In the resin sand production line, we usually adopt the dissolving vibration cleaning ding yi to clean the mold core in the high-efficiency resin sand cleaning equipment, and test and study the influence of different NaOH solution concentration, excitation force and mold core heating temperature on the dissolving vibration cleaning efficiency. Core when heated to a temperature of 300 ℃, different concentration of NaOH solution and the influence of exciting force on the dissolved vibration cleaning efficiency.

Generally speaking, the sand removal rate of core increases with the increase of NaOH concentration. When NaOH solution concentration is 2.5-7.5wt.%, the sand falling rate of the core first increases and then decreases with the increase of excitation force. When the included Angle of the eccentric block is 3/18, the sand falling rate is the maximum. When the cleaning fluid is water, the lye dissolving core reaction does not occur, and the sand removal rate is almost 0. At this time, the magnitude of excitation force has no obvious influence on the sand falling rate of core sample, which indicates that vibration can only promote the cleaning speed of core sample dynamically.

Dissolved in vibration in the cleaning process, NaOH solution in the process of soaking core can have the effect of dissolved soften the core sample, core of silica sand (mainly Si02) and NaOH exothermic chemical reactions can occur, the reaction heat release and promotes Si02 reaction with NaOH, reaction of sodium silicate is soluble in water, applying external force in the process and will accelerate the sodium silicate fall off from the surface of core sample, from acid sodium fall off from the surface of core sample, thus accelerate the reaction. In terms of reaction thermodynamics, the higher the concentration of NaOH solution, the faster the reaction rate, and the larger the core mass reduction in a certain period of time. In the dissolving vibration cleaning process, the reactant of silica sand and sodium hydroxide solution can be rapidly detached from the surface of the core sample and the cleaning efficiency of the core can be accelerated by the vibration. In vibration cleaning, the casting is thrown up and down and colliding with the body, and the sand falling rate is the best when the relative speed is the maximum. At this time, the vibration motor will hit the casting once every revolution of the spindle, and the time interval between the two impacts is the same as the vibration period of the vibration motor, so the cleaning effect is the best.

In the actual pouring process, the heating temperature of different parts of the core is different, so it is necessary to study the influence of different heating temperature of the core on the cleaning efficiency of dissolved vibration.

Increased as the core is heated temperature from 250 ℃ to 400 ℃, the cleaning efficiency of core gradually increase female core the influence of heating temperature on the cleaning efficiency reasons are as follows:

(1) higher heating temperature will lead to more serious burning damage of the bonding bridge of the coated sand core sample and the binder film coated with silica sand, and the binder film will have defects such as cracks, thus reducing the residual strength of the core, so it is easy to clean up;