釉瓷和搪瓷 耐化学腐蚀性的测定 第3部分 通过使用六角形容器的碱性液体测定耐化学腐蚀性

[中文适用范围]： 本文件描述了测定玻璃和搪瓷制品在 25 °C 至 95 °C 温度下耐碱性液体侵蚀的测试方法。 所使用的装置是六边形容器，其中六个搪瓷样品或四边形玻璃瓶，其中四个搪瓷样品同时进行测试。 注 1：可以测定对任何碱性液体的耐受性。 然而，该测试方法最初用于测定对用于洗涤纺织品的中性和碱性范围内的热洗涤剂溶液的耐受性。 注 2：由于洗涤剂的成分不断发生变化，因此指定了标准测试溶液，就其碱度、润湿特性和络合行为而言，可以将其视为市场上现有洗涤剂的典型成分。 标准测试溶液的pH值和碱度取决于三聚磷酸钠、碳酸钠和过硼酸钠的含量；三聚磷酸钠同时充当络合剂。 标准测试溶液的润湿性能是通过添加烷基磺酸盐获得的。 较高的过硼酸钠含量并不被认为是必要的，因为氧对牙釉质的影响并不重要，并且过硼酸盐含量的增加不会导致标准测试溶液的碱度发生任何显着变化。 使用本标准测试溶液和其他测试溶液（包括5％焦磷酸钠溶液）对不同搪瓷进行的测试证明了使用本标准测试溶液来测定搪瓷对热洗涤剂溶液的耐受性是合理的。 [外文原描述]： ISO 28706-3:2017 describes a test method for the determination of the resistance of vitreous and porcelain enamelled articles to attack by alkaline liquids at temperatures between 25 °C and 95 °C. The apparatus used is a hexagonal vessel in which six enamelled specimens or a tetragonal glass bottle in which four enamelled specimens are simultaneously tested. NOTE 1 The resistance to any alkaline liquid can be determined. However, the test method was originally used for the determination of the resistance to hot detergent solutions, within the neutral and alkaline range, used for washing textiles. NOTE 2 Since detergents are continually subject to alterations in their composition, a standard test solution is specified which, in respect to its alkalinity, wetting properties and complexing behaviour, can be considered as a typical composition for the detergents present on the market. The pH value and alkalinity of the standard test solution depend on the proportions of sodium tripolyphosphate, sodium carbonate and sodium perborate present; sodium tripolyphosphate acts simultaneously as a complexing agent. The wetting properties of the standard test solution are obtained by the addition of alkylsulfonate. A higher sodium perborate content is not considered necessary since the effect of oxygen on enamel is unimportant and an increase in the perborate content does not cause any significant alteration in the alkalinity of the standard test solution. The testing of different enamels using this standard test solution and other test solutions (including 5 % sodium pyrophosphate solution) has justified the use of this standard test solution for determining the resistance of enamels to hot detergent solutions.