“JOURNAL OF SCIENCE-INNOVATIVE RESEARCH IN
UZBEKISTAN” JURNALI
VOLUME 2, ISSUE 12, 2024. DECEMBER
ResearchBib Impact Factor: 9.654/2024 ISSN 2992-8869
332
THE IMPACT OF ELONGATION EQUIPMENT ON THE QUALITY OF
RING SPINNING YARN
G. Maxmudova
Assistant, Fergana Polytechnic Institute, Fergana, Uzbekistan
Tursunbayeva Durdona Baxtiyor qizi
Student, Fergana Polytechnic Institute, Fergana, Uzbekistan
Tursunova Farangiz Furqat qizi
Student, Fergana Polytechnic Institute, Fergana, Uzbekistan
Abstract
The purpose of the elongation process is to reduce the linear density of the
product by decreasing the number of fibers in its cross-section through pushing the
fibers relative to each other. The essence of stretching is to increase the speed of the
fibers' movement and allow them to shift relative to each other, redistributing the
fibers.
Keywords
: Fiber, movement, spinning, elasticity, breakage, quality, density,
flexibility, rubber.
Introduction
The Strategy for Further Development of the Republic of Uzbekistan between
2017-2021 set the objectives of "increasing the competitiveness of the national
economy, reducing energy and resource consumption in the economy, and widely
introducing energy-saving technologies in production" [1]. In achieving these tasks,
it is crucial to develop and implement effective spinning technologies and tools that
are based on rational control of the working cylinder rotation speed in cotton
industry enterprises. One of the key technological processes in spinning enterprises
is the elongation equipment, which is responsible for stretching the sliver.
It is known that during yarn spinning, raw materials are progressively thinned
out and ultimately form yarn with the required linear density. Technologically, it is
not recommended to stretch and thin the product all at once. Therefore, the spinning
process is divided into several stages, with one of the most important and complex
“JOURNAL OF SCIENCE-INNOVATIVE RESEARCH IN
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VOLUME 2, ISSUE 12, 2024. DECEMBER
ResearchBib Impact Factor: 9.654/2024 ISSN 2992-8869
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being the stretching and thinning of the product. The purpose of the stretching
process is to reduce the linear density of the product by decreasing the number of
fibers in its cross-section through relative movement between fibers. The essence of
stretching is to increase the movement speed of the fibers, ensuring they shift relative
to each other and redistribute.
In the strtching equipment, each front pair rotates faster than the subsequent
pair. The speed of the front pair is several times greater than the speed of the last
pair, and the product elongates accordingly. As the product elongates, the fibers slide
over each other, changing their positions, meaning they become rearranged. As the
fibers slide, frictional forces are generated: this force straightens the fiber ends and
aligns them parallel to each other. The ratio of the speed of the front cylinder pair to
the speed of the rear cylinder pair in the stretching equipment is called the stretching
ratio, and this ratio serves as the indicator of stretching.
1
2
E
Here:
ye – stretching ratio;
v₁ – speed of the rear pair in m/min;
v₂ – speed of the front pair in m/min.
In the stretching process, the weight of the product does not change; as its
length increases, its linear density decreases by the same proportion. The ratio of the
linear density before and after stretching indicates how many times the product has
been elongated.
,
d
Т
Т
Е
Ч
К
Here:
The linear density before stretching (at the entry point) of the product;
The linear density after stretching (at the exit point) of the product;
The number of added products
The simplest stretching device consisting of two pairs of cylinders (1
and 2) and rollers placed on them is shown.
“JOURNAL OF SCIENCE-INNOVATIVE RESEARCH IN
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The cylinders are driven by a gear transmission, and the rollers convert the
force generated between the cylinders into motion. The front pair of cylinders (2)
rotates faster than the rear pair (1), and this causes the product-yarn-to stretch. In
order for the stretching pairs to engage well with the fibers and fully transfer their
speed to them, the cylinders are made with a threaded (ribbed) surface, while the
rollers are pressed against the cylinders by external loads or springs. The surfaces of
the rollers are made of elastic polymer and rubber materials.
In the stretching process, if the fibers do not slide relative to each other, this
type of stretching is called first-order stretching. If, during the stretching process,
the fibers slide relative to each other over their entire length, this is called second-
order stretching. Currently, only second-order stretching is used in yarn spinning
factories for stretching and thinning the product (yarn, thread). The surface where
fibers can slide relative to each other is called the stretching zone. The distance
between the start and end of the fiber's movement is referred to as the boundary of
the stretching zone.
In the stretching zone, the movement of the fibrous product can be divided
into two categories: uncontrolled (free) fibers and controlled fibers.
Figure 1. Description of the stretching pairs and the movement of the fibers
The fibrous material (yarn or thread) passing between the stretching pairs in
the stretching device is compressed between the cylinder and the roller, creating
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frictional forces on their surfaces. The area where frictional forces act between the
fibers and between the fibers and the details of the stretching device is called the
frictional contact surface.
Figure 2. Frictional Force Surface
For the stretching process to proceed normally, the pressure exerted by the
outgoing pair should be greater than the pressure exerted by the incoming pair. This
ensures that as the front ends of the fibers in the rear pair's nip fall into the nip of the
outgoing pair, the fibers begin to move from the speed of the rear pair to the speed
of the front pair.
Rollers
: In order for the stretching process to proceed normally and for
uniform products to be obtained, the rollers placed on the cylinders must be of high
quality and should press the fibers onto the cylinder with normal pressure. Rollers
are divided into types based on their elasticity, magnetic properties, and the pressure
exerted by their own weight.
The main task of the belts is to regulate the moving fibers in the stretching
device and to improve the uniformity of the yarn.
“JOURNAL OF SCIENCE-INNOVATIVE RESEARCH IN
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Figure 3. Stretching Equipment for Ring Spinning Machines
1 - Yarn, 2 - Rubber coating, 3 - Guide cylinder, 4 - Additional rubber coating, 5 - Spun yarn
Additional rollers are added to the stretching equipment, and special rubber
coatings, such as nephron diamond-shaped mesh, are applied to them. These rollers
are installed after the variable and fixed rollers (the diameter of the fixed rollers is
0.25 m, and the diameter of the variable rollers is 0.28 m). The stretching zones
consist of two stretching zones. The fibers pass through the rollers and the mesh
coating, which ensures proper compression of the mesh. Due to the clarity of the
gaps in the mesh, small impurities from the yarn are left in the gaps and absorbed by
the air. This process helps to improve the stretching process and increases the
parallelism of the fibers. It reduces the amount of waste in the yarn by several times
compared to previous technological processes, thereby improving the quality
indicators of the product (such as strength, smoothness, evenness, breaking length,
and neps count). This leads to an improvement in the fiber's quality indicators as
well.
Furthermore, this process helps save a certain amount of raw materials,
electrical energy, and labor costs, while also increasing efficiency.
Conclusion
Currently, in ring spinning machines, using the elongation equipment
improves yarn quality by reducing the number of neps, increasing smoothness, and
reducing breakage during stretching. Therefore, enhancing ring spinning machines
and implementing high-quality yarn production processes will allow for broader use
“JOURNAL OF SCIENCE-INNOVATIVE RESEARCH IN
UZBEKISTAN” JURNALI
VOLUME 2, ISSUE 12, 2024. DECEMBER
ResearchBib Impact Factor: 9.654/2024 ISSN 2992-8869
337
of these machines in various sectors. This equipment is already being utilized in the
technological production process of Toshkent Textile Group.
References
1.
Tanos, P. Pelos, "Spinning Technology and Equipment"
2.
Rieter Company, Spinning Equipment Brochure, 1999
3.
T.A. G‘aniyev, "Labor Protection in the Textile Industry", Uzbekistan,
1995
4.
Xasanov B.K., Sodiqova N.R., "Theory and Technology of Preparing
Yarns for Weaving", Textbook, "Uzbekistan", 2004
