The difference between organic infiltration agent and inorganic infiltration agent

The difference between organic infiltration agent and inorganic infiltration agent

(1) Water glass is an infiltration agent widely used at the beginning. Water glass belongs to silicate, also called inorganic infiltration agent. Regardless of the inorganic infiltrant of any brand at home and abroad, its main component is Na2O.SiO2, its molecular formula is Na2O.SiO2.H2O, and the aqueous solution of sodium silicate contains more than 60%. Infiltration of water glass began in the 1930s, its greatest advantage can withstand high temperatures, but the disadvantages are also significant, long infiltration process, difficult to clean parts, slow curing speed, high leakage rate and multiple times Repeat infiltration and the like. However, the most critical defect is determined by its chemical composition: 1. The silicate infiltrant contains more than 60% of water molecules, and the residue after heating and dehydration when the inorganic infiltrant is cured (sodium silicate) Na2SiO3) to seal the micropores, which is the reason for repeated infiltration; 2, the solidification mechanism of inorganic infiltration, is a reversible reaction, is a physical change. This is why the carton coated with water glass in the mildew season is soft and damp, and the salt is liquefied for a long time. Assume that an infilled workpiece is stored in an environment of sufficient humidity, and the surface of the workpiece will “runny nose” for a long time. This is the principle of the water glass water-reduction reduction reaction; 3, the cured product. Dehydrated solidified water glass, Na2SiO3, which is an inorganic salt powder similar to fine sand, has no physical strength. In short, the reliability and durability of inorganic impregnation are poor and have been eliminated in most foreign countries.

(2) Synthetic resin has been used since 1940, has good sealing effect, good chemical resistance and can withstand temperatures up to 204 ° C, but its shortcoming is that it contains toxins and harmful solvents that affect health and safety, and requires special Safety equipment increases equipment costs.

(3) Hot water curing type resin and anaerobic curing type resin. The technology began in the United States in the 1940s, and has been developed in Germany and the United Kingdom. In the 1980s, more than 80% of the infiltration market in Europe, America and Japan was organically impregnated with acrylates.

(4) Infiltration treatment was implemented in the United States in the 1930s. Initially, metal sealants were used, and the Internal Pressure Method was used. In the late 1940s, the Vacuum ang Pressure Method was developed and used. In 1951, the military standard MIL-I-17563C was established in the United States, and the two impregnation methods of the A method (internal pressure method) and the B method (vacuum-pressure method) were standardized. Based on the development of these US Army specifications, impregnation treatment has been widely applied to military products, aircraft parts and automotive parts. (5) Infiltration treatment began in China in the late 1980s and was promoted by companies such as FAW, Chunlan and Erqi. Currently entering the Chinese market are: the United States LOCTITE, the United Kingdom ULTRAASEAL and so on. There are currently no industry standards in China.

(VI) In recent years, with the establishment of foreign auto companies entering China, the domestic car industry has developed rapidly. Foreign companies have brought advanced concepts and advanced technologies in the industry. Organic impregnation has been in the domestic die-casting industry since 2000. A lot of adoption. In the engine field, the cylinders and cylinder heads of BMW, TOYOTA, HONDA, Volvo, HYUNDAI, GM, FORD, etc. are all subjected to secondary impregnation (blank, machine addition) to save the pressure and leak detection process; in the automotive air conditioning compressor industry , DELPHI, SANDEN, VALEO, ZEXEL, etc. all use organic impregnation process. Organic impregnation technology is recognized by more and more die-casting colleagues for its outstanding physical and chemical properties, high productivity and high reliability.

(7) The future of organic impregnation. At present, professional counterparts around the world must completely solve the technology of high temperature curing (90 degree) organic infiltration agent: first, efficient water washing; second, color protection of workpiece under high temperature state of complex alloy; The residual glue is recycled and reused, which reduces the material consumption of the customer to less than 3 grams per kilogram.