JPS6189014A - Method of injection molding parison - Google Patents

Abstract

PURPOSE:To complete the cooling of a parison before it reaches a removing section, by molding parison at an injection molding section, and transporting the parison to cooling sections successively to be cooled stepwise. CONSTITUTION:A parison 16 is molded at an injection molding section A, and then is transported by rotating a disk 3 90 deg. to a first cooling section B1. Then, a neck mold 4 and a cooling mold 12 are closed to confine the parison 16 therein, and a cooling core 14 is inserted into the parison to cool it. Then, the disk 3 and the neck mold 4 are rotated 90 deg. to transport the parison to a second cooling section B2, where the neck mold 4 and the cooling mold 12 are closed and the cooling core 14 is inserted into the parison to cool it. By this stepwise cooling, the parison 16 is cooled to room temperature to solidify, and after the mold opening, the parison is transported by the rotation of the disk 3 to a removing section C where it is separated from the neck mold 4.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to a lanceless injection molding method used for stretch blow molding of synthetic resin hollow molded articles.

(Prior Art) One of the stretch blow molding methods for blow molded products is called the cold parison method. Is this method better than traps such as injection molding? This is a molding method in which linone is molded, the required amount of the parison is reheated to the stretch blowing temperature, and used to mold a hollow molded product.

In this method, after controlling the temperature of injection molded crinone,
Hola l-z for immediate stretch blow molding? Compared to IJ Sonon, it is suitable for mass production and has the advantage of easier production adjustment.

However, this mass productivity also depends on the amount of parison supplied, and if there is not a large amount of stock and the formed /4 linone is immediately subjected to stretch blow molding, mass productivity cannot be fully demonstrated.

(Problems to be Solved by the Invention) The e-linon used in the cold parison method is molded using a commonly used multi-cavity injection molding machine. The cooling time of the parison becomes a bottleneck, and the production volume per hour is limited.In order to continuously supply parison to one stretch blow molding machine, multiple injection molding machines are required. It is said that

Therefore, as a method for mass production by shortening the cooling time, some methods include cooling the parison with the injection mold until it is ready to be released from the mold, and cooling and solidifying it immediately after taking it out, such as in a freezing room. It is being carried out in

The problem with methods that employ such cooling means is that
Due to insufficient curing of the yarn during demolding, the yarn may bend into a banana shape during transfer to the freezing room, and the thread formed on the outside of the neck may be easily damaged or deformed. Moreover, in addition to the injection molding machine, a freezing chamber and its ancillary equipment are required, which requires a large amount of equipment costs.

(Means for Solving the Problems) This invention was devised to solve the above-mentioned conventional problems, and its purpose is to provide a device for cooling Yarinon in addition to injection molding machines. A new parison injection method that uses a circulating transfer means that moves intermittently to continuously cool and take out the parison from injection molding, thereby shortening the molding cycle and enabling mass production. The object of the present invention is to provide a molding method.

Another object of the present invention is to provide a new method in which a plurality of injection devices are disposed for one circulation transfer means, and parisons can be continuously cooled and taken out from injection molding at a plurality of locations on the circulation transfer means. A method of injection molding a parison is provided.

According to the invention, an injection molding section, at least two cooling sections, and a take-out section are set in order at a stop position of a circulation transfer means that stops at regular intervals, and in the injection molding section, After molding, the parison is held in the neck mold on the side of the circulation transfer means and is sequentially transferred to the two cooling sections for stepwise cooling. Characterized by completion.

As the circulation transfer means, a disk which is rotated horizontally or vertically by a drive device operated by electric or hydraulic power can be adopted, and a required number of neck molds are attached to the stop position on the circulation transfer means side. It is. This neck mold has a structure in which it closes with the mold of the injection molding section and the mold of the cooling section which are arranged in order at each stop position of the circulation transfer means, and also closes in the radial direction Km at the take-out part. is formed between this neck mold, a closed injection mold, and a core mold inserted into both, and the neck mold is formed between the injection mold and the core mold after opening the injection mold and the core mold. Hold the neck of the parison together with the threaded part formed in z? I
Transport J-nn.

The injection mold and the cooling mold are provided movably relative to the neck mold provided in the circulation transfer means, and a hydraulic device may be employed as the moving device.

The above-mentioned circulation transfer means basically has four stopping positions,
The injection molding section, two cooling sections, and a take-out section are arranged in order at each of the stopping positions, but in order to further improve productivity, the number of stopping positions is increased to eight, and each of the opposing stopping positions is By arranging an injection molding section, a cooling section, and a take-out section, it is also possible to mold parisons at two locations at the same time.

Injection molding of the above-mentioned 9 linone is carried out as usual, and cooling hardening is carried out in an injection mold cooled to 5° to 50°C. This cooling is done for a short time (7 to 1
2 sec), the mold release is immediately performed. The surface temperature just released from the mold is the same as the thickness of the parison (2.5 to 6.0
mm), but the temperature is between 70° and 150°C, except for the neck part held in the neck mold, and as the entire part is not sufficiently cured, it deforms while being transferred to the first cooling section. However, the neck held by the neck mold is cooled more quickly than other parts due to heat transfer to the neck mold, and the threaded part required for cap sealing may be deformed. maintain its accuracy. Also, the deformed portion is restored to its original shape by the cooling core inserted into the cooling section.

In the above first and second cooling, the time required for cooling the parison can be within the time required for molding and cooling the parison in the injection molding section, and cooling can be performed for a longer time than when using an injection mold. can. In addition, in order to perform cooling effectively, the mold temperature of the first cooling section (20° to 100°
It is better to set the mold temperature (5° to 50°C) lower in the second cooling section than C). Cooling is performed each time the circulation transfer means is stopped. Even if the temperature is high, by the time it reaches the ejection part at the final stop position, it will have been cooled to room temperature or close to room temperature.Furthermore, if a parison with a surface temperature of 70° to 15,000°C is cooled to a cooling temperature of 20° to
Since the mold is cooled by inserting it together with a cooled core into a mold set at 1000C, the cooling performed there is rapid cooling, and when the molding material is a crystalline resin, transparency increases.

In addition, Krinon injection molding is not limited to single layer products.
A multilayer e-IJ non having a cross-sectional structure of two or more layers can be easily molded by increasing the number of injection devices disposed in the injection molding section.

Furthermore, the number of parisons that are simultaneously injection molded and cooled can be increased by arranging them in two rows.

(Example) The drawing schematically shows a rotary-type Molinon injection molding machine used to carry out the present invention, and l is a machine stand 2.
A support plate is fixed above, and a disk 3 serving as a circulating transfer means is rotatably attached to the underside of the support plate 1.

Four neck shapes 4° 4 are provided on all sides of the lower surface of this disk 3 so as to be able to open and close in the radial direction, and in the center there is a rotating shaft 6 of the drive device 5 fixed to the upper part of the support plate 1. is a penetration. The drive device 5 is composed of a hydraulic actuator having a rotation range of 90 degrees, and an arm member 7 that rotates the disc 3 by 90 degrees is connected to the tip of a rotation shaft 6.

The stopping positions of the disk 3, that is, the positions where the neck molds 4, 4 stop, are the injection molding part A, the two cooling parts Bl,
It is set as B2 and take-out part C.

The injection molding section A includes an injection mold 10 equipped with a mold clamping device 8, an injection device 9, and a cooling means, and an injection core 11 inserted into the injection mold 10 by passing through the neck mold 4 from above the support plate.
and are arranged.

In the cooling parts Bl and B2, cooling molds 12 and 12 are mounted on lifting devices 13 and 13 having a machine base of φ11, and are arranged to be able to be opened and closed with respect to the neck mold 4, and cooling molds 12 and 12 are placed on the support plate to be able to open and close the neck mold 4. A device 15 is provided for inserting 14 into the parison.

Furthermore, on the support plate of the take-out part C, although omitted in the figure, there is a
A mold opening device is provided which penetrates the support plate 1 and the disc 3 and pushes open the neck mold 4 in the radial direction.

To carry out the present invention using the injection molding machine described above, first, the iE IJ Sonon 6 is molded in the injection molding section A. Next, the injection mold 10 is moved downward, the injection core 11 is moved upward, and the mold is opened. The IJ sonon 6 is transferred to the first cooling section Bl by rotating the disk 3 by 90'. and neck type 4
and the cooling mold 12 are closed, the lint 16 is housed in the mold, and the cooling core 14 is further inserted into the parison for cooling.

After the above cooling has been carried out for a predetermined period of time, the /'P IJ sonon 6 is transferred together with the neck mold 4 to the second cooling part B2 by rotating the disk 3 by 90°, and the neck mold 4 and the cooling mold 12 are closed. and cooling core] 4 and cooled for the same time as last time.

Through this stepwise cooling, the Norinon 16 is cooled to room temperature or near room temperature and solidified, and is transferred to the take-out part C by the rotation of the round holder 3 after opening the mold, and is removed from the IC mold 4 at the take-out part C. Even release from the mold is good.

Work in each of the above sections is performed simultaneously. Therefore, the molding time is the time for the injection molding part where the working time is the longest (for example, the injection time for A IJ with an average wall thickness of 4.2 m is 1Q S
ec, cooling 8SeC1 total 18 seconds) is the base time, and the time added to the mold clamping and transfer time is one molding time.

(Effects of the Invention) As described above, this invention immediately cools the injection molded ・F IJ to a predetermined temperature step by step in at least two cooling parts, so that the cooling time of the parison by the injection mold is reduced. can be shortened.

Furthermore, even if the parison is not sufficiently hardened due to high mold release temperatures, the neck, which requires molding precision, is held in contact with the neck mold, so it is easier to cool down than other parts, and it remains intact. Since it is transferred to the cooling section in its original state, it will not be deformed or damaged.

Furthermore, even if there is a limit to the cooling time in each cooling section, the cooling time required to reach the extraction section is long, and it still has the advantage of being able to change the set temperature for each cooling section, making it possible to improve quality products.・It is possible to shorten the molding time and mass-produce without using a Yarinon freezing chamber. In addition, since no special equipment or incidental equipment other than an injection molding machine is required, equipment costs can be reduced, and costs can also be reduced.

[Brief explanation of the drawing]

The drawings schematically show an injection molding machine used to carry out the parison injection molding method according to the present invention, and FIG. 1 is a plan view with the support plate removed, and FIG. 2 is a longitudinal sectional front view. l...Support plate 2...Machine base 3
... Disc 4 ... Neck mold 5 ... Drive device 8 ... Mold clamping device 9 ... Injection device fii 10 ...
... Injection mold 11 ... Injection core 12 ...
... Cooling mold 14 ... Cooling core 16
...Parison A...Injection molding part
Bl, B2... Cooling section C... Removal section

Claims (1)

[Claims] An injection molding section, at least two cooling sections, and a take-out section are set in order at the stop position of the circulation transfer means that stops at regular intervals, and after molding a parison in the injection molding section,
The parison is sequentially transferred to the two cooling sections while being held in the neck mold on the side of the circulation transfer means to perform stepwise cooling, and cooling of the parison is completed before reaching the take-out section. parison injection molding method.