JPH0735089B2 - Blow molding equipment for plastic containers - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a blow molding device for a plastic container which comprises a container body and a cap body for temporarily closing the opening of the container body.

[0002]

2. Description of the Related Art In a plastic container for packaging medicines containing a liquid medicine or the like, the opening of the container body is temporarily closed by a cap body formed integrally with the container body, and the cap body is filled just before the liquid medicine is filled. After removing and filling the chemical solution, by attaching a separately prepared cap, there is a method to minimize the chance of fine dust and bacteria in the air entering the container, and to maintain high cleanliness inside the container. May be taken.

In a plastic container used for such an application, a parison in a heated state is cut into a length with a sufficient margin, and the upper end of the parison is sandwiched in a mold so that the upper end of the parison protrudes to the outside. For the parison inside, insert the tip of the air mandrel, blow clean air, blow mold into a predetermined shape, then retract the air mandrel, and sandwich the upper end of the parison with a seal mold,
It can be manufactured by forming a cap body that is integral with the container body.

[0004]

According to such a prior art, since the tip of the air mandrel is inserted into the parison when the air is blown into the parison in the mold, the clean air supplied to the air mandrel is managed. Even if it is carried out sufficiently, there is a problem that the risk of invasion of various bacteria into the molded plastic container cannot be completely avoided. That is, the air mandrel, except during its operation,
Since the whole is exposed in the air, if dust and other bacteria in the air adhere to the tip at that time, they will enter the parison when the tip of the air mandrel is inserted into the parison, This is because there is a risk that it will be enclosed in the plastic container after molding.

Therefore, an object of the present invention is to positively prevent bacteria in the air from adhering to the air mandrel by housing the air mandrel in a storage case.
It is an object of the present invention to provide a blow molding device for a plastic container, which can effectively eliminate the possibility of carelessly impairing the cleanliness of the product.

[0006]

The structure of the present invention for achieving the above object is to drive an air mandrel up and down to blow-mold a parison in a mold with clean air, and at least a pair of seals. Equipped with a mold,
It consists of a sealing mechanism that advances above the mold and molds and seals the parison after blow molding.
The main point is to attach a storage case to store the air mandrel.

The storage case can be supplied with clean air inside, and can have a germicidal lamp inside.

Further, the sealing mechanism may be configured such that the upper end portion of the parison after blow molding is molded to have a width smaller than the maximum width of the plastic container for sealing.

[0009]

According to the structure of the invention, since the blow cylinder drives the air mandrel up and down to blow-mold the parison in the mold, and further has a storage case for storing the air mandrel. Air mandrel
Except when driven down for blow molding,
It is always stored in the storage case and can block contact with the outside air.

In this case, if clean air is supplied into the storage case, the inside of the storage case becomes a positive pressure with respect to the outside air, so that there is no possibility that the outside air enters the storage case. Also, when installing a germicidal lamp in the storage case,
With the germicidal lamp, the air mandrel in the storage case can be disinfected and sterilized.

When the sealing mechanism seals the upper end of the parison to a width smaller than the maximum width of the plastic container, the sealed cap does not project laterally of the container, so that the containers can be easily aligned. Yes, it is convenient for handling during transportation and filling of chemicals.

[0012]

Embodiments Embodiments will be described below with reference to the drawings.

The blow molding apparatus for plastic containers comprises blow cylinders 35, 35 for vertically moving air mandrels 35c, 35c, and a sealing mechanism 40 having seal dies 45, 45 (FIG. 1). Three
5, a storage case 36 is attached.

The blow cylinders 35 and 35 and the sealing mechanism 40 are combined with the extruder 10 and the mold M to form a series of extrusion molding devices.

In the extruder 10, a crosshead 12 is attached to the tip of a screw 11a driven by a drive unit 11. A hopper 11b for supplying a plastic raw material is attached to the screw 11a, and the crosshead 12 is attached. Is a nozzle 1 for forming a parison that opens downward.
2a and 12a are attached.

The metal mold M is composed of a pair of mating dies Ma and Ma, which can be divided into two parts in a vertically split state from substantially the center part thereof.
It is held by a U-shaped moving frame 21 via c, 21c and rods 21b, 21b. In addition, the rods 21b and 21b are moved toward and away from each other by a driving mechanism (not shown) incorporated in the moving frame 21.
It can be driven symmetrically, which allows the mold M to
The mating molds Ma and Ma can be brought into close contact with each other or separated from each other.

The moving frame 21 is supported by a column 31 via a pair of link arms 23, 23 (FIG. 2).

A connecting block 23a and a connecting arm 23b are provided on the rear surface of the moving frame 21, and one ends of the link arms 23 and 23 are respectively connected to the connecting block 23.
It is swingably connected to a and the tip of the connecting arm 23b. The other ends of the link arms 23, 23 are swingably connected to the column 31 via fixing pins P1, P1. However, the pair of link arms 23, 23 are arranged in parallel with each other and have the same length. A drive cylinder 24 is provided between the connecting block 23 a and the column 31, and the moving frame 21 is
Expands and contracts the drive cylinder 24 so that the mold M is located directly below the crosshead 12 at the parison receiving position (solid line in the figure) and the mold M is blow cylinders 35, 35.
It is possible to reciprocate while maintaining the same posture with the blow position (two-dot chain line in the figure) located immediately below.

The blow cylinders 35, 35 are mounted downward on a horizontal base 33 via a spacer block 34 (FIGS. 1 and 3).

Each blow cylinder 35 comprises a fixed casing 35a and a movable rod 35b.
An air mandrel 35c is connected to the tip of b. The blow cylinder 35 uses air pressure or hydraulic pressure to
The rod 35b and the air mandrel 35c can be driven up and down, and the air mandrel 35c can inject clean air from its tip by connecting an air source.

On the lower surface of the horizontal base 33, the storage case 3
6 is attached. The storage case 36 is
Rods 35b, 35b, air mandrels 35c, 35c
Besides having round holes 36h and 36h for inserting (FIGS. 3 and 4), the structure is completely sealed.

The storage case 36 has round holes 36h and 36h.
Air pipes 37, 37 and germicidal lamps 38, 38 are installed on both sides of the rods 35, 35, and rods 35b, 35b pass between them. It should be noted that the storage case 36 shortens the blow cylinders 35, 35 so that the air mandrel 35
When c and 35c are raised to the rest position, they can be stored in their entirety (solid line in FIG. 3).
When c and 35c are lowered to the operating position, the round hole 36
Through h and 36h, the whole is advanced below the storage case 36 (two-dot chain line in the figure). Also, it is assumed that the clean air is constantly supplied to the air pipes 37, 37, and the storage case 36 is always filled with the clean air.

The clean air from the air pipes 37, 37 is supplied to the air mandrel 35 stored in the storage case 36.
It is preferable that the c and 35c are jetted toward the tip end portions thereof.

The sealing mechanism 40 is arranged behind the mold M via a horizontal movement mechanism (not shown) (FIG. 1). The sealing mechanism 40 includes, as main members, a pair of moving bodies 44, 44 having seal dies 45, 45 attached to their front ends and cylinders 43, 43 for opening and closing the seal dies 45, 45, and as a whole, the base plate. It is assembled on 41.

The cylinders 43, 43 are movable bodies 44, 44.
Are arranged at right angles to and are arranged in a straight line in opposite directions. Slide bearings 4 provided with slide rods 42b and 42b on both sides of the cylinders 43 and 43, respectively.
2, 42 are arranged side by side. Slide rods 42b, 4
2b slidably penetrates the slide bearings 42, 42, and a connecting plate 42a is attached to one end thereof.
However, it is assumed that the slide rods 42b, 42b have their intermediate portions slidably penetrating the moving body 44 near the slide bearings 42, 42, and are connected to the other moving body 44. The rod 43b of one cylinder 43 is connected to the connecting plate 42a, and the rod 43b of the other cylinder 43 is connected.
b is connected to the moving body 44 on the side where the slide rods 42b, 42b penetrate.

Therefore, if the cylinders 43, 43 are simultaneously expanded and contracted, the moving body 44 on the side far from the cylinders 43, 43 will be described.
Is driven by one cylinder 43 through the connecting plate 42a and the slide rods 42b, 42b, and the cylinder 4
The moving body 44 on the side closer to 3, 43 is the other cylinder 43.
Since the cylinders 43, 43 are driven directly by the seal molds 45, 4 as they move in opposite directions.
5 can be opened and closed in place.

Corrugated surfaces 45a, 45a that mesh with each other are formed inside the tips of the seal dies 45, 45 (FIG. 5). Further, the seal molds 45, 45 are supported on the upper surface level of the mold M, and can be moved back and forth in the arrow direction of the drawing by a horizontal moving mechanism (not shown) that drives the entire sealing mechanism 40. The seal molds 45, 45 are the mold M.
When moving upward, the upper ends of the parison P, P protruding above the mold M can be caught.

The mold M and the seal dies 45, 45 are forcibly cooled. Matching mold Ma of mold M and seal mold 45,
Water circulation hoses H1, H1 ... Are connected to 45 (FIG. 1, FIG. 5), and the cooling water sent through the water circulation hoses H1, H1 ... is fed into the mating molds Ma, Ma and the seal molds 45, 45. It circulates in the formed water jacket (not shown). However, the water jackets of the mating molds Ma are independent of each other, while the water jackets of the pair of seal molds 45, 45 are connected in series via the connecting hose H2 and cooled by one system of cooling water. Can be done (Fig. 5).

The blow molding apparatus for such a plastic container is used as a container for packaging medicines and the like by keeping the inside of the container body PL1 sterile and dust-free and temporarily sealing the opening with the cap body PL2. A very suitable plastic container PL can be manufactured (Fig. 6).

The plastic raw material supplied to the hopper 11b of the extruder 10 is passed through the screw 11a (FIG. 1),
From the nozzles 12a, 12a of the cross head 12, the hollow pipe-shaped parison P, P hangs down (FIG. 7). However, the mold M opens the matching molds Ma and Ma while the parison P is molded, and the column 31 and the moving frame 21 are opened.
It is moved to the parison receiving position by extending the drive cylinder 24 between the two (FIGS. 2 and 7). At this time, the air mandrels 35c, 35c are raised to the rest position, housed in the housing case 36, and are on standby.

When the parison P, P is extruded to a certain length, the mating dies Ma, Ma are closed to form the parison P, P.
Simultaneously with the above, the blade 13b of the cutter device 13 attached to the crosshead 12 moves horizontally via the slide bracket 13a (FIG. 7) to cut the parison P, P. The blade 13b may be a heat cutter. Further, the blade 13b cuts the parison P, P at a position where the parison P, P protrudes sufficiently higher than the upper surface level of the mold M.

Next, the moving frame 21 moves to the blow position (FIG. 2).

Then, when the blow cylinders 35, 35 are extended, the air mandrels 35c, 35c are driven downward, pass through the round holes 36h, 36h of the storage case 36, and the tips thereof are put into the parison in the mold M. Since it is inserted into P and P (two-dot chain line in FIG. 3), the parison P and P
By blowing clean air inside, the parison P, P can be blow molded (solid line in FIG. 4). Immediately after the blow molding, the air mandrels 35c, 35c are placed in the storage case 3
Retract in 6 (two-dot chain line in the figure).

The sealing mechanism 40 is used for the air mandrel 3
5c and 35c are advanced to the mold M side before rising, and the seal molds 45 and 45 stand by at a position slightly above the upper surface level of the mold M and sandwich the air mandrels 35c and 35c (Fig. 4) At the same time as the air mandrels 35c, 35c rise, the seal dies 45, 45 are closed, and the upper ends of the parison P, P are molded and sealed. After that, the mold M is opened, the sealing mechanism 40 is returned to the original position, and the seal molds 45, 45 are opened.
Is discharged downward, so that the plastic container PL can be continuously produced by repeating the same operation.

In the above operation steps, the air mandrels 35c, 35c are cleaned by the clean air from the air pipes 37, 37 while being housed in the housing case 36, and are disinfected by the germicidal lamps 38, 38. Has been done. Further, the inside of the storage case 36 has a positive pressure higher than the outside air due to the clean air. Therefore, the air mandrel 3
The plastic containers PL can be manufactured with extremely high cleanliness, and the plastic containers PL are not likely to be contaminated by various bacteria.

Incidentally, the cap body PL2 of the plastic container PL
Is bent according to the shape of the corrugated surfaces 45a, 45a of the seal dies 45, 45 (FIG. 6), and its width W2 is defined by the container body PL.
It can be smaller than the maximum width W1 of 1. Hat body PL
Since 2 does not project laterally from the container body PL1, it is not only convenient for alignment, but also when packing the plastic container PL, the cap body PL2 does not accidentally break off, so that germs etc. It is possible to eliminate subsequent accidents invading.

[0037]

[Other Embodiments] The inner surfaces of the seal molds 45, 45 are cap bodies P.
As long as the width W2 of L2 can be formed smaller than the maximum width W1 of the container body PL1, it can have any shape, for example, a simple concave surface 45b and a convex surface 45c that fit with each other ( FIG. 8A). Such seal molds 45, 45 can form a flat cap body PL2 (FIG. 2B), and the width W2 of the cap body PL2 can be adjusted by the width W3 of the concave surface 45b.

Further, the seal dies 45, 45 can be provided with pressing dies 45d, 45d on the inner facing surfaces (FIG. 9).
(A)). Ribs R1 and R1 for width determination for restricting the width W2 of the cap body PL2 are formed at the side edge portions on the opposite sides of the press dies 45d and 45d. Further, seal ribs R2 and R2 are formed in the horizontal direction at the central portions of the pressing surfaces of the pressing dies 45d and 45d. By using such seal molds 45, 45, the cap body PL2
Seal grooves R3 and R3 corresponding to the seal ribs R2 and R2 can be formed (FIG. 7B), and the sealing property of the cap body PL2 can be further enhanced.

A plurality of seal dies 45, 45 ...
, And each seal die 45 can be simultaneously driven from the radial direction to one point in the center (FIG. 10).
(A)). For example, when using four seal molds 45, 45, ..., the top of each seal mold 45 is formed into a chevron shape of about 90 degrees, and the water circulation hoses H1 and H1 are formed in each seal mold 45.
Connecting hose H connecting the intake side and outlet side of
2, H2 ... shall be connected in series. Since the cap body PL2 having a cross-shaped cross section can be formed (FIG. 7 (B)), the width W2 of the cap body PL2 can be made extremely small.

In the above description, the blow cylinder 35
Is only one, or a plurality of three or more,
Three or more plastic containers PL can be simultaneously molded in one step. Further, one blow cylinder 35 is used, and one or more arbitrary air mandrels 35 are provided.
It can be commonly used for c, 35c ... However, in this case, the number of nozzles 12a of the crosshead 12, the number of molds of the plastic container PL in the mold M, the shapes and the lengths of the seal molds 45, 45, etc. of the plastic container PL to be molded at the same time, respectively. Shall be adapted to the number.

[0041]

As described above, according to the present invention, the blow cylinder for blow molding the parison in the mold and the upper end portion of the parison after the blow molding are molded and sealed via the air mandrel. By providing the blow cylinder with a storage case for storing the air mandrel, the air mandrel is stored in the storage case until it moves to the rest position and moves to the next blow process. , Since it is possible to prevent contact with the outside air and to prevent bacteria etc. from adhering positively, when inserting the air mandrel into the parison, bacteria etc. in the outside air enter the parison via the air mandrel. There is an excellent effect that there is no possibility of invasion and the risk that the inside of the molded plastic container is contaminated can be effectively eliminated.

[Brief description of drawings]

FIG. 1 is a perspective view of the overall configuration

2 is a view corresponding to the arrow X in FIG.

FIG. 3 is an explanatory cross-sectional view of a main part of FIG.

FIG. 4 is a view corresponding to the central longitudinal section of FIG.

FIG. 5 is an enlarged perspective explanatory view of a main part of FIG.

FIG. 6 is an overall perspective view of a plastic container

7 is a view corresponding to the arrow Z in FIG.

FIG. 8 is a view corresponding to FIGS. 5 and 6 showing another embodiment (1).

FIG. 9 is a view corresponding to FIGS. 5 and 6 showing another embodiment (2).

FIG. 10 is a view corresponding to FIGS. 5 and 6 showing another embodiment (3).

[Explanation of symbols]

 PL ... Plastic container P ... Parison M ... Mold W1 ... Maximum width W2 ... Width 35 ... Blow cylinder 35c ... Air mandrel 36 ... Storage case 38 ... Sterilization lamp 40 ... Sealing mechanism 45 ... Seal type

Claims (4)

[Claims] 1. A parison after blow molding, which comprises a blow cylinder for driving an air mandrel up and down to blow-mold a parison in a mold with clean air, and at least a pair of seal dies, and which is advanced above the mold and blow-molded. A blow molding device for a plastic container, comprising: a sealing mechanism configured to mold and seal the air cylinder, and a storage case for storing the air mandrel attached to the blow cylinder. 2. The blow molding device for a plastic container according to claim 1, wherein clean air is supplied to the inside of the storage case. 3. The blow molding device for a plastic container according to claim 2, wherein the storage case has a germicidal lamp inside. 4. The sealing mechanism molds the upper end of the parison after blow molding into a width smaller than the maximum width of the plastic container to seal the plastic container. A blow molding device for the plastic container described.