JPH03215009A - Molding method - Google Patents

Abstract

PURPOSE:To provide a molding method for improving the fluidity of a molding material by making a mold or dies resonate, which has a specific frequency not being a supersonic wave. CONSTITUTION:The nozzle 28 of a molding machine is brought into press contact with the sprue 23 of a fixed mold 21, and a molding material is injected into a cavity 24 via the sprue 23 so as to conduct molding. At this time, an oscillator 35 makes an excitor 30 produce vibration in order to allow a mold 20 to resonate. In this instance, the vibration frequency is made into a frequency of 10kHz or below in consideration of the shapes, dimensions and the like of the mold 20. In this manner, when the molding is effected while the mold 20 is permitted to resonate through the vibration from the excitor 30, the molding material in the mold 20 resonates together with the mold 20, so that the fluidity thereof is raised, and the speed of flow from the spure 23 to the cavity 24 rises, thereby improving the productivity.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a molding method for molding a molding material such as a polymeric material using a mold or die, and can be used for injection molding, extrusion molding, etc.

[Background technology]

Conventionally, products made of molding materials such as polymeric materials, metals, and glass have been manufactured by injection molding and extrusion molding because of their high productivity.

By the way, in the development of polymer materials, strength, rigidity,
In order to improve physical properties such as sliding properties, higher molecular weight and higher filling are being promoted.

For this reason, the fluidity of the material has deteriorated, making injection molding difficult in many cases. Furthermore, in the extrusion molding field, if the fluidity of the molding material is poor, molded products are likely to be defective, making it difficult to improve productivity.

On the other hand, as shown in Japanese Patent Publication No. 57-2088,
There is a method in which a horn for generating ultrasonic waves is provided at the gate part of an injection molding mold, and injection molding is performed while applying ultrasonic vibrations to the gate part with the horn, thereby maintaining the fluidity of the molding material in the gate part.

In addition, as shown in Japanese Patent Application Laid-Open No. 1-182016, the density of the material is increased by injecting and filling the material while subjecting all or part of the injection mold to high-speed microvibration or ultrasonic vibration. There is also a method of obtaining a dense molded product and significantly improving fluidity without generating a hardened skin layer due to heat generated by vibration.

[Problem to be solved by the invention]

However, the methods described in each of the above publications use ultrasonic vibration (generally with a frequency of 16 to 20 KHz or more),
Because the high-speed micro-vibration is close to ultrasonic vibration, the structure of the mold and die becomes extremely complex when implemented, and there is a problem that the vibration adversely affects the mold itself and other parts of the equipment. .

In addition, when applying ultrasonic vibration, it is applied without considering the effect of vibration on the mold, such as resonance of the mold, so it is not possible to apply sufficient vibration to the molding material during molding. The current situation is that it is not fully effective.

An object of the present invention is to provide a molding method that can sufficiently improve the fluidity of a molding material in injection molding, extrusion molding, or the like.

[Means to solve the problem]

The present invention makes a mold or die resonate with vibrations having a frequency of less than 10 KHz, which is not ultrasonic waves, and
This is a molding method for molding a molding material such as a polymer material.

In the present invention, when applying vibration to the mold or die, it is preferable to apply the vibration so that the resonance abdomen or node of the vibration coincides with the position of the cavity of the mold or the extrusion port of the die.

Further, in the present invention, when applying vibration to the mold or die, it is preferable to apply vibration so that the node caused by the vibration coincides with the position of the mold holding part or the die holding part.

[Effect]

In the molding method according to the present invention, when molding the molding material, vibrations of less than IOKHZ that cause the mold or die to resonate are applied, so the molding material in the mold or die also resonates due to the resonance of the mold, etc. is excited at the resonant frequency,
Its liquidity is enhanced. As a result, even molding materials with poor fluidity, such as organic polymer materials with high molecular weight,
It quickly flows into the mold cavity or flows through the extrusion port of the die, increasing the molding speed and improving productivity. In addition, since the fluidity is increased, the filling performance into the cavity of the mold or the extrusion port of the die is also improved, and the molded product can be shaped more precisely.

〔Example〕

Embodiments of the present invention will be described below with reference to the drawings.

1 and 2 show an embodiment of an injection molding apparatus using the molding method of the present invention.

In FIG. 1, the injection molding apparatus lO according to this embodiment includes a base 11, and a mold clamping cylinder l2 is fixed to the base 11.

An end plate l3 fixed to one end of the mold clamping cylinder l2 has one end of a plurality of rods l4, for example, eight rods l4, two each on the top, bottom, left and right, fixed to the other end of these rods l4. A mounting plate l5 for mounting a fixed mold divided into four parts, that is, as a mold holding part, is fixed.

On the other hand, in the piston rod l6 of the mold clamping cylinder l2,
A sliding plate l7 that is slidable along the rod l4 is fixed, and this sliding plate l7 is divided into four parts vertically and horizontally via a plurality of tie rods l8, for example, eight tie rods (two each on the top, bottom, left and right). A mounting plate l9 for mounting the movable mold, that is, as a mold holding part, is fixed.

A fixed mold 21 is installed between the one four-divided mounting plate 15.
A substantially central portion of the movable mold 22 is fixedly held, and a substantially central portion of the movable mold 22 is fixedly held between the other four-divided mounting plate 19.

The fixed mold 2l is held by the mounting plate 15 by fitting the tapered edge 15A of the mounting plate 15 into a groove 21A provided on the outer circumference of the fixed mold 2I, as shown in FIG. This is done by combining the Therefore, the fixed plate l5
The fixed mold 2l is held by line contact, and the contact area between the fixed mold 2l and the fixed plate l5 is extremely small.

Similarly, the movable mold 22 is held by the mounting plate 19 by fitting the tapered edge 19A of the mounting plate 19 into the groove 22A provided on the outer periphery of the movable mold 22, so that both is assumed to be held by line contact.

A mold 20 is constituted by the fixed mold 2l and the movable mold 22, and a sprue 23 is provided in the fixed mold 21, and a sprue 23 is provided on the contact surface of the movable mold 22 with the fixed mold 2l. A cavity 24 is provided which can communicate with the sprue 23. Further, a nozzle 28 of a molding machine (not shown) is inserted into the fixed mold 2l so as to communicate with the sprue 23.

Through this nozzle 28, the sprue 23 and the cavity 2
4 can be filled with molding material. At this time, the position of the abutting part of the nozzle 28 on the fixed mold 2l is set to match the position where the fixed mold 21 is fixed by the mounting plate 15, that is, the mold holding part.

A vibrating part 3l of a vibrator 30 is fixed to the end of the movable mold 22 on the opposite side from the cavity 24 via a connecting member 33 such as a screw. This vibration exciter 30 is held by the tie rod l8 via a plurality of brackets 34, and moves forward and backward together with the mounting plate l9 and the movable mold 21 as the piston rod l6 moves forward and backward. Also,
An oscillator 35 is connected to the vibrator 30, and this oscillator 3
The vibrator 30 is capable of generating vibrations of less than 1 kHz by the output signal from the vibrator 5. This oscillator 35
For example, it is of an automatic frequency tracking type, and is capable of following changes in resonance frequency due to changes in the state of the mold 20 during molding.

The vibration applied to the mold 20 by the vibrator 30 has a frequency that causes the mold 20 to resonate.

Further, as shown in FIG. 3 or 4, the wavelength that causes the mold 20 to resonate is such that there are n wavelengths with respect to the entire length of the mold 20. The wavelength is resonant. At this time, n in the n-wavelength resonance is m/2 (m is a positive integer), but the mounting plate 15.
In order to match the resonance node (the point where the displacement waveform W intersects and is not vibrating) P with the mold holding part 19 and the contact part of the nozzle 28 with the fixed mold 2l, it is necessary to It is preferable to set the number of nodes P to a small value, for example, n<3.

Furthermore, even in the case of n < 3, if it is important to improve the flow of the molding material, as shown in Fig. Vibrating point) Q is the fixed mold 2l and the movable mold 22
It is preferable that the cavity 24 is set to coincide with the cavity 24 on the contact surface with the contact surface, and resonance is made so that the vibration effect can be utilized as effectively as possible. In this way, the flow of the molding material becomes better.

On the other hand, when it is important to reduce the dimensional shrinkage of the molded product, it is preferable to align the cavity 24 with the resonance node P, as shown in FIG. In this way, the dimensional shrinkage of the molded product is significantly reduced due to the stress effects of the vibrations in the resonant state.

Further, the method of generating vibration in the vibrator 30 is not particularly limited, but examples include a cam-crank type,
A mechanical method such as an unbalanced weight method, an electromagnetic electrical method, an electro-hydraulic method, etc. can be used.

However, an electrodynamic type vibrator, which is a type of electric type, is preferable because it can also apply high-frequency vibrations.

Further, as the vibration mode, known vibration modes such as longitudinal vibration, lateral vibration, torsional vibration, radial vibration, and flexural vibration can be used.

Further, the timing of the oscillation that applies vibration to the mold 20 may be an appropriate time from the start of mold clamping to the time when the mold is opened.

The mold 20 can be made of metal, ceramics, graphite, etc., but it is also possible to use a material that has less transmission loss of the vibration of the vibrator 30 and less fatigue even when the amplitude of the vibration is increased, such as titanium alloy, It is preferable to use K-monel, phosphor bronze, duralumin, or the like.

Conversely, when heating a part of the molded product within the mold 20,
A material having a large vibration transmission loss, that is, a material that generates heat due to vibration, may be provided in the portion of the mold 20 to be heated.

Furthermore, the surface of the mold 20 may be subjected to treatments such as plating, coating, and even graining, if necessary. Furthermore, the mold 20 can be divided into three or more pieces, but in this case, the dividing plane should be placed as close to the resonant abdomen Q as possible in order to improve the transmission of vibrations by the vibrator 30. It is preferable to locate the

Furthermore, the mold 20 can be equipped with a mechanism that converts the direction of vibration, and if this vibration conversion mechanism is installed at the position that becomes the node P at the time of resonance, a part of the mold 20 can be installed. It is also possible to resonate only the

In addition, known methods can be used for controlling the temperature of the mold 20, ejecting the molded product, and the like. On this occasion,
A joint attached to the mold 20 for introducing or discharging the mold temperature control medium into the mold 2o is a joint P.
It is preferable to mount it near the mount to avoid vibration fatigue of the mount. In addition, when providing an ejector pin for a molded product in the mold 20, use an ejector pin that has been surface-treated to improve slippage, and make sure that the clearance between the ejector pin and the hole through which it passes is adjusted before ejecting. It is preferable to set the minimum value at the position of the resonance node P in the state of .

Furthermore, when spraying a liquid material for coating a molded product into the mold 20, the resonance belly Q in the mold 20 is
It is preferable to provide a spray nozzle.

In this way, when the mold 20 is resonated and sprayed,
The liquid substance can be made into fine particles by the action of resonance.

Next, the operation of this embodiment will be explained.

The mold clamping cylinder 11 of the injection molding apparatus 10 is driven to clamp the fixed mold 2l and the movable mold 22 at a predetermined pressure. In this state, the nozzle 28 of the molding machine (not shown) is connected to the fixed mold 2.
1, and molding material is injected into the cavity 24 through this sprue 23 to perform molding. At this time, the mold 20 is caused to resonate by causing the oscillator 35 to generate vibrations. The timing for generating vibrations of the vibrator 30 can be selected depending on the desired effect.

The vibration frequency at this time can be selected arbitrarily, but in order to make the vibration effect extremely effective on the material during molding,
Considering the shape and dimensions of the mold 20, 100Hz~lOK
Preferably, the frequency is less than Hz. The larger the amplitude of the vibration of the vibrator 30, the more effective it can be, but it is preferable to set it in accordance with the fatigue strength of the material of the mold 20.

When the mold 20 is molded while being resonated by the vibrations from the vibrator 30 as described above, the molding material in the mold 20 also resonates with the mold 20, increasing its fluidity, and the molding material is released from the sprue 23 into the cavity. 24 increases.

As a result, molding cycle time is shortened and productivity is improved.

Furthermore, due to the improved fluidity, the molding material can sufficiently flow into the finely shaped portions of the cavity 24, allowing precision molding to be performed.

According to this embodiment as described above, there are the following effects.

That is, since the mold 20 is caused to resonate by the vibration of the vibrator 30, the vibration can be efficiently transmitted. Furthermore, since the abdomen Q of the resonance displacement waveform W is set to be located at the joint surface between the vibrating part 3l of the vibrator 30 and the mold 20, the vibration effect of the vibrator 30 can be maximized. The fluidity of the molding material can be improved.

At this time, as shown in FIG. 3, if the abdomen Q of the displacement waveform W is located at the position of the cavity 24, that is, the contact surface between the fixed mold 2l and the movable mold 22, the entire mold 20 Combined with the resonance at It becomes easier.

On the other hand, if the node P of the displacement waveform W is located at the position of the cavity 24, as shown in FIG. The dimensional shrinkage of the molded product can be significantly reduced compared to the case where an electric current is applied. Therefore, products with excellent physical properties and dimensional accuracy can be molded.

Furthermore, the mold 20 and the mounting plate 15.19 are held together by the groove 21.
A. 22A and the tapered edges 15A and 19A, the contact area between the mold 20 and the mounting plate 15, 19 can be extremely reduced. Therefore, this mounting plate 1
This has the effect that the outflow of mold vibrations from the part 5.19 to the outside can be minimized, and other parts of the apparatus are not adversely affected. At this time, if the mold holding part by the mounting plate 15.19 is set at the node P of the resonant displacement waveform W, together with the small contact area due to the line contact, the outflow of vibration to the outside can be further reduced. can be reduced.

In addition, in the present invention, moldable molding materials include:
Materials that have some fluidity during molding include organic materials such as plastics, rubber, and elastomer pitch, inorganic materials such as inorganic polymers, ceramics, metals, and glass, other foodstuffs, and mixed materials thereof.

Injection molding in the present invention includes multicolor molding, insert molding, outsert molding, injection compression molding, injection foam molding, reaction injection molding, mixed color injection molding, magnetic field injection molding, etc. This includes all molding methods that employ a method in which a molding material in a similar state is press-fitted into a mold, shaped into a predetermined shape, and then the molded product is taken out.

(Experimental Example) Hereinafter, the results of an experiment conducted to confirm the effects of this example will be explained while comparing with a comparative example.

Using the injection molding apparatus shown in FIG. The cavity 24 formed in the mold 22 had a spiral shape, like the cavity 24A shown in FIG. The shape of this spiral is determined by the groove depth (thickness of the molded product)
is 0.31, the groove width is 2 ms, and the width between the grooves is 2 mm, and the molding material is injected from the sprue 23 into the center of the spiral. In addition, a groove having a width of 1 cm was provided in the radial direction of the circle of the spiral for venting air at the outer peripheral end of the spiral so as to communicate with the outside air.

The outer shape of the mold 20 is a prismatic shape with a cross section of 120w x 120mm, and the material is 845C.

The vibrator 30 is an electrodynamic vibrator, and the oscillator 35 is a model with a basic frequency of 9 KHz and an automatic frequency tracking system, that is, a model with a slight resonant frequency that corresponds to load fluctuations during molding. We selected a model that can always automatically track changes in

The molding material used was linear low density polyethylene (LLDPE, 5034G manufactured by Idemitsu Petrochemical Co., Ltd.).

The molding conditions were: mold clamping force 3.5 (ton), injection pressure 940 (kg/cd), resin temperature 150 (℃).
, the amplitude was 5 μm, and the resonance state was one wavelength resonator for the entire length of the mold 20, as shown in FIG.

Injection molding was performed under the conditions described above while causing the mold 20 to resonate, and the flow length of the molding material into the cavity 24A at that time was determined. The flow length was evaluated by measuring the length of the resin flowing into the cavity 24A and using the average value of 10 measurements.

The results are shown in Table I.

- 几1 The experiment was conducted under the same conditions as in Experimental Example 1 except that vibration was not applied to the mold 20 by the vibrator 30 to prevent resonance.

- And J day LL - As shown in FIG. 7, the experimental example was performed except that the vibrator 30 was not used and the ultrasonic vibrator 38 was positioned at the contact part between the fixed mold 21 and the movable mold 22. The experiment was conducted under the same conditions as 1. At this time, the mold 20 was not in a resonant state.

The results of Comparative Examples 1 and 2 are shown in Table 1.

Table-1 As a result, according to Experimental Example 1 according to the present invention, the vibration exciter 30
It can be seen that the fluidity of the molding material is much better than when ultrasonic vibrations are not applied, as well as when ultrasonic vibrations are simply applied.

One stage t2 The first stage where the fixed mold 2l and the movable mold 22 are somewhat elongated.
Using the injection molding apparatus 10 shown in the figure, the cavity 24 formed in the movable mold 22 of the mold 20 was in the shape of a flat disk, like the cavity 24B shown in FIG. The shape of this disc has a depth (thickness of the molded product) of lm,
The diameter is 20sem, and there is a sprue 23 in the center of the circle.
The molding material is now injected through the gate.

The outer diameter of the mold 20 is 120m+++ x 120m in cross section.
M (7) It has a prismatic shape, and the material is titanium alloy (6Al
-4V).

The vibrator 30 is an electrodynamic vibrator, and the oscillator 35 is a model with a basic frequency of 9 KHz and an automatic frequency tracking system, that is, a model with a slight resonant frequency that corresponds to load fluctuations during molding. We selected a model that can always automatically track changes in

The oscillation timing of the vibrator 30 was set from the time of filling the molding material to the time of the pressure holding process.

Polypropylene (PP; J-700G manufactured by Idemitsu Petrochemical Co., Ltd.) was used as the molding material.

The molding conditions were: mold clamping force 3.5 (ton), injection pressure 940 (kg/crI), resin temperature 220 (℃),
The amplitude was 50 μm, and the resonance state was a 1.5 wavelength resonator for the entire length of the mold 20, as shown in FIG.

Injection molding was performed under the conditions described above while causing the mold 20 to resonate, and the diameter of the molded product at that time was measured. The evaluation was performed using the average value of the measured values of 10 molded products.

The results are shown in Table-2.

Retraction U The experiment was conducted under the same conditions as Experimental Example 2 except that vibration was not applied to the mold 20 by the vibrator 30 to prevent resonance.

- and] I1 support As in the comparative example 2 shown in FIG. The experiment was conducted under the same conditions as in Experimental Example 2 except for the following.

The results of Comparative Examples 3 and 4 are shown in Table-2.

As a result, according to Experimental Example 2 according to the present invention, the vibration exciter 30
It can be seen that it is possible to obtain a molded product with significantly smaller dimensional shrinkage than when ultrasonic vibration is applied, as well as when ultrasonic vibration is not applied.

Next, an embodiment of an extrusion molding apparatus using the molding method of the present invention will be described based on FIG.

The extrusion molding apparatus 40 according to this embodiment includes a die 50, which includes a die member 51 and a die member 52.
It is divided into two parts. Inside one die member 5l,
An inflow hole 53 for the molding material is formed, and a flow path 54 is formed at the joint surface of both die members 51 and 52.
This flow path 54 is opened on the peripheral surface of the die 50, and this opening is used as an extrusion port 55.

Flanges 56, 57 serving as die holding parts are fixed to approximately the center of each of the two die members 51, 52, and these flanges 56, 57 are held together by a plurality of tie bolts 58 to apply a tightening force at the joint surface. are tightened so that they are even. These tie bolts 58 are prevented from touching the dice 50.

An extruder 6 is provided in the inflow hole 53 of the one die member 5l.
The molding material supplied from the nozzle 61 passes through the inflow hole 53 and the flow path 54 and is finally extruded from the extrusion port 55.

The contact position of this nozzle 6l with the die member 5l is made equal to the mounting position of the flange 56, and this position is arranged so as to be a node of the displacement waveform when the die 50 resonates with the vibration exciter to be described later. has been done. Also, nozzle 6
1 and the die member 5l are fixed by mounting means such as screws (not shown).

In the other die member 52, the excitation part 7l of the vibrator 70 is connected to a connecting member 73 such as a screw on the side opposite to the joint surface.
has been fixed through. Vibrating section 71 of this vibrating machine 70
A horn capable of converting the amplitude of vibration is coupled between the die member 52 and the die member 52 as necessary.

An oscillator 75 is connected to the vibrator 70, and the output signal from the oscillator 75 causes the vibrator 70 to
It is designed to generate vibrations of less than

The vibrations applied to the dice 50 by the vibrator 70 are as follows:
This is the frequency that causes the dice 70 to resonate. Further, the wavelengths that cause the dice 70 to resonate are such that there are n wavelengths for the entire length of the dice 50, as in the injection molding apparatus IO in the above embodiment.
There is so-called n-wavelength resonance.

In addition, by applying vibration by the vibrator 70, the dice 50
is resonated, but the displacement wavelength of this resonance is due to the contact surface between the excitation part 7l and the die member 52 and both die members 51 and 52.
The abutting surfaces of the flanges 5 and 5
The joint portion between the die member 6.57 and the two die members 5l, 5.2 and the joint portion between the die member 5l and the nozzle 6l form a knot.

As a result, the vibration transmission efficiency between the vibrator 70 and the die 50 is improved, the fluidity of the molding material in the flow path 54 is increased, and the flange 56 from the die 50 is
．． External outflow of vibration energy through the nozzle 57 or the nozzle 6l is suppressed. At this time, flanges 56, 57
To make the joint between the die 50 and the die 50 as thin as possible,
This is preferable because vibration loss in this portion can be reduced.

Furthermore, the outflow of vibrations to the outside is also suppressed because the tie bolts 58 are provided so as not to touch the dice 50.

The die 50 can be made of various materials such as metal, ceramics, graphite, etc. Among these materials, it is preferable to use a material with less transmission loss of vibration caused by the vibration exciter 70 at the molding temperature. It is preferable to use {particularly}
Preferred are duralumin, titanium alloy, K-monel, phosphor bronze, and graphite.

Furthermore, it is preferable that the contact surfaces between the divided die member 5l and the die member 52 be in surface contact as much as possible in order to ensure that the vibrations caused by the vibrator 70 are transmitted efficiently.

Depending on the shape of the molded product to be molded, the die 5
It is also possible to make 0 into an undivided, integral form, or conversely into three or more parts. When dividing the dice 50, the dice 50 are separated so that the vibrations of the vibrator 70 are efficiently transmitted.
It is preferable that the dividing plane is provided as close to the resonance abdomen as possible.

Furthermore, the die 50 can be equipped with a mechanism for changing the direction of vibration, and by appropriately selecting the shape of the die 50, it is also possible to change the amplitude of the vibration transmitted through the die 50.

Note that the configurations of the vibrator 70, oscillator 75, etc. are the same as in the embodiment of the injection molding apparatus IO.

Next, the operation of the extrusion molding apparatus 40 according to this embodiment will be explained.

The nozzle 6l of the extruder 60 is connected to one die member 5l, and the molding material is supplied to the die 50 to perform extrusion molding.The oscillator 75 generates vibrations in the vibrator 70, and the vibrations cause the die 50 to move. Make it resonate.

The vibration frequency at this time can be arbitrarily selected, but it is preferably less than 100 Hz - 10 KHz in order to have a very effective vibration effect on the fluidized material.

Furthermore, the amplitude of the vibration applied to the die 50 must be 0.1 μm-100 μm in order to effectively improve the fluidity of the molding material.
It is preferable to set it to μm. In addition, the method of generating vibration is
Although not particularly limited, a mechanical system such as a camouflage crank type or an unbalanced weight type, an electromagnetic type electric system, an electrohydraulic system, or the like can be used. but,
An electrodynamic vibrator, which is a type of electric vibrator, is preferable.

When molding is performed while making the die 50 resonate with the vibrations from the vibrator 70 as described above, the molding material inside the die 50 also resonates with the die 50, increasing its fluidity, and flowing from the inflow hole 53 to the flow path 54. The speed of movement to the extrusion port 55 is increased.

As a result, molding time is shortened and productivity is improved.

According to the extrusion molding apparatus 40 according to the present embodiment as described above, the following effects are achieved.

That is, since the vibration of the vibrator 70 can be made to work effectively by causing the dice 50 to resonate,
Vibration can be transmitted efficiently. In addition, by utilizing the resonance abdomen, it is possible to improve the fluidity of molding materials, especially materials with poor fluidity, within the die 50, reduce the occurrence of melt fractures that deteriorate the surface quality, and dramatically improve the productivity of extrusion molding. can be improved.

In addition, according to the extrusion molding apparatus 40 of this embodiment, productivity can be improved by improving the fluidity of the molding material, and the connecting part between the flanges 56 and 57 as a die holding part and the die 50 can be Joint and both flanges 56.5
Since the tie port 58 connecting the parts 7 is made not to contact the die 50, there is an effect that vibration loss can be extremely reduced.

Furthermore, since the connecting portion between the flanges 56, 57 or the nozzle 6l and the die 50 is a resonant node as described above, the connecting portion will not suffer fatigue failure.

Note that the die 50 shown in the lθ diagram in the above embodiment
In this case, the vibration of the vibrator 70 is transmitted to the die 50 perpendicularly to the direction in which the molding material flows out. However, the 11th
As shown in the figure, the other die member 52A is embedded in one die member 51A of the die 50A, and an inlet hole 53A is formed in one die member 51A, and a flow path 54A is formed in the other die member 52A. Further, the material is inflowed so that an extrusion port 54A is opened between the outer periphery of the other die member 52A and one die member 51A in a direction perpendicular to the connection direction of the inflow hole 53A with the nozzle 61A. By selecting the arrangement of the hole 53A and the extrusion port 54A, it is possible to transmit the vibration of the vibrator 70 in parallel to the direction in which the molding material flows out. This method provides a uniform vibration effect to the molded product when molding a molded product with a two-dimensional cross section such as a pipe.
It is valid.

The molding materials that can be molded by the extrusion molding apparatus 40 according to this embodiment include organic materials such as plastics, rubber, and elastomers, inorganic materials such as inorganic polymers, ceramics, metals, and glass, and other foods and materials. Examples include materials that have at least some fluidity during molding, such as mixed materials. In particular, when applied to plastics, the occurrence of melt fractures that deteriorate the surface properties of products is reduced, and molded products with high product value can be obtained.

In addition, in the extrusion molding in this example, the molding material in a fluid state is formed into a predetermined shape by inflation molding, sheet molding, round bar molding, vibrator molding, profile extrusion molding, multilayer coextrusion molding, electric wire coating, filament molding, etc. This includes all forms that involve passing through a die in order to extrude the material.

The extrusion molding method and apparatus of this embodiment can also be applied to pultrusion molding, which is basically similar to extrusion molding.
In that case as well, a remarkable effect can be found in suppressing surface roughness of the molded product.

(Experimental Example) Hereinafter, the results of an experiment conducted to confirm the effects of this example will be explained while comparing with a comparative example.

IF PRODUCTION - An extrusion molding apparatus 40 shown in FIG. lθ is used, and a straight manifold type T die is used as the die 50. The shape of this die 50 is as follows:
The lip opening is 0.5 mm and the seat width is 30 mm. Vibration is applied to the die 50 formed in this way, and the first
As shown in FIG. 2, the die 50 is a one-wavelength resonator in which one wavelength corresponds to a displacement waveform W over the entire length. At this time, the node P of the displacement waveform W is positioned to match the position of both flanges 56 and 57, and the abdomen Q is positioned at the center of the die 50. In addition, in this Experimental Example 3, the joint surface 59 of both die members 51 and 52 is located at a position shifted from the center position of the die 50, that is, at the extrusion port 5.
5 is the intermediate portion between the resonant abdomen Q and the node P.

As the molding material, polyethylene (PE. Idemitsu Petrochemical Co., Ltd. 640 11F inflation grade) was used.

The extrusion conditions were: material temperature 160°C, die temperature 160°C,
Extrusion speed 0. 5 ~5. It was set to 0 (wax) kg/hr.

Under the above conditions, extrusion molding was performed while the die 50 was resonated, and the occurrence of melt fractures at that time was investigated. In addition, the pressure inside the nozzle 6l, which is a measure of the flow resistance of the molding material that occurs from the nozzle 61 to the die 50, is
Extrusion speed 0. Measured at 5 kg/hr.

1 Slice 1 An experiment was conducted under the same conditions as Experimental Example 3, except that the die 50 was used with the extrusion port 55 positioned at the abdomen Q due to resonance.

The results of Experimental Examples 3 and 4 are shown in Table 3.

Mr. J The experiment was conducted under the same conditions as Experimental Example 3 except that the vibration by the vibrator 70 was stopped.

One pot! As shown in Fig. 13 of Shoichi, without using the vibrator 70,
The experiment was conducted under the same conditions as Experimental Example 3, except that the ultrasonic transducer 78 was pressed against the position of the joint 59 between the die member 5l and the die member 52. At this time, the dice 50 was in a non-resonant state.

The results of Comparative Examples 5 and 6 are shown in Table-3.

Table 3 As a result, by applying the vibration of the vibrator 70 to resonate the T-die, the flow resistance of the molding material is reduced and the occurrence of melt fracture can be suppressed up to extremely high extrusion speeds. , it can be seen that productivity can be improved.

〔Effect of the invention〕

As described above, according to the molding method of the present invention, the fluidity of the molding material can be improved regardless of injection molding, extrusion molding, etc., and there is an effect that productivity can be improved.

[Brief explanation of drawings]

Fig. 1 is a partially cutaway side view showing an embodiment in which the present invention is applied to an injection molding machine, Fig. 2 is a sectional view taken along the line ■-■ of Fig. 1, and Figs. Figure 5 is a front view of the cavity used in Experimental Example 1. Figure 6 is an explanatory diagram of the displacement waveform and wavelength during mold resonance in Experimental Example 1. Figure 7 is an explanatory diagram showing different resonance states of the mold. A schematic configuration diagram showing the device of Comparative Example 2 using an ultrasonic transducer, FIG. 8 is a front view of the cavity of Experimental Example 2, FIG. 9 is an explanatory diagram of the resonance state of Experimental Example 2, and FIG. 10 is A side view showing an embodiment in which the present invention is applied to an extrusion molding apparatus, FIG. 11 is a partially cutaway side view showing a modification of the embodiment shown in FIG. 10, and FIG. 12 is an explanation of the resonance conditions of Experimental Example 3. 13 are schematic configuration diagrams showing an apparatus of Comparative Example 6 using an ultrasonic transducer. lO...Injection molding device, 15.19...Mounting plate as mold holding, 20...Mold, 2l...Fixed mold,
22... Movable mold, 24... Cavity, 30...
- Vibrator, 35... Oscillator, 40... Extrusion molding device, 50.5OA... Dice, 56.57... Flange as die holding part, 60... Extruder, 6l...
・Nozzle, 70... Vibrator, 75... Oscillator, W.
...Displacement waveform, P... Node, Q... Abdomen.

Claims (4)

[Claims] (1) A molding method characterized by molding a molding material such as a polymeric material while causing a mold or die to resonate with vibrations having a frequency of less than 10 KHz. (2) The molding method according to claim 1, characterized in that vibration is applied to the mold or die so that the resonance region due to the vibration coincides with the position of the cavity of the mold or the extrusion port of the die. (3) The molding method according to claim 1, characterized in that vibration is applied to the mold or die so that a node of resonance due to the vibration coincides with a position of a cavity of the mold or an extrusion port of the die. (4) The molding method according to claim 1 or 2, characterized in that vibration is applied to the mold or die so that a node of resonance due to the vibration coincides with a position of a mold holding part or a die holding part. .