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Lightweight, 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.

In 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 UPF_B. UPF_B data were correlated with AATCC 183-2004 and yielded high correlation, R² 0.977. It was concluded that UPF 50 corresponds to UPF_B 94.3. Thermal comfort properties were measured on the Alambeta and water-vapour resistance on the Permetest. Linear programming (LP) was used to optimize UPF_B and comfort. Linear optimization focused on maximizing UPF_B while keeping the thermophysiological comfort and areal density as constraints.

The resulting linear geometrical and sensitivity analyses generated multiple technically feasible solutions of fabrics thickness and porosity that gave valid UPF_B, 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 UPF_B 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 UPF_B above the threshold, that is, higher than 94.3. The mathematical model demonstrated good correlations with the optimized parameters and experimental values.

The optimization software predicted the optimum UPF_B 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.

The 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.

Weft 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.

Linear 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.

The 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.

In this research project, electrical conductive yarns were knitted together with 100 per cent cotton yarns to create knitted fabrics that would be used as electromagnetic (EM) shielding materials. The paper aims to discuss these issues.

1×1 plain fabrics knitted on double-bed hand knitting machines of five and seven gauges. Several strands of the cotton yarns were used together in order to knit samples with good handling properties. The electrical conductive yarn has six plies and each ply has 29 filaments with Naño-coating of silver and having an electrical resistance of 4 Ohms per 100 mm and a count of 96 Tex. The knitted fabrics have similar texture but vary in term of specific weight, fabric density, loop length, Tex, tightness factor, thickness and electrical conductivity. These variations affected the properties of the fabrics, determining factors of a good shielding or not. A special designed Faraday cage was built to measure the EMSE of each knitted fabrics. The EM waves were sent through the signal generator at different frequencies as from 400 to 1,100 MHz and with three different power inputs of 10, 20 and 30 dBm. EMSE measurements were also carried out after the knitted samples were rotated clockwise.

Good EMSE shielding results were achieved with the knitted samples, however in this study it was found that different knitted fabrics shielded better at specific frequencies and power inputs.

Knitted fabrics can be used to develop comfortable garments that can be used to shield EM waves and protect the wearer.

The choice of using the conductive yarns is exclusive. In addition the EMSE were measured with fabrics knitted in the same structure but on different knitting machine gauge. Three different power inputs were considered and EMSE measurements were taken using frequencies as from 400 to 1,100 MHz. A new method for measuring the electrical resistance on the knitted fabrics and the method used for measuring the EMSE for each knitted fabric were considered.

The tourist sector in Mauritius is aiming at welcoming 2 million tourists by the year 2015 and coming up with creative ideas and products branded with ‘Made in Mauritius’ to boost the country’s craft sector. This project looks into the manufacture of paper-yarn. Different types of paper were cut into ribbons of varying widths and converted into yarn by two methods: twisting and folding. The folds were made along the axis of a ribbon while twisting required prior moistening and was carried out on a modified yarn-twist measuring device. The relationship between the number of folds/twists and the strength of the resulting paper yarn was investigated. Yarn of high quality can be obtained by twisting ribbons of relatively smaller widths or folding relatively wider ribbons. The yarn can be used for manufacturing craft products.