JPH11245236A - Method for molding resin - Google Patents

Abstract

PROBLEM TO BE SOLVED: To easily and surely prevent the formation of burrs at the tip of a through hole from occurring by forming a projecting part in a first die toward a second die, and at the same time, arranging a deformed member on the second die side, and further, filling a cavity with a resin in such a state that the tip of the projecting part is pressed. SOLUTION: A first die 27 with a formed projecting part 19b for an ink ejection hole is arranged opposite to a second die 29, a heat insulating film 31 being interposed between these dies 27, 29. Further, the first die 27 and the second die 29 are closed and one of the ends of the heat insulating film 31 is brought into contact with the second die 29 so that the tip of the projecting part 19b for the ink ejection hole is pressing the heat insulating film 31. In this case, a recessed part 31a is formed following the deformation of the heat insulating film 31. Next, a cavity 33 between the first die 27 and the heat insulating film 31 is filled with a fluidized resin 35. Consequently, the heat insulating film 31 is surely brought into contact tightly with the second die 29 under the pressure of the resin 35. Thus moldings 37 are produced by setting the resin 35.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of molding a resin, and more particularly to a method of molding a resin for molding a molded article having a through hole.

[0002]

2. Description of the Related Art FIG. 7 shows an enlarged part of a part of an ink jet printer head. In this part, a large number of partition walls 1 are formed at intervals of, for example, about 50 to 70 μm. . An ink flow path 2 through which ink for a printer flows is formed between the partition walls 1, and an ink discharge hole 3 for ejecting ink to the outside is formed in the ink flow path 2.

[0003] A silicon substrate (not shown) provided with a heater serving as a lid is brought into close contact with the partition 1. Conventionally, the manufacture of the components of such an ink jet printer head is performed by using, for example, injection molding of the ink ejection hole 3 by using a mold in which a protrusion for an ink passage having a shape corresponding to the ink passage 2 is formed. After forming a member that is not formed,
Ink ejection hole 3 by excimer laser ablation
It is manufactured by forming.

[0004]

However, in such a conventional manufacturing method, since the ink discharge holes 3 are formed by excimer laser ablation, a dedicated excimer laser irradiating device is required, which results in cost reduction and maintenance of the device. There was a problem that management costs became very expensive.

In addition, since the ink discharge holes 3 are formed by ablation processing, soot 4 adheres to the ink discharge holes 3, and there is a problem that a large number of man-hours are required for the cleaning and removal. Therefore, the present inventor tried to form the ink ejection hole 3 by using a mold in which a protrusion having a shape corresponding to the ink ejection hole 3 was formed. When a minute gap is formed between the tip of the protruding portion and the opposing mold to prevent abrasion of the mold due to the collision, a burr is formed at the tip of the ink ejection hole 3 by the resin flowing in the gap. Problem.

The present invention has been made to solve such a conventional problem, and provides a resin molding method capable of easily and reliably preventing burrs from being formed at the tip of a through hole of a molded product. The purpose is to do.

[0007]

According to a first aspect of the present invention, there is provided a resin molding method comprising the steps of: filling a cavity formed between a first mold and a second mold with a resin in a flowing state; The resin is solidified in the cavity to form a molded article, and thereafter, the first mold and the second mold are relatively moved in opposite directions to form the molded article. In the method, a protrusion is formed on the first mold toward the second mold to form a through hole in the molded article, and the protrusion is formed on the second mold side. A deformable member that is deformed by pressing the tip of the protruding portion is arranged, and the cavity is filled with the resin in the flowing state with the deforming member pressed against the tip of the protruding portion.

According to a second aspect of the present invention, in the resin molding method according to the first aspect, the deformable member is made of a heat-resistant film and is movable along the first mold. It is characterized by. The resin molding method according to claim 3 is the resin molding method according to claim 1 or 2,
The through hole of the molded product is an ink ejection hole of an ink jet printer head.

(Function) In the resin molding method of the first aspect,
Since the cavity is filled with the resin in the flowing state while the tip of the protrusion formed on the first mold is pressed against the deformable member arranged on the second mold side, the deformable member No gap is formed between the protrusion and the protrusion.

In the resin molding method of the present invention, after the molded article is taken out, the deformable member made of a heat-resistant film is moved along the first mold, and the deformable member has no deformation mark in the cavity. Is located. In the resin molding method according to the third aspect, the through hole of the molded product is used as the ink ejection hole of the ink jet printer head.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the resin molding method of the present invention will be described below in detail with reference to the drawings. In the resin molding method of this embodiment, the components of the ink jet printer head as shown in FIG. 1 are manufactured by, for example, injection molding.

That is, FIG. 1 is an enlarged view of a part of the components of an ink jet printer head. In this component, a large number of partition portions 11 are formed at minute intervals of, for example, about 50 to 70 μm. I have. An ink flow path 13 through which ink for a printer flows is formed between the partition walls 11, and an ink discharge hole 15 for ejecting ink to the outside is formed in the ink flow path 13.

The ink discharge hole 15 has a truncated cone shape, and the inner diameter of the ink flow path 13 is, for example, 30 μm. Then, a silicon substrate (not shown) provided with a heater serving as a lid is brought into close contact with the partition 11. FIG.
3 and FIG. 3 show a first mold matrix 17 for molding parts of the ink jet printer head of FIG.

The matrix 17 is formed by integrally forming a projection 19a for an ink flow path and a projection 19b for an ink discharge hole on a mold body 19 made of, for example, brass.
The ink flow path projections 19a are for forming the ink flow path 13 shown in FIG. 1, and are formed in parallel at a small interval. The protrusion 19a for the ink flow path
Has a rectangular parallelepiped shape.

The ink ejection hole projection 19b is for forming the ink ejection hole 15 shown in FIG.
It is integrally formed on the upper surface of the ink flow path protrusion 19a. The ink flow path protrusion 19a has a truncated conical shape. In this embodiment, in consideration of durability, an electroforming mold manufactured by performing two inversions by nickel electroforming on the basis of the above-described matrix 17 is used as the first mold.

The first mold is manufactured as described below. First, as shown in FIG. 4, based on the matrix 17 manufactured as described above, an inverted hole 25a having a shape obtained by inverting the shapes of the ink flow path protrusion 19a and the ink discharge hole protrusion 19b. , 25b are formed.

The intermediate mold 25 is manufactured by performing reversal by nickel electroforming. Next, as shown in FIG. 5, a first mold 27 in which the ink flow path protrusion 19a and the ink discharge hole protrusion 19b are formed using the intermediate mold 25 described above is manufactured. The first mold 2
7 is, for example, 50 μm in order to improve the durability of the mold.
After the electroless nickel plating layer 27a having a thickness of m is grown, nickel electroforming is performed to grow the electroless nickel plating layer 27a to a predetermined thickness.

Hereinafter, the resin molding method of this embodiment will be described in detail. In this embodiment, as shown in FIG.
First mold 27, second mold 29 and heat insulating film 3
1 is used to mold the resin, and the components of the ink jet printer head as shown in FIG. 1 are manufactured. The first mold 27 is manufactured by the above-described method. The first mold 27 is formed with an ink flow path protrusion 19a and an ink discharge hole protrusion 19b.

The first mold 27 and the second mold 29 are arranged to face each other, the first mold 27 is a movable mold, and the second mold 29 is a fixed mold. A heat insulating film 31 is arranged between the first mold 27 and the second mold 29. In this embodiment, for example, Kapton tape manufactured by Sumitomo 3M is used for the heat insulating film 31.

This Kapton tape has, for example, a heat resistance temperature of 260 ° C. and a thickness of 70 μm. In this embodiment, both sides of the long heat insulating film 31 are wound around a roll (not shown), and are movable along the first mold 27 by rotating the roll. .
In the resin molding method of this embodiment, first, FIG.
As shown in (b), from the state where the first mold 27 and the second mold 29 are opened, the first mold 27 is moved toward the second mold 29, and as shown in (b). Then, the first mold 27 and the second mold 29 are closed.

In this state, one side of the heat insulating film 31 is in contact with the second mold 29, and the tip of the protrusion 19 b for the ink discharge hole is pressed against the heat insulating film 31. The tip of the ink ejection hole protrusion 19b and the second mold 2
9 is, for example, from 60 μm to 65 μm, whereby a concave portion 31 a having a depth of 10 μm to 5 μm is formed in the heat insulating film 31 having a thickness of 70 μm by deformation of the heat insulating film 31. .

Then, the first mold 27 and the heat insulating film 3
1, a cavity 33 is formed. The cavity 33 is filled with a resin 35 in a flowing state, and the pressure of the resin 35 causes the heat insulating film 31 to move into the second mold 29.
Is firmly adhered to. The temperature of the resin 35 is, for example,
The temperature is about 160 ° C., and the heat insulating film 31 is not damaged.

Then, a molded article 37 is manufactured by solidifying the resin 35 in the cavity 33. After this,
As shown in (c), the first mold 27 is connected to the second mold 2.
9 is moved to the opposite side. Then, in this state, a roll (not shown) is rotated to apply tension to the heat insulating film 31, whereby the heat insulating film 31 is peeled off from the second mold 29, and the concave portion 31a formed on the heat insulating film 31 is formed. Is moved to the outside of the cavity 33 together with the heat insulating film 31.

Thereafter, the molded article 37 is taken out of the first mold 27 by operating an ejector pin (not shown) arranged on the first mold 27. In the resin molding method according to this embodiment, the tip of the ink discharge hole projection 19b formed in the first mold 27 is pressed against the heat insulating film 31 disposed on the second mold 29 side. Since the cavity 33 is filled with the resin 35 in a flowing state, the heat insulating film 31 and the protrusions 19b for the ink discharge holes are formed.
No gap is formed between them, thereby making it possible to easily and reliably prevent burrs from being formed at the tips of the ink ejection holes 15 of the molded product 37.

In the resin molding method described above, after the molded article 37 is taken out, the heat insulating film 31 is moved along the first mold 27. The heat insulating film 31 without a certain concave portion 31a can always be used. In the resin molding method described above, the ink ejection holes 15 of the inkjet printer head having no burrs at the tip can be easily and reliably obtained.

In the above-described embodiment, an example has been described in which the heat insulating film 31 is movably arranged. For example, a deformable member having elasticity and high durability is fixed to the second mold 29. You may do it.

[0027]

As described above, according to the resin molding method of the first aspect, the tip of the projecting portion formed on the first mold is
In a state where it is pressed against the deformable member arranged on the second mold side,
Since the cavity is filled with the resin in a flowing state, a gap is not formed between the deformable member and the protruding portion, whereby a burr is formed at the tip of the through hole of the molded product. Can be easily and reliably prevented.

In the resin molding method according to the second aspect, after the molded article is taken out, the deformable member made of a heat-resistant film is moved along the first mold, so that the deformable member having no trace of deformation is removed. Can always be used. According to the resin molding method of the third aspect, it is possible to easily and reliably obtain an ink ejection hole of an ink jet printer head having no burrs at the tip.

[Brief description of the drawings]

FIG. 1 is a perspective view showing parts of an ink jet printer head manufactured by a resin molding method of the present invention.

FIG. 2 is a perspective view showing a mother die of a first mold used in the resin molding method of the present invention.

FIG. 3 is an enlarged perspective view showing a main part of FIG. 2;

FIG. 4 is an explanatory view showing a method of manufacturing an intermediate mold manufactured based on the matrix shown in FIG. 2;

FIG. 5 is an explanatory view showing a method of manufacturing a first mold manufactured based on the intermediate mold of FIG.

FIG. 6 is an explanatory view showing one embodiment of the resin molding method of the present invention.

FIG. 7 is an explanatory diagram showing parts of the ink jet printer head.

[Explanation of symbols]

 15 Ink ejection hole 19b Ink ejection hole protrusion 27 First mold 29 Second mold 31 Heat insulation film 33 Cavity 35 Resin 37 Molded product

Claims (3)

[Claims] After filling a cavity formed between a first mold and a second mold with a resin in a flowing state, the resin is solidified in the cavity to form a molded product. After that, in the resin molding method for relatively moving the first mold and the second mold in opposite directions and taking out the molded product, the first mold and the second mold Forming a protrusion for forming a through hole in the molded product, and disposing a deformable member that is deformed by pressing the tip of the protrusion on the second mold side. And filling the cavity with the resin in the flowing state with the tip of the protruding portion pressed against the deformable member. 2. The resin molding method according to claim 1, wherein the deformable member is made of a heat-resistant film and is movable along the first mold. . 3. The resin molding method according to claim 1, wherein the through hole of the molded product is an ink ejection hole of an ink jet printer head.