JPH01204718A - Germfree vessel made of synthetic resin and manufacture thereof - Google Patents

Abstract

PURPOSE:To enable the title method to form a vessel where inactive gas is filled out and sealed up tightly while keeping the inside at a germfree state, by performing blow molding by blowing the inactive gas into parison through an air nozzle. CONSTITUTION:A blow head 1 connecting with a resin melting and extruding machine forms parison 3 by extruding resin through the circumference of an air nozzle 2 for blowing-in of inactive gas. Blow molding molds 4A, 4B are arranged on the lower part of the blow head 1 so that they are facing on each other by placing the parison between them. A sealing metal fittings 9 sealing the parison 3 and an air cylinder 10 performing shuttle sliding of the sealing metal fittings 9 horizontally are arranged close by the top of the molds 4A, 4B. The inactive gas is blown into the parison 3 through the air nozzle 2 and after completion of blow molding, the sealing metal fittings 9 seals the parison 3 laying within an auxiliary cavity 6 by placing both sides of the parison 3 between the sealing metal fittings.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a sterile container made of synthetic resin whose interior is sterile, and a method for manufacturing the same.

[Conventional technology]

Recently, aseptic filling has been adopted for filling milk, juice, soft drinks, etc. In order to perform aseptic filling, not only must the filling liquid be sterilized to make it sterile, but also the container must be sterilized to make it dent-free.

As one such aseptic filling method, a method has been developed that eliminates the need for sterilizing the inside of the container in an aseptic filling machine by using a container that has been previously manufactured and sealed in an aseptic state.

On the other hand, when aseptically filling food contents for long-term storage, the presence of oxygen is a problem that affects the quality of the food contents. There are two types of oxygen: oxygen that permeates through the walls of the container, and oxygen that exists in the space (headspace) left at the top of the container during aseptic filling. Among these, as a means to eliminate the former effect of oxygen, there is a method such as using a resin with low oxygen permeability as a synthetic resin material for the container, and as a means to eliminate the latter effect of oxygen, there is a method to eliminate the influence of oxygen in the head space during aseptic filling. There are methods such as replacing the oxygen present in the gas with an inert gas.

[Problem to be solved by the invention]

However, the gas replacement method carried out in an aseptic filling machine has the problem of poor replacement efficiency, complicating the aseptic filling process, requiring a large space for the aseptic filling device, and increasing equipment costs. Further, there was also the problem that gas replacement was difficult depending on the shape of the container.

An object of the present invention is to solve the above-mentioned problems and provide a sterile container made of synthetic resin that is useful for aseptic filling of foods and the like, and a method for manufacturing the same.

[Means to solve the problem]

The present invention extrudes synthetic resin from around the air nozzle for blow molding of a blow head to form a cylindrical parison, and the parison is connected to the blow head to surround the parison and close the mold. Blow molding is performed by blowing an inert gas into the parison,
By sealing and separating the parison between the container portion filled with the inert gas and the blow head,
It has a structure in which an inert gas is kept sealed inside under a positive pressure state.

Further, the synthetic resin is composed of two or more kinds of synthetic resin materials including a resin with low oxygen permeability.

[Effect]

The aseptic container made of synthetic resin of the present invention is sealed with only an inert gas filled in an aseptic state, and the upper end of the container is opened in a clean booth during the aseptic filling process to aseptically fill the container with food, etc. At this time, the inert gas inside the container is pushed out to the outside of the container, thereby preventing oxygen from flowing into the container, and the head space of the container after the ineffective filling is filled only with inert gas.

〔Example〕

Embodiments of the present invention will be described below with reference to FIGS. 1 to 7. In FIG. 1, a blow head 1 connected to a resin melt extruder (not shown) forms a parison 3 that extrudes resin into a cylindrical shape from around an air nozzle 2 for blowing inert gas. The air nozzle 2 is connected to a drive device (not shown) that moves the air nozzle 2 up and down, and is attached to the blow head 1 so as to be able to move up and down. Blow molding molds 4A and 4B are arranged below the blow head 1 so as to face each other with the parison 3 in between. The molds 4A and 4B are held by a mold clamping device (not shown) and can be closed to surround the parison 3 as shown in FIG.

Further, the molds 4A and 4B have a main cavity 5 for forming the outer shape of the container portion 3a, and an auxiliary cavity 6 for forming the thin tube portion 3b at the upper end of the container portion 3a,
Sides of the auxiliary cavity 6 and the main cavity 5
It has a recess 7.8 below it for storing unnecessary parisons. Further, near the upper ends of the molds 4A and 4B, a sealing fitting 9 for sealing the rim 3 and an air cylinder 10 for horizontally reciprocating the sealing fittings are arranged. As shown in FIGS. 3 and 4, inert gas is blown into the parison 3 from the air nozzle 2 to complete the blow molding, and the air nozzle 2 is positioned above the seal fitting 9, as shown in FIGS. 3 and 4. After being pulled up, the air cylinder 10 moves forward to pinch and seal the parison in the auxiliary cavity 6 from both sides. It has the function of cutting the parison that has been cut.

FIG. 5 shows a schematic arrangement of the blow head 1 and a blow inert gas supply device 14 for supplying compressed inert gas to the air nozzle 2 in the blow head 1 in an embodiment of the present invention. It is a diagram. The blow head 1 is installed in a clean booth 1 together with the molds 4A and 4B.
2, and the blow head 1 is supplied with molten resin from a resin extruder 13.

The blowing inert gas supply device 14 includes an inert gas supply section 15a, a compressed air supply section 15b, and a steam supply section 20.
have. The piping from the inert gas supply section 15a and the piping from the compressed air supply section 15b are connected and merged after passing through manual valves V and V1, respectively, and a mist separator 16 and a pressure reducing valve are provided on the downstream side thereof. 17, an air filter 18, and a sterile filter 9 for removing germs from the passing gas are arranged in this order.

Further, the piping from the steam supply section 20 is connected to the steam filter 2.
After passing through 1, it is connected to a pipe that enters the sterile filter 9. Further, in the illustrated example, manual valves V to v14 and air-operated automatic valves DV and D are provided at predetermined positions.
v2, solenoid valve SV and pressure gauge P ~ P3
is located.

Next, a method for manufacturing a sterile container according to the present invention will be explained with reference to FIGS. 1 to 6. First, the inside of the pipe of the blowing inert gas supply device 14 and the sterile filter 9 are sterilized. This sterilization is performed by the valves V2, V4, V5, V7, V
8, Vl 1, Vl2.

With Vl3 closed, open the valve v3 to release steam (
For example, source pressure 2'. This is done by supplying 5 to 3hg/a&g) into the tube. After an appropriate period of time, the valve■
6 to stop steam supply, and open the valve v2 to supply compressed air (for example, source pressure 5) from the compressed air supply section 15b.
~6 kg/CIll G> is sent into the pipe, the valves for each drain are opened to discharge the internal drain, and the inside of the pipe is cooled and dried. As described above, at least the inert gas supply path from the sterile filter 9 to the blow head 1 is sterilized.

Then, the valve V1 for supplying inert gas is opened, and the valve V for supplying compressed air is opened. Close the inert gas supply section 1
Preparation for blow molding is completed by supplying inert gas from 5a to the blowing inert gas supply device 14. In this example, compressed air was used to drain the drain after steam sterilization and cool the inside of the pipe in order to save on inert gas, but it is also possible to use inert gas for everything. There are no particular restrictions on the inert gas as long as it does not oxidize food and is safe, such as nitrogen gas, carbon gas, or argon gas.

Note that the sterilization of the inside of the pipe and the sterile filter 19 is not limited to steam sterilization, and other sterilization methods may be used, for example, a method of sterilizing by sending gas containing a sterilizing agent mist instead of steam.

Next, in the blowing inert gas supply device 14,
The valves Vl, V2, V9, V12.

Vl4 and DV2 are opened, the valve vio is opened to the extent that a minute amount of inert gas can pass through, and the other valves are closed. Therefore, the sterile inert gas that has passed through the sterile filter 19 is transferred to the valves DV2 and VIO.
A small amount of air is supplied to the blow head 1 through the air nozzle 2, and then blown out from the air nozzle 2. In this state, as shown in FIG. 4B is opened and the resin is extruded from the blow head 1 to blow out the parison 3. Form. At this time,
The lower end of the parison 3 has already been closed by the previous molding process, so that outside air will not enter the inside of the parison 3 during molding of the parison 3, and the inside will not be contaminated with germs. Note that the air nozzle 2 is in a sterile state. The amount of inert gas blown out is selected so that negative pressure does not develop inside the parison 3. This selection is preferable because even if the parison 3 has a hole, outside air will not enter the parison 3.

Next, as shown in FIG. 1, the mold 4A.

After the parison 3 is formed longer than the main cavity 5 of the mold 4B, the molds 4A and 4B are closed and the parison 3 is inserted into the main cavity 5 of the mold 4A and 4B, as shown in FIG. The air nozzle 2 is then stored in the auxiliary cavity 6, and unnecessary parts are cut off. 5 so that the opening is inside. Then, in FIG. 5, the valve DV2 is closed and the valve DI is opened.

As a result, the sterile inert gas that has passed through the sterile filter enters the mold 4A through the air nozzle 2 under high pressure.
, 4B into the parison 3, and blow molding is performed through zero or more operations to form a container portion 3a and a thin tube portion 3b connected to its upper end, as shown in FIG.

Next, the valve DVI is closed, and the valve S1 is opened to exhaust the inert gas in the container portion 3a. The fFflfM period of the valve SV1 is set by a timer (not shown), and the valve SV1 is closed when the inside of the container portion 3a becomes slightly positive pressure with respect to the external pressure. Thereafter, the air nozzle 2 rises to the position shown in FIG. 3, and then the seal fittings 9.9 are advanced by the air cylinder 10.10 from both sides of the thin tube section 3b, sandwiching the thin tube section 3b and sealing. and seal.

At the same time, cut the center of the sealed part. Thereafter, the molds 4A and 4B are opened and the molded container portion 3a is taken out from the molds, thereby obtaining the container shown in FIG. 6. The blow-molded container is sealed without exposing the inside to the outside air, and the inside is maintained in a sterile state.

After opening the molds 4A and 4B, the valve DV2 is opened again, and the parison 3 is extruded while blowing out a small amount of sterile inert gas from the air nozzle 2. state. Thereafter, the same operation is repeated.

The cross-sectional structure of the parison 3, which is the basis of the cross-sectional structure of the wall surface of the sterile container of the present invention, may be a five-layer structure as shown in FIG. 7. In this case, the outermost layers 31.
1 is a P E 'I'' type resin as the main polymer, the innermost layer 33 is an ethylene vinyl acetate copolymer generator resin as an oxygen barrier layer, and the intermediate layer 32.32 is a modified polyethylene resin as an adhesive layer. , it is possible to effectively prevent oxygen from penetrating into the container through the wall surface of the container.

〔Effect of the invention〕

According to the present invention, it is possible to form a container that is filled with an inert gas and sealed while the inside remains aseptic. In such a container, only the outside of the container is sterilized and the upper end of the container is sterilized in the aseptic filling process. Since the container can be opened, filled with food, etc., and sealed, the inert gas inside the container is only pushed out to the outside of the container, and oxygen cannot flow into the container.
The head space of the container after aseptic filling is filled only with inert gas, which has the effect of enabling long-term storage of the contents, such as food.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal cross-sectional view showing an example of the apparatus for producing a sterile container made of synthetic resin according to the present invention, FIG. 2 is a longitudinal cross-sectional view showing the state of the apparatus during blow molding, and FIG. 4 is a cross-sectional view taken along the line ■-■ in FIG. 2, FIG. 5 is a schematic diagram of the manufacturing device for carrying out the present invention, and FIG. 1 of the sterile container made of synthetic resin of the present invention
FIG. 7 is a side view showing the embodiment, and a cross-sectional view showing the cross-sectional structure of the parison used in the present invention. 1...Blow head, 2...Air nozzle, 3...
Parison, 3a... Container part, 3b... Thin tube part, 4A
, 4B...Mold, 5...Main cavity, 6...Auxiliary cavity, 9...Seal fitting, 10...Air cylinder, 12...Clean booth, 13...Resin extruder , 14... Inert gas supply device for blowing, 19.
... Sterile filter. Applicant's representative Yasuo Ishikawa Figure 1 Figure 2 Figure 3 Figure 4 Figure 6 Figure 7

Claims (1)

[Scope of Claims] 1. A synthetic resin container manufactured by blow molding by blowing gas into a parison formed by extruding a synthetic resin, wherein the container is formed from around the blow molding air nozzle of the blow head. A synthetic resin is extruded to form a cylindrical parison, the parison is connected to the blow head, the mold is closed surrounding the parison, and an inert gas is blown into the parison from the air nozzle to perform blow molding. The synthetic resin is characterized in that the parison between the container portion filled with the inert gas and the blow head is sealed and separated, so that the inert gas is kept sealed inside under a positive pressure state. sterile container. 2. Extrude synthetic resin from around the air nozzle for blow molding of the blow head to form a cylindrical parison, surround the parison with the parison connected to the blow head, close the mold, and extrude the synthetic resin from the air nozzle. A sterile container made of synthetic resin, characterized in that blow molding is performed by blowing an active gas into the parison, and the parison between the container portion filled with the inert gas and the blow head is sealed and separated. manufacturing method.