WO2019074134A1

WO2019074134A1 - Molding device for carbon prepreg compression forming

Info

Publication number: WO2019074134A1
Application number: PCT/KR2017/011179
Authority: WO
Inventors: 이준상
Original assignee: (주)티엔케이
Priority date: 2017-10-11
Filing date: 2017-10-11
Publication date: 2019-04-18

Abstract

The present invention relates to a molding device for carbon prepreg compression forming, the device comprising: a body; a lower mold which is replaceably disposed inside the body and generates heat through the entire surface of the lower mold; a cover for opening or closing the inside of the body; an upper mold which is installed on a lower surface of the cover and is expanded by pneumatic pressure; a pneumatic pressure supplying unit for supplying pneumatic pressure to expand the upper mold; and a gas discharge unit for discharging exhaust gas generated inside the body to the outside, wherein, in a state where a carbon prepreg is placed above the lower mold, the lower mold heats the carbon prepreg and the upper mold is expanded and deformed according to a shape of the carbon prepreg so as to enable the carbon prepreg to come into close contact with an upper surface of the lower mold.

Description

Carbon prepreg compression mold device

The present invention relates to a carbon prepreg compression mold apparatus.

The carbon prepreg compression mold apparatus is a device for producing a carbon fiber reinforced plastic (CARBON FIBER REINFORCED PLASTIC) by compressing and hardening a carbon prepreg at a time.

Using a carbon prepreg compression mold device, carbon fiber-reinforced plastic can be rapidly produced in large quantities.

Carbon prepreg compression molds with these advantages are manufactured by several competitors. However, currently manufactured carbon prepreg compression mold apparatuses have various problems.

For example, a carbon prepreg molding die apparatus manufactured by Mitsubishi Rayon Co., Ltd. is equipped with a high-pressure press apparatus and a high-temperature heater, resulting in high manufacturing cost. Further, since the heating heater heats the metal mold in a line rather than a plane, there is a problem that the surface temperature of the metal mold can not be uniformly heated.

As another example, a carbon prepreg compression molding die apparatus manufactured by Rock Tool Co., Ltd., has an induction heating apparatus and a cooling system, which has a problem that the manufacturing cost is too high.

It is an object of the present invention to provide a carbon prepreg compression mold apparatus capable of solving all the problems described above.

In order to accomplish the above object, there is provided a carbon prepreg compression mold apparatus,

main body;

A lower mold interchangeably placed inside the body and generating heat across the surface;

A lid for opening and closing the inside of the main body;

An upper mold installed on a lower surface of the lid and inflated by pneumatic pressure;

A pneumatic pressure providing unit for providing a pneumatic pressure for expanding the upper mold; And

And a gas exhaust unit for exhausting the exhaust gas generated inside the body to the outside,

The upper mold is deformed and expanded in accordance with the shape of the carbon prepreg so that the carbon prepreg is placed on the upper surface of the lower mold, To be in close contact with each other.

In the present invention, the lower mold is interchangeably placed in the interior of the body, and the upper mold is expanded to fit the shape of the carbon prepreg while closely adhering the carbon prepreg to the upper surface of the lower mold. This makes it possible to rapidly produce carbon fiber-reinforced plastics of different sizes and shapes by replacing only the lower molds without having to make new mold devices each time to make carbon fiber-reinforced plastics of different sizes and shapes.

The present invention is not limited to a silicone material capable of expanding and contracting an upper mold, but may be made of a rigid material having an upper shape of a carbon fiber reinforced plastic and engageable with a lower mold. In this case, the upper mold is replaced as the top shape of the carbon fiber-reinforced plastic changes. This makes it possible to rapidly produce carbon fiber-reinforced plastics of different sizes and shapes, by replacing only the upper mold and the lower mold, without having to make a new mold apparatus each time to make carbon fiber-reinforced plastics of different sizes and shapes . Further, when the upper mold is made of a rigid material, the pneumatic pressure providing unit becomes unnecessary, and the configuration of the mold apparatus becomes simpler.

The lower mold of the present invention is composed of a mold plate on which a carbon prepreg is placed and a carbon sheet attached to a lower surface of the mold plate to generate heat. The carbon sheet is thin, so that even if the shape of the mold plate is complicated, it can be attached along the mold plate.

Further, since the carbon sheet directly contacts the lower surface of the mold plate, there is little heat loss transmitted to the mold plate.

Further, since the carbon sheet is heated to the entire surface, heat can be uniformly transmitted to the entire mold plate, and carbon fiber-reinforced plastic having uniform quality can be produced.

Further, since the carbon sheet is simply attached to the lower surface of the mold plate, it is not necessary to insert a heater wire to form a mold plate. Thus, the material of the mold plate can be varied, and even the mold plate can be made of glass. If the mold plate is made of glass, it can be made of carbon fiber-reinforced plastic with a clean bottom like a glass surface.

In the present invention, a layer is formed inside the body in such a manner that the lower mold can be placed in accordance with the size of the lower mold, and a terminal capable of supplying electricity to the carbon sheet is provided on the end. Therefore, if the lower mold capable of making the carbon fiber-reinforced plastic into a predetermined size and shape is picked up and placed on the stepped end, the installation of the lower mold is completed. The reason why the layer can be formed in the step inside the main body is that the upper mold is expanded to fit the height of the step even if the height of the step is different, and the carbon prepreg placed on the lower mold can be brought into close contact with the lower mold.

The carbon sheet of the present invention may be composed of only PAN-based carbon fibers, or may be composed of mixed PAN-based carbon fibers and pitch-based carbon fibers. The reason for this is to adjust the mixing ratio of the PAN-based carbon fibers or the pitch-based carbon fibers to precisely control the resistance per unit area. Therefore, even if the size of the carbon sheet is changed, the carbon sheet can generate the same calorific value as a whole under the same current by adjusting the resistance per unit area. This leads to energy savings.

The present invention may further comprise a gas recycling unit that provides a part of the exhaust gas to the pneumatic pressure providing unit. As a result, a part of the exhaust gas can be mixed with the air for expanding the upper mold to raise the temperature of the upper mold. As a result, the temperature difference between the lower mold and the upper mold is reduced, so that a carbon fiber-reinforced plastic having uniform quality can be produced.

Since the present invention is configured without an expensive induction heating device and a cooling system, the manufacturing cost is low.

1 is a view showing a carbon prepreg compression molding die apparatus according to a first embodiment of the present invention.

FIG. 2 is a top view of a terminal formed on the stage and a step formed inside the body shown in FIG. 1. FIG.

Fig. 3 is a view showing the lower mold shown in Fig. 1. Fig.

Fig. 4 is a view showing the carbon sheet shown in Fig. 3. Fig.

5 is a view showing a carbon sheet according to a modification.

6 is a view showing a lower mold according to a modification.

7 is a view showing a carbon prepreg compression mold apparatus according to a second embodiment of the present invention.

Hereinafter, a carbon prepreg compression mold apparatus according to a first embodiment of the present invention will be described.

1, the carbon prepreg molding die apparatus 1 according to the first embodiment of the present invention includes a main body 10, a lower mold 20, a lid 30, an upper mold 40, A pneumatic pressure providing unit 50, and a gas discharge unit 60. [

The body 10 has an empty box shape. Of course, the size and shape of the main body 10 can be variously modified. Inside the body 10, an internal space S1 in which the lower mold 20 is placed is formed. The upper portion of the main body 10 is open. The body (10) has an exhaust gas passage (11). An exhaust gas passage (11) is vertically lowered from the upper surface of the main body (10) and bent toward the right side wall. Of course, the position of the exhaust gas passage 11 may vary. Exhaust gas generated while the carbon prepreg (P) is heated is exhausted to the outside through the exhaust gas passage (11).

As shown in Fig. 2, an end 12 is formed in the body 10 as a layer. The step (12) is formed by grasping the inner wall of the main body (10).

The stage 12 is composed of a first stage 12a, a second stage 12b, and a third stage 12c. Of course, stage 12 may be composed of more stages.

A second end 12b is formed under the first end 12a and a third end 12c is formed under the second end 12b. As the distance from the first stage 12a to the third stage 12c decreases, the space inside the stage 12 becomes smaller. Due to the step 12 structure, the lower mold 20, which is gradually smaller in size, can be placed on the stage 12 while descending from the first stage 12a to the third stage 12c, The mold 20 can be easily replaced.

A terminal (13) is provided on the stage (12).

The first terminal 12a is provided with a first terminal 13a. The first terminal 13a is composed of a + terminal and a terminal.

And a second terminal 13b is provided in the second end 12b. The second terminal 13b is composed of a + terminal and a terminal.

And the third terminal 12c is provided with a third terminal 13c. The third terminal 13c is composed of a + terminal and a terminal.

When the lower mold 20 is placed on the

stages

12a, 12b and 12c, the electrodes 23 (see Fig. 3) provided on the lower mold 20 and the terminals 13 are brought into contact with each other.

The power supply unit (not shown) supplies electricity to the electrode 23 through the terminal 13. When electricity is supplied to the electrode 23, heat is generated in the carbon sheet 22 (see Fig. 3).

3, the lower mold 20 is composed of a mold plate 21, a carbon sheet 22, an electrode 23, a heat insulating material 24, and an adhesive layer 25.

The mold plate 21 is made of an insulating glass. Therefore, it is not necessary to provide the mold plate 21 with another insulating property. The thickness of the mold plate 21 is 5 to 10 mm.

On the other hand, the mold plate 21 can be made of aluminum. In this case, the mold plate 21 is anodized to impart insulation.

On the other hand, the mold plate 21 can be made of steel. In this case, the mold plate 21 is coated to provide insulation, or an insulating film is attached to the mold plate 21 to impart insulation.

As shown in Fig. 4, the carbon sheet 22 is composed of PAN-based carbon fibers 22a.

The PAN-based carbon fibers 22a are randomly arranged so as to overlap with each other so that current flows. The resistance per unit area of the exothermic article can be controlled by adjusting the amount of the PAN-based carbon fibers 22a. The preferable resistance per unit area is 1 to 100? / ?. The carbon sheet 22 is made to have a thickness of 0.001 to 2 mm.

The current supplied from the power supply unit (not shown) flows to the carbon sheet 22 through the terminal 13 and the electrode 23. At this time, heat is generated in the PAN-based carbon fiber 22a which is a resistor. The heat is transferred to the mold plate 21. Due to the heat transferred to the mold plate 21, the carbon prepreg P placed on the mold plate 21 is cured.

As shown in FIG. 5, the carbon sheet 22 'may be composed of a PAN-based carbon fiber 22a and a pitch-based carbon fiber 22b.

The PAN-based carbon fibers 22a and the pitch-based carbon fibers 22b are randomly arranged so as to overlap with each other so that current flows.

The PAN-based carbon fiber 22a has a higher resistance than the pitch-based carbon fiber 22b and is inexpensive.

By adjusting the mixing ratio of the PAN-based carbon fibers 22a and the pitch-based carbon fibers 22b, the resistance per unit area can be precisely controlled.

For example, it is possible to reduce the resistance per unit area by mixing the P-type carbon fibers 22b having a low resistance to the PAN-based carbon fibers 22a. When the pitch-based carbon fibers 202 having a low resistance are mixed with the PAN-based carbon fibers 201 to reduce the resistance per unit area, the carbon sheet 22 can generate the same calorific value as the whole under the same current.

The current supplied from the power supply unit (not shown) flows to the carbon sheet 22 through the terminal 12 and the electrode 23. At this time, heat is generated in the PAN-based carbon fibers 22a and the pitch-based carbon fibers 22b, which are the resistors. The heat is transferred to the mold plate 21. Due to the heat transferred to the mold plate 21, the carbon prepreg P placed on the mold plate 21 is cured.

As shown in Fig. 3, the electrode 23 is laid over the carbon sheet 22. Electricity is supplied to the carbon sheet 22 through the electrode 23. The electrode 23 is composed of a pair of the positive electrode 23a and the electrode 23b. The electrode 23 has a thickness of 0.01 to 3 mm. The electrode 23 is made of copper or metallic paint.

The heat insulating material 24 surrounds the carbon sheet 22 and the electrode 23 so that heat generated in the carbon sheet 22 is transmitted only to the mold plate 21 side. The insulation 24 is made of a nonwoven fabric made of alumina fibers, a soft block made of alumina fibers, and a hard block made of alumina fibers.

The adhesive layer 25 fixes the carbon sheet 22, the electrode 23 and the heat insulating material 24 to the lower surface of the mold plate 21. [ The adhesive layer 25 is made of rubber or heat-resistant silicone.

As shown in FIG. 6, the lower mold 20 'according to the modification includes a mold plate 21', a carbon sheet 22 ', an electrode 23', a heat insulating material 24 ', an adhesive layer 25' . Each of the carbon sheet 22 ', the electrode 23', the heat insulating material 24 'and the adhesive layer 25' of the lower mold 20 'according to the modified embodiment is formed of the carbon sheet 22' ), The electrode 23, the heat insulating material 24, and the adhesive layer 25, respectively, and therefore the description thereof will be omitted.

The lower mold 20 'according to the modified example has a shape in which the center of the mold plate 21' is recessed.

A carbon sheet 22 ', an electrode 23', and a heat insulating material 24 'are installed along the shape of the lower mold 20'.

In addition, the shape of the mold plate 21 'can be variously modified in accordance with the shape of the carbon fiber-reinforced plastic to be regenerated.

Even if the shape of the mold plate 21 'is changed, since the carbon sheet 22' is very thin, the carbon sheet 22 'can be attached along the shape of the mold plate 21'.

Therefore, even if the shape of the mold plate 21 'is complicated, the carbon sheet 22' can uniformly transfer heat to the entire mold plate 21 '.

As shown in Fig. 1, the lid 30 opens and closes the inside of the main body 10. An air inflow passage (31) is provided at an upper portion of the lid (30). Of course, the position of the air inflow passage 31 may be changed.

A rim 32 is formed along the inner wall of the lid 30.

The lid 30 is coupled to a side of the main body 10 with a hinge 33. The lid 30 can be opened and closed with the hinge 33 as the center.

An O-ring O is provided between the lid 30 and the main body 10. The O-ring O is inserted into the O-ring groove 14 formed on the upper surface of the main body 10. Owing to the O-ring O, when the lid 30 is closed, the internal space S1 of the main body 10 is sealed.

The upper mold 40 is made of a silicone material capable of expanding and contracting. The upper mold 40 is fixed to the rim 32. When the upper mold 40 is fixed to the rim 32, an enclosed space S2 is formed between the inside of the lid 33 and the upper mold 40. When the air is introduced into the closed space S2, the upper mold 40 deforms and expands according to the shape of the carbon prepreg P while closely adhering the carbon prepreg P to the lower mold 20. [

On the other hand, the upper mold 40 may be made of a rigid material having an upper shape of carbon fiber-reinforced plastic and capable of engaging with the lower molds 20 and 20 ', rather than a silicone material capable of expanding and contracting the upper mold 40. In this case, the upper mold 40 can be replaced according to the top shape of the carbon fiber-reinforced plastic. The rigid material may be glass, aluminum, steel or the like, which is a material of the mold plates 21 and 21 '. When the upper mold 40 is made of a rigid material, the pneumatic pressure providing unit 50 becomes unnecessary, and the configuration of the mold apparatus is further simplified.

The air pressure providing unit 50 supplies air into the closed space S2 through the air inflow passage 31. [ The air pressure providing unit 50 is composed of a pipe 51, a valve 52, and a pump (not shown).

The gas exhaust unit 60 exhausts the exhaust gas generated while the carbon prepreg P is cured. Further, the gas exhaust unit 60 forms a vacuum in the internal space S1. The gas discharge unit 60 is composed of a pipe 61, a valve 62, and a pump (not shown).

Hereinafter, the operation of the carbon prepreg compression molding apparatus according to the first embodiment of the present invention will be described. 1 to 4 are basically referred to.

Open the lid 30. The lower mold 20 is placed on the end 12 corresponding to the size of the lower mold 20. A carbon prepreg (P) is placed on the lower mold (20). Close the lid (30).

The air pressure providing unit 50 supplies air to the closed space S2 through the air supply passage 31. [ The upper mold 40 is expanded by the pressure of the air. The upper mold 40 deforms and expands in accordance with the shape of the carbon prepreg P while closely adhering the carbon prepreg P to the lower mold 20. [

A power supply unit (not shown) supplies electricity to the carbon sheet 22 through the terminal 12 and the electrode 23.

The carbon sheet 22 generates heat. The generated heat is transferred to the mold plate 21.

The carbon prepreg (P) is heated by the transferred heat.

The carbon prepreg P is heated and exhaust gas is generated.

The gas exhaust unit 60 discharges the exhaust gas to the outside.

The carbon prepreg P is cured by receiving heat in a state in which the carbon prepreg P is in close contact with the lower mold 20.

Carbon fiber reinforced plastic is made.

Hereinafter, a carbon prepreg compression mold apparatus according to a second embodiment of the present invention will be described. The same constituent elements as those of the carbon prepreg compression mold apparatus according to the first embodiment of the present invention are given the same reference numerals.

7, the carbon prepreg compression mold apparatus 1 'according to the second embodiment of the present invention includes a main body 10, a lower mold 20, a lid 30, an upper mold 40 ), A pneumatic pressure providing unit 50, a gas exhaust unit 60, and a gas recycling unit 70.

The main body 10, the lower mold 20, the lid 30, the upper mold 40, the pneumatic pressure providing unit 50 of the carbon prepreg compression molding apparatus 1 'according to the second embodiment of the present invention, , And the gas exhaust unit (60)

The lower mold 20, the lid 30, the upper mold 40, the pneumatic pressure providing unit 50, and the upper mold 40 of the carbon prepreg compression molding apparatus 1 according to the first embodiment of the present invention, And the gas discharge unit 60, respectively, so that the description thereof will be omitted.

The gas recycling unit 70 recovers a part of the exhaust gas discharged through the gas discharging unit 60 and provides it to the air pressure providing unit 50.

The gas recycling unit 70 is composed of a pipe 71 and a filter 72. The pipe 71 connects the valve 62 of the gas discharging unit 60 and the valve 52 of the air pressure providing unit 50. The filter 70 is installed on the pipe 71. The filter 70 filters the foreign substances in the exhaust gas.

The recovered exhaust gas mixes with the air supplied by the air pressure providing unit 50 and flows into the closed space S2. The heat of the exhaust gas causes the upper mold 40 to be heated. As a result, the temperature difference between the upper mold 40 and the lower mold 20 is reduced.

Hereinafter, the operation of the carbon prepreg compression mold apparatus according to the second embodiment of the present invention will be described. 2 to 4 and 7 are basically referred to.

The carbon prepreg (P) is heated by the transferred heat.

The carbon prepreg P is heated and exhaust gas is generated.

The gas exhaust unit 60 discharges the exhaust gas to the outside.

The gas recycling unit 70 provides a part of the exhaust gas to the air pressure providing unit 50.

Is mixed with the exhaust gas supplied from the gas recycling unit (70) and the air supplied by the air pressure providing unit (50) and supplied to the closed space (S2).

The heat of the exhaust gas causes the upper mold 40 to be heated.

Carbon fiber reinforced plastic is made.

Claims

main body;

A lower mold interchangeably placed inside the body and generating heat across the surface;

A lid for opening and closing the inside of the main body;

An upper mold installed on a lower surface of the lid and inflated by pneumatic pressure;

A pneumatic pressure providing unit for providing a pneumatic pressure for expanding the upper mold; And

And a gas exhaust unit for exhausting the exhaust gas generated inside the body to the outside,

The upper mold is deformed and expanded in accordance with the shape of the carbon prepreg so that the carbon prepreg is placed on the upper surface of the lower mold, And the mold is pressed against the mold.
The method as claimed in claim 1,

A mold plate made of insulating glass;

A carbon sheet attached to a lower surface of the mold plate;

An electrode provided on the carbon sheet;

A heat insulating material surrounding the carbon sheet and the electrode; And

And an adhesive layer for fixing the carbon sheet, the electrode, and the heat insulating material to the lower surface of the mold plate.
3. The method of claim 2,

Wherein a step is formed on an inner wall of the body,

And a terminal is provided on the step.
The carbon fiber sheet according to claim 1,

Wherein the carbon-based carbon fiber and the pitch-based carbon fiber are mixed with each other.
5. The method of claim 4, wherein the resistance per unit area of the carbon sheet

Wherein the ratio of the PAN-based carbon fibers to the pitch-based carbon fibers is adjusted.
The method according to claim 1,

Characterized in that it is made of a silicone material.
The method according to claim 1,

And a gas recycling unit for supplying a part of the exhaust gas to the pneumatic pressure providing unit.