For people engaged in the foundry industry, the sand casting trachoma problems, has been plagued by a lot of people. Take this as long as the casting method, trachoma will go hand in hand with students. Although not completely eliminated, but we can improve the technology well to control trachoma. When there trachoma affects the performance of large steel casting node, such as strength decreases when steel castings leakage, or customer dissatisfaction is a serious problem. You must take effective measures to control.

Good control, castings trachoma would be greatly reduced, so little to what extent is it to trachoma less to the number, size, size can achieve acceptance criteria and does not affect the customer's use of the principle;? And poor control of trachoma too many, too large an area, the depth is too deep, it will lead to trachoma scrap steel castings directly, because this level of trachoma is very dangerous, it is necessary to prevent sticking good castings trachoma control, and the fight against trachoma is sand casting workers an eternal topic. That being the case, how do we control trachoma from the source it?

Where does the sand come from?

The first source is a low-intensity surface sand or sand core, sand core sand-type wall or stand on high-temperature molten metal erosion and peel off.

The second source is due to take water injection system design is unreasonable, causing the water injection system to take off it happened sand, red sand, sand and extrusion coating shedding down.

The third source is the mold cavity has occurred off the sand, red sand, sand and sand extrusion coating loss caused by, for example, core head gap caused by the small reserve crowded sand.

The fourth source is pouring too fast, the impact of the molten metal caused by too much sand falling off the wall type or sand cores.

The fifth source is the operator does not fit me carefully result. Such as floating sand around the lower core type can not be blown clean inside or out of the vent hole wall and empty sand, sharp sand did not come in.

Li down, or endo, pouring riser on imaginary sand, sharp sand did not blow down, the result after closing the box or the steel casting manufacturing process and falling down; or handling, press box vibration, impact caused by sand falling down.

The sixth source is outside after closing the box has clear sand from the riser, Ming vent on sprue or fall due.

We can say that six is way above the source of sand. Sand control, especially the control group deadly sand, sand source block, which is the key to solving the problem of trachoma. Trachoma isolated loose sand formed due to the shallow depth, and thus will not result in scrap steel castings up to the surface is not smooth, trachoma only sand blocks, sand group formed of steel castings is fatal.