Common Fault of Automatic garbage bag Bagging Machine: How to Solve the Problem of Lax Edge Sealing?

One of the most common faults in the production of automatic garbage bag bagging machine is weak edge sealing. The sealing position of cloth bag is easy to crack and leak, easy to separate when gently pulled, directly causing a lot of waste, waste PE film raw material, reduce production efficiency. Many operators encounter poor edge sealing, blind heating and other problems, often palliative, even caused paint film burn through, bag brittleness and other new problems. The sealing quality of garbage bag is influenced by temperature, pressure, feeding speed, hot sealing knife state, sealing material and so on. In this paper, the causes of weak edge sealing are analyzed, and corresponding troubleshooting and solutions are provided to help operators deal with faults quickly and reduce production losses.
The most common reason is unreasonable the heat sealing temperature setting. Plastic garbage bags are made from high-density polyethylene (HDPE) or low-density polyethylene (LDPE) films, which vary widely in thickness and melting temperature range. When the temperature is too low, the plastic doesn't completely melt and bond. Only the surface is heated, and when cooled, it can easily tear. This is known as a virtual seal. If the temperature is too high, the plastic can burn, become brittle and may bond, but its toughness drops significantly and it can break under light pressure. Thin household garbage bags require lower temperatures, while thick industrial garbage bags require higher heat sealing temperatures. Solution: Adjust the temperature control slightly based on the thickness of the film, without immediately causing a noticeable increase in temperature. Observe the seal and find the appropriate temperature range to ensure the film melts without burning.
The second core factor is insufficient or uneven distribution of the insufficient heat sealing pressure. Heat sealing knife depends on pressure to press and fuse two thin films. If the pressure of the heat sealing knife knife is too low, the two films willnot be able to bond closely, even if the temperature meets the standards, also cannot achieve effective fusion. In addition, after long-term use, hot sealing knife may tilt, spring aging, resulting in uneven local pressure, resulting in a tight seal, a false seal phenomenon. Troubleshooting method: stop to check the flatness of the heat seal knife, adjust the pressure spring to ensure that the overall force is uniform when the heat seal knife is closed; pressure should not be too high, because the pressure is too high to squeeze the film, resulting in thinner seal, more easily torn.
The third reason is a mismatch in production speed. If the equipment feed speed is too fast, it will shorten the film through the hot sealing time, heating time is not enough to completely melt, resulting in weak edge sealing. In order to increase production, many manufacturers blindly increase the speed of the mainframe, more than equipment and film adaptation, the scrap rate will rise sharply. Solution: reduce the traction speed of the bag machine, prolong the contact time of the film heat seal; adjust the speed, adjust the temperature synchronously, match all three. It is not possible to adjust individual parameters individually.
The fourth problem that was easily overlooked was that the surface of the hot sealing knife is dirty and worn. Long-term production will lead to plastic slag and oil stains on the surface of the hot sealing knife, separating the hot sealing knife from the film, causing poor heat transfer, resulting in intermittent edge sealing failure. At the same time, long-term friction and use of the heat sealing knife knife will cause the gap and blade wear, will also lead to local sealing failure. In daily maintenance, it is necessary to stop the machine regularly to clean the residue on the surface of the hot sealing knife and to use a high temperature adhesive coating. If the blade is worn badly, it needs to be polished or replaced with a hot sealing knife.
In addition, quality of the film itself can also lead to edge sealing failures. Excessive addition of recycled materials and lubricants will reduce its heat sealing performance of the films. No matter how the temperature and pressure are regulated, the sealing strength is still not up to standard. In addition, moisture on the film also affects the heat sealing effect. In such situations, it is necessary to replace the raw material film or reduce the proportion of recycled material.
Finally, the troubleshooting sequence of rapid on-site maintenance is summarized: first check the quality of the film raw material, then check surface cleanliness of the heat seal knife; then adjust the heat sealing temperature, pressure and feed speed in turn; and finally check whether the heat seal knife is deformed or worn. Correct inspection and regular maintenance of equipment inspection in daily production, early cleaning of hot sealing knife residue, and pre-set parameters according to film specifications, can significantly reduce the probability of sealing failure. Do not debug blindly when encountering poor edge sealing. Follow the order from simple to difficult, quickly solve problems, reduce waste generation, ensure the stable operation of bagging production line.