JP3522293B2 - Injection stretch blow molding method - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hot parison type injection stretch blow molding method in which at least a preform (parison) injection molding step, a blow molding step and an eject step are continuously performed in one stage.

[0002]

A typical one-stage blow molding apparatus of this type is disclosed in Japanese Examined Patent Publication No. 53-22096.
This apparatus is provided with an injection molding station, a temperature control station, a blow molding station and an eject station on four sides of a machine base, and a rotary disk is rotatably arranged above it. Neck molds for holding the neck portion of the preform or bottle are arranged at four positions on this rotating disk. Then, by driving the rotating disk intermittently at 90 ° intervals, the four neck molds are sequentially conveyed to each station,
Processing is performed at each station.

Japanese Unexamined Patent Publication (Kokai) No. 1-275122 is an improvement proposal for improving the production efficiency of the above-mentioned apparatus per hour, and two rows of neck molds are arranged at four positions of the rotary disk.

In Japanese Patent Publication No. 64-3657, both of the above-mentioned two devices are of the rotary transfer type,
This is an improvement of the transfer system that transfers the neck type in a straight line. In this apparatus, the stations for injection molding, temperature control and blow molding are arranged in a horizontal row, and the neck mold is conveyed asynchronously with the injection molding cycle to facilitate setting of molding timing.

By the way, the hourly production efficiency of bottles produced by the blow molding apparatus is determined by the operating rate of the blow mold at the blow molding station. It has been pointed out that the above-described one-stage type blow molding device has lower production efficiency than the two-stage type blow molding device. A two-stage type blow molding device is a device that performs injection molding of a preform and blow molding of a bottle using the preform in different stages. In this two-stage type blow molding apparatus, since preforms can be supplied to the blow molding station in accordance with the blow molding cycle time, relatively high production efficiency can be realized. However, in the one-stage type blow molding apparatus, since the molding cycle time is determined by the injection molding time that requires a longer time than the blow molding time, it is impossible to supply the preform according to the blow molding cycle time. is there. For this reason, the operation rate of the blow mold at the blow molding station is low.

In order to improve the operating rate of a blow molding station in a system capable of conveying a neck mold asynchronously with the injection molding cycle, the applicant of the present invention has disclosed that it is disclosed in Japanese Patent Application Laid-Open No. 3-1.
The proposal is made in Japanese Patent Publication No. 59726.

In this apparatus, a preform injection molding station, a temperature control station, a blow molding station and an eject station are arranged along one longitudinal side of a rectangular outer shape, and a neck mold is injection molded along the other longitudinal side. It has a return line for carrying back to the station. Further, the injection molding station and the temperature control station are arranged in two rows, and the blow molding station and the subsequent rows are arranged in one row. According to such an apparatus, the preforms that have been injection-molded and temperature-controlled in the lines in two rows can be loaded into the blow molding station after being aligned in one row. The operating efficiency of the mold can be increased.

However, when the preforms are simultaneously molded in the two rows of injection molding stations, the preforms of one line can be immediately carried into the blow molding station, while the preforms of the other line can be preformed. I have to keep you waiting. In this type of hot parison type blow molding device, blow molding is carried out by utilizing the heat retained during injection molding, but the preform temperature fluctuates during the waiting time, and uniform quality is achieved in each row. It becomes impossible to mold the bottle.

As described above, in the prior art, after performing injection molding and temperature control of preforms in different rows,
It was not possible to blow mold the preforms in each row under equal conditions.

Further, according to the above-mentioned conventional technique, in order to return and convey the ejected neck mold to the injection molding station, the neck mold is returned and conveyed over a relatively long distance from the injection molding station to the length of the eject station. There must be. Therefore, as suggested above,
The neck dies must be on standby for each row at the standby position in front of the injection molding station for each row.
Therefore, the number of neck molds must be at least two more than the total number of stations.

By the way, the neck mold used in this type of one-stage type blow molding apparatus is also used as a neck cavity mold in the injection molding station, and it requires considerable dimensional accuracy, which makes the price expensive. Therefore,
Providing a larger number of neck molds than the number of stations raises the problem of increasing the overall price of the device.

Therefore, an object of the present invention is to perform preform injection molding at each of a plurality of injection molding stations, but to perform subsequent blow molding under the same conditions. It is an object of the present invention to provide an injection stretch blow molding method capable of making the quality of a hollow container produced uniform while increasing the operating rate of a molding die.

Still another object of the present invention is as follows.
(EN) Provided is an injection stretch blow molding method capable of molding a hollow container at a low cost while suppressing an increase in the number of neck mold moving units as much as possible while improving the operation efficiency of a blow mold and improving the production efficiency. Especially.

[0014]

According to the present invention, there is provided at least a preform injection unit for injecting at least a neck mold moving unit for supporting and conveying a hollow container and a plurality of neck molds for holding a neck portion of a preform for molding the hollow container. A molding station, a blow molding station and an eject station, which are sequentially circulated and conveyed, an injection molding step of the preform, a blow molding step of blow molding the hollow container using the preform that retains heat during injection molding, and In the injection stretch blow molding method in which the subsequent ejecting step of the hollow container is repeatedly performed, M (M> N) injection molding stations are provided for N blow molding stations, and When the injection molding cycle time is T, the injection opening is performed at each injection molding station. Perform injection molding of the preform shifted by pot ho timing T / M time, by moving the neck mold moving units in the order in which the injection molding is completed in the blow molding station vacant station from said injection molding station The blow molding process is performed, and the blow molding cycle time at the blow molding station is set within N · T / M time.

[0015]

For example, the case where two injection molding stations are provided for one blow molding station will be described. In the two injection molding stations, the injection start timing is almost half the injection molding cycle time T. Of time, that is, the time of T / 2. on the other hand,
In one subsequent blow molding station, the blow molding cycle time is set within T / 2. Therefore, the blow molding process using the preform molded in one injection molding station is completed before the injection molding process of the preform is completed in the other injection molding station. Therefore, the preforms conveyed at a time difference between the two injection molding stations can be carried into the blow molding station under the same conditions without waiting at all, and the quality of the blow molded hollow containers is made uniform. be able to.

In carrying out the method of the present invention, a plurality of rows of transfer lines are arranged in parallel with the first row of transfer lines in which the blow molding station and the eject station are arranged, and an injection molding station is provided in each of these rows. It is good to provide one each. Then, unlike the conventional device, it is no longer necessary to carry the ejected neck type moving unit over a long distance and return it to the injection molding station, and only by circulating the same number of the neck type moving units as the total number of stations, a series of The steps can be carried out smoothly.

When a temperature control station is provided before the blow molding station, it is preferable to provide it on the transfer line in the first row. Then, if the temperature control cycle time in the temperature control station is also set in the same manner as the blow molding cycle time, the preforms injection-molded in each row are transferred to the temperature control and blow molding station under the same conditions. be able to. Further, according to the above-mentioned layout, the transfer line connecting the stations does not become extremely long, so that it is possible to perform a series of steps by only providing one extra neck type moving unit than the total number of stations, if necessary. It can be implemented smoothly.

[0018]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be specifically described below with reference to the drawings.

FIGS. 1 and 2 are plan views showing an apparatus for carrying out the method of this embodiment, and in particular, the arrangement of stations for realizing a one-cycle molding process.
The molding apparatus has a substantially square outer shape, and the first injection molding station 10 is arranged at the center position thereof. A second injection molding station 12 is arranged, for example, on the left side of the first injection molding station 10. Further, on the right side of the first injection molding station 10, the temperature control station 14, the blow molding station 1
6 and the eject station 18 are arranged in a line. The apparatus of this embodiment is provided with as many neck type moving units 20 as there are stations, that is, five. The neck type moving unit 20 holds a plurality of, for example, eight neck types. The neck mold detachably holds the neck portion of the preform or the bottle, and is also used as the neck cavity mold in the injection molding stations 10 and 12. The transfer route of the neck type moving unit 20 is as follows. That is, the temperature control station 14, the blow molding station 16, and the eject station 18 are arranged on the transfer line 22 in the first row. The transfer lines 24 and 26 of the second and third rows are provided in parallel with the transfer line 22 of the first row.
First and second stations 10 and 12 are arranged at 4 and 26, respectively. Furthermore, the transfer lines 2 of the second and third rows
Supply transfer line 28a for supplying and transporting the neck type moving unit 20 from the transfer lines 22 and 26 to the transfer line 22 of the first row.
Is provided. Similarly, from the first line transfer line 22,
The neck type moving unit 20 is provided in the second and third rows 24 and 26.
A return transfer line 28b is provided for returning and transporting.

First and second injection molding stations 10,
12 have the same configuration, and each of them has an injection device 30,
Has 32. Explaining the first injection molding station 10, a hot runner mold that is nozzle-touchable with the injection device 30 is provided, and an injection cavity mold is arranged thereon. Furthermore, the neck type moving unit 20
An injection core mold is arranged above the injection cavity mold. Then, the injection cavity mold, the neck mold, and the injection core mold are clamped to enable injection molding of the preform. Second injection molding station 1
2 also has the same configuration as the first injection molding station 10.

The temperature adjusting station 14 is for adjusting the temperature of the injection-molded preform to an appropriate temperature for stretching. The temperature control station 14 has a temperature control core and a temperature control pot above and below the neck type moving unit 20. By arranging the temperature control core and the temperature control pot at predetermined positions, the temperature can be controlled from the inside and outside of the preform, for example.

The blow molding station 16 introduces blow air into a preform whose temperature is adjusted to a suitable stretching temperature, and drives a stretching rod inserted in the preform in the vertical axis to biaxially stretch blow-mold a bottle. It is a thing. The blow molding station 16 has a combination of a blow core and a stretching rod above the neck type moving unit 20, and a blow cavity type below the combination.

The eject station 18 separates the blow-molded bottle from the neck mold provided in the neck mold moving unit 20. That is, by opening and driving the neck mold configured as two split molds,
It is possible to take out the bottle.

The molding apparatus having the two injection molding stations 10 and 12 as described above is constructed by unitizing as shown in FIG. 2, for example. That is, a basic molding unit 40 is configured by a device having the first injection molding station 10, the temperature control station 14, the blow molding station 16, and the eject station 18. A part of the second injection molding station 12 and the transfer lines 28 a and 28 b are configured as an additional unit 42. The molding unit 40 alone can realize a series of molding steps from injection molding of preforms to removal of bottles, but by connecting the additional unit 42 as in this embodiment, the number of bottles molded per hour can be increased. An apparatus with high throughput can be configured.

Next, an example method of the method of the present invention carried out by the apparatus of the above embodiment will be described with reference to FIGS. 3 and 4.

In each figure, reference numerals A to E indicate the types of the neck type moving unit 20, and the state shown in FIG. 3A shows the initial positions of the neck type moving units A to E. . FIG. 4 is a timing chart for explaining the arrangement of the neck type moving units A to E in each station. In FIG. 4, the transfer time between the stations is ignored for convenience of explanation. In FIG. 4, the time T corresponds to the first and second injection molding stations 10 and 12.
3 shows the injection molding cycle time in FIG. The injection molding cycle time T indicates the time from the start of mold clamping at the stations 10 and 12 to the completion of the loading of the next new neck mold moving unit 20 after the completion of injection molding. There is a time difference t between the injection molding start timings in the first and second injection molding stations 10 and 12, and in the present embodiment, this time difference t = T / 2. Further, in the present embodiment, each cycle time at the temperature control station 14, the blow molding station 16 and the eject station 18 is the same as the time difference t of the deviation of the injection molding start timing for convenience of description.

FIG. 3A shows the installation state of the neck type moving units A to E at the timing t1 in FIG.
At this time, the first and second injection molding stations 10, 1
Although the neck type moving units A and B are present in 2 respectively, the injection molding operation is already completed in the first injection molding station 10 and the neck type moving unit A is ready to be transferred. Therefore, using the first transfer loop 50 shown in FIG. 3 (A), four neck type moving units A,
Circulation transfer of CE is performed. As a result, at the timing t2 shown in FIG. 4, the respective neck type moving units AE are installed as shown in FIG. 3 (B). In this state at the timing t2, the injection molding operation is completed in the second injection molding station 12, and the neck mold moving unit B can be transferred. Therefore, the second transfer loop 52 shown in FIG. 3B is used to transfer the four neck type moving units A to D. As a result, at the timing t3 shown in FIG. 4, the neck type moving units A to E are installed at the positions shown in FIG. After that, similarly, the first and second injection molding stations 10,
Since the injection molding operation is alternately finished at 12, various installation states shown in FIGS. 3D to 3F are realized by alternately performing the transfer by the first transfer loop 50 and the second transfer loop 52. it can. In the installed state of FIG. 3 (F), the neck type moving unit A that has been subjected to injection molding at the first injection molding station 10 in the initial state passes through the temperature control station 14, the blow molding station 16 and the eject station 18. It is transported back to the injection molding station again. At this time, this neck type moving unit A
Will be located at the second injection molding station 12. As described above, in the present embodiment, the first and second injection molding stations 10 and 12 are arranged, and the time difference t (= T / 2) is provided between the injection molding start timings of the injection molding stations 10 and 12. , The injection cycle T is required at each of the injection molding stations 10 and 12, but the movement cycle of the neck moving unit 20 is T / 2.
It can be done every time. This means that the blow molding station 16 can realize the blow molding operation twice within the injection molding cycle time T, and the number of products produced per hour is doubled as compared with the conventional method. Further, in this embodiment, the number of neck type moving units 20 can be reduced while securing the production efficiency twice as high as the conventional one. That is, in order to double the production efficiency in the conventional method, two injection molding stations, two temperature control stations, one blow molding station and one eject station are provided, and as a result, the number of neck type moving units is eight. . On the other hand, according to the present embodiment, the number of the neck type moving units 20 is 5 in order to secure the same production efficiency, and the number of the neck type moving units 20 can be reduced to 5/8. The neck mold provided in the neck mold moving unit 20 is also used as a neck cavity mold, and it is expensive because dimensional accuracy is required, which is a drawback of the one-stage type molding apparatus. By using the method of this embodiment, it is possible to reduce the number of neck molds while increasing the production efficiency, and as a result, it is possible to reduce the cost of the device.

FIG. 5 is a timing chart showing the method of the above embodiment in more detail in consideration of the transfer time between stations. As the time distribution of the injection molding cycle time T,
T = T1 + T2 + T3. T1 indicates the time from the mold clamping to the end of the injection operation. T2 represents the time for cooling the preform in the mold after the injection operation is completed. T3
Indicates the time until the neck mold moving unit 20 is carried out after the mold is opened and a new neck mold moving unit 20 is carried into the injection molding station. In this embodiment, the injection cycle time T is 16 seconds and T1 = T / 2 is set. The time T4 in the temperature control station 14 indicates the time for substantially performing the temperature control operation. This time T4 includes the closing drive of the temperature control pot and the temperature control core, the temperature control step, and the subsequent opening drive time. T5 at temperature control station 14
Is a neck type moving unit 2 to this station 14.
0 indicates the carry-in and carry-out time. In this embodiment, T4 + T
5 = T / 2 is set. In FIG. 5, there is a deviation between the timing after the injection cycle time T has elapsed in the injection molding stations 10 and 12 and the movement start timing in the temperature adjustment station 14. This is because it takes time to move the neck moving unit 20 from the injection molding stations 10 and 12 to the temperature adjusting station 14 as shown in FIG.

The time T6 at the blow molding station 16 indicates the time required for the blow molding operation at this station 16. That is, the time T6 indicates the time from the mold clamping to the mold opening through the blow molding operation. The time T7 at the blow molding station 16 is
6 shows the carry-in and carry-out time of the neck type moving unit 20 in FIG. In this embodiment, T6 + T7 = T / 2.

The time T8 at the eject station 18 indicates the time required for ejecting, which ends in a relatively short time. Therefore, the transfer time T9 before and after that can be secured relatively long. In this embodiment, T8 + T9 = T /
It is set to 2.

As is apparent from the timing charts shown in FIGS. 4 and 5, one injection molding station 10 is provided.
Or 12, the injection molding cycle time is T, and the time required for the neck moving unit 20 to cycle through each station is 2.5T. Therefore, the temperature adjusting station 14, the blow molding station 16, and the eject station 18 are It can be seen that the processing time in 1 is required to be within 1.5 T hours. The ejecting time T8 at the ejecting station 18 and the transporting time T9 before and after it are T / 2 hours, which is sufficient, so that the processing time at the temperature adjusting station 14 and the blow molding station 16 are T / 2, respectively.
It is possible to secure time by time. Here, the neck type moving unit 20 carried out from the first and second injection molding stations 10 and 12 which is operated by shifting the injection molding start timing by the time difference of T / 2 is always operated after the elapse of a certain time. To set within 14,
The cycle time at the temperature control station 14 and the blow molding station 16 thereafter is T / 2, which is the time difference.
It is necessary to do it within the time. If each process is not completed within this time, the number of blow molding stations for one injection molding station may be increased. For example, three injection molding stations may be arranged and two blow molding stations may be arranged. If each cycle time in the temperature control station 14 and the blow molding station 16 can be further shortened, three or more injection molding stations can be provided for one temperature control station 14 and one blow molding station 16, respectively. . FIG. 6 shows the first to
An example of a configuration in which the third injection molding stations 10, 12, 34 are arranged is shown. In this case, another additional unit 44 is connected to the molding unit 40 and the additional unit 42 shown in FIG. The operation of the molding apparatus shown in FIG. 6 is shown in the timing chart of FIG. As shown in the figure, three injection molding stations 10, 1
In Nos. 2 and 34, the injection molding start timings are each shifted by a time difference of T / 3. Further, each cycle time in the temperature adjustment station 14 and the blow molding station 16 is set so as to end within the time difference T / 3 which is the deviation time of the injection molding start timing described above. According to such an apparatus, the number of moldings per hour is tripled as compared with the conventional method, and if the number of the neck type moving units 20 is 6, which is the same as the total number of the stations, the number is 6 compared with the conventional method. The number of neck type moving units 20 can be reduced to 1/2 (= 6 units / 12 units).

The present invention is not limited to the above embodiment, but various modifications can be made within the scope of the gist of the present invention.

For example, as a layout for arranging the first and second injection molding stations 10 and 12 as shown in FIG. 2, the configuration shown in FIG. 8 may be adopted. In the figure, the additional unit 42 is connected to the right side of the molding unit 40. By doing so, the temperature control station 1 is changed from the first and second injection molding stations 10 and 12.
Transport distances up to 4 can be set equally. Similarly, the return transport distance from the eject station 18 to the first and second injection molding stations 10 and 12 can be made equal. With such a line-symmetrical arrangement, the positional relationship between the transfer lines 22 in the second and third rows and the transfer line 22 in the first row is the same, and the same transfer cycle can be realized by the two transfer loops.

Further, as described above, it is possible to arrange three injection molding stations for two temperature control stations. An example of the configuration in this case is shown in FIG. As shown in the figure, two molding units 40, 40 are connected to each other, and an additional unit 42 is added to one molding unit 40.
Are connected. In this case, the deviation time t of the injection start timing in the three injection molding stations is t =
It may be set to T / 3. In addition, the temperature control station 14
The operation cycle time at the blow molding station 16 may be set within 2T / 3 hours. In short, N
When M (M> N) injection molding stations are arranged for each blow molding station, the injection start timing deviation time t at each injection molding station
And t = T / M, and the operation cycle time at the temperature control station 14 and the blow molding station 16 is N · T / M.
It may be set within M.

In each of the blow molding apparatuses shown in FIGS. 2, 8 and 9, the number of neck mold moving units 20 is set to be the same as the total number of stations, but if necessary, one more than the total number of stations is set. A number of neck type moving units 20 may be arranged. In particular, the first line transfer line 22
When a plurality of injection molding stations are arranged with different transport distances, for example, as shown in FIGS. 2 and 9, in order to realize a smooth transfer cycle,
An extra neck type moving unit 20 can be provided so as to stand by on any transfer line other than the station, for example, in a stage before the injection molding station. That is, according to the layout as in each embodiment, it is not necessary to form the return transfer path over a long distance as in Japanese Patent Laid-Open No. 3-159726, so that the total number of stations is 1
It suffices to arrange the number of the neck type moving units 20 that is added only, and the increase in the number of expensive neck type moving units 20 can be suppressed to a minimum.

1 for the total number of stations that perform substantial processing
FIG. 10 shows a configuration example in which one extra neck type moving unit 20 is arranged. In the apparatus shown in the figure, a replacement station 60 is provided in the first line transfer line 22. The replacement station 60 is not a station for performing substantial processing, but is for making the unit 20 stand by for a short time until the time when the neck type moving unit 20 is loaded into the blow molding station 14. In this embodiment, six neck type moving units 20 are provided. And stations 10, 12, 14, 1
In addition to the five neck-type moving units 20 arranged at 6 and 18, one neck-type moving unit 20 is present on the supply transfer line 28 or the replacement station 60. Immediately before the operation at the blow molding station 14 is completed, this extra neck type moving unit 20 reaches the replacement station 60 with a margin.

Furthermore, in each of the embodiments, the temperature control station 14 is provided, but the present invention can be applied to a molding apparatus that performs blow molding immediately after injection molding.
Further, in the present invention, it is necessary to provide a plurality of injection molding stations, but in this case, it is not always necessary to provide a plurality of injection devices independently, and the resin from one injection device is switched to a valve or the like. It is also possible to lead to multiple injection molding stations.

[0038]

As described above, according to the method of the present invention, the preforms are injection-molded in a plurality of rows with a time difference, respectively, and then the preforms molded in each row are blown in the subsequent stage under the same conditions. It can be loaded into the molding station. Therefore, it is possible to make the quality of the molded hollow container uniform while increasing the operating efficiency of the blow mold at the blow molding station and increasing the number of moldings per hour.

[Brief description of drawings]

FIG. 1 is a plan view of a blow molding apparatus used for carrying out the method of the present invention.

FIG. 2 is a plan view for explaining a transfer line of a neck type moving unit of the blow molding apparatus shown in FIG.

FIGS. 3A to 3F are schematic explanatory views showing the installation state of a neck type moving unit that is circulated and transferred to each station.

FIG. 4 is a timing chart for explaining a molding method in the blow molding device shown in FIG.

5 is a timing chart for explaining another blow molding operation in the blow molding apparatus shown in FIG.

FIG. 6 is a plan view showing a modified example in which three injection molding stations are arranged with respect to one blow molding station.

FIG. 7 is a timing chart for explaining the operation of the blow molding apparatus shown in FIG.

FIG. 8 is a plan view for explaining different layouts of two injection molding stations.

FIG. 9 is a plan view for explaining a layout in which two blow molding stations and three injection molding stations are arranged.

FIG. 10 is a plan view of a blow molding apparatus provided with one extra neck type moving unit for a substantial total number of processing stations.

[Explanation of symbols]

10 First injection molding station 12 Second injection molding station 14 Temperature control station 16 Blow molding station 18 eject station 20 Neck type moving unit 22 First line transfer line 24 Second line transfer line 26 Third line transfer line 28a Supply transfer line 28b Return transfer line 30,32 injection device 34 Third injection molding station

─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Kazuyuki Yokobayashi 4586 Ko Komoro-shi Nagano 3 Nissei ASB Machinery Co., Ltd. (56) Reference JP-A-3-159726 (JP, A) JP 57-93125 (JP, A) JP-A-1-275122 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) B29C 49/00-49/80

Claims (3)

(57) [Claims] 1. A neck mold moving unit for supporting and conveying a hollow container and a plurality of neck molds holding a neck portion of a preform for molding the hollow container, at least a preform injection molding station, a blow molding station, and an eject. Sequentially circulated to the station, injection molding step of the preform, blow molding step of blow molding the hollow container using the preform that retains heat during injection molding, and subsequent ejecting step of the hollow container In an injection stretch blow molding method in which the above steps are repeatedly performed, M (M>
N) number of the injection molding stations are provided, and when the injection molding cycle time at each injection molding station is T, the injection start timing is shifted by approximately T / M time at each injection molding station. Molding is performed, and the neck mold moving unit is moved from the injection molding station to the blow molding station that has become an empty station in the order in which the injection molding is completed to perform a blow molding process, and blow at the blow molding station is performed. the molding cycle time is set in the N · T / M times, wherein the transfer line of the first column of the neck mold moving units
Blow molding station and eject station
A plurality of rows of transfer lines provided in parallel with the first line transfer line.
One injection molding station is installed at each in
Injection molding station, blow molding station
And the number of eject stations
The injection stretch blow molding method is characterized in that the K-shaped moving unit is circulated and conveyed to each station . 2. A hollow container and a preform for molding the same.
Support multiple neck molds to hold the neck of the foam
At least a preform for the neck type moving unit to be transported.
Injection molding station, temperature control station,
-Sequentially to molding station and eject station
Circulating and conveying, injection molding process of the preform, injection
Warm the preform that retains the heat during molding to an appropriate temperature for stretching.
Temperature control process to control, using the temperature controlled preform
A blow molding step of blow molding the hollow container, and
Repeatedly ejecting the hollow container after
In the injection stretch blow molding method, M (M> M) for N blow molding stations.
N) Each injection molding station is equipped with the above-mentioned injection molding stations.
Let the injection molding cycle time at the station be T
At each injection molding station, the injection start timing
Injection of the preform by shifting T by approximately T / M time
Molded and moved the neck mold in the order that injection molding was completed
Remove the unit from the injection molding station
After the temperature control station became
Move to the shaping station and carry out the blow molding process,
And the temperature control cycle time at the temperature control station,
During the blow molding cycle at the blow molding station
And N / T / M time respectively, and the transfer line in the first row of the neck type moving unit is set to the above.
Temperature control station, the blow molding station and
Injecting station is installed, and the transfer line of this first row
The above-mentioned injection molding lines are connected to a plurality of rows of transfer lines in parallel with
Stations are installed one by one and the injection molding station
Temperature control station, blow molding station and
The same number of neck type movements as the total number of eject stations
An injection stretch blow molding method characterized in that the unit is circulated to each station . 3. The neck type moving unit according to claim 1 or 2 , wherein the number of the neck type moving units to be circulated and conveyed is set to be one more than the total number of the stations, and the number of the neck type moving units is set to one on any transfer line other than the respective stations. An injection stretch blow molding method characterized in that the neck type moving unit is made to stand by.