Abstract: Solvent-free compounding process is becoming more and more widely used. This article details the cost of solvent-free compounding, the scope of solvent-free compounding, the compatibility of solvent-free glue and ink, the generation of solvent-free compound bubbles and joint bubbles, Appearance of thread, empty glue and solutions.
The rapid development of solvent-free compounding in China was in the years 2010 to 2013. It is foreseeable that it will develop more rapidly in the next few years. At present, some domestic companies still have misunderstandings about solvent-free compounding, and believe that solvent-free compounding has poor fastness and cannot be cooked or made of aluminized and pure aluminum materials. This understanding is wrong. Not only does solvent-free compounding meet the requirements in terms of performance, but also in terms of environmental protection alone, it has great advantages in controlling residual solvents. Secondly, the equipment has no oven, which can greatly reduce electricity costs, so the development prospects of solvent-free compounding are very good.
First, the cost of solvent-free composite machine
1. Equipment can't bring costs, glue can't bring costs, and the only thing that can bring costs to the enterprise is personnel. Therefore, personnel is the best cost control for an enterprise. Proper use will be a considerable cost. Equipment brings energy saving, glue brings solvent-free, personnel brings money, quality, efficiency, and cost control.
2. The cost of the solvent-free laminating machine is much lower than that of the dry laminating machine. If the operation is correct, the amount of glue applied will save costs than the dry laminating machine. It does not require solvent dilution and does not require oven electricity costs. Secondly, if the production of ordinary structure products is faster than the dry laminating machine, it can reach a speed of more than 300m / min. On the contrary, if improper operation or lack of responsibility, 300m / min can bring efficiency and loss, so personnel Cost is the best cost control.
Second, solvent-free composite adaptation range
1. Solvent-free can basically adapt to the composition of most structures, depending on auxiliary materials and operators and methods and processes. The two materials of VMPET and AL should be more concerned by everyone. This depends on the product, including the color, performance, and material of the printing layout. It is also important to see how the operator operates. Some domestic companies have already done very mature, while others have frequent problems, which depends on the technological level of the enterprise. At present, solvent-free composites have been used in 121 ° C cooking products, boiled products, aluminized composites, pure aluminum composites, inflatable bags and other structures, which can prove that the scope of application of solvent-free composites is still relatively wide.
2. Solvent-free is not suitable for transparent inks. I personally think that the effect of solvent-free composite yellow inks is slightly worse.
Compatibility of solvent-free glue with ink
When solvent-free compounding (especially when compounding VMPET) appears with white spots, bubbles, and lack of fastness, glue manufacturers generally recommend replacing the ink, which is considered to be caused by the incompatibility between the ink and the glue.
When there are white spots, bubbles, and no fastness, we first look at whether the white spots are full or partial. Is there any regularity and what are the bubbles? Is it related to fastness and sizing? Is the operation process correct? These factors are likely to form white spots. Generally, the composite aluminum plating material will have some white spots, but this does not mean that the ink is incompatible with the glue, and that the cost of a company's replacement of each ink is wasteful and troublesome.
At this time, the most effective way to solve the problem is the sample: the substrate is replaced and compounded, and the speed is marked. Without considering other factors, control the amount of glue, temperature, and pressure in all aspects. Both the sample and the problem can be analyzed. There is also a possibility that the ink is light, whether the dots are too light, and whether the residual solvent of the ink is volatile (can be rewinded before laminating, blown down by a fan during rewinding, or put into the curing chamber in small batches). Bake it and then recombine it to see if the effect is the same as before.) Secondly, you can do the compound test on the dry compound, so that you can analyze which link is the problem, and then solve the problem, which can save time and effectively for the enterprise. The problem is that you don't have to spend a lot of time replacing different ink compounds.
Fourth, the generation of solvent-free composite bubbles and joint bubbles
It is very simple and easy to solve the problem of bubble generation without solvent. Generally, if the bubble appears, first check whether the bubble is regular or irregular. If it is regular, consider the rubber roller. If it is not regular, consider whether the amount of glue is sufficient. Water leveling is not good, temperature control, residual solvent in printing film, too fast speed will generate air bubbles. When this happens, it should be solved according to the air bubble sample, increase the pressure, control the amount and speed of glue, you can increase the temperature, This can solve the appearance of bubbles. Generally speaking, normal air bubbles can be solved through the above solutions. If air bubbles appear in the anti-counterfeiting label on a salt bag in winter, the solution must be solved according to the sample.
There is also a special kind of air bubbles. When the compounding process and shut-down material are turned on, air bubbles appear through the tape connector (may not be produced by some manufacturers). This happens when the base film is PE with a thickness of 5 or more. Generally, a large area of bubbles is generated through the joint. The operator cuts and pierces with a knife. This is a dangerous operation and a waste during the operation. The solution to this problem is simple: when the machine is shut down, the tape can be applied. There are air bubbles in the front, and the material will be broken when the bag is reversely attached. The positive and negative stickers can not only solve the air bubbles but also ensure the continuous production of the bag. The effect is better, and the composite loss and bag making loss are less. Due to the angle of the compound press roller of the compound machine and the joint compound bubble caused by the advanced compound press roller at the tail when the tape is being applied, the two sides have the best effect and the least waste.
V. Appearance and solution of knife line and empty glue
The generation of knife lines should be very clear and often encountered. Knife lines generally refer to the presence of impurities, dust, particles, etc. in the glue. Everyone also knows how to solve it. Adjusting the lower blade roller can basically solve it.
However, there are two possibilities for empty rubber: one is similar to the knife line, there are impurities and dust particles falling in the rubber roller, which causes the glue to be scraped off; and the other is on the transfer steel roller. The grooves are deeply printed. Generally, the imprints on steel rollers are hard and worn by impurities. One type is to rub the grooves that have been rubbed for a long time at the position where the standard pressure roller and baffle rub. It is easy to transfer no glue on a wide compound material. This situation depends on the quality of the transfer roller, the surface treatment, and the material of the baffle. When placing the baffle, you can coat the inside of the baffle with some curing agent, which can reduce friction.
In the solvent-free composite process, personnel is the cost, and management personnel can control the quality of the product; production of a product must understand product performance, materials, glue performance and equipment performance; understand the service life of the glue when it is stationary; habit formation The habit of seeing the sample at the first inspection; record the process parameters of each product; control and calculate the size of the glue.
Practice the truth. Solvent-free is not a complicated process. Don't think too simple about it; don't deny it without experimentation; learn to analyze, test, exclude, record, etc. if there are problems, don't go blind in conclusion.