Design And Improvement Of Cleaning Formulations For The Exterior Surface Of High-speed Trains

With the development of high-speed railways,there is an increasing demand for high-efficiency and environmentally friendly high-speed rail exterior surface cleaning agents.The main components of the cleaning agent for the outer surface of high-speed trains are surfactants,solvents or detergency builders and corrosion inhibitors.Surfactants are the most important components in conventional detergent formulations,which work through mechanisms include roll-up,wetting and emulsification.Effects can be achieved by adding organic solvents into surfactant aqueous solutions:improving the storage stability of cleaners and increasing the ability of cleaners to dissolve oily soils.For the builders of the cleaning agent used for the exterior surface of high-speed trains,chelating agent,buffer agent and bleaching agents can be selected.In addition,it is necessary to add corrosion inhibitors in the formulation to prevent the material surface from corrosion.Based on emulsification experiment,contact angle experiment,solvent solubility experiment and decontamination effect,the initial formulation for high-speed rail surface cleaner was obtained.The initial formulation uses nonionic surfactants including AEb 3%and13a 4%,alcohol ether E₄ 10%as the solvent,citric acid 3%as the detergency builder,and a mixture of benzotriazole（BTA）1%,sodium benzoate（SB）1%and triethanolamine（TEOA）5%as the corrosion inhibitor.For special applications,several improved detergent formulations were provided.By adding sodium percarbonate 3%,the stubborn dirt can be effectively cleaned.For high-temperature cleaning sites,increasing BTA mass fraction to 2%,TEOA to 12%,adding linoleic acid 2%,CIA 3%,and Antirust C 3%,can significantly reduce metal corrosivity at80°C.By controlling the BTA concentration not to exceed 0.5%or adding an appropriate amount of SXS,the cleaning agent can be stored at 60°C for 6 h without delamination and precipitation.Adding block polyether 0.25%,can reduce foaming in cleaning process.The performance test results show that not only the initial formulation（A）and the improved formulations（B₁^B₄）meet the basic requirements,but also the improved formula shows better performance in terms of cleaning ability（B₁）,high temperature corrosion resistance（B₂）,high temperature stability（B₃）or decrease in foam volume（B₄）.