JPS5993606A - Device and method of sealing can - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention] This fi [! EJ relates to an apparatus for sealing steel and/or aluminum cans with sealing compounds used in the manufacture of cans.

Traditionally, metal cans for soft drinks, food and other products have a cylindrical body around which two closing elements (commonly known as can lids) are tightened, one at each end. It has been made from. The can manufacturing company tightens one of the can lids and sends the empty can and the can top lid to the filling equipment. When the can is sold as a product, the filling device tightens the lid on the other side. Recently, so-called 2-bin cans have been widely introduced.
0 If this type of color is used, one of the body and lid should be placed on the wall 1-11.
The drawing and forming process and the recalibration process are formed from one piece of material so that only one coat is required for the can. For any type of can, the lid of the can is
Provides a harm-tight seal on the body of the can to prevent ingress of bacteria or leakage of the contents of the can. In order to obtain the above-mentioned hermetic seal, it is necessary to cover the groove of the can lid with some material (known as a sealing compound). This operation is performed by the can manufacturing company during the lid manufacturing process. This material is applied in liquid form against the can lid groove when the can lid is rotating at high speed so that centrifugal forces allow proper distribution of the sealing compound within the lid groove. It is applied by spraying it into the grooves.

Sealing or sealing compounds may be of two types, heretofore known as water-based compounds and solvent-based cono-compounds. Water-based compounds consist of a dispersion of a material composition in water, while solvent-based compounds consist of a solution of one composition and a dispersion of another composition in an organic liquid medium, usually hexane. It has become.

When a can lid is sealed with a liquid compound, it is necessary to separate the liquid phase to obtain a secure seam. In the case of solvent-based compounds, this is accomplished simply by evaporating the solvent under ambient conditions. In the case of wood-based compounds, the sealing compound has traditionally been dried by applying heat and passing the pre-sealed lid through some type of oven. Generally, two types of furnaces are used, known as tunnel furnaces and vertical furnaces.

A tunnel furnace consists of a long furnace with a conveyor belt passing through the furnace, heated by gas or hot air, usually supplied by a burner.

A stacked lid is placed on top of the bell I, which usually has a height of about 2
It is conveyed through the furnace for a residence time or elapsed time of 0 minutes. At the exit of the furnace, the stacked lids are separated manually and stored in a suitable manner for use in the stocking interior or for shipment to a filling device.

A spiral furnace consists of a pair of endless rotating screws arranged vertically and held within a hot air furnace. The lid of the can is fed from a closure device in which the compound is already automatically fed against an endless screw, the gyroscopic movement of said screw conveying the lid vertically, and the capping is applied to the pin of the threaded part of the screw. Separated by /ch. The residence time in a spiral furnace is generally 4 minutes. The conventional length of the vertical screw is that required to provide one minute of travel time from the bottom of the screw to the top of each can lid. Therefore, this type of furnace generally has four sets of screws with alternating right-handed and left-handed threads.

The can lid is mechanically transferred from the end of one set of screws to the beginning of the next set. At the exit of the furnace, the lids are automatically fed into a defined position (correctly deposited) and from now on the lids are loaded with human hair for use in the factory or for feeding into filling equipment. Transferred by

Tunnel furnaces are mechanically very reliable because they simply have a conveyor belt passing through the furnace, but the deposits are loaded by a large moon at one end and collected at the other end. It requires a lot of manpower because it has to be done. While screw type furnaces do not require as much manpower, they are very susceptible to mechanical failure because of the mechanism by which the can lid is transferred from one set of screws to the next. Such mechanical problems result in lost idle time and thus reduce the overall efficiency of the can lid manufacturing process.

In the case of solvent-based compounds, the lids are automatically transferred from the sealing device to a short conveyor system from which the lids are manually transferred to any suitable container for use within the factory or for transport to the filling equipment. This compound does not require any type of furnace as it is also transferred in a form.

Most of the organic solvent evaporates while the can lid is on the conveyor system, and a small amount remains evaporates during storage.

From the above description, it is clear that solvent-based compounds are the most appropriate type of compound to be used from the perspective of can manufacturing companies. However, the presence of organic solvents constitutes a problem for countries that have legislation regarding environmental toxicants and safety conditions in the workplace.

Obviously, hexane vapor is present in the atmosphere surrounding the coating machine, and the permissible concentrations of hexane in the air are subject to legislation in many countries. Additionally, in many countries there are limits on the amount of ifa vapors that can be produced from factories such as solvent-based lacquers and can sealing compounds. Therefore, there is a movement in many countries to avoid the use of solvent-based compounds. However, there is considerable resistance on the part of manufacturing companies to switch to furnaces for drying wood-based compounds, which eliminate the problems associated with those mentioned above. Moreover, even for can manufacturing companies that commonly use water-based Comparan IS with conventional furnaces, significant benefits can be obtained by eliminating the use of such furnaces.

These considerations led to the development of a new class of water-based water-based products with a high solids content that can be dried without the use of ovens and that provide a seam with all the properties for a good can sealing. Compounds have been developed to However, despite the fact that this compound can be air dried, the time required for the seam to dry is dependent on the environmental conditions at the can manufacturing plant, i.e. the temperature and relative humidity of the air, and the amount of time the can can be wrapped in and after the injection process. Much depends on how it is stored. Due to this limitation, the present invention relates to a method developed to eliminate such uncertainties regarding drying times without the use of conventional ovens. This method thus combines the advantages of easy wicking of solvent-based compounds with the advantages of water-based compounds with respect to toxicity and environmental pollution.

The basic idea of the method consists in heating the lid before it is sealed so that the compound is applied to the preheated lid. If the lid is sufficiently heated, some of the moisture present in the cono-compound will be released simultaneously with the application of the compound to the jar, and most of the moisture will be released when the lid is used with solvent-based compounds. Similarly, it is evaporated as it is transferred along the conveyor system. As a result, when the lid is removed from the conveyor system and packed for storage, the moisture remaining in the seam is sufficiently low that this residue evaporates during short periods of storage.

The lid is sealed after sealing instead of sealing as occurs in conventional furnaces.
1- Due to the fact that it is heated before
It is concluded that there is no advantage in heating the lid before instead of after sealing 11: the device for heating the lid is known as a "preheating device". However, this is not valid in this case. In conventional methods, unless the process of drying the injection compound occurs suddenly at very high temperatures for a short period of time, the compound tends to form bubbles. This is due to the fact that the surface of the compound first dries to form a crust that prevents the evaporation of moisture from the interior, thus forming air bubbles on the underside of the crust. As a result, there are limitations on how quickly the coat sealed in the oven can dry, which means a limitation on the temperatures that can be used. Also, with conventional water-based compounds, it is necessary to ensure that the NIh compound is completely dry when the lid exits the oven. Such restrictions impose minimal limits on furnace size. However, in a preheater, since the lid is not heated, there is no limit to the speed at which it can be heated, and therefore heating can be done as quickly as needed, and the result is that! ! : The device can be manufactured in a completely compact form. The preheating device can be integrated onto the existing equipment used in sealing can lids instead of the machine in which the lids are fed inside the device, but this is not necessary as in the case of furnaces. This means no extra floor space is required.

2 depending on whether the coating is steel or aluminum acid.
Two different preheater configurations are used. In either case, the garment is heated by the action of hot air generated from the air passing through the electrical resistance by means of a fan.

In the case of steel lids, due to the low thermal conductivity of copper, it is necessary to separate the lid so that hot air can be blown between the lids. This is done using a magnetic hopper. The magnetic hopper consists of a cylindrical stainless steel tube with a set of permanent magnets placed on either side of the tube.

The magnetic field created between the two magnets induces magnetism in the steel lid, so that the lids repel each other and are automatically separated. The distance between individual lids can be controlled by magnetic separation. The lids are removed from the bottom of this magnetic hopper by a feed mechanism of the closure device and fed to the injection station, while at the same time the lids are fed at the top by a conveyor belt advancing from the press in which the lids are made. Magnetic Hopper 〇 During the passage from top to bottom, the lid is heated by the hot air blown in between.

In the case of aluminum acid lids, there is no need to separate them due to their much greater thermal conductivity compared to their steel lids, so preheaters for aluminum acid lids are
The wood consists of an insulated cylindrical jacket into which hot air is blown to the sides and then exits from the top.

In this cylindrical chamber, double partitions are used to ensure proper circulation of air. In both preheater types, to increase the overall thermal efficiency of the process,
The hot air coming out of the preheater can be recirculated to the blower.

In the case of preheaters with steel lids, the transfer of heat from the hot air to the heat sink is highly dependent on the gap between the lids. As a result, it is necessary to perform this separation accurately to ensure good temperature control.

The usual method of operating a sealing device that is automatically fed with deposits from a press consists of operating the sealing device at a speed slightly greater than the operating speed of the press. for example,
If the press produces 300 lids per minute, the sealing device is adjusted to produce 310 lids per minute. The lid supply from the sealing device is equipped with a proximity detector to detect the height of the lid. When the lid deposit reaches a certain fixed lower limit, the supply of lids from the deposit to the sealing device is automatically delayed until the end of the deposit reaches a certain fixed lower limit. Thus, the press operates continuously, but the sealing device operates intermittently. As is clear,
It is impossible to reliably match the speeds of the two devices. It is more difficult to run the press intermittently, and it is desirable that the sealing device run faster than the press and not vice versa. If the device is used with a preheater for steel lids, the number of lids in the magnetic hopper changes continuously, which further changes the separation between the individual lids. To solve this problem, a bidirectional electronic counter was developed that operates in the following manner. That is, when the lid is fed to the top of the magnetic hopper - the sword's proximity detector detects the lid, and when the lid comes out of the seal + l - device the other proximity detector detects the lid. When the required number of lids are fed into the preheater to create the necessary separation between the lids and the press and sealing equipment is operated, a bi-directional counter or sealing equipment Count the number of lids that come out. When such a number deviates from a predetermined bow, say four, feeding from the base of the hopper is interrupted and restarted when four lids have been fed to the top of the ho, par. As a result, the number of lids in the hopper is never 4.
Therefore, the separation between the ends does not change significantly.

It must be pointed out that the magnetic hopper used in conjunction with the steel preheater is not in itself indispensable. Magnetic hoppers have been used commercially for several years as a means of reducing the weight of stacked lids in the feed mechanism of closure devices.

When the buds are sealed and exit the sealing device, the lids are moved along the conveyor device to the packaging station. This conveyor device usually consists of a semicircular bridge section. If this bridge is used in the preheater process, the water vapor evaporating from the hot lid cannot escape and condenses at the bottom of said bridge, thus ensuring rapid evaporation of the water on the container. For,
The conveyor arrangement will be such as to allow good circulation of air around the lid. It has been found that the best way to ensure this circulation is to replace the semi-circular bridge with a four rail arrangement as shown in the accompanying drawings.

Typical operating conditions for copper preheaters are 6
It is based on heating the lid to temperatures between 0 and 120°C. However, it does not ensure that the lid dries within a certain amount of time.
The actual temperature required for heating depends on several factors, such as the size of the lid, the weight of the compound in the lid, the actual packaging of the lid used in a particular factory, and the actual method of storage. ing. In the case of aluminum lids, the feature is that they can be easily opened to insert the lid into other equipment, so aluminum lids can be sealed!
-Due to the fact that the conveyor system from the sealing device is usually very long, very low temperatures, generally between 50 and 120 DEG C., can be used.

The objects of the invention will be better understood by reading the description of this application in conjunction with the accompanying drawings.

In the 11th Δ, the press that forms the lid is indicated by reference number l, 2 is a device for conveying the product from the press to the preheating device, 3 is the sealing device, 4 is the preheating device, and 5 is the packaging device. It is a schematic diagram showing that it is a second conveyor device for collecting clothes.

Figure 2 shows the preheating device for the aluminum acid lid;
In this, 6 designates the cylindrical jacket in which the lid is stored, and 7 designates the blower which heats the lid by driving air through a heating element 8.

FIG. 3 is a side elevational view of a preheater for a steel lid, in which 9 designates the permanent magnet, 10 designates the blower and 11 designates the heating element.

Figure 4 shows, in side elevation, the different preheater control elements, in which A is the thermocouple, B is the hopper detector for deposits on the hopper, and C is the hopper detector for deposits on the hopper. A counter for incoming lids, D indicates a counter for lids exiting the hopper.

Although the nature of the invention has been fully described in the text, including the manner in which it is constructed, the details of the form may be changed, and such changes may alter the basic principles of the invention. It should be noted that this is not the case.

[Brief explanation of drawings]

1 shows an elevational view of the device according to the invention, FIG. 2 shows an elevational view of the preheater for an aluminum acid lid, and FIG. 3 shows a side elevational view of the preheater for a steel lid; and FIG. 4 is a diagram similar to FIG. 3 in which the control sensors of the machine are shown. 1... Lid forming press, 2... Lid conveying device,
3...M+to device, 4...Preheating device, 5...Second
conveyor device, 6...lid storage rack yt., 7
... Blower, 8... Heating element, 9... Permanent magnet,
10...Blower, 11...Heating element, A...
Thermocouple, B...hopper detector, C...lid entry counter, D...lid output counter. Engraving of drawings (no changes in content) FIG, 1st α2 0α4 December 1981 9B Japan Patent Office + (Th Ao # O L1 Husband 1,
Display of incidents

Claims (1)

[Claims] 1. MI for steel and/or aluminum lids of cans using Ji let powder. The apparatus includes a conveyor device at ambient temperature for the lids coming out of the production press, a sealing W device, and a preheating device assembled in the machine for heating the lids coming out of the conveyor prior to sealing. , a counting device for counting the lids supplied to the preheating device and the beginning coming out of the sealing device, and a second conveyor for collecting the lids from the sealing device and transporting them to a packaging station. and wherein said lid is properly positioned to complete the drying process. 2. The preheating device for the steel lid consists of a magnetic hopper for the lid, the hopper consists of a stainless steel cylindrical tube or chamber, with two water magnets facing the phase q outside the chamber. placed and preheated before the lid comes out of the blower; while being heated by air;
Apparatus as claimed in claim 1, in which the lid is automatically separated into phases by a magnetic field formed between the lids for blowing air between the lids. 3. According to claim 1 or 2, the heating of the lid is carried out laterally by the blower which sends air through at least one opening in the lr& direction in the cylindrical chamber of the preheating device. equipment. 4. The preheating device for the aluminum lid consists of an insulated cylindrical chamber, inside which hot air is blown into the bottom and discharged from the top, and the chamber has a series of holes to ensure proper circulation of the air. Apparatus according to claims 1 and 3, having a partition of. 5. 1i A 14-direction electronic counting device is provided with an approach detection device for detecting the height of a stacked lid for detecting deposition when the lid is supplied to the top of the magnetic hopper of the preheating device; and a second proximity detection device for detecting the loose material coming out of the compounding device; when the press and compounding device are operated, an inward dual-purpose counter detects the amount of material being supplied to the preheating device and the lid coming out of the compounding device. 5. Device according to any one of claims 1 to 4, characterized in that: 6. The normal operating condition of the steel lid preheating device is to heat the lid to a temperature of 60-120°C when marketed for 4 months, while the temperature for aluminum lid is 50-120°C.
Apparatus according to any one of claims 1 to 5, varying between 0<0>C. 7. As substantially set forth in the text and shown in the accompanying drawings (!
Device for sealing steel and/or aluminum lids for sH, +F compounds. 8. A method of applying a water-based compound to the lid of the can prior to joining a steel and/or aluminum cap to the can, wherein the sealing compound is applied to the lid of the can. A method characterized in that, prior to application, the lid is heated to initiate immediate evaporation of moisture from the compound. 9. After application of a sealing compound to the preheated lid, the lid is transferred along a conveyor during which further evaporation of H from the compound occurs. Method.