In-Vitro Analysis of the Effect of Constructional Parameters and Dye Class on the UV Protection Property of Cotton Knitted Fabrics

Abstract

Cotton knitted fabrics were manufactured with different yarn types (conventional ring spun yarn and torque-free ring spun yarn) with different fibre types (combed cotton and combed Supima cotton) and yarn fineness (Ne30 and Ne40). These fabrics were then dyed with three types of dye (reactive, direct and sulphur dye) with three dye concentrations (0.1%, 1.0% and 5.0% on-weight of fabric (owf)) in three colours (red, yellow and blue). This study examined the impact of constructional parameters and dyeing on ultraviolet (UV) protection properties of cotton knitted fabric. In-vitro test with spectrophotometer was used for evaluating the UV protection property of dyed cotton knitted fabrics. Among the six parameters investigated, fineness of yarn and dye concentration were the most significant factors affecting UPF while the color effect is the least significant. Experimental results revealed that the UPF value of dyed fabrics made from combed cotton is generally higher than the combed Supima cotton since combed cotton is composed of shorter fibres which facilitate the blocking or absorption of UV radiation. Second, fabrics made with twist yarn (i.e. ring spun yarn) have higher UPF value than the corresponding ESTex one (i.e. torque-free yarn) in general since fabrics made with ring spun yarn tend to shrink during wet processing and so it is more compact. Third, the UPF value of fabrics made with 30Ne yarn was higher than the 40Ne one since it is thicker and has lower fabric porosity. Fourth, fabrics dyed with lower concentration of dye gave the lowest UPF. Fifth, the sulphur dyed samples performed worse than the reactive and direct dyed samples in terms of UV protection property. Sixth, there is no significant difference in UPF for red, yellow and blue coloured fabrics. Seventh, this study also demonstrated that lightness of fabric is negatively related to UV protection property.

In situ growth of CuO nanoparticles onto cotton textiles

“…The UPF of a fabric is influenced by different characteristics, such as porosity, weight, thickness, type of fabric, fabric structure, laundering method, and colour [44]. In addition, the dye concentration and L* value of the colour coordinates of the CIE L*a*b* system have a direct and inverse relationship with the UPF values, respectively [45]. The higher the dye concentration, the higher the UPF value and vice versa; the higher the lightness of the fabric, the lower the UPF.…”

“…Additionally, figure 6 shows that when the copper acetate concentration in the exhaustion bath increased from 0.2% to 30% owf, the value of the colour coordinate L* decreased from 92.4 to 70.0, and there was an increase in the UPF values of the textiles. This improvement in UV protection may be due to the grayish-brown shade of the textile given by the CuO and the presence of CuO NPs, which can absorb and block the transmission of ultraviolet radiation through the textile, thus improving the UV protection [36,45]. Finally, according to the AS/NZS 4399:1996 standard and the results obtained, the functionalised cotton textiles could be categorised as providing good to very good UV protection.…”

Assessment of UV Protection for Children's Summer Clothing

“…The color white or lightly colored garments were intentionally chosen from each style available to compare values based on composition and reduce the impact of pigmentation on UPF values. Clothing dyes can increase the UPF value independent of the composition and construction of the textile although not as significantly as the construction of the textile alone [ 24 ]. Another limitation to note is that an initial UPF value was obtained upon purchase of the garment and not after washing.…”

Slip versus Slop: A Head-to-Head Comparison of UV-Protective Clothing to Sunscreen

“…Dark colors absorb more UVR and thus provide higher protection than light colors [29,[31][32][33]. Other factors that impact penetration of UVR through the clothing include: stretch, wetness, wear (from use or washing), color loss (bleaching), UVR-absorbing additives, and yarn morphology [34][35][36][37]. Although all clothing blocks some degree of UVR, some studies suggest many commonly worn fabrics may provide insufficient UVR protection [29,38,39].…”