38 research outputs found
Evaluating Thermophysiological Comfort Using the Principles of Sensory Analysis
Thermophysiological comfort applies to the way in which clothing lets through or retains heat and moisture and helps the body retain heat balance in rest position or at various levels of activities. In this paper, the principles of sensory analysis are used to define the protocol of new method for the evaluation of thermophysiological comfort wearing different garments. Sensory analysis was chosen because as a scientific discipline that applies experiment principles using human senses is used for the evaluation of consumer goods. Test protocol using assessors described in this paper consists of the following steps: defining the interview content, finding potential assessors and making an interview, creating a survey, conducting a survey, group discussion, test and group discussion scoring, selection of assessors, assessment preparation and subjective assessment. On average the most distinctive increase in the sensation of warmth was recorded for the polyester clothing ensemble, and the lowest one for the cotton clothing ensemble. Concerning the average grades of comfort given by assesors, the most comfortable clothing ensemble is the one made of viscose. It was also found out that the method is especially suitable if a representative group of assessors is formed
Study on the Inuence of Calendaring Process on Thermal Resistance of Polypropylene Nonwoven Fabric Structure
Thepurposeofthispaperistoinvestigatetheinuenceofcalenderingprocessonpolypropylenenonwoven structureandthermalresistance. Thestudywasfocusedontheinuenceofmassperunitarea, thickness, density, porosity, characteristic opening size and additional thermal bonding by calendering. Thermal resistance of polypropylene nonwoven fabric manufactured using the mechanical carding process and bonding using the needling process, where a part of the samples was additionally bonded by the thermal calendering process, were investigated. The nonwoven fabrics were tested for thermal resistance on the guarded hot plate. Statistical analyses were performed to examine the signicance between the observed parameters. Correlation matrix analyses were used to reveal relationship behaviour among the variables. A change in structure of the calendered samples caused a considerably lower thermal resistance i.e. better thermal conductivity. A change of the average value of thermal resistance after calendering related to non-calendered fabric mass between 150 and 500 g/m2 ranged from 53.9 to 41.0%. With increasing nonwoven fabric mass, the dierence between thermal resistances of needled and needled as well as additionally bonded by calendering the nonwoven fabric was reduced
Inuence of Pressure on Water Permeability and Characteristic Opening Size of Nonwoven Geotextiles
Nonwoven geotextiles manufactured by mechanical carding process and bonding by needling process are investigated in this paper. Part of the samples was additionally bonded by thermal calendaring process. Sampling was conducted according to the standard for geotextile with certain modications. The samples were tested for water permeability perpendicular to the plane of samples using loads of 2, 20 and 200 kPa. Characteristic opening size of geotextiles was tested using sieving method. Research shows that dierent applied pressures signicantly change structure and properties i.e. thickness and water permeability normal to the plain under load of geotextile
Measurement of thermal parameters of skin-fabric environment
Background and Purpose: In combination with metabolic heat, the
heat generated by human activities and worn garment produce 6 basic factors (sometimes called 6 basic parameters because they are in space and time, but fixed representative values are frequently used in analyses) which define thermal body environments. The aim of this paper is to investigate the impact of one parameter ā clothing insulation on the total transfer of heat and water vapor.
Materials and Methods: The measurement was carried out on knitted
fabrics commercially used for the production of underwear or different
types of next-to-skin-wear. The transfer of heat and moisture trough fabrics was observed in two simulated climatic environments (moderate and hot) with the constant parameters metabolic energy and air velocity.
Results: The results indicated that the heat resistance increases by laying a knitted fabric layer or under real conditions when the body is dressed in lightweight knitwear by 25%. The test results of the samples under different environment conditions indicated a reduction in heat resistance under moderate conditions. It also applies to the measurement results of the resistance to water vapor transfer, but the differences within the observed relationships are higher than it was in the case of heat transfer resistance.
Conclusions: The study showed that both heat and moisture transfers are freely movable controlling elements of comfort perception. Therefore, the optimal design of clothing systems is important factor of comfort
Measurement of thermal parameters of skin-fabric environment
Background and Purpose: In combination with metabolic heat, the
heat generated by human activities and worn garment produce 6 basic factors (sometimes called 6 basic parameters because they are in space and time, but fixed representative values are frequently used in analyses) which define thermal body environments. The aim of this paper is to investigate the impact of one parameter ā clothing insulation on the total transfer of heat and water vapor.
Materials and Methods: The measurement was carried out on knitted
fabrics commercially used for the production of underwear or different
types of next-to-skin-wear. The transfer of heat and moisture trough fabrics was observed in two simulated climatic environments (moderate and hot) with the constant parameters metabolic energy and air velocity.
Results: The results indicated that the heat resistance increases by laying a knitted fabric layer or under real conditions when the body is dressed in lightweight knitwear by 25%. The test results of the samples under different environment conditions indicated a reduction in heat resistance under moderate conditions. It also applies to the measurement results of the resistance to water vapor transfer, but the differences within the observed relationships are higher than it was in the case of heat transfer resistance.
Conclusions: The study showed that both heat and moisture transfers are freely movable controlling elements of comfort perception. Therefore, the optimal design of clothing systems is important factor of comfort
Tribological properties of cotton yarns: surface friction factor
Trenje koje nastaje prolazom preÄe kroz razliÄite metalne elemente tijekom proizvodnje ploÅ”nih proizvoda, ovisno je o nizu parametara koji mogu biti vezani uz karakteristike, kao Å”to su dlakavost preÄe, broj uvoja, oblik popreÄnog presjeka, posebnosti u strukturi preÄe i povrÅ”inska obrada preÄe. U radu je ispitano povrÅ”insko trenje parafiniranih pamuÄnih preÄa ispredenih od turskog, sudanskog i egipatskog pamuka. PreÄe su izraÄene u Äetiri finoÄe (14, 17, 20 i 25 tex) te s Äetiri razliÄita postotka iÅ”Äeska (14, 16, 18 i 20 %). Faktor povrÅ”inskog trenja parafiniranih uzoraka manji je i do 63 % od vrijednosti tog faktora za neparafinirane uzorke. Kod uzoraka preÄa izraÄenih od sudanskog pamuka postoji odreÄena pravilnost u smanjenju faktora povrÅ”inskog trenja nakon provedenog postupka parafiniranja, te se taj faktor prosjeÄno smanjuje za 40 %. NajveÄi nerazmjer u razlikama vrijednosti faktora povrÅ”inskog trenja prisutan je kod preÄa izraÄenih od turskog pamuka.The friction caused by the passage of yarn through various metal parts during manufacture of fabrics depends on a number of parameters that can be related to characteristics such as hairiness of yarn, twist level, shape of the cross section, specific structure of the yarn and yarn surface treatment. The paper examines the surface friction of lubricated cotton yarns spun from Turkish, Sudanese and Egyptian cotton. Yarns were made in four counts (14, 17, 20 and 25 tex) and with four different percentages of noil (14, 16, 18 and 20 %). Surface friction factor of the lubricated samples decreased up to 63 % of the value of the same for the non-lubricated samples. In the yarn samples made from Sudanese cotton there is a certain regularity in reducing surface friction factor after the lubricating procedure, and it is then reduced by an average of 40 %. The greatest discrepancy in the differences of surface friction factor is present in yarns made from Turkish cotton
Comparison of Subjective and Objective Measurement of Sweat Transfer Rate
Sweat absorption is investigated using the subjective and objective methods. The subjective investigation analyses the physiological responses of male and female volunteers wearing two kinds of textile fabrics (cotton and polyester) during certain physical activity. The subjects were exposed to the different conditions of ambient temperature (23, 26, 29 and 32 Ā°C) and constant relative humidity of 67 Ā± 3%. In the objective investigation the sweating guarded hotplate (SGHP) system was used that stimulates the processes of sweat transfer between the human skin, textile material and environment. The results of mass absorption obtained from the objective measurement on the sweating guarded hotplate show the similar trend as the results obtained during the subjective measurement
Impact of yarn count, noil percentage and yarn tension on structure of jersey fabric
KlasiÄnim postupkom predenja na prstenastoj predilici ispredene su preÄe iz egipatskog pamuka Giza 75 FG finoÄa 14,3, 16,7, 20,0 i 25,0 tex. Svaka od navedenih preÄa ispredena je sa veÄim koeficijentom uvijanja i razliÄitim postotkom isÄeska 14, 16, 18 i 20 %. Na kružnopletaÄem jednoigleniÄnom stroju malog promjera iz navedenih preÄa izraÄene su dvije grupe glatko kulirnih desno-lijevih pletiva s razliÄitom napetosti preÄe pri njenom ulasku u pletaÄi sistem. Prva je grupa uzoraka izraÄena s uobiÄajenom napetosti preÄe koja se koristi kod izrade ovakvih pletiva (0,15 cN/tex), dok je druga grupa uzoraka izraÄena s veÄom napetosti (0,40 cN/tex). Dobivena mjerenja statistiÄki su obraÄena i testirana.Using the combed cotton spinning route, a number of yarns from Egyptian cotton Giza 75 FG with counts of 14.3, 16.7, 20.0 and 25.0 tex were spun. Each of the yarns were spun with a higher twist factor and different noil percentage of 14, 16, 18 and 20%. The yarns are being used to knit two groups of plain single jersey fabrics on a small diameter single bed circular knitting machine with two different yarn tensions at the knitting zone. The first group of samples was knitted with a usual yarn tension used in making knitted fabrics underwear (0.15 cN/tex), while the other group of sample was knitted with a higher tension (0.40 cN/tex). The measurements are statistically analyzed and tested