Most cement companies use gas conveying cement filling methods during cement filling. The exhaust problem during cement filling cannot be solved. One is that the filling efficiency is affected, and the other is that the qualified rate of bag weight cannot meet the requirements. For the laminated plastic woven bag, it is also necessary to consider the phenomenon of running, emitting, ash leakage during filling and moisture prevention during transportation. The vent is large, the number of holes is large, the vent performance is good, and the filling efficiency is high, but the cement runs out seriously during filling, and the moisture resistance is poor; the vent is small, the number of holes is small, and the exhaust performance is poor. Low efficiency, but less cement runaway during filling, and good moisture resistance. Therefore, the size and density of the needle hole is the key to affecting the ash emission phenomenon and the moisture resistance of the cement during cement filling. The needle diameter of 2mm or 1.5mm can meet both requirements at the same time.

The general operation is: one needle hole every 6mm in the longitudinal direction of the laminated cloth, and one needle hole every 8mm in the transverse direction. The punching needle is a tapered needle, and the exhaust hole is punched from the inside out. Through the laminated plastic woven bag treated in this way, the gas can be easily discharged from the inside to the outside during filling, which meets the exhaust gas requirements during cement filling, and can also ensure the pass rate of the bag weight, and at the same time run off during filling. The gray phenomenon has also been resolved. The packaging bag filled with cement is automatically closed after the exhaust hole contacts the belt during the contact with the belt conveying process, which better solves the moisture-proof performance of the cement packaging during the transportation and storage process.