Let’s learn the coating technology of woven bag

The principle of coating is to coat the resin on the woven fabric of the substrate in the molten state. Only the melt resin is coated on the woven fabric and cooled immediately to obtain two in one woven fabric. If the melt resin film is sandwiched between the woven fabric and paper or plastic film during lamination, and then cooled to obtain three in one woven fabric, coating can be applied to one side of plain fabric to obtain sheet fabric, or to both sides of cylinder fabric to obtain coated cylinder fabric.

Specifically, after heating, the extruder melts the polypropylene material, extrudes it through the die head, and extrudes and composes with the cylindrical plastic woven cloth on the production line, then cools and shapes it into a coating cloth base. After the cloth base passes through the first guide and the first preheating to the first coating film from the unwinding frame, the cloth base is turned 180 degrees through the cross turnover frame on the production line, so that the uncoated surface is upward, and the cloth base passes through the second guide, the second preheating and the second coating film to complete the double-sided coating film, so as to ensure the continuous production without stopping the machine.

During the coating process, if the car is returned for some reason, the corona machine, preheating and cooling roll water valve should be closed in time. Open them one by one after entering the car. If serious ruffles appear in the woven fabric, do not put it on the operation surface to correct the deviation, and appropriately increase the unwinding tension. Before the coating material is poured into the mixer, the dust on the outer skin of the packaging bag shall be cleaned. The coating shall be kept clean during mixing to avoid dust entering the hopper.