JPH0114091B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a gas exchange packaging method and apparatus for reducing the amount of residual oxygen as much as possible and preventing scattering of powder and granules when packaging them by replacing gas with gas. . Conventionally, in gas exchange packaging for powder and granular materials, a method is generally used in which the air inside the packaging container is extracted and then filled with inert gas. It is difficult to remove the air that is present, and the residual oxygen rate in the gas replacement method is usually 3% or more.
Furthermore, conventionally, in the nitrogen filled packaging method for bean confectionery, etc., the bean confectionery and nitrogen gas were supplied from one side of the open chute, and the nitrogen gas was allowed to overflow when bags were made and packaged from the other side of the open chute. The method was known (Special Publication No. 35094, Showa 60). However, even if it is easy to replace air and nitrogen gas with relatively large particles such as the bean confectionery mentioned above, in the case of small powders such as powdered milk, it is difficult to replace the gas with the open chute. was difficult. Therefore, the inventor of this invention conducted research on deoxidizing powder and granules in advance, but if the handling after deoxidization is not appropriate, the amount of residual oxygen may be extremely low (for example, below 1%). I couldn't do it. However, in this invention, when measuring, transporting, and supplying the deoxidized powder or granular material for packaging, all of the steps are carried out in an inert gas atmosphere, and care is taken not to give an excessive flow rate to the blowing of the inert gas. At the same time, the above-mentioned problem was solved by constantly maintaining the gas pressure at a positive pressure. In particular, in order not to apply a flow rate higher than a certain value to the inert gas, we have used multiple nozzles and have devised the transfer path, and also provided a larger amount of gas than the required amount to provide positive pressure even during rapid suction operations. The desired purpose was achieved by maintaining the structure in a state where it could at least prevent the inflow of outside air. The present invention is particularly suitable for packaging staple packs. That is, in this invention, the granular material 1 which has been deoxidized in advance in the hopper 2 is transferred from the lower part of the hopper 2 to the measuring device 3.
into the measuring hole 5 of the measuring board 4. In this way, when the measuring plate 4 rotates around the shaft 6 and the measuring hole 5 stops directly above the upper transfer pipe 7, nitrogen gas is sprayed from the nozzle 8 as shown by the arrow 14. , the powder 1 in the measuring hole 5 is dropped into the transfer pipe 7 as shown by the arrow 15. This granular material 1 descends in a lower transfer pipe 7a connected to the lower end of the transfer pipe 7, and further flows through a supply pipe 9 connected to the lower end of the transfer pipe 7a.
It is supplied into the cylindrical bag 16 through the. In the above, the upper side walls of the transfer pipes 7 and 7a are provided with nozzles 8a and 8a, respectively.
8b is inserted and opened and nitrogen gas is blown in as shown by arrows 17 and 18, so that the transfer pipes 7 and 7a and the supply pipe 9 (these pipes form a transfer path) are filled with nitrogen gas, and Maintained under positive pressure. Therefore, the excess gas is discharged to the outside world from the exhaust pipe 19 installed above the transfer pipe 7a. The exhaust pipe 19 has a diameter of, for example, 10 mm and a length of 1000 mm (the volume of the bag is, for example, 0.06 mm), and when the packaging bag descends, the space within the transfer path is momentarily depressurized, so that the exhaust pipe 19 is 10 mm in diameter and 1000 mm in length. The gas in the pipe 19 enters the suction state, the inert gas flows back into the transfer path, the outside air descends to the middle of the exhaust pipe 19, and the reduced pressure in the transfer path is quickly restored. Therefore, by the exhaust pipe 19,
An increase in the degree of vacuum in the transfer path or an infiltration of outside air is prevented. Next, when a certain amount of powder or granules enters the cylindrical bag 16, the cylindrical bag 16 is lowered by one bag along with the bag film 20, and the upper part of the cylindrical bag 16 is touched by the hot plate 22 and the roller 1.
The upper end of the cylindrical bag 16 is sealed by a preliminary sealing part 11, and the lower end of the cylindrical bag 16 is permanently sealed by a hot plate 12. Further, the bag 16a which is connected to the lower part of the already sealed cylindrical bag 16 is cut off from the heat-sealed portion by the cutter 13. Next, an example of an apparatus for carrying out the packaging method of the present invention will be described with reference to the accompanying drawings. One side of a measuring device 3 is connected to the lower part of the powder hopper 2 having a funnel-shaped cross section, and a measuring board 4 is installed inside the measuring device 3.
A cylindrical transfer pipe 7 with a smaller diameter at the bottom is connected to the lower end of one side of the measuring instrument 3, and a cylindrical lower transfer pipe 7 is connected to the lower end of the transfer pipe 7. The upper end of the pipe 7a is eccentrically fitted and loosely fitted, and the measuring device 3 is provided with a gas blowing nozzle 8, and the measuring device 3 is provided with a transfer pipe 7 connected to the measuring device 3, and the transfer pipe 7 connected thereto.
a has nozzles 8a and 8b for blowing gas, respectively.
is coming. A lid 25 with an exhaust pipe 19 is placed on top of the transfer pipe 7a. The exhaust pipe 19 is used to adjust the internal pressure to prevent air from flowing in by automatically inhaling inert gas when the pressure is rapidly reduced during bagging, and is provided with a capacity necessary for automatic inhalation. On the other hand, both ends of the packaging film 20 transferred from the film supply section 21 are sandwiched and welded by the hot plate 22 and the roller 10 so that the packaging film 20 is sequentially formed into a cylindrical shape, and the packaging film 20 is fitted into the supply pipe 9. Below the supply pipe 9, there are provided a preliminary sealing part 11 and a hot plate 12 for pressing and heat-welding the cylindrical packaging bag 16 at predetermined intervals, and further below a heat-welding part. A cutter 13 for cutting is provided. In the figure, 24 is a film guide roll. In this embodiment, the gas blowing nozzle 8 faces the meter 3 connected to the hopper 2, but the location of the nozzle is not limited. Further, the measuring device itself may be a device in which no nozzle is exposed. Further, although one gas blowing nozzle 8a, 8b is provided to each of the transfer pipes 7, 7a, the number and blowing amount thereof are not limited. Although nitrogen gas was used as the inert gas in the above, it goes without saying that carbon dioxide gas or a combination of nitrogen gas and carbon dioxide gas may also be used. Although the hopper 2 was used in the above embodiment, a container or a bag may be used instead of the hopper. Next, the residual oxygen rate in the above implementation was measured, and the results shown in Table 1 were obtained. Conditions: (1) Filling amount: 15g/bag (2) Filling capacity: 30 bags/minute (3) Number of nitrogen gas blowing nozzles: 3 (4) Powder is skim milk powder

[Table] (Note) Measured values on the 9th day after filling. The amount of air flow in the table is the total amount from the three nozzles.
In addition, we tested the effect of pretreatment of raw milk powder for filling in cylindrical bag packaging by using an oxygen scavenger, and the results shown in Table 2 were obtained. Conditions: (1) Filled sample 8.8g/bag (2) Number of nitrogen gas blowing nozzles: 3 (3) Oxygen scavenger is brand name "Ageless" (used by Mitsubishi Gas Chemical Co., Ltd.)

[Table] (Note) Measured values on the 9th day after filling In other words, according to the present invention, powder and granules that have been deoxidized in advance are transferred into a packaging bag through a measuring device, a transfer pipe, and a supply pipe in an inert gas atmosphere. Since the gas in the transfer path was always maintained at a positive pressure during the delivery, there was no fear that the powder or granules would come into contact with the outside air after deoxidation treatment, and the amount of residual oxygen in the packaging bag could be kept extremely low. Furthermore, according to the device of the present invention, inert gas is blown through multiple nozzles, so there is no rapid flow of gas and no backflow of powder or granules, even though there is always positive pressure inside the transfer pipe and supply pipe. There is an effect that there is no fear. In addition, an exhaust pipe with the necessary capacity is installed above the supply pipe to alleviate sudden pressure reduction with automatic inhalation of inert gas and prevent air from entering the supply pipe, making it easy to pack. During the instantaneous pressure reduction that occurs, the inert gas in the exhaust pipe is sucked into the supply pipe. At this time, the exhaust pipe has an appropriate capacity, so there is no risk of inhaling air. Next, an example of the method of this invention will be described. When 25 kg of milk powder was added with 160 g of oxygen absorber (Ageless) packaged in a breathable bag and left in a hopper for 24 hours (stirring as necessary), the residual oxygen rate was less than 1%. Therefore, this powdered milk is weighed to 8.8 g, and nitrogen gas is fed at 30/min from three nozzles 8, 8a, and 3b, respectively, when it is charged into a packaging bag via a transfer pipe and a supply pipe. In this case, the capacity of the packaging bag was 0.06. The packaging bag was sealed to complete the method of the invention. After the packaging bags thus obtained were left for 9 days, the residual oxygen percentage was measured for 10 bags, and the average was 0.6%.

[Brief explanation of drawings]

FIG. 1 is a partially cutaway front view of the apparatus used to carry out the present invention, FIG. 2 is an enlarged perspective view of the bag making section, FIG. 3 is an enlarged sectional view of the measuring instrument, and FIG.
The figure is an enlarged plan view of the measuring board, and FIG. 5 is an enlarged partial cross-sectional view showing the relationship between the supply pipe and the cylindrical bag. 1... Powder, 2... Hopper, 3... Measuring device, 4...
Measuring board, 7, 7a... Transfer pipe, 8, 8a, 8b... Nozzle, 9... Supply pipe, 16... Cylindrical bag, 19... Exhaust pipe.

Claims (1)

[Claims] 1. Weighing the granular material that has been deoxidized in advance to a fixed amount,
When transferring this into the packaging bag, inert gas is blown into the discharge transfer path from the measuring device and the transfer path connected thereto to create a positive pressure inert gas atmosphere in the transfer path, and A gas replacement packaging method characterized by reducing the amount of active gas by automatically inhaling inert gas to reduce the instantaneous pressure reduction that occurs during bagging, thereby preventing air from being inhaled into the transfer path. 2. The gas replacement packaging method according to claim 1, wherein the positive pressure is such that a pressure difference between the measuring device, the transfer path, the packaging bag, and the transfer path is such that outside air is not sucked in from the outside air. 3. A measuring device is connected to the lower part of the hopper that stores the powder and granular material that has been subjected to deoxidation treatment in advance, and one end of a transfer pipe for transferring the powder and granular material is connected to the discharge side of the measuring device, and other than the transfer pipe One end of the supply pipe is connected to the end, and the other end of the supply pipe is inserted into the packaging bag. At the same time, an inert gas nozzle is opened in the measuring device and a part of the transfer pipe, and a momentary gas is applied to the upper part of the supply pipe. A gas displacement packaging device characterized by having an upright exhaust pipe with a capacity suitable for rapid suction due to reduced pressure. 4. Claim 3, wherein the measuring device is a rotary disk having a measuring hole, and has a connecting portion to the supply port of the hopper at the upper part of one side, and a connecting portion to the transfer pipe at the lower part of the other side.
Gas displacement packaging equipment as described in Section 1. 5. The gas displacement packaging device according to claim 3, wherein the gas nozzle provided in the measuring device is provided at the upper part of the discharge side of the measuring device. 6. The gas exchange packaging device according to claim 3, wherein the transfer pipe is constituted by an upper transfer pipe and a lower transfer pipe, and the lower end of the upper transfer pipe is eccentrically inserted and connected inside the upper end of the lower transfer pipe. 7. The gas exchange packaging device according to claim 3 or 6, wherein the gas nozzle opening into the transfer pipe is projected from the upper side wall of each of the upper transfer pipe and the lower transfer pipe, and the opening end is directed obliquely downward. 8. The gas exchange packaging device according to claim 3, wherein the supply pipe is inserted into the inside of the packaging bag and has an outer diameter such that the inner wall of the packaging bag can slide down.