The production of cans is basically a rectangular or round container made of Aleppo or aluminum foil with a maximum packaging capacity of 5 kg. Food cans are a type of packaging to protect food, or in other words, it is a system that stores its container goods. It preserves it between production and consumption and protects it from various damages..
The types of cans in terms of the weight of their container products include the following:
5000g can 2000g 1000g 500g 500g short (diameter 99cm), 400g can (height 85 and diameter 73mm), 330g can (for juice), 275g can (for tuna), 175g cans and 300, 200 and 70 grams stretch cans below shows the classification of metal cans.
The shape of the production of cans is usually cylindrical in appearance and consists of three parts, the head and the bottom, the two parts of which are completely similar to each other.
The outer surface of the head and bottom can have a tin coating equal to 8.2 grams per square meter if it is covered with a secondary coating of rust-resistant lacquer, otherwise, the minimum tin coating is determined to be 6.5 grams per square meter. Cans should have a coating of varnish resistant to physical and chemical factors.
In general, the varnish should not contain any toxic substances and should not create toxic compounds in the contents of the can, and solvents should be ineffective on it, should have sufficient adhesion to the can and against physical damage caused by transportation on the outer surface of the can. It should be resistant and not brittle.
Regarding cans of green beans and green peas, due to the presence of protein substances, sulfur varnish and its thickness should be strictly observed. The cans that are produced are usually open and when the lid is connected to the body and the lid is closed when the can is filled with food. The lid of the can should be closed through a double lid so that the two edges of the body are locked together.
Uses and uses of the product
Metal cans, including canned cans, etc., are used to pack food in order to protect it from spoilage factors, increase the shelf life of food, and make it easier and faster to transport.
Examining alternative products and analyzing their effects on product consumption
Today, the can as a leader and a type of packaging due to its ease of use, high strength, attractive appearance, and flexibility in terms of use.
Production line of cans
Nowadays, metal containers as a part of food packaging in different forms are integrated with people’s daily life and all the people of the society face one or more of their different forms in most of their daily uses.
In general, metal packaging has different forms, such as cans, soda cans, aerosol cans, aluminum tubes, sprays, paint cans, medical products, chemical packaging, food and industrial oil cans, barrels, gallons. And … that steel sheets and aluminum sheets are the main raw materials of this industry.
The steel sheets used in the food packaging industry have a coating of tin with a specific thickness on both sides of the sheet, and in other materials, both aluminum and steel sheets are used to protect the wall of the metal container and its contents with a polymer coating called varnish on the inner surfaces. They have that the type of varnish depends on the type of content of the packaging container.
Metal can production steps:
With the first methods, a good and skilled Garger produced four cans per day, while today the production speed of advanced canning lines even reaches more than a thousand cans per minute.
During the years after the canning industry, many changes have been made in the machines and knowledge of this technology, and we are always witnessing progress and hearing new news in this field. , the emergence of various forms of launching, known as easy to open, in them, along with reducing the weight of cans, are the main indicators of the progress of canning.
Methods of producing metal cans
The production of canned tins made of coated tin sheet, contrary to the public opinion that it is easy, requires many new skills and modern technology. The precision and dimensions of the parts in the production equipment and machines have a tolerance of a few microns, which makes this industry It belongs to the precision industries group. The most important types of cans are food or non-food metal cans in two pieces or three pieces.
1-Varnishing of coated tin sheet in the varnishing line
2-Cutting the parts of the can body in the double scissors machine
3- Can body cylinder production in the body making machine
4- Covering the weld of the body from the inside with powder or varnish in an electrostatic way to protect this part of the food
5- Baking and sticking the powder or varnish outside the seam to the body cylinder in a special oven
6- Carrying out operations: dividing the body, making it curved, changing the shape of the cross-section of the can, turning the edge of the body, sewing the bottom to the body, which is used in one or more stages in one or more machines according to the needs and type of equipment at the end of the production operation. Done . The points of interest and problems and limitations related to the coated grain sheet in the can industry are briefly as follows:
1- It is necessary to carefully observe the specifications of the consumable sheet suggested by the machine manufacturer in the can body making machines, especially the high speed machines.
2- It is mandatory to observe rolling in the can body production line with resistance welding method.
3-Non-observance of dimension tolerances in a bundle of sheet, varnishing operation, creating a precise strip without varnish and cutting the body with scissors will cause problems.
4- The operation of turning the edges for sheets with hardness higher than the specified limit is done by rotary grinding, while this operation is done with a new method for sheets with temper and low hardness, the cost of parts and equipment of the rotary method is much higher than the second method.
The return behavior of the sheet spring under the same conditions in terms of parts and production machines changes with the change in the hardness of the sheet, and the sewing factors of the can reveal changes as the most basic quality factor of the product.
The profile of the parts used to create the bends in the body of the can is fixed and the sheet hardness changes have a significant effect on the depth of these bends and as a result the moment of inertia obtained and the resistance to the internal pressures of the filled can.
5- Most of the machines of the can industry in Iran are fed with tin-plated tin, and due to the lack of lacquer and chop-rolling facilities in the country, this type of product is not used directly.
6-Tin: Research shows an increase in welding current.
الف – Two-piece can
1-A long two-piece can that is formed by the process of vatting the sheet in a tension mold, and the bottom and the body are made of the same material.
2- Two-piece stretchable cans: Two-piece cans are produced with less stretch and material flow into the mold, and the body and bottom of the can are made of the same material.
Two-piece can production steps
1-Varnishing of coated tin sheet in the varnishing line
2-Cutting body sheets in zigzag or simple form or cutting body in sheet feeding method
3-Feeding the coated sheet into the press and producing two-piece stretchable cans is returned in a special press, which combines the stretching and retraction of frills cutting and turning the edges.
Most canning lines in Iran have been equipped with new and modern machines during the last decade. The tendency to use thinner coated tin sheets in order to save raw materials consumption is one of the main characteristics of these lines, reducing the thickness of the sheets along with increasing the production speed requires observing as much as possible the different quality ranges required in the production of raw materials, especially sheets. It is tin plated.
It should be mentioned that the design printed on the two-piece stretchable cans is designed with a special software. In these types of cans, the design printed on the sheet finds its original shape after being stretched. The Spanish company Logitech is one of the centers that provides this service and many Iranian companies order their designs there.
Three piece can
