KR101567949B1 - Method for manufacturing thermoplastic composite - Google Patents

Abstract

The present invention relates to a method of forming a thermoplastic composite material (7) in the form of a part or product by using a thermoplastic material (2) having a thermoplastic resin and a reinforcing fiber bonded thereto, (2) caused by removal of the thermoplastic material (2), rapid cooling of the material (2) exposed to the room temperature during the movement between the processes, deformation of the fiber arrangement upon pressurization and squeeze-out In order to compensate for the disadvantages of the manufacturing process of the mold 2 and the complicated manufacturing process, the thermoplastic material 2 is put into the closed preheating mold 1 in which the product shape is embossed, The thermoplastic resin melted in the inside of the reinforcing fiber can be appropriately impregnated into the reinforcing fiber so that excellent moldability can be ensured.

Description

[0001] METHOD FOR MANUFACTURING THERMOPLASTIC COMPOSITE [0002]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a composite material manufacturing method, and more particularly, to an improvement of a method of manufacturing a thermoplastic composite material in the form of a part or a product by using a thermoplastic material combined with a thermoplastic resin and a reinforcing fiber.

Generally, thermoplastic materials are fabricated by using fiber yarns such as glass fiber, basalt fiber, carbon fiber, and aramid fiber to fabricate UD (Uni-Direction), fabric (Twill, Plain, etc.) (PP), polyethylene terephthalate (PET), polytetrafluoroethylene (TPU), polystyrene (PMMA), polyethylene terephthalate (PA), and polyethylene terephthalate (PEEK) are combined with a thermoplastic resin processed in the form of a powder or film form), which is made into a part or product form, and becomes a thermoplastic composite.

A known method for producing a thermoplastic composite material is a method using a static pressure press. More specifically, an example of a method for producing a thermoplastic composite material is a method in which a thermoplastic material is formed into a flat sheet by preheating impregnation and cooling molding in a flat mold (Open mold) Melted, transferred to a molding mold, and subjected to cooling molding to produce a composite part or a product.

However, such a conventional method is complicated and requires a complicated process. When the preheated thermoplastic material is detached from the flat mold, the thermoplastic material is fused to the flat mold to damage the thermoplastic material. In the preheating process, The thermoplastic material is exposed to normal temperature, and thus the molten resin is rapidly cooled before pressurization of the cold process, so that impregnability and moldability are deteriorated.

In particular, in the case of UD or multifilament unconstrained fibers in which the fibers are arranged in a single direction, the resin and the fibers are squeezed out in a direction perpendicular to the fiber array during the preheating process and the cold process of the open mold, There is a disadvantage in that the loss of the material largely occurs and the fiber arrangement is deformed to deteriorate the dimensional stability, moldability, and mechanical properties of the thermoplastic composite product.

As a typical thermoplastic composite manufacturing method recently used in overseas advanced companies, a thermoplastic material is continuously supplied to various parts of preheating parts and cold parts, and preheating and cold processing are sequentially performed to produce sheet-like flat plates There is a way.

This is advantageous in that the mechanical properties of the composite material can be improved by continuously removing the voids in the thermoplastic material in one direction during the molding. However, in order to mold the thermoplastic composite material with high cost and complexity, additional preheating equipment and cold equipment So that the manufacturing cost is inevitably increased.

As another manufacturing method, there is a method of forming a thermoplastic composite material by using a heater and cooling water in a single mold. That is, a thermoplastic material is laminated on the mold, and the thermoplastic material in the mold is heated and pressurized by induction heating to preheat the thermoplastic material and quickly cool and press the mold with the cooling water to produce the thermoplastic composite product (7) Method.

This method has advantages of reduction of cycle time, reduction of facility installation area and improvement of mechanical properties due to simplification of the manufacturing process, but it is difficult to modify the mold when the molding cost is high and the shape of the thermoplastic composite product is changed, .

Accordingly, an object of the present invention is to provide a thermoplastic composite material which can simplify a manufacturing process, minimize investment cost, and can be formed into a complicated shape when manufacturing a thermoplastic composite material in the form of a part or a product by using a thermoplastic material, Method.

(2) is impregnated in a pre-heating mold (1) having a two-sided or four-sided closed type and the shape of a thermoplastic composite product is embossed therein, and the pre-heated impregnated thermoplastic material (2) Is inserted into the cold mold (3) as a whole and is then subjected to pressure and cold molding to obtain a thermoplastic composite material (7) in the form of a part or a product.

The thermoplastic material 2 may be in the form of a UD (Uni-Direction), a fabric (e.g. Twill, Plain, etc.), or the like, using reinforcing fibers including glass fiber, basalt fiber, carbon fiber and aramid fiber. A multi-axial non-crimped fabric, and a thermoplastic resin processed in the form of a powder or a film.

In the manufacturing method of the present invention, the preheating mold 1 into which the thermoplastic material 2 having the thermoplastic resin and the reinforcing fiber bonded thereto is preheated to a temperature of 150 ° C or higher at which the thermoplastic resin can be melted, 1) is pressurized in the preheating press to a pressure of 40 kgf / cm2 or more to a pressure less than the pressing force of the cold mold (3) to impregnate the thermoplastic resin into the reinforcing fiber do.

In the manufacturing method of the present invention, the preheating mold 1 having completed the preheating of the thermoplastic material 2 is pressed in the cold press at a pressure of 80 kgf / cm 2 or more to impregnate the thermoplastic material 2, Is formed by impregnation with a pressure to be removed.

The preheating mold 1 and the preheating mold 3 respectively coupled to the upper and lower plates of the cooling mold 3 by the key 6 coupling using the keyway 5 formed between the upper and lower plates of the preheating mold 1 and the cold mold 3, The upper and lower plates of the thermoplastic composite material 1 are separated to demould the thermoplastic composite material 7 in the product state.

The present invention allows the thermoplastic composite to be molded in the preheat mold by charging the preheated mold with the thermoplastic composite material in a closed form and preheating the preheated mold and cooling the preheated mold as a whole, In terms of productivity, it has the following effects.

First, from the economic point of view, it is possible to minimize the initial facility investment by sharing the conventional static pressure press which is currently used for mass production of automobile parts, and it is possible to manufacture only the preheating mold according to the necessity in the new manufacture of the mold, .

From the technical point of view, the use of closed molds minimizes or prevents the extrusion of the thermoplastic material during pressurization, thereby reducing the appearance and dimensional stability of the thermoplastic composite product. And it is possible to improve the impregnation of the resin and the mechanical properties of the thermoplastic composite product at the time of pressurization.

Finally, from a productive point of view, it is possible to shorten the cooling time by quenching a hot preheating mold with cooling water, shorten the preheating time of the mold by simultaneously heating several same or different molds in a single preheating press, It is possible to improve the productivity by shortening the cycle cycle.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a manufacturing process for producing a thermoplastic composite according to an embodiment of the present invention;
Fig. 2 is a perspective view of the assembled state of the two-sided or four-sided closed preheat mold of the present invention,
3 is an exploded perspective view of the two-sided or four-sided closed preheat mold of the present invention,
Fig. 4 is a perspective view of a cold mold having a shape in which a preheating mold can be completely inserted, Fig.
5 to 9 are views showing a process of obtaining a thermoplastic composite material in the form of a part or product by pressurizing and cooling molding a pre-heated mold as a whole in a cold mold according to the present invention.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

The thermoplastic composite material produced according to the present invention can be obtained by using a thermoplastic material having a resin (PP, PET, TPU, PMMA, PA6, PEEK or the like) combined with reinforcing fibers (glass fiber, basalt fiber, carbon fiber, aramid fiber, Is manufactured based on the manufacturing process as shown in Fig.

FIG. 1 is a process flow diagram for manufacturing a thermoplastic composite material according to an embodiment of the present invention. FIG. 1 shows a process of manufacturing a thermoplastic composite material according to the present invention, which includes a preheating mold preheating process (S1), a thermoplastic material input and preheating mold preheating process (S2), a preheating mold , A product molding process (S4) through cooling molding, and a product demolding process (S5).

As shown in FIGS. 2 and 3, the preheating mold 1 according to the present invention is composed of upper and lower plates, two or four sides of which are closed, and the shape of the thermoplastic composite product to be manufactured is embossed therein. At the left and right ends of the upper and lower plates, a key groove 5 is formed for key connection with the upper and lower plates of the cold mold 3, A guide groove for guiding the inner dolphin is formed.

The preheating and cold press applied to the present invention is a flat-plate static pressure press, and the preheating press for the preheating mold 1 can be heated by 350 ° C or more by direct or indirect heating and can be pressurized to 80 kgf / cm 2 or more, The cold press of the mold 3 is constituted by a facility capable of pressurization of 220 kgf / cm 2 or more.

In the present invention, the preheating mold 1 having the keyway 5 formed in the upper plate and the lower plate is preheated at a predetermined temperature and a predetermined time in the preheating press (step S1 of FIG. 1).

In order to minimize the extrusion of resin in the vertical direction of the fiber arrangement in the thermoplastic material (2) and to minimize the deformation of the material, UD (Uni-Direction) It is preferable to use a pre-heating mold 1 of a two-face-closed type as shown in Figs. 2 (a) and 3 (a) in which a two-sided opening is formed and the flow of the resin is induced in the direction of both- . Also, in the case of multi-axially unflexed fiber form or fiber form in which the reinforcing fibers are cross-laminated, in order to prevent the resin from being extruded in all directions, all the faces as shown in Figs. 2B and 3B are closed It is preferable to use the preheating mold 1 of the face-closed type.

The thermoplastic material 2 having the thermoplastic resin and the reinforcing fiber bonded to the preheated preheating mold 1 is introduced and the preheating mold 1 is pressurized and preheated at a predetermined temperature, ) Is melted and impregnated into the reinforcing fiber (step S2 of Fig. 1).

In the present invention, the preheating mold (1) into which the thermoplastic material (2) is charged is preheated to a temperature of 150 ° C or higher to impregnate the thermoplastic resin into the reinforcing fiber, and the preheating mold (1) the thermoplastic material 2 in the preheating mold 1 is pressurized with a pressure of f / cm2 or higher but the thermoplastic material 2 is pressed at a pressure lower than the pressing force applied by the cold mold 3 in the next step.

The pressure range of from 40 kgf / cm2 or more to the pressing force of the cooling mold 3 reaches a melting point of the resin, so that the thermoplastic resin which starts to melt can be impregnated into the reinforcing fiber, There is a critical meaning.

In the present invention, the preheating mold (1) having completed the preheating of the thermoplastic material (2) is transferred as a whole to the cold mold (3) mounted on the cold press. Since the pre-heating mold (1) to be transferred as a whole is closed at two or four sides, exposure to room temperature during conveyance to the cold mold (3) is minimized, thereby improving impregnability and reducing porosity.

The perspective configuration of the cold mold 3 according to the present invention is shown in Fig.

The cold mold 3 of the present invention shown in Fig. 4 has a form capable of receiving the preheating mold 1 as a whole.

A space for accommodating the preheating mold 1 in a whole can be formed between the upper plate and the lower plate of the cold mold 3 and the upper and lower plates of the left and right cold molds 3, A key groove 5 to be fitted with the key groove 5 is formed. A cooling water line (4) is arranged inside the upper and lower plates of the cooling mold (3) so that cooling water can circulate.

In the present invention, the preheating mold 1, which has been preheated, is entirely introduced into the cooling mold 3 (step S3 of FIG. 1).

More specifically, the preheating mold 1 having completed preheating is placed in the space for receiving the lower plate of the cold mold 3 from which the upper and lower plates are separated (see FIG. 5), and then covers the upper plate of the cooling mold 3. 6, the preheating mold 1 at a high temperature is put into the cooling mold 3, and at this time, the preheating mold 1 and the key groove 5 of the upper and lower plates of the cooling mold 3 are cooled, .

The key grooves 5 which are individually aligned are formed in a preheating mold 1 in which an upper plate of the preheating mold 1 key-coupled to the upper plate of the cooling mold 3 through engagement of the key 6 at the time of demolding is keyed to the lower plate of the cooling mold 3, And can be demolded from the lower plate of the heat exchanger (1).

The preheating mold 1 having been preheated is put into the cooling mold 3 as a whole and then the preheating mold 1 is pressed at a constant pressure for a predetermined time in the cold press so that the molten thermoplastic resin on the thermoplastic material At the same time as the impregnation, the cooling water is circulated through the cooling water line 4 inside the cold mold 3 to cool the preheating mold 1 at a high temperature to room temperature. Thus, rapid cooling molding of the thermoplastic material 2 contained in the preheating mold 1 can be completed (step S4 of FIG. 1).

According to the present invention, in the cooling press, the preheating mold 1 in which the preheating of the thermoplastic material 2 has been completed is pressed at a pressure of 80 kgf / cm2 or more in the cold press. This is so that the thermoplastic resin in the impregnated state is melted and spread in the whole of the reinforcing fiber, and at the same time, the pores are removed from the inside of the material in the impregnation state due to squeezing at a pressure of 80 kgf / cm 2 or more.

In the present invention, four keys (not shown) are provided in the keyway 5 of the preheating mold 1 and the cold mold 3, as shown in Fig. 7, in order to demold the thermoplastic composite product 7 that has been molded in the preheating mold 1. [ 6 so that the upper plate of the preheating mold 1 is lifted and then the upper plate and the lower plate of the preheating mold 1 are separated as shown in FIG. The thermoplastic composite 7 can be demoulded (step S5 of FIG. 1).

While the present invention has been described in connection with what is presently considered to be practical exemplary embodiments, it is to be understood that the invention is not limited to the disclosed embodiments. Therefore, the scope of the present invention should not be limited by the described embodiments, but should be determined by the scope of claims and equivalents thereof.

(1) --- Preheating mold
(2) --- Thermoplastic material
(3) --- Cold mold
(4) --- Cooling water line
(5) --- Keyway
(6) --- key
(7) --- Thermoplastic composites

Claims (5)

A method for producing a thermoplastic composite material,
(2) is placed in a preheated preheat mold (1), and a thermoplastic material (2) is placed in a preheated preheat mold (1) after the preheating mold (1) The material (2) is a UD (Uni-Direction) fiber form including a thermoplastic resin and a reinforcing fiber. In order to minimize the extrusion of the resin in the vertical direction of the fiber arrangement in the thermoplastic material (2) The thermoplastic material 2 is preheated by impregnating the preheating mold 1 so that the fiber yarns are arranged in a direction parallel to the two-face openings,
The preheating mold 1 containing the impregnated thermoplastic material 2 is entirely transferred and the upper and lower plates are inserted into the cold mold 3 having the key groove 5 so that the upper and lower plates of the preheating mold 1 and the cold mold 3 The key 6 is fitted to the key groove 5 of each of the upper and lower plates to separate the upper and lower plates of the preheating mold 1 by aligning them with the key groove 5, To obtain a thermoplastic composite material (7) in the form of a part or a product.
A method for producing a thermoplastic composite material,
A pre-heating mold 1 having a key groove 5 on each of the upper and lower plates is preheated as a four-face-closed type, a thermoplastic material 2 is placed in a preheated preheating mold 1, The material (2) is a thermoplastic material which is composed of a thermoplastic resin and a reinforcing fiber and is composed of a multi-axially unflexible fiber structure or a fabric type in which reinforcing fibers are alternately stacked, and the resin is prevented from being extruded in all directions by the four- ) Is placed in a preheating mold (1) to be preheated and impregnated,
The preheating mold 1 containing the impregnated thermoplastic material 2 is entirely transferred and the upper and lower plates are inserted into the cold mold 3 having the key groove 5 so that the upper and lower plates of the preheating mold 1 and the cold mold 3 The key 6 is fitted to the key groove 5 of each of the upper and lower plates to separate the upper and lower plates of the preheating mold 1 by aligning them with the key groove 5, To obtain a thermoplastic composite material (7) in the form of a part or a product.
The method according to claim 1 or 2, wherein the preheating mold (1) into which the thermoplastic material (2) having the thermoplastic resin and the reinforcing fiber bonded thereto is preheated to a temperature of 150 ° C or higher at which the thermoplastic resin can be melted, The thermoplastic resin 2 is impregnated into the reinforcing fiber by pressurizing the thermoplastic material 2 inside the preheating mold 1 at a pressure of 40 kgf / cm 2 or more to a pressure lower than the pressing force of the cold mold 3 in the preheating press 1 Of the thermoplastic composite.
The method for producing a thermoplastic material according to claim 1 or 2, characterized in that the preheating mold (1) having completed preheating of the thermoplastic material (2) is pressed at a pressure of 80 kgf / cm2 or more in a cold press to impregnate the thermoplastic material Of the thermoplastic composite.
The thermoplastic resin composition according to claim 1 or 2, wherein the reinforcing fiber comprises at least one of glass fiber, basalt fiber, carbon fiber, and aramid fiber, and the thermoplastic resin is a resin processed in the form of a powder or a film. A method for manufacturing a composite material.

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