It mainly produces thin plates with a thickness of 0. 15mm- several mm without specifications.
It is classified by thickness.
Tinplate: zinc, iron alloy (zinc is coating)
A brief history of tinplate development/
18 10: The world's first tinplate can was invented by the British and patented.
At that time, a can-making expert could make 60 empty cans a day.
1900: invention of electric welding machine.
1847: American invented can-making machine to replace manual labor.
1965: the aluminum easy-to-open lid began to be used to make cans.
1973: iron easy-to-open lid was used to make cans.
1990: improve the canning process and produce more than 1 0,000 cans per minute.
The origin of tinplate name/
Tinplate was called tinplate in the early days, and its official name should be tinned steel plate. Because the first batch of foreign iron in China was imported from Macau in the middle of Qing Dynasty, Macau was transliterated as "Ma Kou" at that time, so China people generally called it "Tinplate".
Characteristics and advantages of tinplate
1. Opacity/
In addition to food deterioration, light can also cause changes in protein and amino acids. However, after being exposed to light, vitamin C is more likely to interact with other food ingredients, causing a lot of losses. According to research and analysis, the loss of vitamin C in transparent glass bottled milk is 14 times higher than that in dark bottled milk. Light will also cause oxidation smell in milk, and the loss of nutritional value due to the cracking of nuclides and methionine. Opaque tin cans make the preservation rate of vitamin C the highest.
2. Good sealing performance/
The barrier of packaging containers to air and other volatile gases is very important for preserving nutrition and sensory quality. Comparing various fruit juice packaging containers, it is proved that the oxygen permeability of containers directly affects the browning of fruit juice and the preservation of vitamin C. Metal cans, glass bottles, laminated aluminum foils and cartons with low oxygen permeability can better preserve vitamin C, among which iron cans are the best.
3. Reduction of tin/
Tin in the inner wall of tinplate will react with the residual oxygen in the container during filling, reducing the chance of oxidation of food components. The reduction of tin has a good preservation effect on the flavor and color of light-colored fruits and juices. Therefore, canned fruit juice packed in unpainted tin cans has better nutrition preservation, slight browning, better flavor quality acceptability and longer shelf life than canned fruit juice packed in other packaging materials.
4. Provide an effective source of iron/
Tinplate canned food, except for a few light-colored fruit and juice cans, mostly uses empty cans painted inside to improve the corrosion resistance of containers; Due to the electrochemical action of metals, a small amount of iron will be dissolved from painted cans during storage, and it exists in sealed cans in the form of bivalent iron, which is easily absorbed by human body, and the content is about 1 ~ 10 ppm. As far as fruit and vegetable products are concerned, the iron content of raw materials is not much. Iron can products can provide 1.75mg of iron, which is about one tenth of the daily intake 18mg based on the iron content of each 350 ml beverage can. If canned fruit and vegetable juice drinks are rich in vitamin C, iron is more easily absorbed, so canned food and drinks are good sources of iron, which has far-reaching significance for providing nutrition for canned food.
Because of these characteristics, tinplate can provides a closed system, which is completely isolated from environmental factors except heat. Color-avoiding foods will deteriorate due to light, oxygen and humidity, and will not be weakened by aroma or changed by environmental odor. The storage stability of food is better than other packaging materials, with the highest preservation rate of vitamin C and the best preservation of nutrients.