JPH018346Y2 - - Google Patents

Description

[Detailed description of the invention] [Field of industrial application] The present invention relates to the structure of a flooring that is assembled and used in an extruder die, and eliminates the black line that is the joint between the synthetic resin material and the masterbatch. It is intended for this purpose.

[Conventional technology]

A die 1 (see Fig. 1) of an extrusion molding machine has an extrusion passage 8 for extruding the synthetic resin material from the extruder 11, and a flooring is used to limit the passage area of this extrusion passage 8 as necessary. is now ready to be assembled.

This flooring regulates the amount of molten synthetic resin material extruded at one time from the extruder 11 according to the scale of the molding device connected to the die 1.
It is designed to be detachably attached to the head 2 which is the main part of the die 1.

Since the conventional flooring simply regulated the passage area of the extrusion passage 8 and set it to a constant value, its shape was a simple straight cylindrical shape.

By the way, when blow molding a synthetic resin bottle using an extruder 11 and die 1 as shown in FIG. 1, it is common to add pigments to the synthetic resin material used as the molding material to decorate with color. is being carried out.

When molding a blow bottle with this color decoration, especially when applying a light color decoration, the separation of the virgin material and masterbatch in the hopper will cause the seam line between the virgin material and the masterbatch to be (black lines) often appear on blow bottles, which are molded products.

This black line appears because the virgin material and masterbatch are not sufficiently stirred, but conventionally the synthetic resin material and pigment are stirred only on the extruder 11 side. However, no stirring means was provided on the die 1 side.

Since the stirring means on the extruder 11 side utilizes the rotational action of a screw almost without exception, its stirring ability is not constant and can be increased or decreased as necessary.

Further, the reason why stirring means was not provided on the die 1 side was because there was a risk of making the structure of the die 1 unnecessarily complicated, and there was no suitable stirring means.

[Problems to be solved by the invention] However, as mentioned above, when applying light-colored decoration, the degree of agitation on the extruder 11 side may be insufficient, resulting in the occurrence of black lines. Therefore, there was a desire for more thorough stirring, but there was no suitable means to meet this demand.

[Means for solving problems]

The present invention was devised to meet the demands of the above-mentioned conventional example, and the flooring provided in the extrusion passage 8 in the die 1 is
This flooring was designed to provide stirring ability to the flooring, focusing on the fact that it provides a large flow resistance to the synthetic resin material and pigments passing through the flooring.

Below, FIGS. 1 and 2 show examples of the present invention.
This will be explained with reference to the figures.

The flooring 5 according to the present invention is assembled to the die 1 to limit the passage area of the extrusion passage 8 formed in the die 1 assembled to the extruder 11, and includes a main body 5a having a linear cylindrical shape. It is constructed by carving a spiral groove 6 on the inner circumferential surface.

The spiral groove 6 is designed to stir the molten synthetic resin material passing through the flooring 5 by disturbing the streamlines of the molten synthetic resin material, so it has a relatively large width and depth. It is molded with a relatively small pitch.

[Effect]

Since the flooring 5 according to the present invention has the above-described structure, when the molten synthetic resin material mixed with the masterbatch is extruded from the extruder 11, the extruded molten synthetic resin material passes through the extrusion passage 8 in the die 1. However, when passing through the flooring 5 section of the extrusion passage 8, the flow rate is regulated by this flooring 5, so the flow resistance at this flooring 5 section becomes large, and The flow velocity increases.

Since the spiral groove 6 is carved on the inner circumferential surface of the flooring 5 where the flow resistance and flow velocity of the molten synthetic resin material become large in this way, the spiral groove 6 allows the molten synthetic resin material to flow through the flooring 5. The synthetic resin material will be vigorously stirred to achieve sufficient agitation between the synthetic resin material and the masterbatch.

When the molten synthetic resin material that has been sufficiently stirred in the flooring 5 section passes through the flooring 5 section, its flow velocity and flow resistance return to the state when it was extruded from the extruder 11, and it becomes a stable fluid state. It is extruded from the extrusion port 9 and formed into a parison.

〔Example〕

In the illustrated embodiment, the die 1 includes a head 2 which is the main body of the die 1, a die head 3 that is detachably attached to the tip of the head 2 (lower end in the illustrated embodiment), and a die head 3 that is detachably attached to the tip of the die head 3. A die ring 4 that sets the dimensions of the parison to be assembled and molded, and a mandrel 7 that forms an air passage 10 inside and is assembled and positioned at the center of the die 1.
It is composed of.

The flooring 5 is assembled into the extrusion passage 8 inside the tip of the head 2 described above, and can be attached and detached by attaching and detaching the die head 3.

[Effect of idea]

As is clear from the above explanation, since the flooring according to the present invention has spiral grooves carved on its inner circumferential surface, the molten synthetic resin material and pigment that pass through this flooring part are mutually stirred violently. This makes it possible to reliably prevent the occurrence of black lines, and since it has a simple structure of simply carving a spiral groove on the inner circumferential surface, it is easy to manufacture, and its usage is easy. Since it is exactly the same as the conventional one, it does not require any special operation for use, so it is easy to implement and exhibits many excellent effects.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal sectional view showing an embodiment of an extrusion die in which a flooring according to the present invention is assembled.
FIG. 2 is a partially cutaway overall perspective view showing one embodiment of the flooring according to the present invention. Explanation of symbols, 1...Dice, 2...Head, 3
...Die head, 4...Die ring, 5...Flooring, 5a...Main body, 6...Spiral groove, 7...
Mandrel, 8... Extrusion passage, 9... Extrusion port, 1
0...Air path, 11...Extruder.

Claims (1)

[Scope of utility model registration request] A straight cylindrical main body 5 which is a flooring assembled to the die of an extrusion molding machine to limit the flow area of an extrusion passage formed in the die.
A flooring in an extruder die, which is formed by carving a spiral groove 6 on the inner circumferential surface of a.