What are the functions of tinplate inner coating?

What are the functions of tinplate inner coating?

(-) Coating purpose and requirements

Tinned plate, chrome plated and aluminum alloy thin plate made of cans are susceptible to corrosion and cause the contents to deteriorate. Therefore, most food cans require coatings inside the cans. Different food cans have different coating requirements.

  1. Purpose of coating

(1) Protein-rich aquatic products, poultry and meat cans use anti-sulfur coatings to prevent sulfidation corrosion caused by thermal decomposition of proteins, such as vulcanization spots and iron sulfide.

(2) The acidic tomato sauce and pickled cucumber adopt acid-resistant paint to prevent acid corrosion of the cans and ensure that the canned food has a certain shelf life.

(3) Certain anthocyanin-containing fruits, such as strawberries, cherries, and bayberry, use general coating material to prevent anthocyanins from corroding cans and contents from fading due to tin reduction

 

(4) Steamed fish and luncheon meat are easy to stick to the cans. The coating containing anti-sticking agent makes the contents easy to pour out and keep the shape complete and beautiful.

(6) Canned beer coating material is (spraying after weaving) to eliminate pores and prevent iron ions from dissolving, which affects the flavor and transparency of beer.

  1. Coating requirements

(1) The coating should be non-toxic after film formation, without affecting the flavor and color of the contents.

(2) After the coating film is formed, it can effectively prevent the contents from corroding the cans.

(3) The coating has good adhesion after film formation, has the required hardness, punch resistance and solder heat resistance, etc., which can meet the requirements of can making process.

(4) After sterilization of the canned product, the coating film will not change color, soften and fall off.

(5) Convenient construction, simple operation, and a good coating film can be formed after drying.

(6) The coating material and solvent price are cheap.

(7) The coating material has good storage stability.

Tips for making tinplate lids

Tips for making tinplate lids
The selection of can lids making equipment should first consider product specifications, output scale, quality requirements, followed by is equipment costs, labor costs, operating costs, plant conditions and other factors.
Generally speaking, for the production of metal covers with few specifications and varieties, large output, and high quality requirements, equipment with high production efficiency and high degree of automation should be selected, such as various types of multi-function combined machines configured as automatic production lines. Due to the small specifications, it is not necessary to change molds and debugging equipment frequently, and it is easy to take advantage of the large-scale production of high-speed automatic production lines to avoid the damage caused by the handling of semi-finished products in the semi-automatic production process. At present, more advanced lid-making equipment can be provided in China, such as corrugated plate shearing machine, double-head automatic punching machine, glue injection drying combined machine, etc. For the production of special-shaped lids with quality requirements, it is best to choose a full lids curl machine to improve the sealing quality. The small size special-shaped cover can be directly selected the automatic curl & glue lining combined machine.The large-size special-shaped cover lining machine is relatively in low production speed. So, For large-size lids lining can use multi-gun semi-automatic lining machine or automatic lining machine. The dryer can be preferred to use a vertical dryer, and its drying quality is better than that of tunnel dryer. For products with many specifications and a lack of large quantity demand, and the production of metal covers with general quality requirements, you can consider choosing multiple semi-automatic stand-alone equipment.On the one hand, you can reduce the number of mold replacements and machine adjustments.On the other hand, you can also reduce the equipment. Investment costs. The rounded edge of the special-shaped cover can be considered to use half-curl or full-curl. As far as possible, the glue injection should not use the printing glue that is facing elimination. The tunnel dryer is suitable for any size and shape of metal cover, but it covers a large area and has high energy consumption. The drying quality is not as good as the vertical dryer, and it needs manual loading and unloading. The aluminum easy-open cover has fewer varieties and specifications, but the output is extremely large, so it requires a high-speed large-scale automatic production line, which is not yet available in China. The current demand for tinplate full opening is relatively small. The production capacity of domestic production lines has reached more than 80 pieces / min. The product quality also meets the requirements for use. Compared with similar foreign products, the price is low and should be preferred.

How much do you know about tinplate cans?

(1) Classification by material

Can be divided into two major categories of steel and aluminum. The steel series mainly includes low-carbon thin steel plate, tin-plated thin steel plate, chrome-plated thin steel plate, aluminized thin steel plate, galvanized thin steel plate, etc .; the aluminum series mainly includes aluminum alloy thin plate and aluminum foil.

(2) Classification by material thickness

For plates and foils. The sheet is mainly used for manufacturing packaging containers, and the foil is mainly a component of the composite material.

 

The development history of metal packaging materials

The application of metal packaging materials began in 1200 AD. At that time, Bohemia, Czechoslovakia produced tinplate, but its production technology was not spread until 1620, when the Grand Duke of Southern Germany obtained the technology. Metal packaging has only begun to be widely used. In the latter part of the 17th century, people began to use tinplate to make metal buckets to hold dry food. In the 18th century, people began to use food cans to store food. In 1809, a chef and confectioner Nicholas Appert in Paris invented a can storage method, that is, to put food in a wide-mouth bottle, cover it with a cork stopper, give enough temperature to heat sterilize and remove the air, then seal Method can save food for a long time without corruption. In 1810, the British Peter Durand invented the technology of storing food in tin cans using the above principle, and tin cans were born. Before the Second World War, with the improvement of rolling technology and the invention of metal can making machines, the output of tinplate increased greatly. After the Second World War, due to the shortage of tin resources, in order to save tin, people developed tin-making materials or tin-free tin-making materials. As a result, poor-thickness tinplate, low-tinplate, and tin free thin steel plate came out one after another. In the 20th century, with the improvement of aluminum metallurgy technology, the improvement of rolling technology and the appearance of aluminum foil, aluminum began to be widely used in the packaging industry.

In recent years, the can-making technology has developed rapidly. It started as a three-piece can consisting of three parts: the can body, the can bottom, and the can lid.Later, the can body and the can bottom joined together and the can lid was composed of two parts. Tablet cans. The traditional three-piece tin soldering can uses tin-lead solder to weld the seam of the can body, which consumes much tin, and the lead content in the solder can contaminate the built-in food. With the appearance of tin free thin steel plate, people have successfully developed seam welding process. The process of seam welding cans is based on contact resistance, electric heating and melting, and then applying pressure to weld the can body. Later, there emerged a bonding can, which uses organic adhesives to bond the can body seam making process. Both of these methods eliminate the pollution of lead to the food in the can, and solve the problem that the tin-free steel plate cannot be tin-welded. They are widely used in the packaging of beer and carbonated beverages. The modern and advanced three-piece can manufacturing methods mostly use the seam welding method and the bonding method. It has broad development prospects, and tin solder cans have been eliminated in advanced countries such as Europe, America, and Japan. With the widespread use of aluminum in packaging, two-piece cans have appeared. Its structural integrity is strong, easy to decorate and print, and soon occupied the beverage packaging market. However, the production of aluminum consumes a lot of electric energy and its high price limits its usage. However, with the continuous improvement of the can-making process, two-piece cans have been successfully produced using tin-plated thin steel plates and tin free thin steel plates, and automated production lines have been used in industrial production to greatly improve the efficiency of can-making( It can reach 400 cans / min; the production speed of two-piece cans can reach 800-1200 cans / min), so the application prospect of metal cans in packaging is still very optimistic.

Which materials are better for the packaging of tea tin cans?

In the tea market, tinplate cans are what consumers are most keen on, so which materials are better? We understand from the following points.

Main properties of metal packaging materials

(1) Advantages

①The metal packaging material has high strength. Therefore, the wall thickness of the packaging container can be very thin, so that the weight is light, the strength is high, and it is not easy to be damaged.

For storage and transportation, it has good protection for commodities.

②The metal packaging material has an unique luster, which is convenient for printing and decoration, and makes the appearance of the product beautiful and gorgeous. In addition, metal foil and gold-plated film are ideal trademark materials.

③Metal packaging materials have good comprehensive protection performance. Metals have low permeability to water and gas, and are opaque, which can effectively avoid harmful effects such as ultraviolet rays. It has good comprehensive performance and can maintain the quality of the goods for a long time.Some packages are valid for up to two years.

④ Metal packaging materials are rich in resources and have good processing performance. The recoverable amount of steel on the earth is 1294 × 10 ° t, ranking first, followed by aluminum, which is 68 × 10 ° t. Metal packaging materials can be processed with different methods to produce containers of different shapes and sizes.

⑤The production of metal cans has a long history and the process is relatively mature. Now it has automated production and high production efficiency.

2) Disadvantages

①Pb and As in metals and solder easily penetrate into food and contaminate food; in addition, metal ions will also affect the flavor of food.

②When the metal container uses phenolic resin as the inner wall coating, if the processing technology is improper, it will also affect the quality of the food.

Main properties of several major types of metal packaging materials

(1) Steel

With rich steel resources and low production costs, it ranks first in metal packaging materials. The main properties of steel used as packaging materials are good comprehensive mechanical properties and certain corrosion resistance. In order to meet the requirements of comprehensive mechanical performance, the packaging steel plate mainly uses low-carbon thin steel plate, which is used to manufacture containers, ordinary steel drums, and can also be used as a strapping material, which is widely used in transportation packaging. In order to ensure the requirements of corrosion resistance, tin, chrome, aluminum, galvanization and the application of corresponding coatings can be carried out on the basis of low-carbon thin steel plates to improve their corrosion resistance. Can also be made into sales packaging containers, widely used in food, medicine and other packaging

Why do biscuits generally use tinplate cans?

People’s life and production are inseparable from packaging, because packaging has multiple functions. Why do biscuits generally use tinplate cans? Can we understand from the following aspects?

(1) Protection function. The protection function of the packaging is the most basic and the most important function. It should protect the product from damage and loss. In the circulation process of goods, the factors that cause harm to them are: environmental conditions, such as temperature, humidity, gas, radiation, microbial insects, rodents, etc., which may damage the packaging and harm the product; human factors, the goods are transported, During storage, due to careless or improper operation, the goods are damaged by shock, vibration, or fall, or they are crushed due to too many stacked layers. Therefore, according to factors such as the shape, characteristics, transportation environment, sales environment and other factors of different products, the most appropriate materials, reasonable design of packaging containers and technologies should be given to the packaging to provide sufficient protection functions to protect the safety of the products inside, and the special use of dangerous goods Packaging, pay attention to prevent its damage to the surrounding environment and people and creatures.

(2) Convenience function Modern product packaging can bring many conveniences to people, which plays an important role in improving work efficiency and quality of life. The convenient function of packaging should be reflected in the following aspects.

①Convenient production For mass-produced products, packaging should meet the needs of mechanization, specialization and automation of production enterprises, taking into account resource capacity and production costs, and increase labor productivity as much as possible.

②Convenient storage and transportation For the quality and volume (size, shape, etc.) of each packaging container, the convenient loading and unloading of various transportation vehicles should be considered for stacking; also consider that the quality of manual loading and unloading of goods generally does not exceed 40% of the worker’s weight (limited to about 20kg), etc .; at the same time, it should also consider the storage and stacking method of storage and transportation into warehouses, shops, and residences during circulation Indoor decoration and storage during the process.

③ Convenient use of suitable packaging should make consumers feel convenient when opening, using, storing and storing. Such as carton sealed with adhesive tape, cans, spray packaging, portable packaging, etc., in a concise language or icon, to explain the precautions and methods of use to consumers to facilitate the use.

④Convenient handling means that some packages have the function of repeated use. For example, the recycling of various materials, glass bottles for beer and beverages, and the recycling of packaging waste (paper packaging, wooden packaging, metal packaging, etc.) are convenient for environmental protection and conducive to resource conservation.

(3) Selling functional packaging is like a silent salesman. Good packaging can attract consumers ‘attention and stimulate consumers’ purchases. The sales function of packaging is achieved through packaging design. Excellent packaging design, with its exquisite shape, reasonable structure, eye-catching trademarks, decent text and bright colors and other artistic language, directly stimulates the purchase desire of the consumer lunch, and leads to purchase behavior. Some packaging also has potential value, such as beautiful and suitable packaging containers, which can be used to hold other items after the contents are used up. Uniquely shaped containers and beautifully printed decorations can not only increase the selling price of goods, and promote the sale of goods. At the same time, it can also be collected as an art appreciation.