荧光增白剂对洗衣液国标去污力及循环洗涤性能测试的影响

在标准洗衣液中添加不同种类和用量的荧光增白剂,根据GB/T 13174-2008进行国标去污力和循环洗涤性能测试。结果表明,若测试光源中包含紫外光,添加荧光增白剂的标准洗衣液的去污力和循环洗涤性能测试结果明显好于标准洗衣液,且荧光增白剂添加量增大,去污值和白度保持值增大;若测试光源中不包含紫外光,两者的去污力和循环洗涤性能测试结果并无明显差异。可见,荧光增白剂没有去污作用和抗污垢再沉积作用,但会显著提高国标去污力和循环洗涤性能的测试值。若要更加合理评价产品去污力,有必要按照GB/T 13174-2008进行洗涤,采用色度仪在不包含紫外光(滤除400 nm以下光源)的光源下测试,或者在含紫外光的正常光源下测试,但使用含有荧光增白剂的标准洗衣液作为参比。同时,GB/T 13174-2008未对白度计型号作出统一规定,使用不同规格的白度计测量添加荧光增白剂的洗涤剂产品时,将有不同的去污力和循环洗涤性能测试结果,建议尽快完善该标准。

Influence of fluorescent brightening agent on determination of standard detergency and cycle of washing performance for liquid detergent

According to GB/T 13174-2008, standard detergency and cycle of washing performance of reference liquid detergents appended with separate kinds and concentrations of fluorescent brightening agent were tested. Results showed that standard detergency and cycle of washing performance of the reference liquid detergents containing fluorescent brightening agent are significantly better than the reference liquid detergents if UV containing light source is used. Meanwhile, the more the dosage of fluorescent brightening agent, the higher the value of detergency and brilliance preserved. There are no obvious differences in standard detergency and cycle of washing performance between them if the light source does not include UV. It is clear that fluorescent brightening agent does not display detergency and anti soil re-precipitation performance, but it will improve the determination results of standard detergency and cycle of washing performance of liquid detergent obviously. The essential suggestions of more reasonable evaluation of detergency are that when washing is proceeded according to GB/T 13174-2008, the samples are tested by colorimeter under the illuminant without UV (in this case, the illuminant with wavelength lower than 400 nm has been filtered out), or the samples are tested under the illuminant with UV, but by using liquid detergents appended with fluorescent brightening agent as the reference. Meanwhile, there is no unified stipulation with respect to type and specification of the brightness meter to be used in GB/T 13174-2008. Different data of detergency and brightness preserved after cycle of washing will be obtained if the detergents appended with fluorescent brightening agent are tested with brightness meter of different types or specification. Therefore, the regulations in GB/T 13174-2008 should be revised for improvement as soon as possible.