Study And Appliance Of Low Temperature Less Dregs And Quick Phosphate Solution

Surface's phosphate treatment of metal is a chemical treatment in acid phosphate Solution. It will produce an undissolved phosphate film on the surface of metal. This film can improve the rust proofing and adhering of the coating. It uses general in the auto's surface treatment process before coating. Most of this process in the world use middle temperature phosphate solution(40 ~50 ). The main disadvantages of middle temperature process are: energy-waste, high cost, low efficiency and heavy pollution. So there are many people study the low temperature phosphate treatment. Until today only a little Japanese auto factories use low temperature phosphate Solution. Most of the auto factories in Europe and America use middle temperature process. The study and appliance of the low temperature, less dregs and quick phosphate solution is the main trend of the pre-treatment for the auto coating in 21 century.This article is based on: at first analysing the present situation of the low temperature phosphate solution in the world, then according to a series experiments analyse the result of those experiments and get a new formulation of the low temperature, less dregs and quick phosphate solution. The appliance possibility of this phosphate solution that is used in pre-treatment of auto coating industry is proved through a series experiments. The main conclusions of the article are:1.According to the experiments, make sured the formulation of the new low temperature, less dregs and quick phosphate solution (DKL2000). 2.Based on the new formulation, the appearance of the phosphate film, weight of the film, film structure, anti-salt, anti-alkalinity, adaptability with electrophoretic coating, dregs producing and the adaptation with whole process were proved through a series experiments. Below are main advantages, which are proved through all the experiments:1) Working temperature is low. It can spare a lot of energy.2) It can produce less dregs than the other process. It is good for the product quality. It can spare raw material and reduce the environmental pollution. 3) Less time to produce the film, phosphate time is between 120s~180s. It can improve the speed of the produce line.4) The shape of the phosphate film is good, anti-salt is good too. It can mix with the present phosphate solution. All the other characters are satisfied with the auto process.So, DKL2000 is reasonable and feasible.3. Based on the formulation analyse of the new low temperature, less dregs and quick phosphate Solution, and according to the theory analyse of the phosphating, we get the results: Increasing the oxygenation of the catalyse, improving the total acidity, reducing the concentration of free acid, changing the concentration of metal ion, improving their activity, controlling the concentration proportion of P043-/NO3-, adding dihydroxybutanedioic acid, adding citric acid and F" can reach the process requirement of the low temperature,less dregs and quick phosphating.