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.

由于目前地球表面的紫外线辐射水平，衣服是使健康危害最小化的最有效措施之一。用天然纤维制成并用天然颜料染色的织物是减少紫外线照射的极佳方法。在这项研究中，在植物纤维织物（麻）上测试了紫外线防护性能，该织物用来自芥末，栗子，洋葱，旋覆花和原木的水提取物以三种递增浓度染色。染色提取物来自不同的来源：农业食品工业的残留物（栗子和洋葱），自发的（菊糖）和商业的染色厂（mad木和原木）。进行了水染料提取物的定量表征，以评估染色前和染色后溶液中的染料量以及固定在织物上的染料。固定在织物上的染料的百分比值，就所有植物而言，相对于植物干重而言，相对较低。织物紫外线防护系数（在室外条件下，使用实验室分光光度计和分光辐射计对UPF进行了评估。随着染料浴浓度的增加，UPF逐渐增加。在最高染浴浓度下达到最低保护水平（UPF = 15）的栗子和洋葱被认为是最有效的。暴露在阳光下并反复洗涤后，还要评估织物的UPF持久性。通过本研究中测试的染色程序获得的颜色和紫外线防护特性可以为麻织物提供附加值，并满足不断扩展的“生态友好”市场的需求。