Early, cans are made of aluminum materials, aluminum cans, small density, high strength, not easy to corrosion, cheap price. But aluminium reacts easily with carbonic acid, can produce adverse reaction to human body, change steel qualitative easy to pull so can now.

Sprite, coke, beer and a class of cans is also called two cans, the whole packaging cans by the body and the lid of the cans, so called two cans.

Advantages and disadvantages of two cans

The sealing of two pieces of cans is good, the tank body is directly formed by the punching process, no welding seal, beautiful shape at the same time to avoid the lead pollution of tin cans, and high temperature sterilization resistance, can ensure product hygiene, only two pieces of cans have two parts, and the manufacturing process of the tank body is simple, to simplify the process, improve the production capacity is of great benefit. The tank body of the two-piece tank is formed as a whole. There is no longitudinal seam of the tank body and joint with the bottom of the tank, which also saves materials. However, two-piece cans have higher requirements on material performance, canning technology, canning equipment, etc., and fewer types of filling materials.

The sad history of Chinese cans

One of the main materials of the cans is what we call tinplate, it also has a higher scientific name pretend bility called electroplated tin sheet metal, refers to the commercial pure tin coated on both sides of the cold rolled low-carbon sheet steel or steel belt.

Before 1998, domestic tin plate, especially food grade, all rely on imports from South Korea, Japan, the price was as high as 8,000 yuan a ton. To ease domestic demand, production began in China after 1998, pushing prices as low as 5,000 yuan a ton. But despite the low prices, food companies have refused to use chinese-made products.

Over the past 20 years, China has grown from 400,000 tons in 1998 to 1.2 million tons today and exported to other parts of the world.

Production and application of tinplate

The main production process of tinplate is: pickling low-carbon thin steel plate, tin plating, soft solution treatment, passivation treatment, oil coating, inspection, cutting, classification, packaging.

Tinplate main packaging applications accounted for: food cans accounted for 33%; Beverage cans accounted for 12%; Cover accounted for 7%; Air mist tank accounts for 5%; Miscellaneous tanks accounted for 40%; The other three percent.

The main production plant of our country tinplate includes baosteel, wuhan iron and steel, anshan iron and steel to wait, our country imports certain amount every year at present, the main country that export on the international has Japan, Germany, France, Russia, Australia to wait.

At present, the general trend of packaging tinplate development: one is to reduce the thickness of the material, the other is to improve the mechanical properties of the material.

In terms of reducing the thickness of tinplate substrate, at present, 0.15mm tinplate has been used for cover making in China. Some cold-rolled plate companies have announced that they can produce 0.12mm cold-rolled plate for cover making industry.