JPS6096434A - Injection blow molding method - Google Patents

Abstract

PURPOSE:To enable to make parison obtained by injection molding into a bottle of a desired shape through stretching blow molding by making use of a single mold masking a split type switch gear unnecessary, by a method wherein a neck mold is formed of a mouth part molding tool and a shoulder part molding tool and a shoulder part of a bottle is molded at a neck mold side. CONSTITUTION:A neck mold 1 and an injection mold 5 are clamped together, to begin with, and a core 21 is inserted by piercing through the neck mold 1 from the upper part. Then after clamping of the molds a bottomed parison 22 is molded by pouring molten resin from an injection nozzle 7 into a space ranging from the bottom of a cavity 8 to an opening part form mold 3 of the neck mold 1. Then the parison 22 is pulled out of the cavity 8 under a state wherein the opening part is held in the neck mold 1 in a pinched state, and clamping is done by making an opening end of a sholder part molding tool 4 of the neck mold 1 fit in a hollow part 13 of a blow mold 10 for mold break. Then an extending lever 24 is made to position within the parison 22 by inserting a blow pipe 23 into the neck mold 1 and a bottle 25 is molded by blowing air into the parison 22 further while the same is stretching to the bottom of a cavity 12.

Description

DETAILED DESCRIPTION OF THE INVENTION This invention relates to a method for stretch blow molding an injection molded parison into a bottle in a blow mold.

Split molds are used for blow molding overchamber bottles.

For this reason, the blowing mold is provided with a device for opening and closing a pair of split molds, and also requires an open space for the split molds. When configuring a blowing device, if the installation space for the opening/closing device and the open space for the split mold can be omitted, the machine that continuously performs parison injection molding, bottle blowing, or stretch blow molding can be simplified, and costs can be reduced. be able to.

The use of split molds in bottle blow molding is due to the shoulders preventing the molded bottle from being pulled out of the blow mold. Therefore, as a result of various studies, the inventor discovered that if the neck mold used for parison molding is used to mold the shoulder of the bottle, there is no need to configure the blowing mold into multiple split molds. They discovered this.

Therefore, an object of the present invention is to provide a new method for stretch blow molding an injection molded parison into a bottle of a desired shape using a single mold that does not require a split mold opening/closing device. be.

Another object of the present invention is to configure the neck mold with a mouth mold and a shoulder mold, and use the mouth mold when injection molding the parison and the shoulder mold when blow molding. An object of the present invention is to provide a new injection blow molding method that allows a molded bottle to be extracted from a blow mold.

The features of this invention for the above-mentioned purpose include a split neck mold with a bottle shoulder mold integrally provided on the lower side of the one-mouth mold, and a flange provided at the cavity opening to fit inside the shoulder mold. A step of molding a parison using a molded injection mold; and a step of molding a parison with the parison held between a neck mold and a single blowing mold equipped with a cavity for molding the lower side from the body of the bottle. After closing and forming a molding cavity for the bottle with the shoulder mold and the blow mold, the parison is blow molded into the bottle, and the molded bottle etc. is held in the neck mold while the mold cavity is formed. The purpose is to simplify the blowing device and to rationalize and reduce costs of injection blowing or injection stretch blow molding machines.

The present invention will be explained in detail below using injection stretch blow molding as an example.

In the figure, 1 is a neck type, which consists of a pair of split molds attached to the lower surface of the transfer board 2 so as to be openable and closable. This neck mold 1 includes a mouth mold 3 and a shoulder mold 4 integrally provided on its lower side l. ! −
Force 5 is provided and the mouth of the injection molded bottle is made! During blow molding, the shoulders connected to the bottle mouth can be individually molded.

Reference numeral 5 denotes a single injection mold for molding parinone fixed on the mold clamping plate O, with an injection nozzle 7 located at the bottom.

ing. The cavity opening of the injection mold 5 is provided with a ridge 9 that fits into the shoulder mold 4 and forms a parinon molding cavity 8 together with the mouth mold 6.

Reference numeral 10 denotes a blowing mold, which is composed of a single mold fixed on a base plate 11 that can be raised and lowered, and has a cavity 12 for molding the lower side from the inner barrel body, and an opening of the cavity 12. A recess 13 is formed around the periphery, into which the mouth end of the beveled shoulder mold 4i fits.

The opening of the cavity 12 is formed to have the same diameter as the opening of the shoulder mold 4, and the peripheral wall of the cavity is vertical or slightly inclined outward so that the molded product can be extracted from the cavity 12. The molding method will be explained in order according to each step shown in Plan 1.

First, the neck mold 1 and the injection mold 5 are closed, and the core 21 is inserted into the center of the cavity 11 through the neck mold 1 from above the transfer plate 2. After the mold is clamped, molten resin is injected through an injection nozzle 7 into a space extending from the bottom of the cavity to the mouth mold 6 of the neck mold 1, thereby molding a parison 22 with a bottom.

FIG. 2: After molding, the injection mold 5 is moved downward together with the mold clamping plate 6 to open the mold, and the core 21 is taken out above the transfer plate 2. In this case, since the parison 22 is held at its mouth by the neck mold 1, the injection mold 5 is moved downward and the capacitance 8 is ejected.

FIG. 6 Next, the parison 22 is transferred together with the neck mold 1 to the position of the blow mold 10. Then, the blow mold 1o is raised together with the base plate 11, and the mold is closed with the neck mold 1. By closing the mold, the parison 22 is located at the center of the cavity 12, and the open end of the shoulder mold 4 fits into the recess 13, so that the mold surface of the shoulder mold m4 and the cavity 12 are connected. A cavity for bottle molding is formed in which the mold surfaces are in flush contact with each other.

When the above mold closing is completed, the blowing pipe 26 is inserted into the neck mold 1.
is inserted, the extension rod 24 is positioned within the parison, and the parison 22 is further extended to the bottom of the cavity while air is blown in to form the bottle 25.

Figure 4 After completing the molding of the bottle 25, the blow mold 1° is placed on the base plate 1.
1 and move downward to open the mold.

The bottle 25 was molded using both the neck mold 1 and the blow mold 100, and the shoulder was molded on the neck mold side.
Capity 1 is held in a state of 1c without any resistance.
Exclude from 1.

The 25 molded bottles are further transported to another location together with the neck mold 1, and are released by dividing the neck mold 1.

Note that the above process can also mold a hollow molded product similar to a bottle, so the present invention is not limited to blow molding of bottles.

As described above, this invention forms a neck mold from a mouth mold and a shoulder mold, and molds the shoulder of the bottle on the neck mold side so that it can be extracted from the blowing mold. Therefore, there is no need to form the blow mold into a split mold, and there is no need for a split mold opening/closing device, so the injection blow molding machine can be configured in a smaller size, and costs can be reduced. has.

[Brief explanation of drawings]

The drawings show the injection blow molding method according to the invention,
Figure 1 is a vertical cross-sectional view of the mold during parison molding, Figure 2 is a vertical cross-sectional view of the mold during release from the mold, Figure 3 is a vertical cross-sectional view of the mold during bottle molding, and Figure 4 is a vertical cross-sectional view of the mold during bottle molding. FIG. 3 is a vertical cross-sectional view of the mold when the bottle is taken out. 1...Neck mold 3...Mouth mold 4...Shoulder mold 5...Injection mold 8...Parin molding cavity 9...Protrusion 12...Cavity 22...・Parison 25...Bottle Figure 2 7 Figure 4 2

Claims (1)

[Claims] A parison is made using a split neck mold with a bottle shoulder mold integrated into the lower side of the mouth mold, and an injection mold with a protrusion at the cavity opening that fits inside the shoulder mold. With the above-mentioned parison held in place, the neck mold and a single blowing mold equipped with a cavity for molding the lower side of the bottle body are closed, and the above-mentioned shoulder mold and After forming a molding cavity for a syringe bottle with a blow mold, a step of blow molding the above-mentioned parison into a bottle, and a mold release step of ejecting the molded bottle etc. from the blow mold while being held in the neck mold. An injection stretch blow molding method characterized by: