The final mixing and pouring process of vacuum oil injection equipment is the process of vacuum pouring after the degassed resin and curing agent mixture are finally mixed and stirred evenly. The pouring process is manual operation, and the flow and flow rate are manually controlled to make the mixture enter the mold smoothly. The equipment adopts the method of natural pouring depending on the height difference between the upper and lower tanks. During pouring, the material flow must be properly controlled according to the complexity of the mold cavity and the pouring process. Generally, the horizontal pouring of transformer winding can be controlled at 1.5 ~ 2kg / min, or controlled according to the standard of not blocking the exhaust hole.

The common problems in this process are:

(1) The final mixing process takes too long. If the mixing time is too long, it will force the pouring time to be shortened. Otherwise, after 2 ~ 3H, the material viscosity will increase rapidly, affecting the flow rate and pouring quality. In serious cases, the product will be scrapped or the conveying pipeline will be blocked, and the equipment will be damaged. The temperature should be 65 ~ 70 ℃ and the time should be 30 ~ 45min. Pouring can be carried out after mixing evenly.

(2) During pouring, the material is sprayed backwards. Before pouring, it must be checked that the air pressure in the final mixing tank is slightly higher than that in the pouring tank. Because the equipment adopts the natural pouring method of relying on the pressure difference of atmospheric pressure and the self weight of materials to make the materials naturally flow into the mold for pouring. If there is no pressure difference in the upper and lower tanks or the pressure difference is too small, the pouring speed will be reduced, the flow will be slow and the pouring time will be prolonged. When the air pressure in the lower tank is higher than that in the upper tank, the material in the upper tank will be sprayed back.

(3) The pouring speed is generally 1.5 ~ 2kg / min. If the mold cavity is narrow and long, it is appropriate not to block the gate exhaust hole. The pouring speed must be uniform, not too fast or too slow. The speed is too fast, and the resin mixture overflows from the gate before it can fill all the cavities, giving us the illusion of full pouring. When heating and curing, the material will slowly fill all the cavities, resulting in material shortage at the gate; The speed is too slow. After more than 2h, the viscosity of the material will increase rapidly with time. The longer the time, the greater the viscosity, which is more unfavorable to pouring. In this case, there are often a large number of honeycomb or spotted pores or a large area of material shortage in the cured product.

(4) After pouring, the pouring parts must be quickly pushed into the curing furnace for curing, so as to avoid staying in the low-temperature environment as far as possible, so as to prevent the temperature drop of the mold and affect the flow of materials in the mold. After pouring, the final mixing tank and the valve of the material conveying pipe shall be cleaned in strict accordance with the equipment operation procedures. The equipment shall be thoroughly cleaned with cleaning fluid regularly, and the blocked material delivery pipe and valve shall be cleaned or replaced in time.

(5) After the mold is assembled, heat it evenly in the pouring tank for 6 ~ 8h to make the mold temperature reach 80 ~ 85 ℃, and then vacuum it for pouring. If the internal temperature of the mold cannot be reached, there will also be material shortage after curing.