After decades of continuous precipitation and development of the flexible packaging industry, the product structure and process have been greatly improved and improved. The overall barrier performance of various packaging products to the packaging film is also higher and higher. High barrier and high transparency are not the requirements put forward in the flexible packaging industry market this year. The composite strength of the product and the barrier performance of the product can meet the customer's requirements. It is necessary to use our compound curing chamber. After the semi-finished products are compounded, they need to go through a certain temperature and time, and conduct full crosslinking reaction under specific temperature control. Curing is also called curing. Through stable temperature and certain time conditions, the internal stress of various composite substrates (a base material and B base material) can be balanced and balanced. Through the stable temperature environment and certain time conditions, the crosslinking reaction of AB glue is promoted to achieve the purpose of firmness. (the process of transformation)
The function of curing chamber: it is the process that the composite film is put into the drying room (curing room) to make the main agent and curing agent of polyurethane adhesive react and cross-linked and interact with the surface of composite substrate. The main purpose of curing is to make the main agent and curing agent fully react within a certain period of time to achieve the best composite strength; the second is to remove the residual solvent with low boiling point, such as ethyl acetate, to reduce the residual amount of solvent and reduce the odor.
Curing control mainly refers to the control of curing temperature and curing time, which are determined by the different structure of products used, the different properties of adhesives used and the final performance requirements of products. Different adhesives have different curing temperature and time. If the curing temperature is too low, lower than 20 ℃, the reaction of adhesive is very slow; if the curing temperature is too high, the additives of the substrate film will precipitate, which will affect the performance of the composite membrane and increase the odor. If the aging time is too long, it will also affect the performance of the composite membrane and increase the odor, which is mainly caused by the processing aids in the polyethylene film.

Scientific design and reasonable layout of curing room:

1. The structure is reasonable, and the position is in line with the process flow. Usually, we can use a corner of the compound workshop to set up, and install a sealed door.
2. The curing room is generally set up as cabinet or tower type, usually 2-3 meters high, and there are some higher ones, which need to be reasonably constructed according to the overall product structure of the enterprise and the structure of the curing room. Usually we will leave a vent or air vent at the top to eliminate the odor of the curing chamber.
3. Make an air inlet in the curing chamber and install a small blower to blast the curing chamber regularly. The best way is to blow the air to the heat dissipation device. The main purpose is to keep the temperature of the curing chamber consistent, but also to speed up the circulation of the gas produced by the cross-linking reaction of the products in the curing chamber.
4. For the establishment of iron frame placed on the wall of the curing chamber, a honeycomb shaped steel pipe can be set up from the ground about 60cm away from the ground, which is similar to the diameter of PVC water pipe. Then, a slide way is made between each vertical frame, and a blowing honeycomb steel pipe is added in the middle of the slide. According to the size of the curing chamber, several more layers can be made to facilitate the ripening of the product. At the same time, we should prepare a certain length of steel pipe, and install sliding shaft at both ends for compound semi-finished product suspension for curing.
5. The core insulation in the core has low energy consumption (stable effect and low energy consumption). The insulation effect and material of the wall and roof of the curing room should be 100 mm insulation asbestos as far as possible. The insulation effect of polystyrene extruded board is 2-3 times of that of polyurethane foam board and 8-10 times of that of asbestos. After spraying on the wall with high temperature resistant foam adhesive and sticking with 40mm polyphenylene glycol board, it is beneficial to heat preservation and save energy and cost.
6. Temperature control system of curing room. Generally, the ripening time of our flexible packaging products is controlled in the range of 24-72h. Power distribution heating and cooling device, as well as steam, heating switch device. Automatic temperature control device is installed near the wall of the curing room, so as to better realize automatic constant temperature control. Some of them adopt computer automatic temperature control system. It can further improve the independent control of product temperature and time. Reducing artificial operation and control is conducive to the stability of product aging quality.
7. It is convenient for the product to enter and exit (the cart can enter and leave the door unobstructed, and the door will cool down). It is better to pass through one door, which is conducive to the operation and semi-finished product turnover, and can further improve the work efficiency.
8. Large storage capacity (designed according to 3.5 times of the daily product volume), it must be circulating air with temperature difference of ± 1 ℃
9. Application of air curtain technology (frequent door opening and closing, no cooling)
Reasonable layout:
1. The overall structure of the curing chamber is easy to move. After moving, one side should be fixed against the workshop wall as far as possible.
2. The curing room must not be built in the printing workshop (to avoid free odor of benzene, grease and other solvents).
3. If the curing room is built in the bag making workshop and compound workshop, special attention should be paid to: (the exhaust must be directly to the outside, and the supplementary air must be used outdoors, so as to avoid the cross flow again, saturation free and mutual adhesion) the large circulation of the overall air system of the curing room must be free to discharge waste in the lower inlet, upper outlet and top, and the inlet and outlet must be sealed with filter screen.
The temperature and time conditions of aging products also need to pay attention to the following factors: polyurethane adhesives are divided into component A and component B, namely colloid and curing agent, and the length of chemical cycle reaction time is determined according to temperature.
Time setting: the curing time of general polyurethane two-component adhesive is designed according to 24 hours. The molecular cross-linking reaction reaches more than 90% within 24 hours (that is, the product tends to be stable after various changes and reactions in a day). The more permeable the contents are, the more high-temperature cooking bag products are. When choosing adhesives, the effect of chronic curing is better, and the colloid is stable and not easy to break. The tolerance time is long. (for example: ad811a needs to be aged for more than 72 hours) aging time: it is scientific to determine the aging time according to the characteristics of composite membrane and adhesive. Others are also affected by the following aspects:
1. The aging temperature of pet, BOPA, Al, CPP films can be increased due to their good heat resistance and high shrinkage temperature. The temperature of LDPE, EVA, BOPP and other materials should not be too high.
2. The product with the amount of glue can be cured by increasing the temperature according to the structure of the film.
3. The aging time and temperature can be appropriately reduced if the film is delivered from the factory.
4. The thickness and specification of the film roll, and the larger the diameter of the film roll, can appropriately extend the aging time.
5. Due to the problem of residual amount, the aging time can be appropriately prolonged to reduce the residual solvent.
3. The products coming out of the curing room must be well marked, and can be marked on the film roll and placed in the designated warehouse out area at the same time. Figure 3 identification card for storage of mature products 4. The products in the curing room should be classified and put into storage according to different structures and product types to avoid mixing. Mixing is very disadvantageous to the management of the curing room. It has the influence of cross penetration of different products in the curing room. More importantly, it can not meet the production requirements of the following process.
Objective: to be standard, orderly and clear.
5. If the time is not up or the product is delivered in advance, we suggest that it is better not to operate in this way, which is too arbitrary, that is, the product process is not rigorous. Due to special circumstances, the products that need to be delivered out of the warehouse in advance must be sampled and tested before they can be delivered out of the warehouse. The phenomenon of delayed delivery occurs from time to time, which will have a great impact on the implementation of product process and product performance characteristics. Similar problems should be avoided as far as possible. It is suggested that the management system of curing room should be formulated to strengthen the management.
6. If the enterprise can not be cured normally due to abnormal conditions, relevant time records must be made, and the time difference of residual temperature should be fully considered in the supplementary time. Avoid aging.
7. When the aging process of our products needs to be changed, it is better to try first and then pass the inspection, and then make changes on the basis of the original, and publicize it in the form of notice.
8. In addition to materials and glue, we also need to consider the requirements of customer's packaging film and the processing technology of subsequent processes when we formulate the curing process. In this way, the most comprehensive and scientific way is to comprehensively consider. At the same time, we should compare the existing process characteristics to find a more suitable curing process for reasonable and efficient aging.
To sum up, it needs to be pointed out that when making the curing room of flexible packaging enterprises, it is necessary to fully consider the existing products, whether it uses electric energy or steam energy, the energy-saving technical scheme, and the orientation and development direction of the enterprise. In the process design of the curing room, the structural characteristics of the enterprise's products, the materials used, such as ink, glue, etc., should be fully considered Some enterprises think that the control of residual solvent is mainly in the control of curing room, which is a very incorrect concept. Of course, curing chamber is also one aspect of reducing residue control, but the most important comes from printing ink, viscosity, solvent, drying ability, compounding speed, drying ability, materials and so on.
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. We uphold the integrity of cooperation, good quality, good service business philosophy, won the industry's approval, products sold to all over the world; welcome friends from all walks of life to inquire, visit our factory to investigate guidance and business negotiations.