户外服装多为化纤面料,在户外环境比较干燥时,容易产生静电问题,表现为服装易起毛起球、易沾染灰尘污垢,贴近皮肤会产生静电吸附。如果携带电子罗盘、高度计、GPS导航仪等精密电子仪器,有可能因服装静电干扰而产生误差,造成严重后果。[1]
防静电织物分为非耐久型和耐久型两种,国内常用的测试方法有静电压半衰期法、静电荷面密度法、点电荷量法等。GB/T12703《纺织品静电性能的评定》共包括7个部分,其中3个部分已经实施,其余尚在制定中。GB/T12703.1《纺织品静电性能的评定第1部分:静电压半衰期》的原理是使试样在高压静电场中带电至稳定状态,断开高压电源,通过接地的金属平台让其电压自然衰减,测量其电压衰减至初始值一半所需的时间,以秒为单位,数值越小,表示防静电性能越好。 标准规定a级≤2.0s、b级≤5.0s、c级≤15.0s。对于非耐久性防静电纺织品,洗涤前应满足此要求;对于耐久性防静电纺织品,洗涤前后均应满足此要求。GB/T12703.2《纺织品静电性能的评定第2部分:电荷面密度》的原理是将经摩擦装置摩擦过的试样插入法拉第筒内,测量试样的电荷面密度。该方法的带电方式反映织物在穿着时的实际摩擦带电情况,剥离过程类似于剥落过程,可反映织物带电时的电晕放电能力。 适用于测试添加导电丝的防静电织物,但测试结果会受到人为因素及被测试织物在静电势序列中的位置影响。电荷面密度越小,防静电性能越好。标准要求:非耐久防静电织物,洗前表面电荷密度不超过7.0?c/m2;耐久防静电织物洗前洗后表面电荷密度均不得超过7.0?c/m2。GB/T12703.3《纺织品静电性能的评定第3部分:电荷量》测量原理是利用摩擦装置模拟样品摩擦带电,将样品插入法拉第筒中,测量其点电荷量。电荷越小,防静电性能越好。标准要求:非耐久防静电纺织品,洗前电荷不超过0.6?c/件;耐久防静电纺织品,洗前洗后电荷均不得超过0.6?c/件。
对比现有的国家及行业标准,各方法的评价指标有所不同,且不同测试方法得到的结果不具有可比性。电荷面密度法可以有效模拟户外服装在实际穿着过程中的带电过程,是适合测试户外服装防静电性能的方法。
抗紫外线
The evaluation parameter for textile protection against ultraviolet radiation uses the ultraviolet protection coefficient upf value, which represents the ratio of the average effect of ultraviolet radiation calculated when the skin is not protected and the average effect of ultraviolet radiation calculated when the skin is protected by fabric. GB/T18830-2009 "Evaluation of UV Protection Performance of Textiles" specifies the test methods, expression, evaluation, and identification of the UV protection level of textiles against sunlight. The testing principle is to use monochromatic or multi-color UV radiation samples, collect the total spectral transmission rays, and determine the total spectral transmission ratio t( λ), And calculate the UV protection coefficient upf value of the sample. Parallel light beams can be used to illuminate the sample, and an integrating sphere can be used to collect all transmitted light; Alternatively, a hemisphere of light can be used to illuminate the sample and collect parallel transmitted light. In practical operation, the detection instrument can automatically calculate the upf value and t of the sample( λ). When the upf value of the sample is greater than 50, it is represented as "upf>50”。 按照此标准,当样品的UPF大于40,且T(UVA)AV小于5%时,即可称为“抗紫外线产品”。
