Analysis on the current situation of the most popu

Analysis of the current situation of steel drums for export packaging in China

there are many kinds of steel drums for export packaging in China, most of which are between 15 and 200 liters in size, of which two kinds of mouth types are more common, namely, full open barrels and closed barrels. Full opening barrels are sealed with large caps and hoops, mainly containing solid and semi-solid; Closed barrels are mostly used to hold grease and liquids. As the packaging of export commodities, the most used is, of course, 200 liter steel barrels, which are called 53 gallon barrels in foreign countries. In the past decade, leakage has occurred from time to time when containing grease and other liquid raw materials. It is understood that although the barrel making technology and equipment are also developing in recent years, the overall quality has not improved much. At present, few domestic 200 liter steel barrels can really pass the drop test without leakage. Therefore, solving the leakage problem of export steel drums has always been listed as the key project of export containers. After investigation, it is found that the location and proportion of steel barrel leakage are roughly as follows: 10% is at the barrel mouth and end; Barrel body welds account for 5%; The triangular area of crimping and welding seam accounts for 85%, and the triangular area is the most

to solve the leakage problem, we should mainly start from the following aspects:

1. Adopt advanced seam welding machine to reduce the width and thickness of seam welding overlap, which can greatly reduce seam welding leakage and curling leakage

at present, the steel barrel seam welding machine used by most bucket manufacturers in China is still a semi-automatic domestic machine, and the overlap of seam welding is mostly about 10mm. At the lap welding part, the thickness of the material is about twice that of the plate. When this part is rolled and sealed, because it is thicker than other parts, there are often uncompacted gaps at the transition from thick to thin, so leakage occurs. In order to solve this problem, some barrel manufacturers have adopted a variety of improvement methods, and some progress has been made at present. For example, the seam welding machine device of Tianjin jingdashi company is improved on the original semi-automatic seam welding machine, which can not only improve the seam welding speed, but also have smaller overlap and thinner overlap thickness; Others use the edge roller to roll the lap edge after welding, and thin the double-layer edge; The most advanced is the full-automatic seam welding machine. The welding lap width is only 2 ~ 4mm, and the welding quality can be fully guaranteed. At present, the more advanced technology abroad is the use of laser welding technology, which can realize the butt welding of steel plates, and its performance is more excellent

2. Improve the crimping process, so that the crimping can reach seven layers, and the crimping is compacted

ten years ago, the bottom and body of steel drums in China were all rectangular five layer crimping. In recent years, foreign seven layer round crimping technology has gradually been popularized in China. Therefore, the problem of curling leakage is greatly reduced. However, the quality is endless. Today, the problem of curling leakage has become the key to seriously affect the development of steel barrels. From a technical point of view, the leakage of crimping has the following aspects:

⑴ the crimping level is not enough. This kind of situation is quite common, because under the situation that the country began to engage in round crimping, many manufacturers did not really master this technology, but produced it after changing the groove shape of the crimping roller to meet the requirements of users. This kind of round crimping is indeed round crimping from the appearance, but the real internal quality is not guaranteed. The most obvious difference is that the number of crimping layers does not reach seven at all, and some are only five. Therefore, curling leakage is inevitable. To solve this problem, we must produce according to the correct process of round crimping, which of course requires investment. At least, we should change the blanking size of the bottom and top of the barrel to make the edge material of crimping sufficient; Moreover, it is necessary to add a pre roll glue sprayer at the bottom and top of the barrel, roll the edge of the bottom and top into a groove in advance and fill in the sealant before crimping and sealing; In addition, the flanging width of the barrel body should be increased accordingly. Only in this way can the seven layer crimping be guaranteed

⑵ the crimping level is not tight. Some steel drums have seven layers of curling, but the curling is not compact. Because there are cracks, leakage has become a normal thing. The main reason for this situation is the incorrect groove shape of the crimping roller or the insufficient pressing force of the roller. Roller groove is the most critical technology in crimping technology. Generally, only a few manufacturers have mastered it, and some manufacturers have not really mastered it. The quality is sometimes good and sometimes bad, and some still need to be further discussed. Because the process parameters, process methods and equipment of various manufacturers are different, the groove type and other parameters of the roller are also different, but as long as you master the essentials of the design, you can adapt

⑶ uneven crimping size. The steel drums produced by some manufacturers have uneven crimping size due to the influence of process quality, so there are gaps in some places. For example, the flanging size of the barrel body is not the same width around, the seam welding overlap is too thick, and the thickness of raw materials is uneven. This factor can cause gaps in crimping, which must be paid enough attention

3. The sealant that prevents leakage should be strictly controlled. Unqualified sealant cannot be used, and it should be produced in strict accordance with the process, and there should be no wet sealant involved

in the operation of steel drum crimping and sealing, sealant must be sprayed to fill the gap of the material in the crimping. However, the quality of some sealants is not good, and some curing components are too few, and there is a gap after the glue is dry; Some sealants are not resistant to high temperature. When the steel barrel is coated and enters the drying oven for drying, the glue liquid flows out of the curling gap; Some sealants fail after reacting with the goods in the steel barrel; Some seals have weak adhesive force and are squeezed out of the crimping during crimping operation. Therefore, the selvage sealant of the steel barrel must choose products with guaranteed quality, otherwise the selvage quality is difficult to guarantee

the glue spraying operation must be carried out when the bottom cover of the barrel is pre-set, and it can be used for curling after 24 hours of drying. Because the wet glue can not be sealed after being rolled into the curling, and because it occupies the gap space, it cannot be solidified for a long time, and it is very easy to flow out after the steel barrel is impacted, resulting in leakage, so the pre roll glue spraying process must be strictly controlled

4. The barrel mouth pressing process, especially the quality, should be tight and compact

most of the leakage at the barrel mouth is caused by the problem of the barrel mouth stamping die. Mold aging, barrel organization deployment, process optimization action in the new material industry, changes in the size of the mouth, quality problems of the sealing ring, and the reaction between the sealing ring and the contents of the steel barrel may cause leakage if the query conditions are not set. Therefore, stamping dies must be replaced regularly; It is necessary to purchase barrel mouth parts from a unified supplier. If the supplier changes, the mold must be redesigned and manufactured; The sealing ring should be complete and consistent in size; The user's goods should be studied to ensure that the material of the sealing ring will not react with the goods and lose the sealing effect

some problems are often found in the use of export steel drums. There are mainly the following categories:

1. Quality problems of internal coating barrel

some export commodities need to be internally coated with full opening steel barrels or lined with polyethylene. This kind of steel barrel is easy to leak, and the barrel mouth must be padded. Some inner coated barrels are used to hold food, such as applesauce, ketchup, honey, etc. because the inner coating does not meet the requirements of food hygiene, the content goods are polluted. Some spraying quality is poor, and the coating falls off seriously, resulting in rust on the inner surface of the barrel. Some do not use special sealant for food barrels, which also causes food contamination. These situations should not happen. As long as the quality is strictly controlled in production, the internal coating quality of the steel barrel can be guaranteed

2. Structural problems of steel drums

steel drums containing grease are often placed in the open air, and some end gaskets react with the contents and lose sealing effect, which is also prone to leakage; In rainy days, the loose bucket mouth is easy to water, which makes the grease sour and deteriorate. This may be caused by the unreasonable structure of our steel barrel at present, because the barrel mouth is lower than the outer edge of the barrel, so the water is easy to seep in. This will not happen if the international standard steel barrel structure is that the barrel mouth is higher than the barrel edge. Therefore, to completely solve this problem, we must implement international standards as soon as possible, introduce advanced technology, and change the unreasonable product structure

3. Surface coating problem

the paint color on the surface of steel barrels is generally black for oil, and blue, green, brown and other colors for chemical raw materials. However, the color of steel barrels produced by steel barrel manufacturers is always somewhat different, so that the color of successive batches of steel barrels is different, which has a great impact on foreign chemical products that pay attention to brand and packaging, and should be avoided as far as possible

it is understood that most of the reasons for this situation are the fault of paint suppliers, who have set up many branches and joint ventures in more than 20 cities in China. They allocate and supply paint to barrel factories by batch, but the colors of different batches are always different, which cannot guarantee consistency. To solve this problem, we must establish a long-term fixed relationship with the paint supplier to tighten the loose parts, and strictly inspect and control the quality of the paint. In addition, in the use of paint, try to mix evenly to make the paint color consistent

4. Steel problem

it is a development trend in recent years to minimize the cost of export packaging steel drums. At present, many manufacturers use coil production, which really saves a lot of costs; In addition, the thinness of materials is also a way to save costs, but it should be enough, and it should be determined in combination with the process and technology status of each family, so as not to cause new quality problems

in order to save costs, some manufacturers use 0.8mm steel plates to make 200 liter steel drums. Of course, this is not impossible in one-time export packaging, but we must consider the actual needs of the goods inside, and we must not use ultra-thin steel plates uniformly. In addition, some manufacturers use steel plates with uneven thickness or serious corrosion to manufacture steel drums, which also causes quality problems to varying degrees. I hope this situation will not happen again