Talking about the quality of steel drums for dangerous goods packaging

Talking about the quality of steel drums for dangerous goods packaging

Xin Qiaojuan

After joining the WTO, China's foreign trade has further increased. In the case of packaging steel drums, the annual steel drums used for the packaging and transportation of dangerous goods are also increasing year by year. It is reported that there were more than 60,000 steel drums used to hold dangerous goods in our province last year, and this year is expected to be around 100,000. However, from the overall situation of China's dangerous goods packaging steel drums, its quality level can not meet the requirements. In the course of transportation, the damage of packaging steel drums often occurs, and sometimes the situation is quite serious. The direct loss of fire, explosion, corrosion and other accidents caused by the damage of chemical dangerous goods every year is as high as several million yuan. The number of claims for dangerous goods exported by foreign trade also showed an increasing trend. Due to the damage, leakage and other causes of packaging steel drums, the amount of claims caused by such accidents far exceeded the loss of dangerous goods. Therefore, how to improve the quality of steel drums for dangerous goods packaging and reduce the quality accidents in the storage and transportation of dangerous goods is an urgent problem that needs to be solved urgently.

Recently, I encountered such a few things in my work that made me anxious:

The first is the 200-liter closed steel drum supplied by our factory to a chemical company. In order to reduce the cost, the thickness of the steel barrel material purchased by the user is 1.0mm and 1.2mm. The thin one is only for short-distance storage. Used; the thicker steel drums are mainly used for long-distance transportation and export of dangerous goods. However, in the use of the user, due to management confusion, the export of dangerous goods is contained in the thin steel drum of the sheet, causing damage to the steel drum and leakage of raw materials;

The second is that the user knows very little about the management methods for the inspection and transportation of dangerous goods. It is believed that the goods in the steel drums can be exported as long as the quality performance indicators meet the requirements. It is not known that the export of steel drums must be subject to exporter inspection and type testing. The series of tests, so often lead to passive and mistakes in the work. Today, I met such a customer. When I pulled the barrel in the morning, I also said that the products were sold domestically, but when I got off work in the afternoon, I called for a commodity inspection certificate, saying that the products were temporarily changed to export. After three days, the goods were sold. Must arrive at the Tianjin port, otherwise it will delay the delivery period, etc.;

Third, the user has a large proportion of dangerous goods, but in order to reduce the production cost, the user blindly adopts a steel drum with a thin material thickness, and the strength of the steel drum itself cannot meet the demand of the product, thus causing leakage. .

In order to reduce the quality accidents in the storage and transportation of dangerous goods packaging steel drums, we must first improve the quality of the packaging steel drum itself. Because a product is produced, used, and used, it is generally subjected to multiple loading, unloading, storage, and transportation processes. In this process, the product will inevitably be hit, dropped, impacted and vibrated. A good steel drum will protect the product well, reduce damage during transportation, and make the product safely reach the user. This is especially important for dangerous goods. So, how can we improve the product quality of steel drums for dangerous goods packaging?

First, we must first recognize the importance of packaging steel drums for dangerous goods.

For a long time, metal container packaging has been neglected due to the influence of the planned economic system. The heads of many enterprises have insufficient understanding of the importance of steel drum packaging, and they are used to bad packaging, and steel drum leakage is more serious. After loading dangerous goods, accidents occur frequently. This ideological contempt has led to insufficient investment in the steel drum packaging industry, low technical content, and backward equipment, processes and tooling. Eventually, the accidents such as metal sodium explosion and calcium carbide explosion occurred on the way of foreign trade export.

Calcium carbide and metal sodium packaging steel drums must have good air tightness, because if the calcium carbide reacts with water in the air, it will produce acetylene gas. When the concentration of acetylene gas reaches a certain level (flash point) and explosive limit concentration, an explosion accident will occur. Metal sodium also chemically reacts with moisture in the air to form strong alkali and hydrogen. Hydrogen is flammable and reaches a certain concentration and explodes. Therefore, when using a steel drum to hold the calcium carbide outlet, it is required to fill the steel drum with 99.99% high-purity inert gas (nitrogen) to protect the calcium carbide from oxidation or reduction. However, there are always some calcium carbide manufacturers who pay insufficient attention to the quality of calcium carbide packaging, and are filled with industrial nitrogen with a purity of 98%. There are also certain quality problems in the steel drums for loading calcium carbide. The barrel body, the bottom of the barrel and the top have different degrees of leakage. The air can be immersed in the interior of the calcium carbide drum at any time. When this kind of calcium carbide was shipped from the factory, the unsafe factors were lurking in the packaging steel drum. As a result, accidents occurred repeatedly during port transshipment, which caused very bad effects.

Metallic sodium also has packaging quality problems when it is shipped from the factory. In general, the packaging steel drums used to hold metal sodium are all open steel drums. If the barrel mouth, barrel body and bottom of the barrel are not tightly sealed, the performance is active. Metal sodium reacts chemically with water in the air. Therefore, when using metal drums to hold metal sodium, in order to prevent explosion accidents, kerosene is generally injected into the steel drum to soak the metal sodium in the kerosene.

Therefore, in order to improve the quality of steel drums for dangerous goods packaging, we must first solve the problem of the knowledge of steel drum packaging for dangerous goods manufacturers. Only by fully recognizing the importance of steel drum packaging for dangerous goods, will the technological improvement and method improvement of steel drum packaging be further promoted.

Second, attach importance to the design and manufacturing process of steel drums and improve the intrinsic quality of steel drums

The steel drums currently used for packaging dangerous goods mainly include small open steel drums and fully open steel drums. The capacity is 200 liters, 215 liters and 230 liters. Small open steel drums are mainly used for liquid and semi-liquid dangerous goods; full-open steel drums are mainly used for containing dangerous goods in powder or granular form.

Due to the different dangerous goods used in steel drums, the performance requirements for steel drums should also be different. The solubility of steel cylinders filled with sealants is not the same. However, at present, most of the steel drums produced in China are sealed at the bottom of the barrel and at the top of the top of the barrel. In order to prevent leakage, sealant is added, and most of them are used in ordinary white latex instead of Use different sealants for different dangerous goods. For this reason, leakage occurs when some organic solvents are contained in steel drums. Therefore, when designing dangerous goods packaging for steel drums, it is necessary to fully consider the characteristics of dangerous goods and design reasonable and appropriate packaging steel drums. For steel drums containing pesticides, when designing and manufacturing, it is necessary to apply two or even three times of sealant. It is strictly forbidden to leak steel tanks and pollute the environment or cause personal injury.

The manufacturing process of steel drums does not meet the quality requirements, which is also the main reason for the damage of steel drum packaging. At present, the main problem of steel drums is that the welding and sealing are not strict in the manufacturing process, and the quality of the inner coating is not good, resulting in leakage of contents, pollution of the environment, and personal health. Take the Tianjin Port calcium carbide barrel explosion accident as an example:

Carbide is commonly known as calcium carbide. It is listed as a Class 1 water-burning item in the "Dangerous Goods Transportation Rules" promulgated by China. After contact with water vapor, it will produce a fierce chemical reaction. Each kilogram of calcium carbide can produce acetylene gas and has 470 kilocalories of heat. The acetylene gas is extremely flammable, and its explosion limit is 2.5%-80%. Therefore, if there is water or steam entering the calcium carbide barrel, acetylene gas will be generated, and the gas in the barrel will explode when it expands. One of the reasons for the explosion of calcium carbide barrels exported from Tianjin Port is the quality of calcium carbide packaging. Since 98% of industrial nitrogen causes moisture to enter. The reason why the calcium carbide barrel explosion occurred in June 1987 was because the sealing of the calcium carbide barrel was not strict. The small nitrogen filling port on the barrel was not matched with the calcium carbide barrel fixing nut, and partially fell off during transportation. In addition, some barrels were visually found to exist. The gap, the barrel has only two layers.

To solve the technical problems in the steel drum manufacturing process, it is necessary to strictly control every link in the steel drum manufacturing process. Dispose of the unqualified processes found in the production process in a timely manner, so that the unqualified processes are eliminated at the station and never flow into the next process. Dispose of the non-conforming products that have been produced in a timely manner, never let the unqualified products leave the factory, prevent unqualified steel drums from flowing to the market, and contain dangerous goods. In addition, new technologies and processes can be used in the production process of steel drums to solve the potential quality hazards that may occur in the backward processing. Because under normal circumstances, most of the problems with steel drums for export packaging are leakage, peeling of the paint on the surface of the steel drum, and leakage of the barrel closure. The main causes of steel leakage, surface paint peeling and barrel leakage are as follows:

1. The mechanical bite is not tight when the steel drum is sealed, and the performance of the sealant is not good.

2. The width of the lap joint is uneven when the barrel is welded, and the welding parameters are unstable, causing leakage after welding of the barrel.

3. The surface of the steel drum is not treated cleanly, and the adhesion of the paint is poor.

4. The sealer is not tightened, causing toxic gas to be emitted; or the sealer itself has a rubber ring and the sealing performance is not good. The lid of the fully open steel drum is covered.

In order to solve these problems, the people in the barrel industry in the country have done a lot of detailed work, and finally reached a consensus and adopted a series of methods:

Firstly, the packaging steel drums used for exporting dangerous goods are all equipped with seven-layer triple-curling technology, and the thickness of raw materials for steel drums is required to be δ1.2mm and above. In the production process, before the sealing, pre-in the barrel A special sealant for steel drum is injected into the bottom and top cover hooks. As the steel drum structure adopts the triple new crimping technology and the thickening of the raw material, the strength performance of the steel drum structure is also strengthened, thereby solving and reducing the leakage problem of the steel drum.

Secondly, under the premise of the availability of funds, the imported automatic seam welding machine is used for welding. However, for most barrel companies, the imported seam welder is unrealistic, and only the current welder is used to meet the production needs. At present, there are successful transformation technologies in China, which can transform the 12mm seam welder produced by Shanghai Electric Welder Factory into a seam welder with a side edge of 4mm and a higher degree of automation. Not only can the welding quality of the steel barrel seam welding be improved, but also the appearance quality of the steel barrel weld seam can be improved, and the leakage of the weld seam and the weld triangle area can be reduced.

Third, the surface of the steel drum is cleaned before washing, that is, before spraying, firstly, the surface of the steel drum is subjected to strong alkali degreasing→one water washing→second water washing→phosphating→drying→spraying. The oil stain on the surface of the steel drum is removed, and the common painting method is electrostatic painting or high-pressure airless painting, thereby enhancing the adhesion and smoothness of the paint on the surface of the steel drum. Due to the change of the painting process of the steel drum, the appearance quality of the steel drum is improved, and the peeling off of the paint on the surface of the steel drum is reduced or eliminated.

Fourth, for closed steel drums, due to poor sealing performance of the sealer, it often causes problems such as the emission of toxic gases and the discoloration of chemical products containing poison. For example, chromic acid anhydride, a dangerous chemical product that is exported in steel drums, is a highly toxic product. In the past, problems such as poor sealing performance of the lid of the barrel and the pollution of the environment caused by toxic gases have occurred. The dangerous chemical raw material used for export is p-methylphenol. It is white or colorless toxic crystal in a closed container below 34 ° C, but the steel drum used for packaging is made into yellow crystal due to poor sealing of the lid. Although its performance has not changed, its quality is inferior. There are also steel drums containing trichloroethylene chemical products. Because of the dissolution of rubber and plastics, trichloroethylene is used in rubber gaskets and plastic gaskets. Both are dissolved, causing leakage of the steel drum. In order to solve this problem, we use experiments to seal different chemical raw materials of different quality with different gaskets. For example, the gaskets and gaskets used in the production of steel drums containing trichloroethylene are made of polytetrafluoroethylene; for steel drums containing concentrated alkali solution, dilute hydrochloric acid, ammonia, ketone, alcohol, ester, ether and other raw materials, The gasket and gasket are made of EPDM rubber; for steel drums containing general raw materials, oil-resistant and acid-resistant nitrile rubber is used. This can solve the problem of poor closure of the closed steel barrel lid. For the sealing problem of the full-open steel drum lid, our barrel makers improved the production process by filling the full-opening lid with a sealing gasket to reduce the leakage rate and improve the tightness by improving the structure of the barrel clamp. Solid. The improvement of the barrel hoop is mainly to change the original plug-type closure for the outlet to a bolt-type type, and to change the original semi-circular barrel hoop to a trapezoidal barrel hoop. With the change of the structure of the hoop and the sealing process of the lid, the sealing of the fully open steel drum is enhanced, and the possibility of deterioration, leakage and explosion of the contents due to poor sealing is eliminated.

Under the strong support and care of the competent authorities of the Export Commodity Inspection and Quarantine Bureau and the Quality and Technical Supervision Bureau, most of the barrel manufacturers, especially the barrel manufacturers that have obtained the export product packaging production license, are constantly in the manufacturing process of the steel drums. The transformation equipment, using advanced production technology and equipment, has greatly improved the quality of steel drums. However, due to the uneven use of packaging steel drums, the packaging steel drums are exposed to dangerous goods, causing leakage, deterioration, pollution and even explosion. Therefore, when using steel drums to package dangerous goods, it is necessary to choose a reasonable packaging method. The higher authorities should strengthen the safety training and relevant business knowledge training for dangerous goods packaging enterprises so that they can understand the export packaging for export packaging. Requirements and work procedures, give full play to the meaning of customer focus in ISO9001:2000, do not blindly require packaging manufacturers to provide such services or services, because some requirements are not in compliance with export commodity inspection rules, will be to the country and Enterprises have caused huge losses.

Third, the development direction of dangerous goods packaging steel drum

With the further development of China's foreign trade, the consumption of dangerous goods packaging steel drums will be further increased. Therefore, in addition to strengthening quality awareness in production and manufacturing, dangerous goods packaging barrel manufacturers should gradually develop towards assembly. Dangerous goods, especially chemical dangerous goods, are flammable, explosive, toxic, and corrosive. They are easy to pollute the environment and threaten human health. The use of collective packaging, the implementation of containerized transportation and mechanized operations, help reduce the risk of personal injury to chemical dangerous goods and strengthen environmental protection, to ensure the safety of freight. In addition, the use of containerized packaging can not only effectively protect the goods, but also make up for the shortage of the packaging steel drum itself, and integrate advanced mechanization operations, especially the door-to-door transportation mode, which is an effective measure to comprehensively control the damage or leakage of the packaging barrel. one. In the form of collective packaging, it can also save packaging costs, reduce packaging costs, and promote the further adoption of international standards for chemical dangerous goods packaging barrels, so that they will not be restricted by the different packaging standards of countries when exporting.

At present, many developed countries and regions in the world, especially in the European Union, use a high proportion of collective packaging and transportation methods. Most of them use international standardized steel drums, ODD-type environmental steel drums, W-shaped ring steel drums, and container-specific packaging steel. In order to be in line with international practices, China should also create conditions. Vigorously develop the containerized transportation of dangerous goods in the chemical industry.