1、 Transfer of laser film
You should have seen some packaging containing laser in the market. Only a few words have laser, but other places do not. How is this kind of packaging made? Everyone's first reaction must be to compound. But it's not compounded. If you tear up the package, look carefully and touch the words with your hand, you can find that the thickness of the place with laser words is the same as that without laser words, which is certain that they are not composite. Moreover, once the laser passes through the temperature of the hot roller, it is almost difficult to pull it down, which causes loss. Of course, some customers may need to replace it, but the common packaging is not compounded.
The laser is transferred above the printing. In the last color of printing, make the root plate, add a small discharge rack, and align the film position with the words that need laser. This edition does not need to be carved too deep. It does not contain ink. It is a white emulsion adhesive. It can also be used as a self-adhesive adhesive. It can only pass through the film of laser. After this version, it can be combined with the printing film. But the laser must be aligned, and the rolls need not be too tight. Laser film does not need tension, by winding and the rotation of the roller can. After the winding is finished, it is immediately unloaded and put into the oven for drying for half an hour to an hour. Then it is taken out and rewound on the slitting machine. The laser film and the printing film are rolled separately. Then the effect is seen and whether it needs to be dried again (pay attention to the control of tension). After the rewinding is finished, the composite is finished, which can not only reduce the cost, but also achieve the effect of laser.
2、 Aluminum transfer
I believe that this problem has been plaguing some flexible packaging enterprises, regardless of the size of enterprises.
The common aluminizing methods are aluminized CPP and aluminized pet. Aluminizing transfer usually occurs on aluminized pet, because it is often used in intermediate composite. Aluminized pet can be divided into two types: one is the aluminum plated, the other is the transferred aluminum. The effect and adhesion of the two kinds of aluminum plating are different. The plating is better, and the transferred products are mostly pet reprocessing with poor purchase by enterprises, and the adhesion capacity is poor. This is because the peeling strength of the film itself is too low, and the bonding strength between the aluminum coating and the base film is poor.
The normal aluminizing film is that there is a layer of primer on the vacuum aluminized surface of the substrate to improve the adhesion of the aluminum coating. Then, the aluminum coating is vacuum plated on the primer, and then the two-component polyurethane adhesive is coated on the aluminum layer to protect the aluminum coating from falling off. The aluminum coating of the aluminum coating film has good firmness and is not easy to fall off. In order to save production cost, some aluminum coating manufacturers do not use primer when producing aluminum coating. The adhesion of aluminum coating is low and not too firm, so it is easy to fall off. So enterprises should pay attention to the difference when choosing materials.
Another factor that may cause the transfer of aluminum plating is that after pulling it open, it is found that there is aluminum on both sides of the aluminum plating and the substrate. Obviously, this indicates that the film has been twice aluminized, that is, the material manufacturer has aluminized the film twice for some reason, and thus the aluminum plating transfer occurs.
Another factor causing the transfer of aluminum plating is the glue. Ordinary glue has small relative molecular weight, strong activity, easy to penetrate into the aluminum plating, affecting the adhesion ability of aluminum plating, thus resulting in aluminum plating transfer. At the same time, the solvent volatilization and release capacity is poor, and the glue solution is easy to penetrate into the aluminum coating and destroy the aluminum coating. Due to the influence of residual solvent after curing, the bonding strength will be reduced, which will affect the peeling strength and aluminum plating transfer.
Now the solution of most manufacturers is to reduce the addition of curing agent. It is difficult to control the dosage of curing agent with the change of weather and the change of temperature and humidity in the workshop, which may cause the problem of batch defective products. Because most of the composite problems need to be cured to know how to deal with it. It is too late to find out after curing. So I don't recommend using this program often.

In terms of glue, I suggest to choose an adhesive with moderate molecular weight, uniform molecular weight distribution, and low initial adhesion. The characteristics of water-based adhesive can meet the above requirements. The molecular weight of water-based adhesive is about 10 times of that of solvent based adhesive, and the molecular weight distribution is relatively uniform. There is no possibility that the aluminum coating will be damaged due to the penetration of solvent. Therefore, the adhesion fastness of aluminum layer will not be affected and the transfer of aluminum coating will not be caused. Water based adhesives are widely used in aluminum plating packaging, such as Shanghai Longhong's two-component water-based 268 and rohmenhaas's one-component waterborne 90d have unique advantages in this respect. Therefore, the choice of adhesive is very important to solve the problem of transferring aluminum coating.

Another reason that can cause the transfer of aluminum plating is the improper operation of technicians. Improper operation methods are shown in the following aspects:
1. If the operation tension is too high, the aluminum coating will be strained, resulting in elastic change and transfer;
2. Too much glue, leading to volatilization dry, false dry, solvent residue leading to transfer;
3. Too much residual solvent will damage the aluminum plating, because the aluminum coating of the aluminum coating film is relatively thin, it is inevitable that there will be some pinholes, so the residual solvent will penetrate into the aluminum coating, causing aluminum coating transfer;
The above are some analysis on the transfer of aluminum plating. I think it is not advisable to reduce the amount of curing agent. Enterprises can choose reinforced aluminum plating or aluminum plating on the surface to solve this problem. Do not select transferred aluminum plating and secondary aluminum plating materials.
3、 Cooking packaging
There are many kinds of cooking problems. The common problems are delamination, wrinkling, bulging, air leakage, peculiar smell and so on.
1. Delamination
Delamination is the phenomenon of material delamination after sterilization at 121 ℃. Usually nylon compound high temperature CP P, materials and ink glue must be high temperature, in the operation of attention to the amount of glue can solve this problem.
2. Wrinkling
Many companies find that the product is good from the drying room, but after bag making, they find that the edge of bag making is wrinkled, which is caused by the lack of curing time. When the bag is cooled, it will be found that the edge is wrinkled. It should be put back to the curing chamber for curing immediately.
3. Bag expansion and air leakage
In this case, we should first distinguish where the problems are and find out the problems one by one with the elimination method. When the food is packaged and steamed and sterilized after vacuumizing, it is found that the bag is bulging and leaking. First, put the package into the water and squeeze it to see where the air leaks. Usually, most of the customers fill the food by themselves, and the sealing is not firm due to the oil in the food, and then the high-temperature sterilization on the mouth will produce the above-mentioned air leakage and swelling package, which will cause odor after a long time.
These are common problems with two-layer cooking. Now we will analyze the cooking problem of the next three layers of aluminum foil. Delamination is usually a stratification between the mask and the aluminum foil. The analysis of this problem is that the glue does not believe that you will use the wrong glue. It should be the cooking glue, which can be replaced by two glue tests. Whether the surface of aluminum foil has been treated clean, whether the fabric used can be high temperature, whether the dyne value has been reached, the problems need to be solved one by one. Its air leakage is the same as that of the two-layer structure. If the sealing is not good, the bag will expand and leak. After a long time, it will give off a peculiar smell. Because of the air leakage, some additives and food in the food will cause the oxidation of the bag with oxygen. In case of odor, pay attention to the selection of fabrics. Although both 0pet and nylon can be used as fabrics, pet is a polar material, which absorbs oil. Here we can do a small experiment, using PE respectively T composite aluminum foil with high temperature CPP, and nylon aluminum foil with high temperature CPP, put into the same food, vacuum sterilization and cleaning, and then put it in the air to dry, you will find that pet feels sticky to the touch, while nylon does not, which is the difference. Because pe-t absorbs oil, so for a long time, we will find that pe-t has a little peculiar smell, while nylon's will not.
4、 Aluminum foil fracture
Many manufacturers of aluminum foil high-temperature cooking will find that after vacuum sterilization, the aluminum foil will break, just like the knife cut. For example, 10 wire aluminum foil breaks after vacuum cooking. If the crack is small, the material should be replaced. Consider whether the material of the inner layer is soft and hard. If fracture occurs, choose a softer material, or increase the thickness and add a wire. The four layer structure is usually PET / Al / PA / rcpp, the thickness of which is 12 wires, and this kind of structure often breaks. Because half of the material of the four-layer structure contains hard bone, fracture will appear in the place with bone teeth and wrinkle after vacuumizing. Although it is fine, it will affect the product after a long time. Therefore, it is necessary to thicken the inner layer or select the material with soft inner layer.
5、 Poor opening
Poor opening refers to that after bag making, it is not easy to rub open at the opening of bag making, which will cause more trouble for customers to pack food.
If CPP has poor opening, we should first tell the material manufacturer that the material with good opening property should pay attention to: first, the unwinding tension of CPP, the other is the winding tension, and then control the ripening temperature and the cold knife for bag making, which can be solved. The opening of PE is similar to this. The unwinding tension of PE must not be large. Why? Because if the tension is large, it will be stretched. The temperature of hot roller cannot be high, the tension of winding can not be large, and the temperature of ripening can not be high. When the curing time is up, it is better to take it out to cool before making bags, which will achieve better results.
Once upon a time, there was an enterprise that used high temperature CPP roll film with nylon. When it was cut out, it was always warped. When it was compounded, it was rolled up, and when it was solidified, it was rolled down. This kind of problem requires the operator to control the tension of CPP, the temperature of oven, the tension of winding, and then control the temperature of curing chamber. After coming out, the problem can be solved by cooling and slitting. Both CP and nylon are easy to stretch and deform due to high temperature or excessive tension. Therefore, edge warping will occur. Controlling these factors can solve the problem.
6、 Common problems of summer compounding
The arrival of summer will certainly have a lot of problems, and summer will make you feel sleepy and irritable, so this reminds everyone to pay attention to safety. Because of the high temperature in summer, more attention should be paid to fire safety.
In summer, you should pay attention to glue. For example, employees should frequently prepare glue before work. One set should be prepared in four times, so that there will not be too much glue left after work. Add some solvent and put it into the refrigerator for preservation. Add it slowly the next morning, and do not mix it at once. In summer, glue has more bubbles in the rubber dish, all white foam. This is because the volatilization is faster, and the glue is running at high speed in the rubber dish to cause the foam to be whitish. Therefore, we should always add solvents, match less, and work well with the glue, and avoid double shadows.
High temperature in summer, but also to control the performance of the material. When compounding each material, you know how to control it as the weather changes.
It is inevitable and must be done to reduce mosquitoes as much as possible. It is necessary to make a separate screen window, install anti mosquito lamp and air shower door, and take anti mosquito water after work every night.
Dongguan Beite packaging materials Co., Ltd. - located in Dongguan City, the world's manufacturing city, is a subsidiary of Beite packaging (China) Co., Ltd., with a plant area of 6000 square meters. It is a flexible packaging enterprise integrating R & D, production and sales. It has a complete set of domestic advanced production equipment, a scientific and humanized management system and a group of experienced technical personnel For backing, to provide customers with quality products and first-class service.
The company produces composite bags, roll film, fruit bags, aluminum foil bags, suction mouth bags, self-supporting bags, zipper bags, anti-static bags, special-shaped bags, etc., which are suitable for the internal and external packaging of food, daily chemicals, electronics, toys, medicine, cosmetics, industrial products and other industries.
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