`
`HEAT, AIR AND WATER VAPOR TRANSFER
`PROPERTIES OF CIRCULAR KNITTED SPACER FABRICS
`
`YUVARLAK ÖRME SANDVİÇ KUMAŞLARIN ISI, HAVA ve SU
`BUHARI TRANSFER ÖZELLİKLERİ
`Gözde ERTEKİN*, Arzu MARMARALI
`
`Ege University, Department of Textile Engineering, İzmir, Turkey
`
`Received: 20.01.2011
`
` Accepted: 13.07.2011
`
`ABSTRACT
`Spacer fabrics are 3D textile structures formed of two fabric layers combined by a spacer yarn or layer. The production method of
`spacer fabrics produced in circular knitting machines is based on the connection of two fabric layers knitted in cylinder and dial with
`tucks. In this study, thermal comfort properties of fabrics which are produced in three different dial heights and two different spacer yarn
`on circular knitting machine by using spacer fabric production method were investigated. It is observed that, fabric weight, thermal
`conductivity, thermal resistivity, air permeability and relative water vapor permeability properties are affected by dial height and the
`type of spacer yarn significantly.
`Key Words: Spacer fabrics, Circular knitting, Dial height, Spacer yarn, Thermal comfort.
`
`ÖZET
`Sandviç tekstiller iki kumaş tabakasının bir bağlantı ipliği veya tabakası ile bağlanması sonucu elde edilen üç boyutlu yapılardır.
`Yuvarlak örme makinelerinde sandviç kumaş üretimi, silindir ve kapak iğneleri tarafından örülen iki kumaş tabakasının, bağlantı
`ipliklerinin her iki yatakta askı yapması ile birleştirilmesi esasına dayanır. Bu çalışmada yuvarlak örme makinelerinde sandviç kumaş
`üretim tekniği ile üç farklı kapak yüksekliğinde ve iki farklı bağlantı ipliği ile üretilen sandviç kumaşların fiziksel ve ısıl konfor
`özellikleri incelenmiştir. Araştırma sonucunda kapak yüksekliği değişiminin ve bağlantı iplik tipinin kumaşların gramaj, ısıl iletkenlik,
`ısıl direnç, hava geçirgenliği ve bağıl su buharı geçirgenliği özellikleri bakımından farklılık yarattığı tespit edilmiştir.
`Anahtar Kelimeler: Sandviç kumaşlar, Yuvarlak örme, Kapak yüksekliği, Bağlantı ipliği, Isıl konfor.
`
`In last decades, increased attention is
`paid to comfort properties of textiles
`and garments. As general opinion,
`personal well-being and high living
`standards nowadays become certainly
`important, the significance of comfort
`is well recognized by
`the people.
`Modern and conscious consumers
`consider comfort as one of the most
`important garment properties. This fact
`should not be surprising since it is well
`known the strong relation between the
`comfort properties of garment and
`human sensations.
`
`* Corresponding Author: Gözde Ertekin, gozde.damci@ege.edu.tr, Tel: +90 232 3112782 Fax: +90 232 3399222
` 1. INTRODUCTION
`entrapped in the fabric. Shoshani and
`There is general agreement that the
`Shaltiel (6) noted that the thermal
`transfer of heat, moisture and air
`insulation increases while the density
`through the fabric are the major factors
`of fabric decreases. Pac et al. (7)
`for
`thermal comfort. Many authors
`investigated
`the
`influence of
`fiber
`have pointed out that the major factors
`morphology, yarn and fabric structures
`influencing heat transfer through a
`on transient thermal properties and
`fabric are the thickness and enclosed
`friction behaviour. They found that, the
`air. A decrease in thickness of fabric,
`contact interfacial area between skin
`together with
`a
`corresponding
`and fabric is small for rough fabrics
`decrease of fabric volume, is generally
`and more air is entrapped on a hairier
`followed by decrease of air entrapped
`fabric surface so these fabrics give
`in fabric structure changing the thermal
`warmer feeling. They also stated that
`properties of
`the
`fabric
`(2, 3).
`structural roughness and warm–cool
`Milenkovic et al. (1) proved that fabric
`feeling of the fabrics change according
`thickness, enclosed still air and
`to fiber type, yarn and fabric structure.
`external air movement are the major
`Anand (8) reported
`that
`the open
`factors that affect the transfer through
`construction 3D eyelet has better
`fabric. Also Greyson (4) and Havenith
`water
`vapor
`permeability
`than
`(5) mentioned that the heat and water
`micromesh, pique and mock
`rib
`vapor resistances increase with the
`structures. Hes et al. (9) developed a
`increase of material thickness and air
`
`Comfort is defined as “the absence of
`displeasure or discomfort” or “a neutral
`state compared to the more active
`state of pleasure” (1).
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`fabric
`knitted
`functional
`new
`possessing double layers by using
`different
`yarn
`components
`(like
`polypropylene and cotton) in order to
`maximize the suction and transport
`moisture properties. Uçar and Yılmaz
`(10) studied the thermal properties of
`rib knitted fabrics and noted that a de-
`crease
`in rib number
`leads
`to a
`decrease in heat loss; the use of 1×1
`rib and tight structure would provide
`better thermal insulation. Despite all
`the
`research
`regarding
`thermal
`comfort, there is very little research
`regarding thermal comfort properties of
`circular knitted spacer fabrics.
`Spacer fabrics are 3D textile structures
`formed of two fabric layers combined
`by a spacer yarn or layer. Due to their
`three dimensional construction, spacer
`fabrics have specific properties which
`cannot be met by conventional textiles.
`There are lots of application areas of
`spacer fabrics such as medical textiles,
`automotive textiles, geotextiles, protective
`textiles, sportswear and composites,
`because of the possibility of using a
`variety of different materials, good
`performance characteristics and the
`three dimensional construction. It is
`possible to produce these fabrics by
`weaving or nonwoven
`techniques
`besides warp and weft knitting
`processes. Knitting technology especially
`warp knitting technique is the most
`commonly known and applied technology
`for the production of spacer fabrics.
`
`fabrics using
`To produce spacer
`circular knitting machine requires the
`use of at least three different yarns for
`each course of fabric. These are; a)
`yarn for the cylinder needles; b) yarn
`
`for the dial needles and c) a spacer
`yarn, generally monofilament yarn
`connecting the two layers by tucks
`(11). The distance between the two
`fabric layers can be set by the dial
`height adjustment. There are
`two
`techniques
`of
`producing
`spacer
`fabrics: tucking on dial and cylinder
`needles at
`the same
`feeder and
`knitting/plating on the dial needles and
`knitting on cylinder needles (12).
`
`lightweight and
`fabrics are
`Spacer
`breathable structures. They have good
`physiological and thermal comfort. They
`transport moisture easily;
`their air
`permeability
`and
`water
`vapour
`permeability values are high. Their
`compression characteristic is also higher
`than conventional textile surfaces.
`
`Spacer warp knitted fabrics have been
`studied globally for many years (13,
`14, 15, 16), but
`the number of
`researches about the properties of
`spacer fabrics produced on circular
`knitting machines are relatively few.
`Anand (12) compared the dimensional,
`comfort and elastic properties of
`fabrics produced with warp and weft
`knitting methods. He found that both
`spacer
`fabrics had more or
`less
`identical tenacity, breaking extension
`and initial modulus properties. The
`comfort properties of weft knitted
`spacer fabrics are better than warp
`knitted spacer fabrics. Wei and Hairu
`(17)
`investigated
`the compression
`behavior of different circular knitted
`spacer fabrics. The results indicate
`that under the stated conditions the
`increase of spacer yarn
`fineness,
`fabric density and
`the distance
`
`between dial and cylinder is favorable
`for reducing compressive deformation
`and improving recoverability. Yip et.al.
`(18) compared the characteristics of
`different spacer fabrics including low-
`stress mechanical properties, air
`permeability and thermal conductivity.
`They found that all tensile, bending
`and compression properties of spacer
`fabrics are greatly depending on the
`structure and the stitch density of
`spacer fabric, the type and the yarn
`count of the spacer yarn beside the
`spacer
`yarn
`configuration.
`Air
`permeability and thermal conductivity
`properties of spacer fabrics are closely
`related to the fabric density.
`
`The increased demand of 3D knitted
`fabrics and lack of comprehensive
`studies
`on
`the
`characteristics
`especially thermal comfort properties
`of weft knitted spacer
`fabrics are
`sound basis for this research. In this
`study,
`the effect of dial height
`arrangement and the type of spacer
`yarn on thermal comfort properties of
`circular knitted spacer fabrics were
`investigated rigorously.
`
`2. MATERIAL AND METHOD
`2.1. Material
`As a spacer yarn, two different type of
`100
`denier
`poliester
`yarns
`(monofilament and multifilament) were
`used and 150 denier multifilament
`polyester yarns were also used for the
`back and face side of the spacer
`fabrics. The non-porous structures
`were selected for both side of fabrics
`(Fig.1).
`
`1st feeder spacer yarn
`
`2nd feeder spacer yarn
`
`3rd feeder yarns for face side of the fabric
`
`4th feeder yarns for face side of the fabric
`
`5 th feeder yarns for back side of the fabric
`
`Figure 1. Needle diagram of spacer fabrics
`
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` Fabrics were produced
`three
`in
`different
`thicknesses by means of
`adjustment of the dial height (3, 3.5, 4
`mm) using both monofilament and
`multifilament spacer yarns. As it is
`known, the distance between the two
`sides of spacer fabrics can be arranged
`by the dial height. Theoretically, this
`distance can be maximum 10 mm; but
`pratically it can be used max. 5mm for
`monofilament spacer yarn. Limitation
`of the distance caused by multifilament
`spacer yarn, these values (3, 3.5, 4
`mm) were chosen for experiments.
`
`The knitting process was performed on
`a 20 gauge and 38”diameter Mayer &
`Cie, OVJA 1.6 E 3 WT circular knitting
`machine with
`constant machine
`settings. The fabric samples were kept
`under
`the
`standard atmospheric
`conditions for the relaxation.
`
`2.2. Method
`
`Alambeta and Permetest instruments
`(Sensora instruments, Czech Republic)
`were used for measurements (19). The
`Alambeta basically simulates the dry
`human skin and its principle depends
`in mathematical processing of time
`course of heat flow passing through
`the
`tested
`fabric due
`to different
`temperatures of bottom measuring
`plate (220C) and measuring head
`(320C)
`(20). Whole measurements
`were repeated five times
`
`Air permeability values were obtained
`by using Textest FX 3300 instrument
`according to TS 391 EN ISO 9237. Its
`principle depends in the measurement
`of air flow passing through the fabric at
`certain pressure gradient ∆p. The
`
`
`results of the measurements, reported
`in Fig. 4 are averages from the values
`of 10 readings. All the measurements
`were done
`in controlled
`laboratory
`conditions.
`
`Relative water vapor permeability was
`measured on Permetest
`instrument
`working on similar skin model principle
`as given by the ISO 11092 (21). The
`results illustrated in Fig. 5 are averages
`from the values of 3 readings.
`
`Evaluation of the test results was
`made using statistical software. To
`determine the statistical importance of
`the variations, ANOVA
`tests were
`applied. To deduce whether
`the
`parameters were significant or not, p
`values were
`examined.
`Ergun
`emphasized that if “p” value of a
`parameter
`is greater
`than 0.05
`(p>0.05), the parameter will not be
`important and should be ignored (22).
`
`3. RESULTS AND DISCUSSION
`
`thermal comfort values and
`The
`statistical differences of the fabrics
`with monofilament and multifilament
`spacer yarns are given in Table 1 and
`Table 2, respectively. In these tables,
`the mean values are marked with the
`letters
`‘a’,
`‘b’ and
`‘c’. Any
`levels
`marked by the same letter showed that
`they were not significantly different (‘a’
`shows the lowest value and ‘c’ shows
`the highest value). For instance the
`fabric weight values of the fabrics with
`multifilament
`spacer
`yarns were
`significantly different and Multi 4
`marked with “c” is heavier than Multi 3
`marked with “a”.
`
`3.1. Thermal Conductivity
`
`Thermal conductivity coefficient λ
`presents the amount of heat, which
`passes from 1m2 area of material
`through the distance 1m within 1s and
`create the temperature difference 1K
`(20). For textile materials, still air in the
`fabric structure is the most important
`factor for conductivity value, as still air
`has the lowest thermal conductivity value
`compared to all fibers (λair = 0.026).
`According
`to statistical evaluation,
`there is not a significant difference
`between thermal conductivity values of
`the fabrics with monofilament spacer
`yarn (Table 1). For the fabrics with
`multifilament spacer yarn, Multi 4 has
`the highest thermal conductivity value.
`The difference between Multi 3 and
`Multi 3,5 is not significant statistically
`(Table 2).
`The fabrics knitted using monofilament
`spacer yarn have higher
`thermal
`conductivity values than the fabrics
`produced with multifilament spacer
`yarn (Fig.2).
`Whole differences are attributed to the
`differences in fabric thickness and the
`amount of entrapped air in the fabric
`structure. While the fabric thickness
`increases, the fabric volume and the
`fabric weight increase also. With the
`increasing of the fabric weight the
`amount of
`fiber
`in
`the unit area
`increases as well and the amount of
`air layer decreases. Therefore heavier
`fabrics that contain less still air have
`higher
`thermal conductivity values,
`because of higher thermal conductivity
`values of
`textile
`fibers
`than of
`entrapped air (23).
`
`Table 1. Thermal comfort properties of the fabrics with monofilament spacer yarn
`
`Fabric
`code
`
`Mono 3
`Mono 3,5
`Mono 4
`
`
`
`Fabric
`code
`
`Multi 3
`Multi 3,5
`Multi 4
`
`Dial
`height
` (mm)
`3
`3,5
`4
`
`Dial
`height
` (mm)
`3
`3,5
`4
`
`Fabric
`weight
` (g/m2)
`380 a
`388 a,b
`393.6 b
`
`Thickness
`(mm)
`
`3.227 a
`3.523 b
`3.425 b
`
`Thermal
`conductivity
`(W/mK)
`0.0525 a
`0.0522 a
`0.0538 a
`
`Thermal
`resistance
`(m2K/W)
`0.0600 a
`0.0675 b
`0.0695 b
`
`Relative water vapor
`permeability
`(%)
`20.90 a
`21.57 a
`24.23 a
`
`Air
`permeability
`(lt/m2s)
`2133 b
`2010 a
`2006 a
`
`Table 2. Thermal comfort properties of the fabrics with multifilament spacer yarn
`
`Fabric
`weight
` (g/m2)
`315.8 a
`324.4 b
`339.0 c
`
`Thickness
`(mm)
`
`2.265 a
`2.313 a
`3.134 b
`
`Thermal
`conductivity
`(W/mK)
`0.0437 a
`0.0429 a
`0.0450 b
`
`Thermal
`resistance
`(m2K/W)
`0.0518 a
`0.0538 a
`0.0565 b
`
`Relative water vapor
`permeability
`(%)
`39.27 a
`40.63 a
`38.80 a
`
`Air
`permeability
`(lt/m2s)
`925.9 b
`899.2 a
`898.6 a
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`3 mm
`3.5 mm
`4 mm
`
`0,06
`
`0,05
`
`0,04
`
`0,03
`
`0,02
`
`0,01
`
`0,00
`
`Thermal conductivity
`
` (W/mK)
`
`
`
`Monofilament spacer yarn
`Multifilament spacer yarn
`Figure 2. Thermal conductivity values of spacer fabrics
`
`
`
`monofilament yarns. This result can be
`explained by the cross sectional view
`of
`the
`fabrics. The
`fabrics with
`monofilament spacer yarns have more
`open structure inside the fabric, so the
`air pass easily through the fabric.
`3.4. Relative Water Vapor Permeability
`Water vapor permeability is the ability
`to
`transmit vapor
`from
`the body.
`Relative water vapor permeability is
`given by the relationship:
`
`
`q
`[%]
`
`=
`
`100
`
`s×
`0
`where qs is the heat flow value with a
`sample (W/m2) and qo is the heat flow
`value without sample (W/m2).
`Statistical evaluations show that the
`effect of dial height on relative water
`vapor
`permeability
`values
`is
`insignificant (Table 1 and 2). However
`the spacer yarn type has a significant
`effect on this property. The water
`vapor permeability values are higher
`for the fabrics with multifilament spacer
`yarns because of capillarity between
`filaments in multifilament yarn.
`
`
`
`
` (2)
`
`3 mm
`3.5 mm
`4 mm
`
`these parameters in Fig. 2 and 3 have
`the same inclination. This contradiction
`might be explained by fabric thickness.
`If the amount of increase in fabric
`thickness is more than the amount of
`increase
`in
`thermal
`conductivity,
`thermal resistance will also increase
`and a significant increase is seen in
`the fabric thickness value (Table 1 and
`Table 2).
`3.3. Air Permeability
`Air permeability is the rate of air flow
`passing perpendicularly
`through a
`known area under a prescribed air
`pressure differential between the two
`surfaces of a material. As illustrated in
`Figure 4, the highest air permeability
`value belongs to the samples knitted
`with the dial height 3 mm for both
`spacer yarn types. Because the fabrics
`get finer, the amount of air passed
`through the fabric increases.
`Statistical analysis show that spacer
`fabrics with monofilament spacer yarn
`have higher air permeability values
`than fabrics with multifilament spacer
`yarn (Table 1 and 2). In fact, an
`opposite result is expected because of
`the higher thickness of fabrics from
`
`2500
`
`2000
`
`1500
`
`1000
`
`500
`
`0
`
`Air permeability (ltm2/s)
`
`3 mm
`3.5 mm
`4 mm
`
`
`3.2. Thermal Resistance
`Thermal resistance is a measure of the
`body's ability to prevent heat from
`flowing through it. Under a certain
`condition of climate, if the thermal
`resistance of clothing is small, the heat
`energy will gradually reduce with a
`sense of coolness. Thermal resistance
`Rct depends on fabric thickness (h)
`and
`thermal conductivity
`(λ) as
`illustrated in Equation 1:
`
`λh
`
`
`
`
`
`(1)
`
`=Rct
`K(m
`W)
`/
`2
`As it is seen from Fig.3, for the both
`spacer yarns, the thermal resistance
`increases as the dial height and fabric
`weight increase as mentioned in a
`previous research (24).
`For the comparison of spacer yarn
`type, the fabrics with monofilament
`spacer yarn have better insulation than
`the fabric with multifilament spacer
`yarn, because of higher still air
`between monofilament yarns.
`Although the general expectation was
`to register an
`inverse relationship
`between
`thermal
`resistance and
`thermal conductivity, the graphs for
`
`0,08
`0,07
`0,06
`0,05
`0,04
`0,03
`0,02
`0,01
`0,00
`
`Thermal resistance (m2K/W)
`
`
`
`Monofilament spacer yarn Multifilament spacer yarn
`
`
` Figure 3. Thermal resistance values of spacer fabrics Figure 4. Air permeability values of spacer fabrics
`
`Monofilament spacer yarn Multifilament spacer yarn
`
`
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`3 mm
`3.5 mm
`4 mm
`
`45
`40
`35
`30
`25
`20
`15
`10
`
`05
`
`Relative water vapor permeability
`
`(%)
`
`Monofilament spacer yarn
`
`Multifilament spacer yarn
`
`
`Figure 5. Relative water vapor permeability values of spacer fabrics
`
`
`
`
`
`4. CONCLUSION
`This study performs a quantitative
`investigation
`of
`various
`fabric
`characteristics, such as fabric weight,
`air permeability, thermal conductivity,
`thermal resistance and relative water
`vapor permeability properties of spacer
`fabrics.
`The results indicate that for monofilament
`spacer yarn as
`the dial height
`
`the parameters such as
`increases;
`thickness,
`and
`thermal
`weight,
`resistance increase and air permeability
`decreases. For multifilament spacer
`yarn by the increasing of the dial height
`weight, thickness, thermal conductivity
`and thermal resistivity values increase
`and air permeability value decreases as
`well.
`The fabrics with monofilament spacer
`yarn have higher weight, thickness,
`
`thermal conductivity, thermal resistivity,
`air permeability values and
`lower
`relative water vapor permeability values
`than
`the
`fabrics with multifilament
`spacer yarn.
`ACKNOWLEDGEMENTS
`We would like to thank Boyteks A.Ş.
`for the production support and to Ege
`University Scientific Research Project
`Office for the financial support.
`
`
`REFERENCES
`1. Milenkovic, L., Skundric, P., Sokolovic, R., Nikolic, T., 1999, “Comfort Properties of Defence Protective Clothing”, The Scientific Journal Facta Universitatis,
`1(4), pp:101–106.
`2. Holcombe, B.V., Hoschke, B.N., 1983, “Dry Heat Transfer Characteristics of Underwear Fabrics”, Textile Research Journal, 6(53), pp:368-374.
`3. Obendorf, S.K., Smith, J.P., 1986, “Heat Transfer Characteristics of Nonwoven Insulating Materials”, Textile Research Journal, 11(56), pp:691-696.
`4. Greyson, M., 1983, “Encyclopedia of Composite Materials and Components”, Wiley & Sons, New York.
`5. Havenith, G., 2002, “The Interaction of Clothing and Thermoregulation”, Exogenous Dermatology, 1(5), pp:221–230.
`6. Shoshani, Y., Shaltiel, S., 1989, “Heat Resistance Characteristics of Weft Knit Single Jersey Inlay Fabrics”, Knitting Times, pp: 70–72.
`7. Pac, M. J., Bueno, M. A., Renner, M., “Warm-Cool Feeling Relative to Tribological Properties of Fabrics”, Textile Research Journal, 71(19), pp:806–812.
`8. Anand, S., 2003, ”Sportwear Fabrics”, Knitting International, June, pp:23-25.
`9. Hes, L, Geraldes, M.J., Araújo, M., 2002, “How to Improve the Thermal Comfort with High Performance PP Fibres”, 2nd AUTEX World Textile Conference,
`Bruges, Belgium, p: 428.
`10. Uçar, N., Yılmaz, T., 2004, “Thermal Properties of 1x1, 2x2, 3x3 Rib Knit Fabrics”, Fibres&Textiles in Eastern Europe, Vol.12, No. 3(47), pp:34-38.
`11. Bruer, S.M., Powell, N., Smith, G., 2005, “Three Dimensionally Knit Spacer Fabrics: a Review of Production Techniques and Applications”, Journal of Textile
`and Apparel, Technology and Management, 4 (4), pp:1-30.
`12. Anand, S., 2003, “Spacers – At the Technical Frontier”, Knitting International, 110 (1305), pp:38-41.
`13. Musiol, M., 2005, “Analysis of Transverse Deformability of Spacer Products”, AUTEX Research Journal, 1(5), pp:67-70.
`14. Wollina, U., Heide, M., Müler-Litz, W., Obenauf, D., Ash, J., 2003, “Functional Textiles in Prevention of Chronic Wounds”, Wound Healing and Tissue
`Engineering, Textiles and the Skin, (31), pp: 82-97.
`15. Pause, B., 2002, “Studies on the Thermophysiological Comfort Provided by Knitted Spacer Fabrics”, Melliand International, 1(8), pp:57-60.
`16. Ye, X., Hu, H., Feng, X., 2005, “An Experimental Investigation on the Properties of the Spacer Knitted Fabrics for Pressure Reduction”, Research Journal of
`Textile and Apparel, 3(9), pp: 52 – 57.
`17. Wei, H., Hairu, L., 2006, “The Investigation on Knitting Technology and Compressive Properties of Weft Knitted Spacer Fabric”, China Textile Leader,11,
`pp:51-53.
`18. Yip, J., Ng, S., 2008, “Study of Three-Dimensional Spacer Fabrics: Physical and Mechanical Properties”, Journal of Materials Processing Technology, 206,
`pp: 359-364.
`19. Hes, L., 2001, “Fast Determination of Surface Moisture Absorptivity of Smart Underwear Knits”, International Textile Conference, Terrassa, Spain.
`20. Hes, L., 2007, “Thermal Comfort Properties of Textile Fabrics in Wet State”, XI. International İzmir Textile and Apparel Symposium, Izmir, Turkey.
`21. ISO 11092, 1993, “Textiles – Determination of Physiological Properties – Measurement of Thermal and Water Vapor Resistance Under Steady-state
`Conditions (Sweating Guarded-Hotplate Test)”.
`22. Ergün, M., 1995, “SPSS for Windows”, Ocak, Ankara, p:107.
`23. Morton, W. E., Hearle, J. W. S.,1993, Physical Properties of Textile Fibre, The Textile Institute, Manchester, England.
`24. Oğlakcıoğlu, N., Marmaralı, A., 2007, “Thermal Comfort Properties of Some Knitted Structures”, Fibers&Textiles in Eastern Europe, 5-6(15), pp:64-65.
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