Ultraviolet Protection Factor Of Fabrics Research Articles

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.

Evaluation of Dyeing and UV Protective Properties on Hemp Fabric of Aqueous Extracts from Vegetal Matrices of Different Origin

Clothes are one of the most effective measures to minimize health hazards due to the current levels of UV radiation on the earth’s surface. Fabrics made of natural fibers and dyed with natural pigments are an excellent means to reduce UV exposure. In this study, the UV protection properties were tested on a vegetal fiber fabric (hemp) dyed with water extracts from madder, chestnut, onion, inula, and logwood, at three increasing concentrations. Dyeing extracts were obtained from different sources: agro-food industry residues (chestnut and onion), spontaneous (inula), and commercial dyeing plants (madder and logwood). The quantitative characterization of water dye extracts was performed to evaluate the amount of dye in pre- and post-dyeing solutions as well as the dye fastened to the fabric. The percentage values of dye fastened to the fabric, in relation to the plant dry weight, were relatively low for all the considered species. The fabric Ultraviolet Protection Factor (UPF) was evaluated using both a laboratory spectrophotometer and a spectroradiometer in outdoor conditions. A progressive increase in UPF with the increase of the dye-bath concentration was shown. Chestnut and onion, reaching the minimum protection level (UPF=15) at the highest dye-bath concentration, can be considered the most effective. The UPF persistence of the fabrics was also evaluated after sun exposure and repeated washing. Colors and UV protective properties obtained by the dyeing procedure tested in this research can provide added value to hemp fabric and meet the demands of an expanding “eco-friendly” market.

Treatment of Cotton Fiber with Newly Synthesized UV Absorbers: Optimization and Protection Efficiency

Two new hetrofunctional triazine based UV absorbers (1a, 2a) were theoretically and experimentally synthesized at our previous work. In the current investigation, these absorbers were applied to woven cotton fabric via the exhaust method of dyeing, that increase the ultraviolet protection factor of fabric by keeping the quantity of finishing chemicals low to combat with the environmental problem. Therefore, a statistical tool central composite rotatable design (CCRD) of response surface methodology (RSM) was selected for process modeling. The CCRD was applied to study the effect of three process variables (salt, alkali and temperature) on the two responses (exhaustion and fixation percentage) and for the evaluation of the interactive effects of the three process variables. The results show that the applied quadratic model was highly significant and fit to the experimental data for both the UV absorbers (1a and 2a). The values of optimized parameters for CCRD, in cotton finishing with newly synthesized UV absorbers (1a and 2a) were respectively as follows; temperature of 61.91 oC, dose of salt 34.28 g/l and dose of alkali 19.82 g/l. Under these conditions, 77.56 (±3) and 76.08 (±3) exhaustion and 81.12 (±3) and 79.23 (±3) fixation percentage obtained for UV absorbers 1a and 2a respectively. The ultraviolet protection factor (UPF) of treated cotton fabric under optimized conditions appeared in very good range. The results reveal that the applied statistical design economically and effectively predicts the optimized conditions of finishing of cotton by keeping the number of experiments low than the one factor at a time method, that ultimately reduce water pollution and wastage of resources.

A comprehensive approach to evaluating and classifying sun-protective clothing

Summary Excessive exposure to sunlight causes skin cancer, the most common cancer in humans. An estimated 80% of melanoma (the most deadly form of skin cancer) cases in Australia could be prevented by reducing sun exposure. Clothing provides a protective barrier that reduces the amount of solar ultraviolet radiation (UVR) reaching the skin. In 1996, Australia pioneered a relative ranking of the sun-protective capabilities of clothing based on the transmission of UVR through fabric, known as the Ultraviolet Protection Factor (UPF). UPF garment swing tags were introduced as part of this original standard (AS/NZS 4399:1996) which was widely adopted by industry. However, it did not consider the body surface area (BSA) covered by garments. Minimum body coverage requirements for the torso and limbs were added to some standards (e.g. European Union, 2003; Australian/New Zealand, 2017) but not others (e.g. USA). In light of recent evidence showing that clothing coverage is important in preventing some of the pigmented moles that develop in childhood (important risk-factor for melanoma), it is imperative that sun-protective clothing rating schemes consider BSA coverage of the garment, in addition to fabric UPF. We developed a new index for rating sun-protective clothing, “the Garment Protection Factor (GPF)” that incorporates both of these important factors. BSA coverage is determined based on the number of lines visible on a clothed versus an unclothed mannequin. GPF increases with BSA coverage of the garment and fabric UPF over 3 categories: GPF 0 to < 3 indicates the garments ‘meets’ minimum standards; 3 to < 6 indicates ‘good’ sun-protection; and GPF ≥ 6 indicates ‘excellent’ protection. Adoption of this rating scheme should provide an incentive for manufacturers to design sun-protective garments that exceed the minimum standard for BSA coverage and fabric UPF, and provide consumers with adequate information on which to base their choice, with positive implications for skin cancer prevention.

Influence of reactive dyes on ultraviolet protection of cotton knitted fabrics with different fabric constructions

The influence of coloration on ultraviolet (UV) protection of cotton knitted fabrics with different knit structures incorporated with the three major stitch types, namely knit, tuck and miss stitches, are studied in four approaches. The effects of color depth and knit structures on the ultraviolet protection factor (UPF) of fabrics are investigated. The influences of hue and color depth on the UPF of fabrics are also compared. Since UV protection offered by dyes mainly depends on their chemical structures, the UPF and color strength of fabrics colored by reactive dyes that varied in reactive groups, such as mono-functional and bi-functional reactive dyes, are examined. The correlations between UPF and the CIELAB color coordinates, color strength ( K/ Ssum), are analyzed. The results show that light-colored fabrics with compact structures achieve similar or even better UV protection than the dark-colored fabrics with loose structures. This implies that color property might not be a reliable indicator for UV protection of knitted fabrics and the effect of coloration on UV protection is affected by fabric construction. The results also denote that the chemical structure of reactive dyes affects the UV protection of fabrics in a qualitative approach that depends on the unique ultraviolet radiation blocking ability of the chemical constituents. Among the color coordinates investigated, only lightness ( L*) and K/ Ssum are found to be correlated with the UPF of the fabrics, but the strength of correlations is not very strong. This is because the fabric characteristics that have significant impacts of UV protection are mostly not involved in the measurement of color properties.

Effects of fabric thickness and inter-yarn pore size on ultraviolet radiation protection by polyester woven fabrics

The effects of fabric thickness and inter-yarn pore size, at same fabric cover %, on the ultraviolet radiation protection by polyester woven fabrics have been explored in this research. Fabric thickness was varied while keeping the cover % constant by maintaining the ratio of diameter to spacing (d/p) of yarns. Before UV absorber treatment, ultraviolet protection factor (UPF) of fabrics decreased with decreasing thickness when fabric cover % was kept constant. After UV absorber treatment, UPF first decreased and then increased with decreasing fabric thickness. The latter effect was more prominent at higher level of fabric cover %. The individual inter-yarn pore size in the fabric played a crucial role in determining the UPF along with fabric thickness. Besides, there was interplay of inter-yarn pore size, fabric thickness, fabric cover % and inherent UV absorption capability of the material which determined the final UPF of fabric.

Modeling Ultraviolet Protection Factor of Polyester-Cotton Blended Woven Fabrics Using Soft Computing Approaches

Ultraviolet protection factor (UPF) of woven fabrics is modeled by using two soft computing approaches, namely adaptive network based fuzzy inference system (ANFIS) and artificial neural network (ANN). Three fabric parameters: proportion of polyester in weft yarns, weft count, and pick density are used as input parameters for predicting fabric UPF. Two levels (low and high) of membership function for each of the input parameters are used to reduce the complexity of ANFIS. The eight linguistic fuzzy rules trained by ANFIS are able to explain the relationship between fabric parameters and UPF. A comparison between ANFIS and ANN models is also presented. Both the models predict the UPF of fabrics with very good prediction accuracy in the testing data sets.

Predicting the ultraviolet radiation protection by polyester–cotton blended woven fabrics using nonlinear regression and artificial neural network models

Ultraviolet protection factor (UPF) of fabric is mainly influenced by fabric cover which is dependent on the primary fabric construction parameters like yarn count and thread density. UPF can be modeled by using these primary fabric parameters as inputs by the help of nonlinear regression as well as artificial neural network (ANN). The objective of this study is to develop prediction models for fabric UPF using nonlinear regression and ANN techniques and compare their relative efficacy. Thirty-six woven fabric samples were produced by varying weft related parameters like proportion of polyester, weft count and pick density. Nonlinear regression and ANN models were developed from same experimental data sets. Prediction accuracy of both the models was evaluated and compared. Trend analysis was performed to check the generalization ability of the ANN model. UPF was well estimated from the three primary fabric parameters by both the nonlinear regression and ANN models. However, ANN model demonstrated better prediction accuracy than the nonlinear regression model. Fabric UPF can be predicted with high degree of accuracy using ANN and nonlinear regression models. These models can be used to estimate the UPF of woven fabrics without spectrophotometer based test.

Comparative analysis of in vitro ultraviolet radiation protection of fabrics woven from cotton and bamboo viscose yarns

Ultraviolet protection factor (UPF) of fabrics made of 100% cotton and 100% bamboo viscose yarns were studied and a comparative analysis carried out using curve fitting technique. Bamboo viscose fabrics showed higher shrinkage, cover percentage, areal density and UPF compared to its cotton counterpart woven with identical yarn counts and fabric sett. However, the predictive model of cotton fabric UPF using fabric areal density as the input was able to estimate the UPF of bamboo viscose fabrics with very good accuracy. Furthermore, the 100% cotton and 100% bamboo viscose fabrics showed the same UPF if their cover percentage and areal density is similar. It is inferred from the analysis that the apparently higher UPF of bamboo viscose fabrics can be attributed to their higher cover percentage and areal density instead of bamboo’s inherent UV protective property which has been claimed in various literatures.

Effect of weave, structural parameters and ultraviolet absorbers onin vitroprotection factor of bleached cotton woven fabrics

The weave, fabric cover, areal density and ultraviolet (UV) absorbers are some of the factors which influence the ultraviolet protection factor (UPF) of cotton fabrics. It will be of interest to know whether fabric cover or fabric areal density is a better predictor of cotton fabric UPF. It will also be of interest to know whether the UV absorbers are equally effective for all kinds of cotton fabric. To understand the role of weave, fabric cover, areal density and UV absorbers on the UPF of cotton fabrics. To establish quantitative relationships between the fabric cover, areal density and UPF for cotton fabrics. Sixty-four woven fabrics were manufactured using different weaves, cotton yarn count and picks per centimetre values. Nonlinear regression models were developed to relate the fabric cover and areal density with the UPF. The role of UV absorbers at different levels of cover has been analysed. In case of bleached cotton fabrics woven with 40 Ne warp yarn count, 40 ends per cm, different weft yarn count (20-40 Ne) and picks per centimetre (15-27), weave does not have a statistically significant effect on the UPF. Fabric areal density is a better predictor of UPF than the fabric cover. The UV absorbers are more effective when the fabric cover is high. The developed equations relating fabric cover and UPF can be used as a primary guideline while selecting fabrics for UV protection.

Effect of Knitted Bamboo Structures Dyed With Natural Colorants on Ultraviolet Radiation Protection

The incidence of skin cancer has been increasing at an alarming rate over the past several decades. While there are many factors involved in the onset of melanoma and non-melanoma skin cancers, overexposure to ultraviolet radiation (UVR) has clearly been identified as an important factor. Apart from avoidance of the sun, the most frequently used form of UV protection is the application of sunscreens. Secondly, the most frequently recommended form of UV protection is the use of hats, and proper selection of clothing. The ultraviolet properties of textiles dyed with synthetic dyes have been widely reported in literature. However, there are limited studies on the ultraviolet protection level of eco-friendly fabrics dyed with natural colorants. This study reports the Ultraviolet Protection Factor (UPF) of bamboo fabric with three different knit structures dyed with natural colorants of plant origin. The bamboo fabrics were dyed with two natural colorants namely Annatto Gold and Eclipta Green. The dyeing parameters were optimised. The Ultraviolet Protection Factor of the fabric with respect to fabric construction, weight, thickness and dyeing was measured in-vitro using Ultraviolet Transmission Analyzer, standard AATCC – 183. The results indicate that there is positive correlation between the weight of the fabric and Ultraviolet Protection Factor. Similarly, thicker the fabric more is the protection. Dyeing with natural colorants dramatically increased the UV protection of all three fabric constructions. Thus, dyeing bamboo fabrics with natural colorants increases the ultraviolet protection of the fabrics and can be considered as an effective protection against ultraviolet rays.

Effects of Woven Fabric Construction and Color on Ultraviolet Protection

This paper presents the effects of woven fabric construction and color on the ultraviolet protection factor. Weave type, fabric tightness, cover factor, volume porosity and color of lightweight summer woven fabrics were observed in this research. Color had the biggest influence on the ultraviolet protection factor of fabrics, whereas woven fabric construction was essential when light pastel colored fabrics were used as ultraviolet protection. This work provides guidelines for engineering woven cotton fabrics with sufficient ultraviolet protection.

Influence of wetness on the ultraviolet protection factor (UPF) of textiles: in vitro and in vivo measurements.

Clothing is an important product for sunburn protection and skin cancer prevention. The moisture content of a fabric, which can increase during its wearing, may decrease the fabric's capability of protecting the skin from solar UV radiation, that is, lower its UPF (ultraviolet protection factor). Due to limited data about the effect of fabric wetness on UPF, this study was undertaken to investigate the following: (a) the effect of saturating a variety of fabrics with tap water and with salt water on fabric UPF and (b) whether wetted-fabric UPF values reflect only the fact that the fabric is wet during testing or the fact that the skin is hydrated and the fabric is wet. For objective a, 69 summer fabrics were spectrophotometrically (in vitro) assessed when "dry" and when saturated with tap and salt water. In vitro UPFs, percent UVA transmission and percent UVB transmission values were calculated from the transmission data. For objective b, 100% cotton and 100% polyester fabrics were tested in vivo to determine in vivo UPF values. The minimal erythema dose (MED) was determined for each of the 12 subjects on unprotected "dry" skin and on "hydrated" unprotected skin. MEDprotected was determined when the subject's skin was covered with "dry" and with saturated fabric. In vivo UPFs were calculated using this data. Student's paired t-tests were used to determine the effect of wetting. With one exception, in vitro UPF values were the same when the fabrics were saturated with tap water and when they were saturated with salt water. However, saturating the fabrics with water had different effects on the UPF, UVA transmission, and UVB transmission values. For linen, viscose and polyester fabrics, UPF significantly increased. For the cotton fabrics and the polyester + TiO2 fabrics, UPF significantly decreased. For the modal + TiO2 fabrics and the polyester crepe + TiO2 fabrics, UPF significantly increased. From the in vivo testing, the MED of the "hydrated unprotected" skin was not different than the MED of "dry unprotected skin." Values obtained from subtracting dry-fabric in vivo UPF values from dry-fabric in vitro values and subtracting wet-fabric in vivo UPF values from wet-fabric in vitro values are not different. Fabrics do not need to be tested when saturated with tap and with salt water. Testing fabrics wet and dry should be done, as the effect of saturating fabric on UPF value varies. Fortunately, UPF values for wetted fabrics reveal only the effect of increased moisture content in the fabric and have nothing to do with wetting of the skin by the fabric.

Determination of the ultraviolet protection factor of fabrics in vitro and in vivo

Determination of the ultraviolet protection factor of fabrics in vitro and in vivo