Because of the different production environments and production processes, different problems often occur in the packaging bag compounding process. The following problems are relatively easy to be ignored.
bubble
The white spot of the aluminized film composite should not be included in the bubble phenomenon. First of all, the bubbles are divided into those that come out of the machine and those that appear after entering the curing room. Generally, most of the products coming out of the machine are related to the poor coating state, which is related to the matching problems of viscosity, concentration and anilox roller. Generally, the bubbles are small and dense, and experienced masters can see which bubbles that come out of the machine will disappear after curing, and which will not. However, the anti-stick phenomenon that occurs after entering the curing room is mostly related to the low purity of the solvent. These bubbles are generally invisible when they come out of the machine, and will become irregular in size after curing, ranging from mung bean to soybean size.
curling corner
The bags made are sometimes uneven, some bags are flat on one side and the other is not flat, and some are flat in this corner and not in that corner. In addition to tension control, which is the reason for the deformation of the film, and the heat sealing temperature is too high, there is also the uneven heating of the film roll during curing, and this uneven heating is not the uneven inside and outside of the film roll, but refers to the film Both ends of the roll are heated unevenly. Careful observation will also find that when the bag is folded, the adjacent side is generally not rolled or much better, while the other adjacent far side is more seriously warped. If this is the reason, the manufacturer’s experience is to leave it at room temperature for a period of time after coming out of the curing room, so that the temperature of the film roll can be restored to uniformity. Of course, it is better to let the film roll be heated as evenly as possible in the curing room, so pay attention to the parking position and method of the film roll in the curing room.
slip agent
The peel strength is low due to the precipitation of the slip agent, which generally occurs in PE films with a thickness of 8C or more. After tearing it open, you will find a layer of misty white frost on the inner membrane, which can be marked by hand. Tear a piece and put it in a high temperature oven for a few minutes and then take it out, the peel strength will increase a lot, but after a few minutes the peel strength will drop again. If it is a composite coil, it can also be put into the curing room and placed in a temperature above 60 degrees for more than 12 hours, which may be compensated. Others did not find any good way.
sticky
That is, curing is not complete. Most of them are related to the low purity of the solvent and the excessive humidity of the environment. It is also caused by dividing a barrel of glue into two preparations, which makes the addition amount of the curing agent inaccurate. Generally, the larger the amount of glue dispensed at one time, the more stable the quality of the composite product. In addition to the phenomenon of anti-sticking, which is easy to cause problems in bag making, there is also a more hidden problem that is more terrifying. That is, there is no problem in placing the finished bag in the factory or at the customer’s place. Once the contents are loaded (usually more than 5 days), the surface of the bag will appear wrinkled. So once you find that the curing is not complete, don’t take chances with the customer easily. At least you have to put the same contents as the customer in your own factory for testing and observation, and then deliver the goods without any problem.
Poor opening after bag making
The opening of the bag is not good. In addition to the reasons of the inner film itself and the aging caused by the poor opening, there is another situation that is easy to occur on the thinner inner film (generally about 3c). Due to the action of the composite binder, the additives of the film migrate to the composite layer as a whole, resulting in an increase in the friction coefficient and poor opening.
Post time: Oct-31-2022