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

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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

 

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

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

How to choose canning machine and sealing machine?

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How to choose canning machine and sealing machine?

(1) Technical requirements for selecting canning equipment

① Whether the sealed tank is an empty tank (open top tank) or a solid tank.

② The shape of the sealed can body and lid.

③ The annual output of the tank (and converted into shift output or output per minute).

④ The size range of the sealed tank (the range of tank diameter and tank height).

⑤ If it is a solid tank, you also need to know the contents and vacuum requirements.

(2) Determination of the type and main parameters of the canning equipment According to the two requirements (1) and (2). in (1), the type of equipment used can be determined.

If it is an empty can or a solid can sealer, whether it is a round can or a shaped can, or whether the shape of the can body and the can lid are consistent. Especially when the shape of the can body and the lid are inconsistent (such as an embossed can), the type of can sealer should be determined according to the shape of the can lid, that is, a canned can or a round can sealer, and then according to the can body The shape of the tank requires the necessary modification of the transport system of the tank body (in general, the design of the tank sealing equipment considers that the shape of the tank body and the lid are consistent, and the difference is only in the size of the tank lid) according to (3) and (4). Two requirements, determine the adaptation range and production capacity of the selected equipment (also consider the matching with the production capacity of other equipment on the production line).

  • Selection of the structure and layout type of the can sealing machine

The actual can sealing machine is usually only vertical due to the need to fill the contents. Empty can sealing machine has horizontal. The distinction between vertical and vertical can be determined according to the working attitude of the can body and the can conveying equipment of other supporting equipment.The horizontal can sealing machine often needs to raise the can body to a higher position, and then rely on gravity. The guide cage dumps the can body to a horizontal state and conveys it to the entrance of the can sealing machine. The vertical can sealing machine does not need to raise the can body, and can use a conveyor belt (or chain) to directly convey the upright can body to the can sealing machine inlet. At present, most of the high-speed can sealing machines are vertical. The vertical can sealing machine has a compact structure and is convenient for maintenance and debugging. It should be given priority when selecting. In the vertical tank sealing machine, whether to choose the sealing wheel type or the track type, the characteristics of the two should be analyzed first. The track type combined machine has a compact structure and a small footprint, but the sealing track is difficult to process, requires high accuracy, and has a high manufacturing cost. At the same time, different tank types cannot be shared. The sealing wheel is simple to process and easy to ensure accuracy.Several tank types can often share one type of sealing wheel, the manufacturing cost is low, and the maintenance and adjustment of the machine are easy and simple.As can be seen from the respective characteristics of the two, the rail type can sealing machine is more suitable Workshop space is limited, and companies that change tanks infrequently use it. In general, more sealing wheel sealing machines are used. The combination of the advantages of the two can sealing machines also has the form of a sealing wheel combined machine, but there is no such product in China. Under the same conditions, the canning machine in the rotating form of the can body should be preferentially selected.The sealing roller of this canning machine can be arbitrarily adjusted with the swing arm, so the diameter of the sealing roller remains unchanged when the tank diameter changes. This allows different tank types to share the same sealing roller. The sealing roller of the eccentric feed can sealing machine can only be adjusted slightly. When the tank type is changed, the sealing roller must be replaced. In the tank body non-rotating can sealing machine, the four sealing roller types are preferred (two for each of the first and second sealing rollers). Because there are many sealing rollers, the crimping quality is high.

(4) Selection of canning machines with different degrees of automation Generally, automatic canning equipment should be selected for large-scale production, and the quality of automatic equipment is stable.

It is not affected by human factors, and the labor intensity of workers is small, and the production capacity is large, so it is more used. For small batches and limited funds, a semi-automatic can sealer can also be used. When the output is not reached, multiple units can be used. Manual can sealing machine is generally only suitable for laboratory use, used for testing can sealing, can also use this can sealing machine to make some sample cans as trial marketing products, so that less investment can be used for market analysis first.

(5) Selection of solid tank sealing equipment In addition to the requirements of vacuum degree, whether to fill with carbon dioxide gas, etc. when selecting solid tank sealing equipment, it is also necessary to consider whether the contents will overflow during the sealing process. Whether the materials are resistant to corrosion and meet food hygiene requirements. Priority should be given to the filling and sealing machine, the reliability of such equipment should be higher than the split equipment, and the cost is lower.

(6) Selection of spray can sealing equipment Spray cans are different from empty cans, and both ends of the can body need to be sealed. So when choosing canning equipment

There are two options. One is to use a horizontal necking, flanging and sealing combined machine.This equipment can simultaneously complete the necking of the tank body and the sealing of the top and bottom cover.It has a compact structure, but its production capacity is low. 60 cans / min, double heads are 120 cans / min; the other option is to use two can sealers to crimp and seal twice, and add a can pouring device and conveying equipment between the two devices.

How to choose canning machine and sealing machine?

How to choose canning machine and sealing machine?

   Factors affecting the quality of can making

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Factors affecting the quality of can making

There are many factors that affect the quality of empty tanks. The quality of materials (including all raw and auxiliary materials), the equipment status and working conditions of each process, as well as the technical level of operators and packaging and transportation have a great impact.

(1) Influence factors of empty tank preparation equipment on the quality of empty tanks. The factors that affect the quality of the cutting board mainly include the positioning accuracy when cutting the board.

And whether the cutting edge clearance is appropriate, the cutting edge is worn. The positioning accuracy of the cutting board is not enough, and the geometry of the cut piece will be inferior. For the gap of the cutting edge, if it is too small, it will be easy to damage the cutting edge. If the cutting edge is too large, it will produce burrs and affect the life of the cutting edge. The quality problems caused by the scribing are mainly the consistency of the scribing depth and the parallelism of the scribing and the edge of the sheet. The radial and axial runout of the scoring blade, the deflection of the guide rail, and the inconsistent size of the blanks will cause the above quality problems.

The quality problems that occur in scraping yellow are incomplete yellow scraping or excessive scraping, which will damage the tin plating layer, and then affect the welding quality. The main reason is the wear of the cutting edge, chipping and the pressure adjustment.

(2) Influencing factors of can body forming and welding equipment on the quality of empty cans In the can body forming and welding equipment, the quality of the plate and the quality of the copper wire, forming, conveying, welding and other processes, insulation, cooling status, etc. will affect the quality of empty tanks.

①Material quality includes the material of the tank body, cutting accuracy and the quality of the copper wire. Mainly the composition of the plate, the amount of tin plating, the degree of quenching and tempering and its uniformity, the thickness of the error surface quality and so on. Copper wire purity, wire diameter tolerance, elongation, surface quality, etc. The dimensional accuracy of the blank angle deviation, the size of the burr, etc.

②Effect of molding The effect of kneading the iron (releasing the surface tension) into a round opening will affect whether the subsequent transportation is smooth.

③ The impact of transportation is not smooth, and the finish of the contact with the tank is not high, which is easy to cause abrasions. The uneven position of the jaws can easily cause welding.

④ The influence of welding includes the adjustment of the sizing gauge itself, the size and relative position of the sizing gauge, the upper and lower welding wheels, and the Z-shaped guide rail;

Adjust the width after flattening, welding pressure and welding current, and match them.

⑤ Other factors affect the reliability of the insulation parts, the temperature and flow rate of the cooling water.

(3) The effect of supplementary coating and drying on the quality of empty cans The coating selection is not suitable, the thickness of the coating is uneven, the width is uneven, and the coating film is too thin

There is exposed iron at the coating, the weld spatter is too large, and the weld overlap is too thick, which is not conducive to repair. If the drying time is not enough, the coating is not completely cured, or the temperature rises too fast, forming air bubbles, and the drying temperature is too high, which causes the tin layer of the can body to melt and the coating film to burn, which will affect the corrosion resistance of the can body.

(4) The influence of beading and slitting on the quality of empty cans. Beading are prone to produce sharp edges, and the oxide layer and coating film at the weld seam of the tank body are broken.

Bad, the can body is scratched. The slitting machine is prone to uneven cuts, end-to-end contact, and abrasion of the tank body. The above phenomena are directly related to the accuracy of mold or tool manufacturing, wear and tear, and installation and adjustment.

(5) The effect of necking and flanging on the quality of empty cans. Necking is prone to wrinkles, uneven necking, abrasion, and difficulty in demolding. Flanging is prone to uneven width, excessive or insufficient flanging, inconsistent ends, flanging damage, cracks at the weld, etc. The main reasons for the above phenomenon are: the mold dimensional accuracy is poor or worn, there are problems with the installation and adjustment of the mold; the ends of the weld are too brittle, there are too long tongues, and the cutting size is not accurate.

(6) Factors affecting the drawing quality of two-piece cans The factors affecting the drawing quality of two-piece cans include the pressure of the blank holder ring, the radius of the fillet radius of the concave-convex die, the choice of the lubricant, the drawing coefficient, and the drawing process The pressure applied by the blank holder ring, such as the stress state of the material, must be appropriate and uniform. Excessive friction will increase the friction between the die, which will easily rupture the part; too small will cause the drawn part to lose stability and cause wrinkles. The pressure can be adjusted during drawing until it is suitable. Using reverse drawing or soft die drawing can increase the radial tensile stress and avoid wrinkling.

   Factors affecting the quality of can making

Factors affecting the quality of can making

three piece can manufacturing process？

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A three-piece can is also called a seam can. It consists of a can body, a can lid, and a can bottom. The material used is mainly tin-plated sheet steel (tinplate and chrome-plated sheet steel).

Since the advent of canning in the early 19th century, three-piece cans have been used as the main packaging container in the food canning industry. The three-piece tinplate cans produced in the early days, whether it is blanking, molding, or the sealing of the can body, as well as the bottom and sealing, are performed manually.All seams are sealed by soldering, which has a very low production efficiency. . With the development of industry and technological progress, the welding technology has also been continuously improved: the advent of automatic can welding machines has eliminated the manual operation of the welding process; the invention of the flanging sealing machine and the use of liquid sealants have made it appear in the early 20th century The sealing (bottom) technology of the “double crimping” has gradually realized mechanization, and the production speed has continued to increase. However, since the advent of the three-piece tin can for more than 100 years, tin solder cans have always dominated.Since tin solder contains a large amount of heavy metal lead, it poses a serious threat to the food hygiene in the can, so the side seam bonding method and Welding of side seams (ie resistance welding). Now resistance welding has become the most important method for manufacturing three-piece cans of food, and soldering has been basically eliminated.

In addition to the widespread use of cans in the canning industry, three-piece cans are also widely used in other industries such as chemical industry and daily necessities. Their structures are the same, but they are different according to the requirements of use, or the structure is appropriately deformed, or a certain structure is added with appropriate accessories. For example, metal cans used for tea, biscuits, candy, solid beverages, and metal cans containing cooking oil, liquid beverages, and chemical products, are basically the same as ordinary three-piece cans.

Since China established its first cannery in 1906, the production of three-piece cans has been limited to the food canning industry. More than 20 years of reform and opening up, China’s canning industry has also developed rapidly. In addition to domestic manufacturers that can provide domestic automatic canning equipment, it has also introduced more than 100 advanced automatic canning production lines from abroad. There are hundreds of iron can manufacturing enterprises in China, and the production capacity has ranked among the top in the world. It can produce a variety of metal cans to meet the needs of the development of the national economy and the improvement of people’s living standards.

The process flow and characteristics of the three-piece can manufacturing process are as follows:

Cutting→ (scribing) → rolling → tack welding → internal and external coating→ drying → (cutting), (rolling), (neck),(Bulging), (Embossing) → Flanging →bottom seaming → Leak detection → (Full internal spray) → (Drying) → Stacking and packaging

The bracketed parts in the above steps can be configured according to the needs of the tank type.

Characteristics of resistance welding process: seam welding of the can body does not require brazing, which fundamentally eliminates the pollution of lead to the food in the solder and saves the solder; the strength of the weld is high and the seal of the weld is good; the weld overlap is small (0.25 -0.8mm), saving raw materials, narrow welding seam, especially after adding gas protection at the welding seam, the appearance is more beautiful and beautiful; the thickness of the welding seam is similar to the thickness of the tank body plate, about 1.3 to 1.5 times, which is convenient for flanging, necking, Sealing; high sealing quality, good air tightness of the can; fast production speed, up to 1000 cans / min.

Three-piece can production line equipment classification Three-piece can production line manufacturing equipment is divided into slitting equipment, expanding and welding equipment, coating equipment, dry equipment, rolling equipment, straddle cutting equipment, necking equipment, bulging, embossing equipment, flanging equipment, cap making equipment, can sealing equipment, leak detection equipment, full internal spray equipment, drying equipment, stacking equipment, packing equipment, etc.

three piece can manufacturing process？

three piece can manufacturing process？