Factors affecting the quality of can making

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?

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?