JPH04323018A - Molding of bent synthetic resin product - Google Patents

Abstract

PURPOSE:To provide the blow molding of a high commercially valuable bent product having no development of flash and the like at the parting line on the outer surface of the product. CONSTITUTION:Parison 2 is extruded from a die 1 and bent so as to form a bent parison 2. The bent synthetic resin product concerned is produced by blow-molding the bent parison 2 under the state being pinched between molds 7 and 8.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a blow molding method for folded synthetic resin products in which the upper part of the product is bent in the transverse direction.

0002

[Prior Art] Conventionally, as a method of forming a bent-neck bottle, which is a folded product with a head bent in the transverse direction, a parison is formed to have a large diameter, and the shape of the cavity of the parison is There is a method of forming a curved-neck bottle by sandwiching the parison with a mold formed in the shape of a curved bottle, cutting off the unnecessary part of the parison at the periphery of the cavity of the mold, and blow-molding the remaining parison. .

[0003] In the bent-neck bottle molded by the above-mentioned molding method, unnecessary portions of the parison are cut off by the mold, so that burrs protrude at the parting line, reducing the commercial value of the product.

0004

[Problems to be Solved by the Invention] The present invention has been made in view of the above-mentioned problems, and is a blow molding method for folded products that does not generate burrs or the like on the parting line on the outer surface of the product and has high commercial value. The technical challenge is to

[0005]

[Means for Solving the Problems] The first invention is a synthesis method in which a parison is extruded from a die, the parison is bent to form a bent parison, and the bent parison is sandwiched between molds and blow-molded. A method for forming folded resin products.

[0006] In the second invention, a bending core rod 32 is inserted into the parison 2 extruded from the die 1, and this core rod 3
2 with its tip 33 as the center of rotation, the parison 2 is bent near the tip 33 of the core rod 32, the parison 2 is moved to a position that matches the cavity 9, and the mold 6 is turned. After the core rod 32 is extracted from the parison 2, the bottom bush 11 of the mold 6 is closed and blow molded.

[0007] The third invention is a parison guide part 1 provided in one of the molds 8, for holding the parison 2 extruded from the die 1.
2 to press and bend the parison 2 to form a bent parison 2, and blow molding by sandwiching the bent parison 2 between one mold 8 and the other mold 7. This method was used to form folded products.

[0008]

[Function] In the present invention, the parison 2 extruded from the die 1 is bent and sandwiched between molds for blow molding, so no unnecessary parts are generated in the parison. Therefore, the parison is not eaten away by the mold, and no burrs or the like are generated on the parting line.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a diagram for explaining one embodiment of the present invention, and the molding machine shown in FIG. 1 is an index type molding machine. In this molding machine, a mold 6 is provided facing inside mold mounting boards 20 (only one mold mounting board etc. is shown in FIG. 1) which are provided facing each other so as to be movable forward and backward by a bar 21.

[0010] The cavity 9 of the mold 6 has a portion extending in the vertical direction for molding the neck portion of the bent-neck bottle to be molded, and a cavity 9 for molding the body portion of the bent-neck bottle to be molded has an inclined portion. It is provided as follows. A bottom bush 11 is provided in this mold 6 in contact with the bottom side of the cavity 9 so as to be slidable in the front-rear direction that is perpendicular to the parting line 10.

Further, an arc-shaped guide rail 25 is provided between the mold mounting plates 20 and extends vertically in a direction parallel to the parting line 10. The center of the arc of the arc-shaped guide rail 25 is centered on the upper part of the inclined portion of the cavity 9 formed in the mold 6.

A holder 26 is slidably mounted on the guide rail 25 with rollers 27. This holding body 26 is provided with a first air cylinder 30. Further, a bending core rod 32 is provided so as to be movable toward the center of the arc of the guide rail 25.

The core rod 32 is connected to the first rod 31, which is moved forward and backward by the first air cylinder 30, so that it can move forward and backward.

A second air cylinder 40 is provided at the upper end of the guide rail 25, and the tip of the second rod 41 of the second air cylinder 40 is connected to the holder 2.
6 is pivotably attached to the shaft. Then, the holding body 2
6 is formed so that it can be turned by the second rod 41 of the second air cylinder 40 according to the guide rail 25.

In order to mold a bent neck bottle using the molding machine, the second rod 41 of the second air cylinder 40 is advanced, the holder 26 is positioned at the lower end of the guide rail 25, and the first air cylinder 30 is The first rod 31 is moved back, and the bending core rod 32 is moved back and placed on standby.

Then, a parison 2 made of synthetic resin is extruded from the die 1. Then, the core rod 32 is advanced by the first air cylinder 30, and the core rod 32 is inserted into the parison 2.

Next, the second rod 41 of the second air cylinder 40 is moved backward, and the holding body 26 is rotated and pulled upward. Then, the core rod 32 provided on the holder 26 rotates around its tip 33 as the center of rotation.

Then, the parison 2 is bent near the tip 33 of the core rod 32, and the parison 2 is moved to a position where it matches the cavity 9. Therefore, mold 6
is closed and the mold is clamped, and the core rod is retreated and extracted from the parison 2, and then the bottom bush 11 of the mold 6 is closed.

Then, air is blown into the parison 2 to mold a synthetic resin bottle with a bent neck.

[0020] Although the above embodiment is for molding a bottle with a bent neck, the present invention can be applied to other products as long as it is blow molding of a bent product by bending a parison.

FIG. 2 is a diagram for explaining another embodiment of the present invention, and the molding machine shown in this diagram is an index type molding machine.

[0022] This molding machine is equipped with mold mounting boards 20, 20 mounted opposite to the bar 21, and the mold mounting boards 20, 20 are mounted opposite to the center part where the die 1 is provided. , are installed so that they face each other and move forward and backward.

Inside the mold mounting plates 20, 20, one mold 8 and the other mold 7 are provided facing each other. The molds 8 and 7 are provided such that the portions for molding the neck portion of the bent-neck bottle 45 to be molded face each other and extend in the vertical direction.

In the part where the cavity 9 for molding the body of the bent-neck bottle 45 is provided, the parting line 10 is inclined so that the lower part of one of the molds 8 protrudes toward the center. be.

As shown in FIG. 3, the front surface of the bottom bush 11 provided in one of the molds 8 is formed into a parison guide portion 12 formed as a vertically elongated recess.

In the molding process using the molding machine, first, the parison 2 is extruded from the die 1 between the opened molds 8 and 7, and the lower end of the parison 2 is placed in front of the parison guide portion 12 of the one mold 8. Extrude until it is located at .

Next, the molds 8 and 7 are advanced toward the center. Then, the lower part of the parison 2 is pressed by the parison guide portion 12 of one of the molds 8 and bent. This bent parison 2 is placed in the cavity 9 of the molds 8 and 7.
The bottle 45 is sandwiched between the plastic bottles 2 and 2, and the mold is clamped, and air is blown into the Parisan 2 to form a synthetic resin bottle 45 with a bent neck.

[0028]

According to the present invention, the parison extruded from a die is bent and sandwiched between the molds, so that the parison is bent into a shape that matches the shape of the cavity and is sandwiched between the molds.

[0029] Therefore, parts other than the bottom of the parison are not cut off by the mold, and burrs etc. do not occur on the parting line of the product, making it possible to blow mold a synthetic resin folded product with high commercial value. .

Furthermore, the second invention is capable of accurately bending a desired portion of the parison, and the third invention is capable of clamping the mold at the same time as folding the parison. The molding time does not become long, and since the parison is folded using a mold, a separate device for folding the parison is not required, and the structure of the molding machine does not become complicated.

[Brief explanation of drawings]

FIG. 1 is a diagram for explaining one embodiment of the present invention.

FIG. 2 is a diagram for explaining another embodiment of the present invention.

FIG. 3 is a diagram showing a parison guide section used in the embodiment of FIG. 2;

[Explanation of symbols]

1. dice 2. parison 6. Mold 7. the other mold 8. one mold 9. cavity 11. bottom bush 12. Parison guide section 32. core rod 33. tip

Claims (3)

[Claims] 1. A method for molding a folded product made of synthetic resin, in which a parison is extruded from a die, the parison is bent to form a folded parison, and the folded parison is sandwiched between molds and blow-molded. 2. A core rod 32 for bending is inserted into the parison 2 extruded from the die 1, and the core rod 32 is turned around its tip 33 as the center of rotation to bend the parison 2. , by bending the core rod 32 near the tip 33,
After the parison 2 is moved to a position that matches the cavity 9, the mold 6 is clamped, and the core rod 32 is extracted from the parison 2, the bottom bush 11 of the mold 6 is closed and the synthetic resin is blow-molded. A method for forming folded products. 3. The parison 2 extruded from the die 1 is pressed by a parison guide section 12 provided in one of the molds 8 to bend the parison 2 to form a bent parison 2, and to form a bent parison 2. A molding method for a synthetic resin folded product in which the bent parison 2 is sandwiched between a mold 8 and the other mold 7 and blow molded.