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12
Section 15. Technical science
Sharipova Saodat Islomovna, Senior lecturer,
Bukhara Engineering and Technology Institute Muminova Umida Tоkhtasinovna, candidate of Technical Sciences, associate professor, Tashkent Institute of Textile and Light Industry Tashpulatov Salikh Shukurovich, doctor of Technical Sciences, professor, Tashkent Institute of Textile and Light Industry, E-mail: ssht61@mail.ru
HYGIENIC PROPERTIES OF MATERIALS FOR CLOTHES OF ADOLESCENTS LIVING IN THE MIDDLE CLIMATE ZONE
Abstract: in this article, the main results of studies on the determination of hygienic properties for tissues and packages of products calculated for the school uniform of adolescents living in the middle climatic zone of the Republic of Uzbekistan are given. The results of these studies are the basis for the selection of tops fabrics, lining materials, and the formation of packages of products for schoolchildren.
Keywords: school uniform, hygienic indicators, fabrics and lining materials, clothing packages.
The scientists and industrial enterprises of the republic the more air is contained in the material, since air has a ther-have a task at the state level to carry out comprehensive research to provide uniforms for schoolchildren with appropriate uniforms.
Previous studies [1-3] could provide the process of making garments with innovative technology and technology, forming bags of garments for cold zones of clothing. However, the average sharply continental climate zone has not been sufficiently addressed.
The degree of suitability of materials for adolescent clothing is determined mainly by their hygienic properties. The most hygienic value is the following: weight, thickness, air permeability, vapor permeability, hygroscopicity, hydrophilic-ity, water capacity and thermal resistance.
Of great importance is a number of other properties that further characterize clothing materials: porosity, elasticity, flexibility, crushing, shrinkage, capillarity, water permeability, drying speed, dust capacity, reflection coefficient. Some properties, such as elasticity, hygroscopicity and some others, depend to a certain extent on the basic substance. Significantly, the quality of clothing materials is determined by the structure of the fabric.
Cloth is not a monolithic entity. It is a complex structure consisting of fibers of the main substance and air, the amount of which is very large and varies depending on the structure of the tissue in a wide range (from 50% in smooth and dense fabrics - up to 99% in cotton wool and batting).
In connection with fluctuations in the air content, the essential properties of the materials, and especially their heat-shielding ability, are significantly altered. The latter is higher
mal conductivity many times smaller than the main substance. This is due to the fact that the greater the thickness of the fabric, the better all other things being equal its thermal protection properties. In the same way, the smaller the volume weight of materials (the ratio of dense substances and air in 1 cubic cm of material), the higher their thermal protection properties. Therefore, by determining the two properties mentioned above, and comparing them with those of materials whose thermal properties are known from the large experience of their use (for example, fur), one can form an impression of the heat-protective properties of this material.
Directly with the bulk weight is associated another important property of the tissues - their porosity. The porosity of the material is determined by the ratio of the pore volume to the volume of the given material, expressed as a percentage.
With the same amount of air in the tissues, it can be placed differently in them (in large pores or small, closed or communicating with each other and the surrounding atmosphere), on which the air permeability, vapor permeability and other tissue properties depend.
Air permeability of tissues, i.e. the degree of its patency for air, largely determines its suitability for a particular type of clothing. It is expressed by the amount of air (in cubic dm) passing per unit time (sec.) Through a unit of tissue surface (1 sq. M.) At a certain pressure (h = 5 mm Hg). Other things being equal, the air permeability of the tissue decreases with increasing thickness.
The main property characterizing the heat-protective effect of the material (or clothes) is its thermal resistance, which
HYGIENIC PROPERTIES OF MATERIALS FOR CLOTHES OF ADOLESCENTS LIVING IN THE MIDDLE CLIMATE ZONE
is estimated by the time (in hours) during which 1 kcal of heat passes through a square. m cloth at a temperature drop of 1 degree. C. Sometimes a unit is identified, the reciprocal of the thermal resistance, is the heat transfer coefficient.
No less important than the heat-protective properties of materials, have properties that determine their relationship to moisture: on the one hand - protection from rain, fog, wet snow, increased dampness, on the other - removing sweat from the skin surface.
Moisture through clothing goes three ways: simple diffusion ofwater vapor; wetting of teenage clothes afterwards and the subsequent evaporation of it from the surface of clothing; as well as evaporation of sweat from the surface of the skin, condensation of it in layers of clothing and further evaporation of condensate.
From the hygienic point of view, the first way is optimal, since moistening of teenage clothes is accompanied by a sharp change in the properties of the tissues of adolescent clothing (increased thermal conductivity, lower air permeability), a decrease in air layers in clothing, and adherence of tissues to each other, which results in a decrease in the heat-protective effect of clothing. In the cooling, the latter is undesirable. Under the conditions of heating, direct evaporation is most favorable, since in this case the excess heat from the body is quickly released to the environment. The ability of adolescent clothing
tissues to pass through water vapor continuously formed in a reliable space determines their vapor permeability, expressed by the amount of water vapor (mg) passing through a unit of tissue surface (1 square cm) per unit time (1 hour).
This property largely depends, on the one hand, on the size of the through pores, on the other hand, on the hygro-scopicity of the basic substance. The hygroscopicity of the fabric characterizes its ability to absorb water vapor from the ambient air and retain them under certain conditions.
Good hygroscopicity is a positive property of the materials used for the inner layers of clothing.
The ability of the tissue to absorb water when immersed in it determines the maximum water capacity, which is measured by the amount of water contained in the tissue after it has been wetted for 24 hours. The weight of the fabric after wringing it by hand and drying between the sheets of filter paper gives a minimum water capacity, expressed as a percentage of the dry weight of the sample. The minimum water capacity of various materials varies from 50 to 100%.
The property of materials to keep a significant part of the pores free and after moistening is of great importance for their air permeability, as well as heat-shielding properties. Thus, the indicators presented above are considered to be the main ones for scientifically based selection of tissues and the formation of an appropriate package of clothes for schoolchildren.
References:
1. Melikov E. H. Development and research of methods of forming parts of clothing. Author. Dis. ... Doctor. tehn. Sciences.-M .: MTILP.- 1986.- 42 p.
2. Tashpulatov S. Sh. The development of high technology resource-saving manufacture of garments. Author. Dis. ... Doctor. tehn. Sciences.- Tashkent: TITLI.- 2008.- 42 p.
3. Cherunova I. V. Theoretical bases of complex designing of special clothes: the author's abstract Author. Dis. ... Doctor. tehn. Sciences / - Shahti: YURGUES,- 2008.- 42 p.
