Common Wet Wipes Packaging Machine Failure Problems

Wet wipes packaging machinery has been used for a long time, especially under continuous work and overload conditions, it is prone to some electrical and mechanical failures, such as: weak sealing, machine going and stopping, fuse blown when starting, and issued during operation" "Squeaking sound", uncontrollable temperature, deformation and bending of the finished bag at the sealing point, bubbles or irregular marks at the embossing point of the sealing knife, etc.

Combined with the actual use experience of the packaging machine, for several of the failures, the causes are analyzed, corresponding solutions are proposed, and the maintenance problems of the continuous sealing machine are explained, hoping to help enterprises and individuals who use the continuous sealing machine.

1. Insufficient sealing. Insufficient sealing is one of the common failures of continuous sealing machines. Inadequate sealing has three meanings:

①The sealing part of the packaging bag cannot be sealed;

②Under the pressure of the sealing knife, although the mouth of the bag is sealed, but a little harder squeezing or tearing, the sealing will crack again;

③ During the peeling test of the sealing part, half of the sealing is firm and the other half is separated. The quality of the sealing of such a packaging bag is still unqualified, because the contents are easily leaked out by squeezing during storage and transportation. This situation often occurs when the composite lining is OPP and blow-molded PE.

The main reasons for the first type of failure are as follows.

(1) The heat-sealing temperature is not enough. Under normal circumstances, for the composite bag with OPP as the lining, when the total thickness of the bag is 80～90μm, the heat sealing temperature should reach 170～180℃; for the composite bag with PE as the lining. When the total thickness of the bag is 85-100μm, the temperature should be controlled at 180-200℃. As long as the total thickness of the bag is increased, the heat sealing temperature must be increased accordingly.

(2) The heat-sealing speed is too fast. The inability to seal the mouth is also related to the speed of the sealing machine. If the speed is too fast, the sealing part will be transported to the cold pressing part for cooling treatment before it can be heated in the future. Naturally, the heat sealing quality requirement will not be met.

(3) The pressure of the cold-pressed rubber wheel is inappropriate. The cold-pressed rubber wheel has one upper and lower one, and the pressure between them should be moderate. When adjusting the pressure, only the spring is needed.

(4) There is a problem with the quality of the heat-sealed film. The inability to seal the seal is also related to the quality of the heat-sealed film. If the corona treatment of the composite lining is uneven, the effect is not good, and it happens to be at the sealing place, it will definitely not be able to seal. This situation is rare, but once it occurs, the product must be scrapped. Therefore, in the color printing and packaging industry, the next process is to supervise the previous process. Once a quality problem is discovered, the cause must be analyzed and resolved in time. If there is moisture and dirt in the seal, it will also cause the seal to be weak. In short, to solve the first problem of weak sealing, generally increase the heat-sealing temperature appropriately, then reduce the heat-sealing speed, and increase the pressure of the cold-pressed rubber wheel at the same time.

The main reasons leading to the second type of failure of the seal are as follows.

(1) The heat-sealing temperature is not enough. The problem can be solved by increasing the heat-sealing temperature appropriately.

(2) The surface of the heat-sealing knife is not flat enough. The heat-sealing knife is divided into upper and lower pieces. Usually thermocouples are installed in them to sense the temperature transfer. There are three screws on the heat-sealing knife. The screw in the middle plays the role of supporting and strengthening the blade. The other two screws are equipped with pressure springs and gaskets, which are mainly used to adjust the pressure of the heat-sealing knife. There are two springs for the upper and lower blades. . The main reason for the uneven surface of the heat-sealing knife is that the middle screw is installed obliquely, not horizontal; or the pressure of the pressure spring of the upper heat-sealing knife is uneven. The solution is to re-correct the position of the middle screw to make it level. If the upper and lower heat-sealing knives are unbalanced, it must be achieved by adjusting the pressure spring, and it can be adjusted to a moderate value. When the spring is retracted outward, the heat-sealing knife will fall downward; when the spring of the lower blade is tightened upward, the heat-sealing knife will move upward.

(3) Uneven pressure of cold-pressed rubber wheels Uneven pressure of cold-pressed rubber wheels can also cause this type of failure of the seal. The solution is similar to the first case.

There are two main reasons leading to the third type of failure of the seal.

(1) Uneven pressure of the heat-sealing knife or uneven pressure of the cold-press knife. The adjustments on the heat-sealing knife and the cold-press knife are exactly the same.

(2) The surface of the heat-sealing knife is not flat enough. Refer to the corresponding solution for the second type of faulty seal.

2. The fuse is blown. The main function of the sealing machine motor is to drive the gearbox and various parts of the gear drive. Sometimes the sealing machine will make a "squeak" sound as soon as it is started, and it will not work normally, or even blow out the fuse on the live wire. To troubleshoot the fault, first check whether the power supply is normal, then cut off the power supply, and check whether the switch is damaged with a resistance file. In addition, check whether the circuit and the motor are short-circuited. Usually when the motor is short-circuited, the winding is burnt out, or the wire is broken, the fuse will blow as soon as the sealing machine is started. Another reason for this failure is that the fuse size is too small, and the problem can be solved by increasing its size accordingly.

3. "Squeak" sound during operation This fault occurs during the operation of the sealing machine, and the "squeak" sound often occurs suddenly. The next step is the uneven sealing speed, which causes bad lines at the sealing and embossing of the packaging bag, which affects the product. Appearance Quality. In the meantime, it can work normally, but it is erratic.

This phenomenon is mostly due to mechanical damage or severe wear, and poor lubrication. First follow the sound emitted to find the faulty part. Disassemble the back protection plate and find that the "squeak" sound is coming from the gearbox. Remove the fixing screws one by one. It is found that the grease in the gearbox is dry and the gears are bright and bright. This shows that the cause of the fault is Lack of oil. Mix the same type of engine oil and grease into the gearbox, and tighten the screws to restore. The "squeak" sound disappears after the machine is turned on and the seal is normal.

In addition, if the joints of the high-temperature belt are loose, severely worn, and are not clean, have dirt on the surface, and are not synchronized with the traction wheel during operation, they will sometimes make a "squeak" sound. The solution is to replace the high temperature belt of the same specification. There are certain skills to replace the high temperature. First compress the pressure wheel spring by hand, and then place one end of the high temperature belt on the rubber wheel, and the other end is held by hand against the other rubber wheel, and the governor is set to a low speed. Motion inertia, the high temperature belt is automatically installed. Sometimes the "squeak" sound is also emitted by the DC shunt motor. It may be caused by lack of oil in the motor bearings. If this is the case, it should be removed and lubricated to eliminate the sound.

4. The sealing temperature is out of control. The fault is manifested by the thermometer display failure, the temperature cannot be controlled, the heat sealing temperature is not constant, the sealing part is either scorched, or the sealing is not strong, and the sealing is deformed, which is ugly. The main reason for this failure is that the thermometer is broken and must be repaired; in addition, the thermocouple may also be broken, and the induced temperature cannot be transmitted to the thermometer normally. Just replace the thermocouple with the same model and specification. The mechanical reason is uneven heat sealing pressure, as long as the pressure spring of the heat sealing knife is adjusted to make the pressure consistent. At the same time, the pressure contact surface of the heat-sealing knife should be kept clean and free of dirt. Another reason is that the heat sealing quality of the composite material itself is not good, and the heat sealing coefficient changes, resulting in inconsistent temperatures.

5. The sealing machine goes and stops. During the production, we have encountered the problem of the sealing machine going and stopping, and the speed is inconsistent. We disassembled the panel on the back of the sealing machine and found that the connection between the shaft of the motor and the gearbox has appeared. Falling off and loosening. Re-tighten the screws to make them all fit, and the problem is solved. In addition, the main motor is operated by the contact of carbon brushes. If the carbon brushes are severely worn, incompletely contacted with the slip ring, or have poor friction, the sealing machine will also stop and go and be replaced with new carbon of the same model. The problem can be solved by swiping.

6. Bubbles and irregular marks on the seal are also common. Although it will not cause leakage of the package, it affects the beauty of the package and destroys the image of the product. The main reasons for this failure are as follows. (1) The equipment has been used for a long time, and dust and plastic scraps are attached to the high-temperature belt, which causes the high-temperature belt to be uneven and uneven, which makes the sealing unevenly heated, and bubbles appear after being pressed by the cold pressing wheel. The fault can be eliminated by cleaning or replacing the high temperature belt again. The high temperature belt is generally 1.5cm wide and about 22μm thick. If the dirt cannot be washed off after being stuck, it has to be scrapped. (2) There are irregularly arranged uneven marks on the cold-pressed rubber wheels, which are directly reflected on the packaging, so that more obvious marks appear at the seal. In order to ensure that the packaging bag is beautifully formed, it is best to replace the cold-pressed rubber wheel.

7. Issues that should be paid attention to in the maintenance of packaging machine equipment (1) The sealing machine should be placed in a ventilated and dry place, and the room temperature should generally be maintained at about 25°C. (2) Every 48 hours of operation, 6# oil should be added to the moving parts, mainly in gears, bearings and gearboxes. (3) Dust should be removed regularly to keep the whole machine clean. It is best to unplug the power when not in use and cover it with a cover cloth. (4) If the running time is too long, the cooling fan should be turned on before shutting down, and then shut down after the temperature drops, because the high temperature zone is easily damaged if the machine is shut down without cooling. (5) The high temperature belt should be cleaned regularly to ensure the sealing quality. (6) Severely worn parts should be replaced in time to extend the life of the whole machine.