Maintenance of common faults of multi-functional plastic film continuous sealing machine

(I) loose sealing is one of the common faults of the continuous sealing machine There are three meanings of loose sealing: ① the sealing part of the packaging bag cannot be sealed; ② under the pressure of the sealing knife, although the opening of the bag is sealed, it will crack again if the bag is squeezed or torn with a little force; ③ During the peeling test on the sealing part, half of the sealing is firm and half of the sealing is separated, so the sealing quality of the packaging bag is still unqualified, because the contents are easy to be missed during the storage and transportation process This situation often occurs when the composite lining is OPP and blow molded PE 1、 The main causes of * kinds of faults are as follows (1) In general, if the heat sealing temperature is not enough, the heat sealing temperature of the compound bag with OPP as the lining should reach 170-180 ℃ when the total thickness of the bag is 80-90 μ m; if the total thickness of the compound bag with PE as the lining is 85-100 μ m, 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 speed of heat sealing is too fast and the speed of sealing machine is too slow If the speed is too fast, and the sealing part is not heated yet, it will be sent to the cold pressing part by the traction roller for cooling treatment, which naturally fails to meet the quality requirements of the heat sealing (3) The pressure of the cold pressing rubber wheel is not suitable There is one above and one below the cold pressing rubber wheel The pressure between them should be moderate When adjusting the pressure, just clamp the spring (4) If the corona treatment of composite lining is not uniform and the effect is not good, and it happens at the sealing place, it will not be able to seal This kind of situation is very rare, but once it appears, the product will inevitably be scrapped Therefore, in the color printing and packaging industry, it is the next process to supervise the previous process Once quality problems are found, the causes must be analyzed and solved in time If there is moisture and dirt in the sealing place, it will also cause the sealing not firm In a word, to solve the problem of poor sealing, it is generally advisable to increase the heat sealing temperature, reduce the heat sealing speed and increase the pressure of cold pressing rubber wheel 2、 The main reasons for the second sealing failure are as follows: (1) if the heat seal temperature is not enough, the problem can be solved by increasing the heat seal temperature properly (2) The surface of the heat sealing knife is not smooth enough The heat sealing knife is divided into two parts, the upper and the lower Usually, the thermo electric coupling is installed in it to sense the transfer of temperature There are three screws on the heat sealing knife The middle screw supports and strengthens the knife The other two screws are equipped with pressure spring and gasket, which are mainly used to adjust the pressure of the heat sealing knife The upper and lower blades have two springs respectively The main reason for the unevenness of the knife face of the heat sealing knife is that the middle screw is inclined, not horizontal; or the pressure of the pressure spring of the upper heat sealing knife is uneven The solution is to recalibrate the position of the intermediate screw to make it horizontal If the upper and lower heat sealing knives are not balanced, it is necessary to adjust the pressure spring to moderate When the spring retreats outward, the heat sealing knife will fall; when the spring of the lower blade is tightened upward, the heat sealing knife will move upward (3) The uneven pressure of the cold pressing rubber wheel will also cause such sealing failure The solution is similar to that of * cases 3、 There are two main reasons for the third kind of sealing failure: (1) the pressure of the hot sealing knife is uneven or the pressure of the cold pressing knife is uneven, and the adjustment on the hot sealing knife and the cold pressing knife is completely consistent; (2) the knife surface of the hot sealing knife is not flat; refer to the corresponding solutions of the second sealing failure (2) The main motor of the fuse fusing 900 multi-functional plastic film continuous sealer is produced by Shanghai Shangwei Jinli Motor Co., Ltd the main function of the motor is to drive the gearbox and gear transmission of various components Sometimes when the sealing machine is started, it will make a "squeak" sound, unable to operate normally, and even the fuse on the live line is blown To remove the fault, first check whether the power supply is normal, then cut off the power supply, use the resistance gear to check whether the switch is damaged, in addition, carefully check whether the circuit and motor are short circuited Generally, when the motor is short circuited, the winding is burnt or the wire is broken, the fuse will be blown as soon as the sealing machine is started Another reason for this fault is that the fuse specification is too small, so the problem can be solved by increasing its specification accordingly (3) "Squeak" occurs during the operation of the sealing machine This fault occurs during the operation of the sealing machine "Squeak" usually occurs suddenly The next problem is the uneven sealing speed, which results in bad lines at the sealing and stamping of the packaging bag and affects the appearance quality of the product Occasionally, it can work normally, but it is capricious This phenomenon is mostly due to mechanical damage or severe wear, as well as poor lubrication Some time ago, the 900 type multi-functional plastic film continuous sealing machine used by Linyi packaging machinery Huzi appeared this phenomenon when sealing We first follow the sound to find the fault Disassemble the back protection plate, and find that the "squeak" sound is from the gearbox Remove each set screw one by one, and find that the grease in the gearbox is dry and solid, and the gear is bright and Clank, which indicates that the fault is caused by lack of oil After mixing the oil and grease of the same model, add them into the gearbox, and tighten the screws to recover After starting up, the "squeak" disappears and the sealing is normal In addition, if the joints of the high-temperature belt are loose, severely worn, unclean and dirty on the surface, it will not be synchronized with the traction wheel during operation, and sometimes it will 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 spring of the pressure wheel by hand, and then place one end of the high-temperature belt on the rubber wheel, and the other end is to hold and lean on the other rubber wheel by hand, and set the governor to low speed As soon as it is started, the high-temperature belt will be installed automatically by the motion inertia Sometimes the "squeak" of string 1 is also emitted by DC shunt motor It may be caused by the lack of oil in the motor bearing If this is the case, it should be removed and lubricated with oil, and the sound can be eliminated 4 The sealing temperature is out of control The fault is that the thermometer display is out of order, the temperature cannot be controlled, the heat sealing temperature is not constant, the sealing part is either burnt, or the sealing is not firm, and the sealing is deformed, which is very ugly The main reason for this failure is that the thermometer is broken and must be repaired; in addition, the thermoelectric coupling may also be broken and cannot normally transmit the induced temperature to the thermometer Replace the thermoelectric coupling of the same model and specification The mechanical reason is that the pressure of the heat seal is uneven As long as the pressure spring of the heat seal knife is adjusted, the pressure can be the same At the same time, the press contact surface of the heat sealing knife shall be kept clean and free of dirt Another reason is the poor heat sealing quality of the composite itself, and the change of the heat sealing coefficient, resulting in the inconsistent temperature 5 Stop and go of sealing machine we have encountered the failure of stop and go of sealing machine and inconsistent speed in production The panel on the back of sealing machine was disassembled, and it was found that the connection between motor shaft rod and gearbox had fallen off and loosed Tighten the screws again to make them all fit, and the problem will be solved In addition, the main motor is operated by the contact of carbon brush If the carbon brush is seriously worn, not completely contacted with the slip ring, or the friction is not good, it will also cause the sealing machine to go and stop Replacing with a new carbon brush of the same model can solve the problem Bubbles and irregular marks at the seal are also common Although they will not cause package leakage, they affect the aesthetic feeling of the package and damage the image of the goods There are two main reasons for this failure (1) The equipment has been used for a long time, dust, plastic chips and other dirt are attached to the high-temperature belt, resulting in the high-temperature belt is not smooth and flat, resulting in uneven heating of the seal, and bubbles appear after the cold pressing wheel is pressed Clean or replace the high temperature belt to eliminate the problem The high-temperature belt is generally 1.5cm wide and 22 μ m thick If the dirt cannot be washed off after sticking, it will have to be scrapped (2) There are irregular concave and convex marks on the cold pressing rubber wheel, which are directly reflected on the package, so that there are more obvious marks on the seal In order to ensure the appearance of the packaging bag, Zui is good to replace the cold pressing rubber wheel 7 Problems to be noticed in equipment maintenance (1) the sealer shall be placed in a ventilated and dry place, and generally the room temperature can be maintained at about 25 ℃ (2) Every 48 hours of operation, 6 engine oil shall be added to all moving parts, mainly at gears, bearings, gearboxes, etc String 6 (3) should be regularly dedusted to keep the whole machine clean When not in use, Zui should unplug the power supply and cover it with a cloth (4) If the operation time is too long, turn on the cooling fan before shutdown, and then turn off the fan after the temperature drops, because it will turn off if not cooled, and the high temperature belt is easy to be damaged (5) The high temperature belt should be cleaned regularly to ensure the sealing quality (6) The severely worn parts shall be replaced in time to extend the service life of the whole machine.