The continuous automatic sealing machine is generally composed of a frame, a speed reduction transmission mechanism, a sealing printing mechanism, a conveying device and an electrical and electronic control system. When the equipment is connected to the power supply, each mechanism starts to work, and the heating element is heated after being energized, so that the upper and lower heating blocks are heated up sharply, and the temperature is controlled to the required temperature by the temperature control system. The printing wheel rotates, and the cooling system starts to cool according to the need, and the
Conveyor Belt is sent and rotated. And adjusted by the speed control device to the required speed.
When the package containing the article is placed on the conveyor belt, the sealing portion of the bag is automatically fed between the two sealing tapes in operation and brought into the heating zone, and the heat of the heating block is transmitted to the sealing portion of the bag through the sealing tape. The film is melted by heat, and then passed through the cooling zone to appropriately lower the surface temperature of the film, and then rolled by a knurling wheel (or a printing wheel) to bond the upper and lower plastic films of the sealing portion and press the mesh pattern (or printed logo) ), the sealed bag is sent out of the machine by the guiding rubber belt and the conveyor belt to complete the sealing operation.
Sealing is not one of the common failures of continuous sealing machines. There are three layers of sealing:
1 The bag can not be sealed at the seal. The main causes of the failure are the following.
(1) The heat sealing temperature is not enough
Under normal circumstances, 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 °C; the total thickness of the composite bag with PE as the lining is 85-100μm. When the temperature is controlled, it is controlled at 180 to 200 °C. As long as the total thickness of the bag is increased, the heat sealing temperature must be increased accordingly.
(2) Heat sealing speed is too fast
Sealing is not related to the speed of the sealing machine. If the speed is too fast, the seal will be transferred to the cold pressure for cooling in the future, and naturally it will not meet the heat seal quality requirements.
(3) Cold pressure rubber wheel pressure is not suitable
There is one on each of the cold-pressing rubber wheels, and the pressure between them should be moderate. When adjusting the pressure, only the spring should be clamped.
(4) There is a problem with the quality of the heat seal film
Sealing is not related to the quality of the heat-sealing film. If the corona treatment of the composite lining is not uniform, the effect is not good, and it appears at the sealing place, and it is certainly impossible to seal. This situation is rare, but once it appears, the product is bound to be scrapped. Therefore, in the color printing and packaging industry, it is the next process of supervision of the next process. Once the quality problem is discovered, the cause must be analyzed and solved in time. If there is moisture or dirt in the seal, it will also cause the seal to be weak.
In short, to solve the problem of the first type of sealing is not strong, generally can properly increase the heat sealing temperature, and then reduce the heat sealing speed, while increasing the pressure of the cold pressing rubber wheel.
2 Under the pressure of the sealing knife, although the bag mouth is sealed, but the force is squeezed or peeled off slightly, the sealing will crack again. The main reasons for the failure of the second type of seal are the following.
(1) The heat sealing temperature is not enough
Simply raise the heat seal temperature to solve the problem.
(2) The surface of the heat sealing knife is not flat enough
The heat sealing knife is divided into two upper and lower pieces, and a thermocouple is usually installed therein to sense the temperature transfer. There are three screws on the heat sealing knife. The middle screw acts as a support and reinforcement blade. The other two screws are equipped with pressure springs and washers, which are mainly used to adjust the pressure of the heat sealing knife. The upper and lower blades each have two springs. . The main reason for the unevenness of the heat-sealing knife surface is that the intermediate screw is inclined, not horizontal; or the pressure spring pressure of the upper heat-sealing knife is uneven. The sealing machine is a heat sealing device suitable for small businesses and home use. It is usually powered by a 220V AC power supply with a heating power of several hundred watts. The sealing machine circuit produced by various manufacturers is similar. The FR-200 sealing machine is taken as an example to analyze the working principle and maintenance examples of the circuit.
3 When the peeling test is carried out on the sealing part, half of the sealing is firm and half separated. The quality of the sealing of such a bag is still unsatisfactory, because the contents are easily leaked by being squeezed during storage and transportation. This situation often occurs when the composite lining is OPP and blown PE.
Maintenance example
The common cause of failure of this machine is that the transformer is burnt out, the thyristor is damaged, and the heating strip is broken.
Example 1: Pressing the handle, the switch K is closed, the RL is energized and heated, and the sealing part of the plastic bag is heated and melted; the thyristor is welded under repair, and measured by a multimeter, it is found that the T1 and T2 poles have penetrated. It can be repaired after replacing the thyristor. The thyristor is selected from 3A/600V, such as TLC336A.
Example 2: After pressing the handle, the BL cannot heat the seal. Open the casing and visually find that the transformer has burned out and the primary coil of the measuring transformer has been broken. At this time, the secondary voltage of about 25V can be used, and the power can be repaired after replacing the same transformer. The local transformer works intermittently, so its power capacity is about 350W. If the temperature is too high, or the continuous use time is too long, it may cause damage to the transformer, which should be paid attention to during use.
Example 3: After pressing the handle, the heating temperature cannot be adjusted when the heater is heated. During maintenance, the potentiometer VR is mainly checked, and the VR carbon film is damaged due to the frequent rotation of the VR. Replace it with a new VR.
The above is the full content of the common problems and solutions for continuous automatic sealing machine that I shared today. I hope I can help you.
