Thermophysiological Comfort Research Articles

Influence of Undergarments on the Comfort Level of Scoliosis Brace Wearers.

Bracing has proven to be an effective method for the conventional treatment of scoliosis in young people. A brace, a therapeutic device, covers the upper body and promotes healing by applying pressure to specific areas. However, wearing a scoliosis brace negatively affects the user's thermo-physiological well-being and often leads to discomfort. In this study, we investigated the influence of T-shirts as an undergarment on the thermo-physiological well-being of the brace wearer. For this purpose, we performed a comparative analysis of six T-shirts made from different special knitted fabrics. We carried out wearing tests in a computer-controlled climate chamber according to a predetermined protocol. The test subject wore the orthopedic brace over the different T-shirts at three different temperatures. The results indicate that the knitted fabrics of undergarments and environmental conditions considerably impact the wearer's thermo-physiological comfort. In the tests, the T-shirts made from the selected functional fabrics performed very well. The T-shirt made from the classic cotton fabric containing elastane yarn also performed well and was the most environmentally friendly. Currently, due to its lower price and easier availability, this cotton T-shirt can be recommended for wearing under a scoliosis brace.

Human thermo-physiological comfort assessment in Lisbon by local climate zones on very hot summer days

Extreme heat is a current and future issue on urban areas, with negative impacts on health and quality of life (increasing morbidity and mortality rates). This paper analyses day (12:00–15:00 h) and nighttime (00:00–03:00 h) thermo-physiological comfort (TC) conditions by Local Climate Zones (LCZ) in Lisbon during a particular Local Weather Type (LWT), very hot summer days. For this, 13 different microscale sample areas were chosen covering urban and non-urban land cover classes (LCZs 1–3, 4–6, 8, 9, A and B). Universal Thermal Climate Index (UTCI) and Mean Radiant Temperature (MRT) were modeled on SkyHelios software for 163 days between 2008 and 2014. Results show that during the day all urban LCZ samples depict the same average TC conditions (average UTCI of 34°C—strong heat stress) and densely wooded areas are 2°C cooler (average UTCI of 32°C—moderate heat stress). However, compact areas (LCZs 1–3) with low sky view factor and some vegetation (street trees) display lower percentages of area with higher thermo-physiological discomfort (TD) levels (83% with strong heat stress against 98% in LCZs 8 and 9 and 100% in LCZs 4–6). When considering the hottest days (air temperatures equal or above 35°C—75th percentile), the moderate heat stress class disappears in all samples and the very strong heat stress class appears only on urban areas, occupying between 12% and 16% on LCZs 1–3, 10%–22% on LCZs 4–6, 16%–22% on LCZs 8 and 9 on LCZ 9. During the nighttime period all samples show no thermal stress, favoring nocturnal physiological recovery. TC conditions in Lisbon are strongly influenced by solar radiation and wind, which explains the need to increase the shading area, preferably by trees, and to promote and preserve ventilation paths.

Evaporation coefficient determination during the capillary rise

Thermo-physiological comfort refers to the heat and moisture transport properties of clothing and how the clothing helps maintain the body's heat balance during various activities. To maintain the thermoregulation of the body, the resulting sweating should be absorbed by wicking fabrics close to the skin and evaporated to the ambient air. In this study, a mathematical model was developed considering evaporation during the capillary rise, based on the geometric configuration of a jersey-knitted fabric and taking evaporation into account. This model was used to calculate the evaporation coefficient. Based on the activities of the worker, sweat diffusion is controlled by capillary diffusion and moisture evaporation. The effect of air velocities of 0 m/s, 1 m/s, and 2 m/s, representing non-walking, walking, and running activities of a worker, respectively, was studied during capillary diffusion. The experiments were conducted at different relative humidities. The results show that the evaporation coefficient depends on the worker’s activities and the relative humidity ratio.

Spreading of water microdroplets simulating human sweating in polyester yarns and fabrics

Thermo-physiological comfort of human body is highly influenced by the moisture transmission behaviour of the fabric. For active sportswear, intimate apparels and inner layer of extreme cold weather clothing, moisture transport is very crucial. The liquid moisture transport of fabrics is analysed using standardised test methods like vertical wicking, absorbency test and moisture management through moisture management tester. These test methods use large reservoir of liquid in contrast to human sweating behaviour. The human skin generates sweats in the form of microdroplets through sweating glands. Hence, the standard test procedures employed to assess the fabric’s liquid moisture transport fail to capture preciously the sweat transport from human skin to the fabrics. Hence, in this work, the spreading behaviour of water microdroplets simulating human sweat through yarns which are the building block of fabrics and knitted fabrics that are widely used as sportswear or inner layer of extreme cold weather clothing are investigated. The purpose of this study is to understand how the microfluid move along the capillary channels in yarns (in the forms of network of yarns crossing over each other and fabric) by keeping yarn count and twist same for all yarns. A single micro drop representing accumulated sweat droplets and multiple drops showing continuous sweating through sweat glands were allowed to wick through the yarns made up of coarser and finer fibres to understand the role of fibre diameter on wicking kinetics. Results from the conventional wicking test were compared with microfluidic wicking. It is found that the initial wicking speed in coarser-fibres yarn is faster in comparison to finer-fibres yarn, but the final wicking height is longer in finer fibre yarn. Overall liquid spreading length found to be similar for both the yarns. Yarn to yarn liquid transfer at crossover junctions is faster with finer-fibre yarn compared to coarser-fibre yarn. Same trends are found in fabrics constructed with these yarns. The effect of yarn tortuosity on liquid spreading behaviour has also been studied. As the yarn path becomes torturous (straight yarn to fabric form) wicking length also decreases.

Influence of Stretching on Liquid Transport in Knitted Fabrics

The transport of liquid sweat in clothing worn close to human skin is very important from the point of view of the thermo-physiological comfort of clothing users. It ensures the drainage of sweat secreted by the human body and condensed on the human skin. In the presented work, knitted fabrics made of cotton and cotton blends with other fibers (elastane, viscose, polyester) were measured in the range of liquid moisture transport using the Moisture Management Tester MMT M290. The fabrics were measured in unstretched form and stretched to 15%. Stretching of the fabrics was performed using the MMT Stretch Fabric Fixture. Obtained results confirmed that stretching significantly changed the values of parameters characterizing the liquid moisture transport in the fabrics. Before stretching, the best liquid sweat transport performance was stated for the KF5 knitted fabric made of 54% cotton and 46% polyester. For this, the greatest value (10 mm) of maximum wetted radius for the bottom surface was obtained. The Overall Moisture Management Capacity (OMMC) of the KF5 fabric was 0.76. This was the highest value among all values obtained for the unstretched fabrics. The lowest value of the OMMC parameter (0.18) was stated for the KF3 knitted fabric. After stretching, the KF4 fabric variant was assessed as the best one. Its OMMC improved from 0.71 before stretching to 0.80 after stretching. The value of the OMMC for the KF5 fabric remained after stretching at the same level (0.77) than before stretching. The most significant improvement was observed for the KF2 fabric. Before stretching, the value of the OMMC parameter for the KF2 fabric was 0.27. After stretching, the OMMC value increased to 0.72. It was also stated that the changes in the liquid moisture transport performance of the investigated knitted fabrics were different for the particular fabrics being investigated. Generally, in all cases, the ability of the investigated knitted fabrics to transfer liquid sweat was improved after stretching.

Optimization of Knitted Fabrics for better Thermo-Physiological Comfort by using Taguchi-based Principal Component Analysis

The water, air permeability and thermal resistance of fabrics are important attributes that have a significant impact on the thermal comfort properties of sportswear fabrics in different environmental conditions. In this work, terry and fleece fabrics were developed by varying the fibre content and mass per unit area of fabrics. Moreover, the thermo-physical properties of the developed fabrics, including air permeability, water vapor permeability and thermal resistance, were analysed before and after washing. The multi-response optimization of the thermal comfort properties of knitted fabrics was performed using principal component analysis (PCA) and the Taguchi signal-to-noise ratio (PCA-S/N ratio) to achieve optimal properties. It was determined that the selected parameters (fabric type, finishing, fibre content and fabric mass per unit area) had a significant effect on the thermal comfort properties of knitted fabrics. The PCA analysis showed that 100% cotton terry fabric before washing with an aerial weight of 220 g/m2 had higher air and water vapor permeability value, but a lower thermal resistance value.

Emerging passive thermoregulatory textiles through tailoring different heat transfer routes

Personal thermal management systems play significant roles in improving personal thermal comfort and decreasing energy consumption resulting from traditional thermoregulation methods such as air conditioning. Thermoregulatory textiles passively regulating human body heat transfer routes through their engineered properties are an effective and promising way to offer personal thermophysiological comfort without extra energy consumption. In this paper, we reviewed recent progress on passive thermoregulatory textiles and classified them into four categories: radiative thermoregulatory textiles, conductive thermoregulatory textiles, single phase convective thermoregulatory textiles, and phase transition convective cooling textiles. By comparing and summarizing their thermoregulatory paths and performance, we found that radiative thermoregulatory textiles are the most promising because of their wide temperature regulation paths, superior thermoregulatory performance, and bidirectional temperature regulation. Furthermore, we provided critical considerations on the various characterization and calculation methods for thermoregulatory performance used in these research works, and pointed out future perspectives in such a burgeoning field.

MOF-Integrated Hierarchical Composite Fiber for Efficient Daytime Radiative Cooling and Antibacterial Protective Textiles.

Incorporating passive radiative cooling into textiles is an effective way to improve individual personalized thermophysiological comfort for the human body. Based on radiative cooling textile design, rational functionalization further facilitates practical applications, especially for medical protective products with customized requirements. Herein, we present a hierarchical polyurethane/metal-organic framework (MOF) composite nanofiber membrane with an integrated radiative cooling effect and photocatalytic antibacterial property. Fabricated by a scalable electrospinning method, the hierarchical nanofiber membrane shows high solar reflectance of 97% and improved thermal emissivity of 93% attributed to the abundant chemical bonds in ZIF-8 nanoparticles, rendering a temperature drop of ∼7.2 °C under direct sunlight and ∼5.5 °C at night. In addition, the photocatalytic activity of ZIF-8 ensures a 96% bacterial mortality rate for preventing bacterial infection. In practical application, our composite fabric can prevent superheating by 4.4 °C compared with the traditional protective suit under direct sunlight. Along with its anti-infection ability, the composite fabric is desirable for medical protective textiles. The innovative integration of passive radiative cooling design and functional MOFs breaks through the traditional cooling mode and provides huge substantial advantages for smart textiles and personal cooling applications.

Analysis of Ring Spun Yarn Wickability Using the Post-Hoc Test

Abstract Yarn wickability achieves high thermo-physiological comfort. Therefore, this paper aimed to investigate yarn wickability and analyze statistically factors affecting yarn wicking performance. Methodology consists of testing wicking height for ring spun yarn produced from three levels of fibre types and twist factors at two levels of doubling. Statistical tools such as ANOVA, T-test and Post-hoc tests analyzed the impacts on wicking heights. Findings showed that the Post-hoc test represented the variation between groups more accurately than ANOVA. Furthermore, a comparison of Bonferroni Alpha with T-test p-values revealed that yarn wicking was significantly affected by interactions of fibre type, doubling, and twist level.

Thermophysiological comfort and objective hand properties of modal, Naia™, cashmere and cotton included denim fabrics

In this study, the thermophysiological comfort and objective hand properties of modal, Naia™, cashmere, and cotton containing denim fabrics were investigated. Therefore, the air permeability, thermal conductivity, thermal absorptivity, thermal resistance, water vapor permeability, overall flexural rigidity, and compressibility of the fabrics were examined. It was concluded that using Naia™ sustainable fiber improved the thermal comfort and objective hand properties of denim fabrics. The elastane containing fabrics (T5 and T6) were uncomfortable because of their lower air permeability, lower water vapor permeability and higher overall flexural rigidity properties. Sulfur dyeing only affects the thermal resistance of fabrics, and the thermal resistance of sulfur dyed fabrics is higher than that of indigo dyed fabrics with the same compositions.

Uticaj sirovinskog sastava muških čarapa na termofiziološki komfor u dinamičkim uslovima

The influence of environmental conditions on the thermo-physiological comfort of men's socks was investigated using an objective assessment of comfort under dynamic conditions. Men's socks made in a 3:1 rib construction from three types of basic yarns (77%) were used: bamboo, cotton, and a cotton/polyester blend. The remaining composition of the socks is identical: filament polyamide yarn (22%) and wrapped rubber thread (1%) for the welt. The influence of climate factors artificially created in the climate chamber was analyzed by measuring three physiological parameters: skin temperature, relative humidity of the skin, and microclimate in the space between the sock and the shoe on both feet. The research results show that the raw material composition of the base yarn used in the manufacture of men's socks has a significant impact on thermo-physiological comfort when wearing socks. Under artificially created conditions in the climate chamber, an ambient temperature of 20 °C and relative humidity of 50% (autumn and spring conditions), socks with basic yarn made of a cotton/polyester blend are preferred, then with a base yarn made of cotton, and finally socks with a base yarn made of bamboo. The data from the study provide valuable information for the clothing industry in designing and defining the choice of base yarn to produce socks, depending on the conditions of use.

Surface-engineered double-layered fabrics for continuous, passive fluid transport.

Textiles with a wicking finish transport moisture away from the skin, such that it is exposed to the environment for fast evaporation, aiding in thermophysiological comfort. Once saturated, such as in highly humid environments or if the wearer dons multiple layers, the efficacy of such a finish is substantially reduced. Here, we develop a new type of fluid transport textile design by combining physical and chemical wettability patterns to transport and remove liquids like sweat. First, a non-toxic, superhydrophobic fabric finish is developed that retains the air permeability of the fabric. Next, two superhydrophobic fabric layers are threaded together, containing wettability channels patterned at the inner/interior side of the fabrics. This design allows for liquid transport through the stitches to the interior channels and keeps both external faces dry. The developed strategy enables directional fluid transport under highly humid conditions, resulting in a ∼20 times faster transport rate than evaporation-based methods. The design principles described here can be used to provide thermophysiological comfort for users in extreme conditions, such as firefighters, law enforcement personnel, and health workers wearing personal protective ensembles.

A study on the effect of material type, structure tightness and finishing process on the physical and thermo-physiological properties of sandwich terry socks for winter wear

Compared to other textiles, socks are made at the lowest cost and have the highest consumption rate, making them one of the least-lasting fabric goods in the clothing industry. Socks are available in a wide range of fibers blends, that is, cotton, wool, nylon, acrylic, polyester, olefin, spandex, etc. As an element of footwear, socks act in tandem with the foot and shoe, influencing the temperature and moisture levels of the feet. The comfort of clothing next to the skin in terms of temperature and moisture is gaining more and more attention. Pilling is a serious issue with wool items, and less pilling is required since it negatively impacts the esthetic, comfort, and longevity of the fabric. This research has investigated socks pilling tendency and thermo-physiological comfort properties, that is, air permeability and thermal resistance made by wool/polypropylene blend yarn. Three different combinations of wool/polypropylene yarns on the main and platting side of the socks were used at two different tightness levels. Polyurethane finish has been applied to check the socks’ behavior after the finish application. Statistical analysis showed that finished samples knitted with wool/polypropylene as a main yarn offer the best results against the pilling test while sample code ANL, an unfinished sample, offers the best results regarding air permeability, thermal resistance, and overall moisture management capacity.

Assessment of comfort property of jute-cotton blend denim trousers after repetitive laundering

In this analysis jute cotton blend denims performance at enzyme wash to 35 times respective laundering, in friction and roughness properties where 5 times laundered sample showed smoother surface in both inner and outer surface. In bending properties, 5 times laundered sample was found second lowest Bending Average Rigidity (BAR) and Bending Work (BW). In compression, highest Compression Average Rigidity (CAR), Recovery Average Rigidity(RAR) and less energy requirement Compression work (CW) to compress in both inner and outer surface was found in 5 times laundered sample. In Sensorial Comfort Aspect (SCA), 5 times laundered sample was found smoother surface property, quite higher bending property and higher compression average rigidity. Therefore, 5 times laundered sample was good sensorial comfort among all the samples. In Maximum Thermal Flux (MTF), 20 times laundered sample gives most warm feeling at inner surface because it provides minimum heat flux which ensure warmness in skin-garment micro environment. For thermo physiological comfort aspect, only 20 times repetitive laundered sample found maximum thermo physiological comfort among all samples. Thus, Jute-Cotton blend denims performance at enzyme wash to 35 times repetitive laundering up to 20 times repetitive laundering sample reported good results and the protruding fibre of jute was visible excessively on the surface.

Impact of varying lactate concentration in sweat on thermo-physiological comfort of multi-layered ensembles

PurposeSweating is thermo-regulatory behaviour that occurs when a person performs vigorous activity even in cold climatic condition. One of important component of sweat is the presence of lactate. Based on climatic condition, age, gender, maturity and nature of activity level, the change in lactate concentration is inevitable. Hence, the present study is focussed on the impact of change in the lactate concentration on the moisture transmission behaviour through the clothing. The purpose of this paper is to investigate the impact of changing lactate concentration on the moisture vapour transmission behaviour through multi-layered clothing ensembles.Design/methodology/approachFor the investigation, sweat solution representing male and female sweat were taken for present study. Two different multi-layered ensembles consisting of either spacer or fleece as middle layer were considered. The water vapour permeability and drying rate test were done at standard atmospheric conditions. After testing, ANOVA analysis was done in order to determine the most significant parameters.FindingsFabric structure (constituent layers) behaved differently when tested individually and as the layered component with different sweat solutions. Water vapour permeability of sweat solution with higher lactate concentration was lower as compared to sweat solution with lower lactate concentration. Individual layers showed higher rate of vapour permeability with sweat solution containing lower lactate concentration as compared to multi-layered ensembles. Role of PU coated nylon fabric was predominant in case of multi-layered ensembles. Difference in transmission of sweat solution was found higher in case of uni-directional stitched multi-layer spacer ensembles whereas marginal difference was observed in case of bi-directional seamed multi-layer spacer ensemble. Drying rate of sweat containing lower concentration of lactate was higher as compared to the other sweat solution for all the selected fabrics. Density of liquid and amount of the water available for drying influenced the drying behaviour and thus accounted for difference in drying rate of sweat solution differing in the lactate concentration. The contribution percentage of layers, i.e. type of structure was higher (nearly 93–96%) compared to that of solution type (3.3–4.9%) in case of individual layers whereas in the case of the multi-layer ensembles; type of seam had maximum contribution percentage (71–77%) followed by solution type (10–15%). Type of layers had least contribution percentage (nearly 7–9%).Practical implicationsThe findings from the study are expected to be realistic and important in designing and development of cold weather garment ensemble for different gender type depending on their activity level especially in case of military personnel and those performing combat activities.Originality/valueThis experimental work based will provide the insight about the behaviour of actual sweat transmission through the layered fabric ensembles and ways to prevent the accumulation of moisture near to human skin surface by manufacturing suitable design structures (in terms of layering composition and seam patterns) per the morphology and requirement of specific consumers.

Analysis of material variation in the design of knitted sportswear compression stockings to escort thermo-physiological comfort using linear regression

Compression sportswear is specialized clothing chiefly designed for the athletes muscle fatigue reduction. Compression stockings are widely used in sportswear to support muscles and control excessive body vibrations. Compression/interface pressure between the wearer and stocking’s surface is considerable in compression sportswear efficacy. However, thermo-physiological comfort is also influential while preparing summer sportswear. The research investigates the effect of fibers type and the inlay yarns number of covering filaments on compression, air permeability, water vapor permeability, and thermal resistance of sportswear compression stockings. Three different fibers, sorbtek (channelized polyester), nylon 6, and micro Nylon (polyamide-6), have been used as main yarns. Also, three distinct levels of covering yarn number of filaments have been utilized. Data have been statistically analyzed using full factorial design of experiment and regression analysis to predict fiber type and the number of covering yarn filaments for achieving desired comfort properties without compromising compression characteristics.

Effect of Yarn Count, Weave Structure, Construction on Thermal Properties and Air Permeability of Fabrics

This Clothing is placed not exclusively to protect the human body from harm, but also because it assists in achieving a state of comfort during strenuous activities or when the environment around the wearer is unfavorable. Clothing comfort is determined by the thermo-physiological comfort properties of the woven fabric, which include air permeability, thermal properties, moisture management, and handling properties. Different high-tech fibers, yarns, woven fabric construction and structure have radically altered people's fundamental need to be clothed as time has progressed. In this study, the thermo-physiological comfort properties of woven fabrics with differing construction and structure are investigated. Then comparisons are made keeping all parameters constant except one. It has been demonstrated that a higher thermal conductivity can be achieved by using coarser yarn in higher interlacing fabrics, such as plain fabric. On the other hand, the thermal conductivity of a fabric with low interlace density, such as 3/1 twill, is reduced when a coarser yarn is used. The thermal conductivity of fabric can be reduced to an acceptable level by using coarser yarn and less interlacing. Fabrics with heavier constructions are less air permeable than those with lighter constructions.

Engineering UPF and comfort parameters of knitted fabrics and validation using statistical techniques

PurposeThe thermophysiological comfort of fabrics is prerequisite as customers covet adequate moisture, heat management-supported and UV protective clothing that measure up to their levels of activities and environmental conditions. Hitherto, scant tasks have been reported with the purpose of engineering both comfort and UV protection simultaneously. From that vantage point, the objective of this work is to develop a model for optimum UPF, air permeability, water-vapour resistance, thermal resistance, thermal absorptivity and areal density of knitted fabrics.Design/methodology/approachWeft knitted fabrics of various compositions were investigated. UPF was tested using the Labsphere UV transmittance analyser. The FX 3300 (Textest instruments) air permeability tester was used to test air permeability. Thermal comfort and water-vapour resistance were evaluated using the Alambeta and Permetest instruments, respectively. Based on image processing, the porosity was measured. Fabrics thickness and areal density were measured according to standard methods. Furthermore, parametric and non-parametric statistical test methods were applied to the data for analysis.FindingsLinear regression was substantiated by Kolmogorov-Smirnov test. Then multiple linear regression of porosity and thickness together on UPF and comfort parameters were visually depicted by virtue of 3D linear plots. Residual analysis with quantile-quantile and probability plots, advocated the tests using the Shapiro-Wilk test. The result was validated by comparison with experimental data tested. The samples gave satisfactory relative errors and were supported by the z-test method. All tests indicated failure to reject the null hypothesis.Originality/valueThe predictive models were embedded into an interactive computer program. Fabric thickness and porosity are the inputs needed to run the program. It will predict the optimum UPF, areal density and thermophysiological comfort parameters. In a nutshell, knitters may use the program to determine optimum structural parameters for diverse permutations of UPF and thermophysiological comfort parameters; scilicet high UV protection together with low thermal insulation combined with low water-vapour resistance and high air permeability.

Investigating the Thermo-Physiological Comfort Properties of Weft-Knitted Smart Structures Having a Negative Poisson’s Ratio

Smart auxetic structures are gaining attention in various areas such as architecture, clothing (sports and protective), civil, and medical applications owing to their negative Poisson’s ratio. Compared to ordinary structures, these structures have better properties (shear resistance, formability, energy absorbance, and robust fracture strength). Auxetic structures show the exceptional property of becoming wider in one direction when stretched from another direction. In this research, three different auxetic weft-knitted structures were fabricated using nylon, polyester, acrylic, and cotton yarns on a Shima Seiki flat-knitting machine. The physical properties, negative Poisson’s ratio, and thermo-physiological comfort properties of these fabrics were checked. Negative Poisson’s ratio strain curves of the developed fabrics were plotted; all fabrics, except for nylon, show the negative Poisson’s ratio (NPR). The NPR decreases with increased strain in the longitudinal direction, and polyester exhibits a maximum value of NPR −0.4 in line structure at 30 mm extension. Results also revealed that structures made with nylon and polyester yarns exhibit a better value of air permeability than acrylic and cotton, while acrylic provides the best thermal resistance values than other materials in line structure and polyester yarn shows better overall moisture management capacity (OMMC) performance in zigzag structures.

Structural modelling of 100% cotton single jersey fabrics for optimum UV protection

PurposeLightweight, open construction cotton knitted fabrics generally do not impart good protection from solar ultraviolet radiation (UVR). As lightweight 100% cotton single jersey is highly cherished for summerwear, it is sine qua non to understand the structural parameters that effectively strike a good balance between UV protection and thermophysiological comfort of the wearer. Relatively heavy fabrics protect from UVR, but comfort is compromised because of waning porosity, increase in thickness and thermal insulation. The purpose of this paper is to engineer knits that will bestow maximum UV protection while preserving the thermophysiological comfort of the wearer.Design/methodology/approachIn total, 27 cotton single jersey fabrics with different areal densities and yarn counts were selected. Ultraviolet protection factor (UPF) was calculated based on the work of Imrith (2022). To précis, the authors constructed a UV box to measure the UPF of fabrics, denoted as UPFB. UPFB data were correlated with AATCC 183-2004 and yielded high correlation, R2 0.977. It was concluded that UPF 50 corresponds to UPFB 94.3. Thermal comfort properties were measured on the Alambeta and water-vapour resistance on the Permetest. Linear programming (LP) was used to optimize UPFB and comfort. Linear optimization focused on maximizing UPFB while keeping the thermophysiological comfort and areal density as constraints.FindingsThe resulting linear geometrical and sensitivity analyses generated multiple technically feasible solutions of fabrics thickness and porosity that gave valid UPFB, thermal absorptivity and water-vapour and thermal resistance. Subsequently, an interactive optimization software was developed to predict the stitch length, tightness factor and yarn count for optimum UPFB from a given areal density. The predicted values were then used to knit seven 100% cotton single jersey fabrics and were tested for UV protection. All seven fabrics gave UPFB above the threshold, that is, higher than 94.3. The mathematical model demonstrated good correlations with the optimized parameters and experimental values.Originality/valueThe optimization software predicted the optimum UPFB reasonably well, starting from the fabric structural and constructional parameters. In addition, the models were developed as interactive user interfaces, which can be used by knitted fabric developers to engineer cotton knits for maximizing UV protection without compromising thermophysiological comfort. It has been demonstrated that LP is an efficient tool for the optimization and prediction of targeted knitted fabrics parameters.