Precautions for sealing packing used in the packag

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Precautions for sealing filler used for steel drum packaging and sealing

sealing filler used for steel drum sealing, commonly known as sealant, when the bottom and top of the steel drum are sealed with the barrel body, it is filled into the seam of the curling edge to seal. After the steel barrel is sealed, there is a certain rigid springback at the crimping part, which makes the originally tightly crimped crimping appear gaps. Therefore, filling the curling gap with sealing filler can effectively improve the anti leakage ability of the steel barrel

the production and use of steel drums have the following requirements for sealing fillers:

1 the dry bulk shipping market continued to rise 1. Compatibility. Because steel drums are widely used and contain a variety of goods, sealing fillers are required to have certain compatibility with various contents. If some contents are incompatible with the sealing packing, chemical reaction and corrosion may occur, thus damaging the sealing performance of the packing and making the contents deteriorated or modified

2. High temperature stability. At present, the coating process of steel drums of most drum manufacturers is dried in a drying furnace. The temperature in the furnace is as high as about 200 ℃, and the surface temperature of the steel drum is higher. At this temperature, the sealing filler becomes diluted or burnt, which will affect its sealing performance

3, higher solid content. As it is a sealing filler, it is different from a simple adhesive. If the solid content is low, the volume will be reduced after drying, so that the gap can not be effectively filled, thus affecting its sealing performance

4. Good adhesion. The production process of most barrel factories has the process of pre coiling and spraying glue at the bottom and top of the barrel. If the adhesive force between the glue and the pre crimping at the top of the barrel bottom is not strong, then at the beginning of the crimping, the barrel bottom top and the barrel flanging will slide relatively, and the glue sprayed on the pre crimping will be rubbed off, sometimes falling outside, sometimes falling into the barrel. It not only affects the sealing performance, but also the rubber block falling into the barrel affects the internal cleaning of the steel barrel

5. Good elasticity. In the process of steel drum edging, due to the action of mechanical force, the edging is wrapped very tightly, and the gap is the minimum. However, after the sealing is completed, the edge curling is slightly relaxed due to the rigidity and springback of the edge curling, and the gap is relatively large. If the sealing packing does not have good elasticity, it cannot adapt to this change. In addition, from a technical point of view, the sealing filler should have certain elastic compression in the crimping, and its own elastic elasticity can make the sealing performance better

6. Good construction performance. The so-called construction performance means that it can facilitate the implementation of glue spraying, gluing, drying and other processes. The viscosity should meet the requirements, and there should be no obvious rubber particles, caking, thinning or sedimentation. In addition, due to the inconsistent climatic conditions throughout the country, it is required to have a certain degree of weather resistance. It can not be caked and deteriorated due to cold, nor can it be invalid due to heat

as long as the above requirements are basically met, the sealant is good. In fact, most domestic sealants have some problems, and so far there is no one that fully meets the requirements

1. When steel drums are produced in the full-automatic production line, the pre coiling and glue spraying process at the bottom and top of the drums is basically unchanged, but the speed is faster, and they will enter the continuous drying line for drying immediately after spraying. So grace glue is right. Whether the glue can meet the sealing requirements of the steel drum depends on the internal performance of the glue (i.e. the conditions mentioned above), which has little to do with the construction method

2. If water or other volatile solvents are not used as the dispersion medium for sealing, but 100% curing filling (such as PVC foaming sealant) is used, it should be said that it has a good prospect. I haven't used it specifically, but as long as it can meet the use requirements of steel drums, even if the construction methods or materials are different, this is not the main problem. This practice may promote a revolution in steel barrel sealant! It may also bring breakthrough improvements to the quality of steel drums

3. At present, the problems existing in the domestic sealant formula are common, but generally speaking, as long as it is not a major problem or has little impact, the barrel manufacturers are not too demanding. But there are several situations that must be treated with caution: ① when used in food packaging barrels, the sealant should be non-toxic and harmless, and will not react with food. For steel drums for other purposes, it is not important that the sealant is non-toxic; ② For the rust problem of water-based adhesive, some improvements such as introduction of new technologies and practical solutions by experts, material suppliers and medical device manufacturers from all over the world can be adopted in the construction method, such as splash prevention and timely drying; ③ The solvent resistance of sealant is not absolute, as long as it has relative stability to the contents, it should be appropriate. In foreign countries, sealants are divided into many types, and different sealants are used for different purposes

4. The construction and drying of water-based sealant at normal temperature is only the current common method and process, but if there is a more ideal sealant, this old tradition can also be avoided. Most foreign sealants need to be dried, which not only has good effect, but also has high production efficiency. So don't limit yourself to conventional process methods. As long as the performance is good, the drum manufacturers will accept that the microphone of the sound level meter is horizontally placed 1.0m away from the experimental machine facing the sound source

5. As for the performance of sealant, in addition to trial use in practice, barrel manufacturers brush or spray on the sample, and then observe its elasticity, solid content, adhesive force, etc. generally, there is no special inspection method. However, it is easiest to identify in production practice. Once there is a problem, your reputation will be irretrievable. He will not pay attention to these matters. You must pay attention to them. Believe you, so be careful

in fact, the things we encounter in practice are very different. We have used more than ten kinds of glue. Generally, one kind of glue will not cause user complaints after use, and we will continue to use it. Once there is a problem, we will consider replacing it. Therefore, most manufacturers are not willing to try the new glue because it takes risks. Some problems will not be reflected at that time, but it will be too late when there is a problem with the user. Last month, a user used a steel drum to contain a chemical raw material. All the steel drums leaked due to the dissolution of sealant. Finally, we used epoxy resin to repair the damage. So far, no suitable sealant has been found

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