosilicon compound (OSC) improves the sewing properties of the threads, increases the elasticity and abrasion resistance of the threads, which improves the quality of the seam, increases heat resistance, and reduces the electrification of the threads.

Quality control of semi-finished products is carried out using the “Uster-Tester-3” device, which is a preventive control action during the start of the thread production process. "Uster-Tester-3" also allows for timely diagnostics of equipment. Quality control of finished threads is carried out using the “Statimat-2” device.

Each reel is marked with a color number.

Thermal properties of LL threads:

melting point 260◦C

<150 ◦С

linear shrinkage in boiling water 1.5% at a temperature of 100◦C

Chemical properties of LL threads:

humidity 1%

Threads have high strength, elasticity, wear resistance, and low shrinkage.

, , , , , ,

Documentation:

reinforced sewing threads, produced in accordance with GOST 6309 – 93 “Cotton and synthetic sewing threads”

Reinforced shoe threads are produced in accordance with GOST 30226 – 93 “Cotton and synthetic shoe threads”

shoe reinforced threads, produced according to TU 8147-028-00319629-2000 “Reinforced threads”

Threads reinforced with cotton braid (LH)

The marking LH (lavsan, cotton) means that the thread consists of a lavsan core and a cotton braid.

Composition of LH threads: 33% cotton + 67% polyester (polyester)

Threads have a right direction of final twist

The high strength of the threads is ensured by a core made of polyester filament thread. Cotton braiding provides good hygienic and sewing properties, protects threads from high temperatures during sewing and ironing.

During the rewinding process on the Jacoba machine, the final finishing by immersion in a liquid composition with an organosilicon compound (OSC) improves the sewing properties of the threads, increases the uniformity, elasticity and abrasion resistance of the threads, which improves the quality of the seam, increases heat resistance, and reduces the electrification of the threads.

Each reel is marked with a color number

Thermal properties of LH threads:

melting point 260◦C

iron bottom plate temperature<200 ◦С

linear shrinkage in boiling water 2% at a temperature of 100◦C

Chemical properties of LH threads:

resistant to acid, alkali, organic solvents, bleaching, microorganisms and mold, chemical and wet washing

humidity 3%

Trade numbers issued by JSC PNK IM KIROVA: , , , ,