Properties and Application of Package Steel Plate

Metallic materials are found in humans and the use of one of the oldest materials in our country and some developing countries, still occupy the dominant position of industrial materials . Metallic materials are commonly used in one of the four major packaging materials , along with modern metal container forming metal coating technology and the development of technology , and its packaging materials industry plays an important role.Below the production and processing of food packaging containers commonly used features and performance thin steel sheet for an introduction of steel barrel making machine.
At present, the packaging is mainly thin steel sheet , hot-rolled by the rolling can be divided into two kinds of steel sheets and cold rolled steel . Packaging used mostly for ordinary carbon steel and low alloy steel hot-rolled steel made ​​of sheet steel , to enhance its corrosion resistance , and usually require surface coating treatment. In accordance with the coating metal can be divided into tinplate , chrome-plated steel sheet , galvanized sheet steel three kinds .
Tinplate
Tinplate tinplate commonly known , is a low-quality surface tinned steel sheet to hot-dip tinning process is called hot-dip tin plate ; with tin plating process is called electroplating tin plate . Corrosion resistance of the tin plate increased, ductility , workability is further improved . This is because after the tin plate , steel and the inner layer is formed between the outer layer of tin Sn alloy layer of dense , thin alloy which has good corrosion resistance. Developed in Japan pre-nickel steel sheet , in addition to improve the weldability of the original plate , but also improve the corrosion resistance of the original plate and paint adhesion . Another first in the original plate coated with chromium (100mg/m2), and then coated with a layer of tin (0.1 ~ 0.3g/m2) made ​​of chrome-plated tin layer plate. This steel weldability and corrosion resistance, reduced paint costs can be high temperature short time baking. Special packaging tin tin plating process using insoluble anodes way , simple technology , high efficiency, coating uniformity , strong, and can achieve positive and negative plating different thickness of the coating , avoid hot dip caused by the need to contain phosphoric acid , chromium emissions of toxic waste , thus saving wastewater treatment costs, reduce environmental pollution .
Tinplate packaging applications often also in the inside of the container that is made ​​from materials in contact with the coated side coating , after drying and then packaged foods and other contents . The coating dense, uniform , the surface of tin plate with good adhesion , easy to fall off during processing and damage. This coating raw materials are mostly epoxy resin, phenolic resin , food is not contaminated , harmless to human body , but also has good corrosion resistance, can prevent food oil, medium deterioration, thus effectively protecting the quality of food . Tin cans welded using high frequency resistance welding techniques can reduce the pollution, but also can improve the quality of welding.
The biggest feature is tinplate corrosion, easy processing, can be washed into type , but also welding , easy device and printing , and non-toxic , harmless, it is suitable for a variety of food , beverage, pharmaceutical packaging , mainly for canned food packaging materials.
In recent years , the French steel company first developed a new type of packaging tin , and put into the market , causing a revolution in the packaging industry . According to the different requirements of the packaging industry , material thickness tinplate , tin content , mechanical properties, and others have different needs. Currently , in Europe, to produce three-piece cans are the material thickness of 0.13mm ~ 0.21mm, can not only save the steel , reduce costs , and the product is not reduced requirements in all aspects .Statistics from the European countries , due to reduced material thickness , businesses receive 20% of revenue , compared to the price of cans reduced by 3 % to 4% gains much higher. Currently , France tinplate production accounts for 40% of the European market , and is growing at a rate of 8% , the main reason is the development of special materials for different purposes . In Europe, some companies have started production of tinplate cans two cans, and the device has been no great changes , is still in use two cans of aluminum production facilities . And to steel and aluminum cans , costs can be reduced by 15 % to 18% , the mechanical strength of the tank by 60 % or more.
Currently, the development of tinplate packaging general trend is: reduce the thickness of the material to improve mechanical properties of materials . Special packaging tinplate products are three main types of tin cans , spray cans and tin cans cosmetics , cover and crown cap closure with tin , paint and chemical product containers with tin , two tin cans , tin and other special purpose packaging .
1 tinplate beverage cans . This beverage cans is characterized by high purity tin , no impurities, more corrosion resistant ; drawing width of up to 1200mm; modeling is very Zhou Zheng , size small error ; continuous annealing , good toughness. It is guaranteed on the basis of good performance tinplate can greatly reduce its thickness, so that tin has excellent mechanical properties and plasticity.
2 horses Nippon Steel food cans . Currently , in Europe produced a series of tin for the production of different types and shapes of food cans . These are continuously coated tinplate tinplate ( DRD coating tank for tank bottom ) , easy open with tinplate, tin cans stretch . Which for the production of ultra-thin tinplate cans and crown caps , so open the bottle is very safe and reliable.
3 spray cans and tin cans cosmetics . Packaging for the manufacture of high pressure tinplate aerosol cans , make this vessel in line with international standards and the environment.
4 coatings and chemical products tinplate containers . As special packaging tinplate has excellent impact resistance and flame resistance, use these containers to packaging coatings and paints , not only toxic substances transportation, storage of the relevant provisions , but also enable manufacturers to save a lot of insurance costs.
5 special purpose packaging tinplate . Special purpose packaging tin has good printability, most suitable for the printing of various containers .
Chrome-plated steel
Chrome -plated chrome-plated mild steel plates called , which is to reduce the amount of tin , reduce production costs and the new developed alternative materials tin plate , also known as chromium or tin-free steel sheet steel Wuxi . Chrome plate poor corrosion resistance , paint coating must be approved prior to use. Chrome coating plate after coating , the coating adhesion large , suitable for the manufacture of food cans and bottom punch cupping. Wuxi tin plate relative to the following advantages and disadvantages:
1 The advantage of tin-free steel
( A ) plating is less , so the cost is relatively low
( 2 ) Coating adhesion is good . Honeycomb surface oxide film and containing -OH isogenic , and thus the adsorption ability of the coating , wettability is very strong,
The same kind of paint adhesion on the tin 2 times to 5 times , and will not appear prone to leakage painted tinplate fish eyes or called crater.
( 3 ) the temperature is good , does not appear tinplate cold " tin plague " phenomenon.
( 4 ) has a high sulfur resistance , high alkali resistance. Because chromium and chromium oxide and sulfur and a base are not so good resistance to sulfur and alkali resistance , not vulcanized black, while its atmosphere, organic solvents, oils with good corrosion resistance etc. .
(2) tin-free steel tin shortcomings with respect to
( A ) adverse spot chromium layer , which require special welding equipment or removing chromium layer welding, welding method generally used for cans and bonding seams . ( 2 ) the oxide film is thick , ductility will be worse. ( 3 ) bad acid corrosion resistance , high acid-resistant paint coating is normally required in order for the acidic environment .
Wuxi plate chrome two-step process using a low concentration of plating method not only reduces the chromium consumption , but also reduce the amount of waste water treatment , help reduce the environmental load , and its thin and uniform coating , relatively low cost.Chrome-plated steel is currently the main application areas beer bottle , beverage, food cans, paint neutral lid for food cans , little. The extensive use of foreign printed Wuxi internally coated outer plates for meat and fish tank , especially two cans, give full play to Wuxi plate excellent resistance to change and sulfur black paint adhesion advantage.
Galvanized steel
Galvanized steel , commonly known as white metal is zinc coated low carbon steel sheet .Zinc coating is a protective coating to protect steel from the atmosphere in the course of the corrosion . Galvanized go through the passivation layer is generally in chromic acid or chromate solution passivation passivation film formed after the difficult role with moist air , anti-corrosion ability. The zinc soluble in acid or alkali and easily with sulfide reaction, suitable for packaging acidic, alkaline or sulfide product .