Development of multi-layered weft-knitted fabrics for thermal insulation

2019 ◽  
pp. 152808371987881
Author(s):  
Vaida Buzaite ◽  
Reazuddin MD Repon ◽  
Daiva Milasiene ◽  
Daiva Mikucioniene
Keyword(s):  
Heat Transfer ◽  
Heat Exchange ◽  
Thermal Insulation ◽  
Raw Materials ◽  
Air Permeability ◽  
Knitted Fabric ◽  
Heated Plate ◽  
Knitted Fabrics ◽  
Knitted Structure ◽  
The One

The main goal of the presented study was to develop new multi-layered weft-knitted structure for thermal insulation and to investigate the dynamic of the heat transfer through this fabric. For knitting of outer and inner layers of this structure, different raw materials of yarns were used, i.e. wool, cotton, polyester and acrylic yarns. All the newly developed multi-layered weft-knitted fabrics show thermal insulation as, after 1 h of observation, temperature on the outer layer of all tested fabrics does not reach 40℃, i.e. the temperature of a heated plate. The results of this research showed that the nature of the yarns has a significant influence on the air permeability and dynamic of the heat exchange through the multi-layered structure, as it influences porosity of the knitted fabric. The results showed that the best fabric was the one where the outer layers are knitted from woollen yarns and the inner layer from polyester filament yarns.

scholarly journals THE EFFECT OF FIBER CROSS-SECTIONAL SHAPE AND TEXTURING TEMPERATURE ON KNITTED FABRIC AIR PERMEABILITY

2019 ◽  
Vol 2019 ◽  
pp. 100-104
Author(s):  
Halil İbrahim ÇELİK ◽  
Hatice Kübra KAYNAK ◽  
Esin SARIOĞLU ◽  
Gizem KARAKAN GÜNAYDIN
Keyword(s):  
Raw Materials ◽  
Air Permeability ◽  
Process Temperature ◽  
Knitted Fabric ◽  
Cross Sectional ◽  
Knitted Fabrics ◽  
Polyester Filament ◽  
Process Factors ◽  
Sectional Shape ◽  
Single Jersey

Texturized yarns are often preferred especially in home textiles and sportswear. To improve polyester filament properties, mechanical, thermal, chemical and combinations of texturing processes are applied. With these processes, filament yarns take on a curved and voluminous structure and gain a permanent form. Properties of the texturized yarn can be varied as raw materials properties, machine type and process factors. This study covers the investigation of the effect of cross-sectional shape of fiber (round and trilobal) and texturing process temperature (150, 175 and 200 0C) on air permeability of false twist textured polyester single jersey knitted fabrics. Results showed that the highest air permeability value was obtained from knitted fabric with round fiber cross-sectional shape polyester filament textured at 150 0C. According to the statistical analysis, both the fiber cross-sectional shape and process temperature were found to have a significant effect on air permeability property.

Heat transfer properties of bifacial fabrics

2016 ◽  
Vol 87 (19) ◽  
pp. 2307-2313 ◽  
Author(s):  
Licheng Zhu ◽  
Maryam Naebe ◽  
Ian Blanchonette ◽  
Xungai Wang
Keyword(s):  
Heat Transfer ◽  
Thermal Resistance ◽  
Air Permeability ◽  
Woven Fabrics ◽  
Knitted Fabrics ◽  
Plain Weave ◽  
Knitted Structure ◽  
Woven Structure ◽  
Transfer Properties ◽  
Single Jersey

Bifacial fabrics were produced on a purpose-built machine, using wool, acrylic and polyester yarns, with the woven structure being plain weave, and the knitted structure being single jersey. In this study, the heat transfer properties of these fabrics were compared with conventional woven and knitted fabrics. The bifacial fabrics had lower air permeability than knitted and woven fabrics, and they were warmer to touch. The thermal resistance of the bifacial fabrics was higher than the knitted and woven fabrics, and the thermal resistance of the two faces of the bifacial fabrics was statistically different.

scholarly journals Modeling of Air Permeability of Knitted Fabric Using the Computational Fluid Dynamics

2018 ◽  
Vol 18 (4) ◽  
pp. 364-376 ◽  
Author(s):  
Adam K. Puszkarz ◽  
Izabella Krucińska
Keyword(s):  
Geometrical Structure ◽  
Raw Materials ◽  
3D Models ◽  
Air Permeability ◽  
Geometrical Parameters ◽  
Knitted Fabric ◽  
Ambient Conditions ◽  
Specific Group ◽  
Knitted Fabrics ◽  
Volume Method

Abstract This article concerns the widespread matter of biophysical comfort. In this work, 10 double-layer knitted fabrics with potential application in multilayer garments addressed to a specific group of users, such as newborns, were investigated. The materials were constructed with the following raw materials: cotton, polypropylene, polyester, polyamide, bamboo, and viscose. The textiles with a comparable geometrical structure and different composition were tested for their air permeability. In the experimental part, the materials were tested in specific constant ambient conditions using an air permeability tester. In the simulation part, 3D models of actual textiles were designed and air permeability based on the performed simulations using finite volume method was calculated. Both measurements and simulations yielded comparable results and showed that the air permeability of the knitted fabric strongly depends on the thickness and geometrical parameters of yarn.

Development of Coolsmart Functional Knitted Fabrics

2012 ◽  
Vol 503-504 ◽  
pp. 498-502 ◽  
Author(s):  
Lan Qing Feng ◽  
Yan Jun Liu
Keyword(s):  
Pattern Formation ◽  
Moisture Absorption ◽  
Raw Materials ◽  
Knitted Fabric ◽  
Machine Code ◽  
Knitted Fabrics ◽  
Bacterial Function ◽  
Fabric Structures ◽  
Selection Of

Based on the main features of coolsmart fiber and the theory of knitted fabric structures， two structures of sports and leisure knitted fabrics with fast moisture absorption, description and anti-bacterial function are introduced in this article, detailing the selection of raw materials, pattern formation effect, the machine code organization and cam set out.

Optimization of Knitted Fabric Comfort and UV Protection using Desirability Function

2016 ◽  
Vol 11 (4) ◽  
pp. 155892501601100 ◽  
Author(s):  
Anindya Ghosh ◽  
Prithwiraj Mal ◽  
Abhijit Majumdar ◽  
Debmalya Banerjee
Keyword(s):  
Thermal Conductivity ◽  
Desirability Function ◽  
Air Permeability ◽  
Quality Parameters ◽  
Uv Protection ◽  
Knitted Fabric ◽  
Uv Resistance ◽  
Knitted Fabrics ◽  
Target Values ◽  
Fabric Comfort

The present study deals with the optimization of multiple quality parameters of single jersey and 1×1 rib knitted fabrics using the desirability function approach. Comfort properties such as air permeability, thermal conductivity and safety properties such as UV protection are combined to yield an ‘overall desirability’ varying from zero to one. The overall desirability has been maximized versus target values for air permeability, thermal conductivity and UV resistance. Experimental validation confirms that the proposed method can be used to design a knitted fabric with desired comfort and UV resistance characteristics.

scholarly journals Changes of the Knitted Fabric Properties due to Exposure to Outdoor Natural Weathering

2014 ◽  
Vol 9 (4) ◽  
pp. 155892501400900
Author(s):  
Ivana Salopek Cubric ◽  
Vesna Marija Potocic Matkovic ◽  
Zenun Skenderi
Keyword(s):  
Heat Resistance ◽  
Unit Area ◽  
Raw Materials ◽  
Weather Conditions ◽  
Natural Weathering ◽  
Knitted Fabric ◽  
Summer Period ◽  
Knitted Fabrics ◽  
Vertical Density ◽  
Single Jersey

In order to investigate the changes of knitted fabric properties due to exposure to outdoor natural weathering, a series of single jersey fabrics made from different raw materials was produced. The fabrics were exposed to summer weather conditions in duration of three months. The exposure of knitted fabrics to outdoor natural weathering in the summer period affected all investigated properties, namely, structural properties, tensile properties and heat resistance. The most significant changes were: the vertical density increased up to 31%, the mass per unit area increased up to 26%, the breaking force decreased in both directions for up to 54% and the heat resistance decreased up to 18%.

Pilot Study of PET/Bamboo Charcoal Warp-Knitted Fabric

2012 ◽  
Vol 184-185 ◽  
pp. 1090-1093 ◽  
Author(s):  
Jia Horng Lin ◽  
Ching Wen Lin ◽  
Chin Mei Lin ◽  
Yi Chang Yang ◽  
Ting Ting Li ◽  
...  
Keyword(s):  
Far Infrared ◽  
Air Permeability ◽  
Weft Yarn ◽  
Knitted Fabric ◽  
Bamboo Charcoal ◽  
Health It ◽  
Warp Yarn ◽  
Knitted Fabrics ◽  
Far Infrared Ray ◽  
Warp Knitted Fabric

In recent years, as improvement of human living life, people begin to focus on themselves health. It is certain that bamboo charcoal has many properties, including water purification, deodorization, anion release and far-infrared ray radiation. This study aims to prepare PET/BC warp-knitted fabric composed of polyester yarn (PET) as warp yarn and bamboo charcoal polyamine yarn (BC) as weft yarn using Velcro Crochet Machine. Afterwards, air permeability, elastic resilience and far-infrared ray emissivity of resulting knitted fabric were discussed by changing weft yarn type. Result shows that, for knitted fabrics, weft yarn type cannot affect the elastic resilience; yet PET weft yarn makes air permeability decreasing.

scholarly journals Numerical Study of Complex Heat Transfer in Blown Impassable Channels of Heating Mains

2019 ◽  
Vol 62 (1) ◽  
pp. 61-76
Author(s):  
V. A. Sednin ◽  
T. V. Bubyr
Keyword(s):  
Heat Transfer ◽  
Heat Exchange ◽  
Numerical Study ◽  
Channel Structure ◽  
Experimental Facility ◽  
Standard Size ◽  
Network Water ◽  
Water Pipelines ◽  
The One ◽  
Full Scale Tests

To solve the problem of increasing the efficiency of operation of thermal networks, placed in impassable channels, the authors previously proposed the scheme-and-structural decision of the regenerative-utilization heat consumption. The technology of forced ventilation of the channel by external followed by the cooling of air and utilization of the withdrawn heat is presented. Research of processes of heat exchange between a stream of air and pipelines of network water on the one hand and between a stream of air and walls of the channel on another hand is a determinant for realization of the presented technology of increase of efficiency of operation of the considered heating mains. Convective heat transfer with the listed components of the channel structure is quite difficult to reduce to any canonical form which makes it possible to use the available design dependences. It is immeasurably more difficult to find a solution when considering the processes of forced convection jointly. Heat exchange takes place in a channel of complex shape that is determined by the presence of supports, compensators and turns along the length of the channel. In the cross section, the sizes of the structure and the restriction of the air flow are determined by a standard size range of diameters of the network water pipelines. Under these conditions, the use of any real experimental facility is associated with unacceptable idealization and the corresponding error, unsuitable for practical use. Full-scale tests can be considered only to verify the adequacy of the experimental results. The way out of this situation can be a usage of a virtual experimental facility created on the basis of a standard software package (in the case under consideration the ANSYS was used). The approaches of creating a virtual experimental facility for the study of heat transfer and aerodynamics in the blown impassable channels of heating mains and methods of conducting experiment using the theory of its planning are considered.

scholarly journals The Effect of Number and Position of Tuck Stitches within the Pattern Repeat on Air Permeability of Weft-knitted Fabrics from Glass Yarn

2019 ◽  
Vol 2 (3) ◽  
pp. 317-323
Author(s):  
Mehmet Erdem İnce
Keyword(s):  
Mechanical Properties ◽  
High Performance ◽  
Physical And Mechanical Properties ◽  
Air Permeability ◽  
Knitted Fabric ◽  
Knitted Fabrics ◽  
Synthetic Fibers ◽  
Fabric Structure ◽  
Knit Fabrics ◽  
Weft Knitted Fabric

The fact that weft knitted fabrics has a stretchable, 3D, porous and interlocking structure makes them unique when manufactured from high performance fibers. Knitted fabrics with different architectures exhibit different properties. Different loop forms like tuck and skip stitches with various loop lengths reveal different physical and mechanical properties. Literature review indicated that wisely arrangement of tuck stitches within the pattern repeat alter the weft-knitted fabric structure from natural and synthetic fibers. Therefore, we studied the effect of number and location of tuck stiches on air permeability of weft-knitted fabrics from glass yarn. Single-bed, flat weft knitting machine was used to knit fabrics with different architectures from three-ply glass yarn. The nominal single-end count of used E-glass yarn was 136 tex. It is anticipated that the number and location of tuck stitches within knit pattern effect physical and air permeability properties of weft-knitted fabrics from glass yarn.

scholarly journals Multifunctional polymer-based composite materials with weft-knitted carbon fibrous fillers

2019 ◽  
Vol 304 ◽  
pp. 01012
Author(s):  
Viktoriia Bezsmertna ◽  
Oleksandra Mazna ◽  
Valerii Kohanyiy ◽  
Yurii Vasilenkov ◽  
Iryna Bilan ◽  
...  
Keyword(s):  
Composite Materials ◽  
Carbon Fibers ◽  
High Strength ◽  
Knitted Fabric ◽  
Strong Anisotropy ◽  
Knitted Fabrics ◽  
Shielding Properties ◽  
Knitted Structure ◽  
2D And 3D ◽  
Fibrous Fillers

The production technology of reinforcement filler for new multifunctional polymer based composites with weft-knitted structure had been proposed. In such reinforcement filler high-strength carbon fibers (CFs) from PAN precursors (wefts) were laid in a knitted fabric as straight continuous yarns, so in such case these CFs were not twisted by knitting machine to form the loops. Various kinds of chemical and inorganic fibers can be used as base yarn in this case, in particular glass, aramid, carbon fibers from hydrate cellulose and etc. Properties of multifunctional polymer-based composite materials with weft-knitted fillers depend upon fiber composition, relative content of weft and base yarns, scheme filler stacking (1D, 2D and 3D composites). The electrical conductivity of weft-knitted fabrics shows the strong anisotropy along high-strength fibers in comparison with looped rows, depending on the direction of high-strength CFs (weft). Investigation of shielding properties of polymer based composites reinforced by carbon weft-knitted fabrics showed the possibility of using them as shielding materials with the ability to absorb electromagnetic radiation.

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