KR101940899B1 - t-RTM Manufacturing Apparatus and t-RTM Manufacturing Method using thereof - Google Patents

Abstract

The t-RTM molding apparatus and method for molding a fiber-reinforced plastic according to one aspect of the present invention is characterized in that reactive ε- caprolactam is melt-injected into a fiber preform, which is a molding to be molded, The present invention relates to a t-RTM molding apparatus for molding a fiber-reinforced plastic by polymerization, and a t-RTM molding apparatus and a molding method, characterized in that molten reactive ? -Caprolactam, a catalyst and a reaction initiator are mixed sequentially or simultaneously.

Description

t-RTM molding apparatus and a t-RTM molding method,

The present invention relates to a thermoplastic resin transfer molding (t-RTM) method and apparatus for forming a fiber reinforced plastic (FRP). More particularly, the present invention relates to a t-RTM molding method and apparatus for molding an FRP by melt-injecting reactive ε- caprolactam into a fiber preform, which is a molding material, . In particular, the present invention relates to a t-RTM molding method and apparatus characterized in that the molten reacted ? -Caprolactam, the catalyst and the reaction initiator are sequentially mixed or simultaneously mixed in the reactor.

FRP is a kind of composite material made by combining thermoplastic resin or thermosetting resin with fiber materials such as carbon fiber, glass fiber, and aramid fiber. FRP is used as a raw material for printed circuit board, cell phone case, and IT device case in the electric and electronic fields. In addition, FRP has material characteristics suitable for the trend of light weight, and recently it has been attracting great interest in automobile field, sports leisure field and various industrial parts.

As one of the molding methods for producing such FRP molded articles, a resin transfer molding (RTM) molding method is known. As shown in FIG. 1, the RTM molding method generally involves placing a fiber preform (preform) (a) cut into a fabric in an RTM molding mold, (b) closing and locking the molding mold, (c) (2-part type or 3-part type resin) in which the resin and the curing agent are mixed in a proper ratio is injected into the RTM molding mold in a state where a negative pressure (vacuum) is applied to the inside of the mold, e) It is the process of making FRP molding. During the injection of the resin liquid, air is discharged from the mold, and depending on the type of resin, heat is applied or ultraviolet (UV) is applied to cure the resin.

As interest in new materials has increased recently, research and development have been actively carried out. Especially, interest in composite materials with low specific gravity and high strength is increasing. In addition, as the research progresses to the stage of mass production of products using composite materials, there is a growing focus on the development of a method for shortening the process time for manufacturing a molded article.

However, such an RTM molding method has an advantage that a uniform product can be produced as compared with a hand lay-up method by hand, but still requires a long curing time.

Thus, in recent years, European automakers and chemical companies have conducted many studies to convert the RTM process from thermosetting resin to thermoplastic. In other words, instead of the method of injecting the thermosetting resin and the curing agent into the mold during the RTM process, the polymerization of the monomer of the thermoplastic resin with the catalyst and the reaction initiator is carried out. Accordingly, a t-RTM (Thermoplastic-Resin Transfer Molding) molding method for producing a molded article by polymerizing nylon 6 in a molding mold using a reactive ε- caprolactam monomer has been developed.

Particularly, the t-RTM molding method is a method jointly developed by Volkswagen and BASF in order to economically produce molded articles such as automobile parts using reactive ε- caprolactam. The t-RTM molding method using the reactive ε- caprolactam is also similar to the conventional RTM molding method. However, there is a difference from the conventional RTM molding method in that a preform of a fiber material located in a molding mold is impregnated with reactive & epsilon -caprolactam and then polymerized to produce a molded article.

Conventional t-RTM molding methods require two melting tanks. One of them is a melting tank in which molten reactive ? -Caprolactam and a catalyst are mixed, and the other is a melting tank in which molten reactive ? -Caprolactam and a reaction initiator are mixed. As described above, the flow of the reactive ε- caprolactam melt from the two melting tanks in which the catalyst and the reaction initiator are respectively mixed is mixed at a ratio of 1: 1 in a heated state at about 100 ° C. As described above, after the mixing is completed, the mixture is injected into the heating mold heated to a temperature of 105 DEG C or higher. After being injected into the molding mold as described above, polymerization is carried out. After that, the molding of the FRP product is completed through demolding.

However, in the conventional t-RTM molding method, voids are two to three times larger than those of other processes, and the volume ratio of the fiber preform to the voids becomes uneven. As a result, And the water content is increased. In addition, there is a disadvantage that mass production is limited because of long molding time.

The present invention relates to two melting tanks, that is, a first melting tank for mixing molten reactive ? -Caprolactam and a reaction initiator, a conventional melting tank for mixing a molten reactive ? -Caprolactam and a catalyst and a second melting tank for mixing the molten reactive ? As an improvement of the RTM molding apparatus and the molding method, it is possible to shorten the molding time by melting the reactive ε- caprolactam flake in one melting tank and then sequentially or simultaneously mixing the catalyst and the reaction initiator in the reactor, To provide a t-RTM molding apparatus and a molding method for producing a low molded article. However, these problems are exemplary and do not limit the scope of the present invention.

The t-RTM molding method for reducing the void ratio and shortening the molding time of the molded article in the present invention comprises a first step in which the reactive ε-caprolactam flake is melted to form a reactive ε-caprolactam melt; A second step of sequentially or simultaneously mixing the reactive ε-caprolactam melt with a catalyst and a reaction initiator; A third step of injecting a reactive epsilon -caprolactam molten mixture containing the catalyst and the reaction initiator into a molding space in which an upper forming mold and a upper forming mold coupled in a complementary manner on the upper side of the lower forming mold are formed by meshing; A fourth step of applying a vacuum to the interior of the molding die; A fifth step in which a reactive ε-caprolactam melt mixed with the catalyst and a reaction initiator is impregnated into a fiber preform, which is a molding, located inside the molding space; A sixth step of polymerizing the reactive? -Caprolactam; And removing air to prevent contact between the molten material and water during each of the steps;

And a control unit.

In the t-RTM molding method of the present invention, the degree of vacuum in the fourth step is -0.1 MPa or less, and the injection pressure of the molten material in the third step is preferably 1 to 7 kgf / cm ² .

The fiber-reinforced plastic molded article of the present invention is characterized by having a void ratio of 15% or less.

The t-RTM molding apparatus for reducing the void ratio and shortening the molding time of the molded article in the present invention is a single melting tank in which the reactive? -Caprolactam flake is melted; A reactor for mixing the molten reactive? -Caprolactam, the catalyst and the reaction initiator sequentially or simultaneously; A molding die having a lower molding die for forming the molding space and an upper molding die coupled in a complementary shape on the upper side of the lower molding die; A fiber preform positioned inside the forming space; A receiver inlet for injecting the molten reacted caprolactam by mixing the catalyst and the reaction initiator into the molding space; And at least one vacuum suction valve installed to remove air inside the molding space.

According to the t-RTM molding apparatus and molding method according to an embodiment of the present invention, since the polymerization of the reactive ε- caprolactam proceeds and the impregnation is completed in the fiber preform after being injected into the molding mold before the viscosity increases, Since the impregnation into the preform is easy, the occurrence of voids in the formed article can be reduced, so that the volume ratio of the preform of the fibrous article becomes uniform and the physical properties of the article are increased. Since the melting of reactive & epsilon -caprolactam flakes is carried out in a single melting tank, the energy consumption can be reduced and the process of melting and mixing the reactive ? -Caprolactam flakes in the two melting tanks is not necessary. Can be shortened. Of course, the scope of the present invention is not limited by these effects.

1 is a schematic diagram of an RTM molding method,
2 is a schematic view of a conventional t-RTM molding apparatus,
3 is a schematic view of a t-RTM molding apparatus according to the present invention.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. It should be understood, however, that the invention is not limited to the disclosed exemplary embodiments, but is capable of other various forms of implementation. The following examples are intended to be illustrative of the present invention, Is provided to fully inform the user. Also, for convenience of explanation, the components may be exaggerated or reduced in size.

In the figures, for example, variations in the shape shown may be expected, depending on manufacturing techniques and / or tolerances. Therefore, the experimental examples of the present invention should not be construed as limited to the specific shapes of the regions shown in this specification, and should include, for example, changes in the shape resulting from manufacturing.

Fig. 2 shows a conventional t-RTM molding apparatus. As it described above in Figure 2, a conventional t-RTM molding device and a first melting tank 21 for mixing with reaction initiator to the melt to a reactive ε- caprolactam flakes (flake), the reactive ε- caprolactam flakes and a second melting tank 22 for melting the flakes and mixing them with the catalyst. In the first melting tank 21 and the second melting tank 22, a molten mixture discharged from the first melting tank 21, that is, a reactive ε- caprolactam molten mixture mixed with a reaction initiator, The molten resin discharged from the reactor 30, that is, the resin transfer pipe 71 for transferring the reactive epsilon -caprolactam molten mixture mixed with the catalyst to the reactor 30 is communicated. The resin transfer pipe 71 transfers the reactive ε- caprolactam molten material transferred from the first melting tank 21 and the reactive ε- caprolactam molten material transferred from the second melting tank to the reactor 30. The reactive ε- caprolactam melt, the reaction initiator and the catalyst are mixed in the reactor (30). A water inlet tube 60 for injecting the molten material into the fiber preform 50 located inside the molding die 40 composed of the upper mold 41 and the lower mold 42 is provided at one end of the reactor 30 . A vacuum suction valve (80) is provided at one end of the molding die (40) to form a vacuum inside the molding die (40).

On the other hand, as shown in FIG. 3, the t-RTM molding apparatus of the present invention has a single melting tank 20 for melting reactive ? -Caprolactam flakes. The single melt tank 20 is provided with a resin transfer pipe 71 for transferring the reactive ε- caprolactam molten material to the reactor 30, and the resin transfer pipe 71 is made of a reactive ε- caprolactam melt, With the reactor 30, which mixes sequentially or concurrently. In addition, at one side of the reactor 30, there are formed an inlet for introducing a reaction initiator and a catalyst into the reactor sequentially or simultaneously, that is, a reaction initiator inlet port 32 and a catalyst inlet port 31, respectively.

A receiver tube inlet pipe 60 for injecting the molten material into the fiber preform 50 located inside the molding die 40 composed of the upper mold 41 and the lower mold 42 is provided at one end of the reactor 30 do. The water inlet pipe 60 communicates with the molding die 40 and a vacuum suction valve 80 is provided at one end of the molding die to form a vacuum inside the molding die.

That is, in the t-RTM molding apparatus of the present invention, the reactive ε- caprolactam flake is melted in a single melting tank 20, the molten material is transferred to the reactor 30 through the resin transfer pipe 71, (30), the catalyst and the reaction initiator are mixed sequentially or simultaneously. Thereafter, this is injected into the molding die 40, and a polymerization process is performed to complete the molding.

As discussed above, conventional t-RTM molding machines require two melting tanks. That is, a first melting tank 21 for melting reactive ε- caprolactam and mixing with a reaction initiator, and a second melting tank 22 for melting the reactive ε- caprolactam to mix the catalyst. As described above, the reactive ε- caprolactam melt mixed in the different melting tanks and containing the catalyst or the reaction initiator is transferred to the reactor 30 through the resin transfer pipe 71 so that the two melts are mixed. At this time, the molten material, the catalyst and the reaction initiator are mixed together. The mixed molten material in the reactor 30 is injected into the molding die 40 through the inlet pipe 60 and then impregnated with the fibrous preform 50. After the middle heap is completed, the molten material is demolded to produce a molding agent. At this time, a vacuum suction valve 80 is provided to introduce a vacuum into the mold.

On the other hand, the t-RTM molding apparatus of the present invention has a single melting tank 20 for melting a reactive & epsilon -caprolactam flake to form a melt, which is passed through a resin transfer pipe 71 to a reactor 30). Thereafter, the catalyst and the reaction initiator are sequentially or simultaneously injected into the reactor 30, and the catalyst and the reaction initiator are mixed and injected into the molding die 40 through the receiver tube 60 after mixing. That is, in the reactor 30, the catalyst is first charged through the catalyst inlet 310 to be mixed with the melt, and then the reaction initiator is introduced into the reactor through the reaction initiator inlet 32 to be mixed with the melt. In another embodiment of the present invention, in the reactor 30, the reaction initiator and the catalyst may be simultaneously charged and mixed with the molten material. The subsequent process is the same as the conventional t-RTM process.

3, the t-RTM molding apparatus according to an embodiment of the present invention comprises melting a reactive ε- caprolactam flake in a single melting tank 20 to form a melt, The catalyst and the reaction initiator are sequentially charged into the melt and mixed with the melt.

That is, in the conventional t-RTM molding apparatus, the reactive ε- caprolactam melt and the reaction initiator or the catalyst are mixed using the two melting tanks, ie, the first melting tank 21 and the second melting tank 22 , it is mixed with a reactive ε- caprolactam melt containing reactive ε- caprolactam melt, with the catalyst comprising a reaction initiator in the reactor. However, the t-RTM molding apparatus of the present invention is characterized in that after melting a reactive ε- caprolactam flake in a single melting tank 20 to form a melt, the melt and the reaction initiator and the catalyst are mixed sequentially or simultaneously in the reactor .

Hereinafter, a method of manufacturing a molded article using the t-RTM molding apparatus according to the present invention will be described.

First, a certain amount of reactive ε -caprolactam flake is metered into the melting tank 20. Since the reactive ε- caprolactam flakes melting temperature of 69 ℃ (flake), the melting tank 20 is molten by melting the lactams reactive ε- caprolactam flakes and maintain the temperature above the melting temperature of the reactive ε- caprolactam flakes . The molten material is transferred to the reactor 30 through the resin transfer pipe 71 communicated with the melting tank 20. The catalyst is first charged into the reactor 30 and then the reaction initiator is introduced, Mixing is done. In another embodiment of the present invention, the reaction initiator and the catalyst in the reactor 30 may be simultaneously charged and mixed with the melt. As described above, the reactive ε -caprolactam melt mixed with the reaction initiator and the catalyst is injected into the molding mold 40 through the water inlet pipe 60 communicated with the reactor 30, and impregnated into the fibrous preform 50 do. The molten material impregnated in the fiber preform 50 is polymerized, and upon completion of the polymerization, the molded article is finished by demolding. The step of removing air between each step may be included in order to prevent the contact between the molten material and the moisture in the air from the step of melting the reactive & epsilon -caprolactam flake to the formation of the final product, have.

Conventional t-RTM molding methods typically use two melting tanks. That is, the first melting tank 21 in which the reactive ε- caprolactam is melted and mixed with the reaction initiator, and the second melting tank 22 in which the reactive ε- caprolactam is melted and mixed with the catalyst is used. This conventional t-RTM molding method has a problem of low productivity because it takes a long time for molding. Accordingly, when the injection pressure of the molten material is increased to improve the productivity, the flow rate of the molten material increases, so that the molten material can be filled in the preform of the fiber material located inside the forming mold in a relatively short time within the forming mold. However, there is a problem that a non-uniform flow of the molten material occurs in the fiber preform and voids are generated in the formed body.

That is, in the mold 40, there is a certain degree of void in the composite composed of the fiber preform and the reactive ε- caprolactam melt. In particular, when the content of the fiber preform is large, voids increase. Generally, the void ratio in the FRP formed body is preferably in the range of 20%. When the void ratio is in the above-described preferable range, the impregnation and dispersion speed of the melt into the fiber preform is improved, and the non-uniform flow of the melt can be reduced

The present invention is characterized in that the molten reactive ε -caprolactam molten in the single melting tank 20, the catalyst, and the reaction initiator are sequentially introduced into the reactor 30 and mixed, unlike the conventional t-RTM molding method.

As described above, the catalyst and the reaction initiator used in the t-RTM process of the present invention may be a known catalyst for polymerization of reactive ε- caprolactam and a reaction initiator. For example, sodium- [ epsilon] -caprolactamate is preferable as the catalyst and toluene diisocyanate is preferable as the reaction initiator. The reason for this is that sodium-ε-caprolactamate produced by the addition of sodium during the anionic polymerization of reactive ε-caprolactam acts as a catalyst, but polymerization does not proceed smoothly when sodium alone is used. Therefore, it is preferable to include a reaction initiator capable of reacting with reactive ε -caprolactam to generate N-acyl caprolactam in order to accelerate the polymerization reaction.

Therefore, when sodium-ε-caprolactamate is used as a catalyst in the molding of a molded article using the t-RTM molding apparatus of the present invention and toluene diisocyanate is used as a reaction initiator, the complex between sodium-ε-caprolactamate and toluene diisocyanate complex to form an induction time. The induction time means a time at which the catalyst is activated, and no polymerization takes place during the induction time. Accordingly, when the catalyst and the reaction initiator as described above are used in the present invention, the efficiency of the molding process can be optimized by increasing the rate of the polymerization reaction.

In the present invention, when the molten reacted ? -Caprolactam, the catalyst and the reaction initiator are mixed sequentially or simultaneously, the catalyst is preferably mixed at 0.1 to 1.0 mol%. When the catalyst is mixed with 0.1 mol% or less, the efficiency of the initiator is lowered due to a low contact frequency between the reaction initiator and the catalyst, thereby lowering the polymerization rate. On the other hand, when the catalyst is added in an amount of 1.0 mol% or more, the activity of the catalyst becomes active and the efficiency is saturated.

In the present invention, it is preferable that the reaction initiator is mixed in an amount of 0.2 to 0.6 mol% when the molten reacted ? -Caprolactam, the catalyst and the reaction initiator are mixed sequentially or simultaneously. When the reaction initiator is mixed in an amount of 0.2 mol% or less, the reaction conversion rate sharply drops and the polymerization reaction may be terminated. On the other hand, when the reaction initiator is mixed with 0.6 mol% or more, the molecular weight gradually decreases beyond the maximum value. That is, when the content of the reaction initiator is increased, the number of the polymer chains increases and the molecular weight decreases after polymerization.

The reactive epsilon -caprolactam melt thus mixed is injected into the molding die through the water inlet pipe 60 communicated with the reactor 30 and is injected into the molding die 40 composed of the upper mold 41 and the lower mold 42 Is impregnated into the fiber preform 50 located inside the preform 50.

A fiber preform is provided in the molding die. The fiber preform to be used in the present invention may be a material used for ordinary fiber reinforcement materials such as carbon fiber, glass fiber, aramid fiber, boron fiber and metal fiber. Among them, carbon fiber, glass fiber and aramid fiber are preferable. The shape of the fiber preform 50 is not particularly limited, and a fabric or a nonwoven fabric can be used.

When the melt of reactive ε- caprolactam is injected into the molding die 40 through the water inlet pipe 70, the air inside the molding die 40 is sucked from the vacuum suction valve 80 formed at one end of the molding die And the degree of vacuum is preferably set to -0.1 MPa or less. When the degree of vacuum in the forming mold is less than -0.1 MPa, voids can be minimized in the formed body by removing the air from the fiber preform at the maximum

After the walking quasi-vacuum inside the forming die as described above, once the resin-introducing tube into the forming die reactive injection pressure of the melt on ε- caprolactam 1 ~ 7 kgf / cm ² through the molding formed in the mold (transfer pressure) It is preferable to perform injection under pressure. When the injection pressure of the molten material is 1 kgf / cm < ² > The impregnation speed of the molten material into the preform of the fiber preform is lowered, so that a large amount of time is required for the upper mold. Conversely, if the injection pressure is 7 kgf / cm ² Or more The flow velocity of the molten material is high and a large number of voids are generated on the surface of the fibrous preform.

For the above reasons, it is necessary to set the injection pressure and the vacuum degree of the molten material into the molding die to an appropriate value after sufficiently considering the characteristics of the reactive resin. After the molten material is impregnated into the fiber preform, the vacuum suction is stopped, and after the polymerization is completed in the molding die, the molding is completed by demolding.

According to the t-RTM molding apparatus for molding an FRP according to an embodiment of the present invention and the t-RTM molding method using the same, polymerization of the reactive ε- caprolactam melt, in which the catalyst and the reaction initiator are sequentially mixed, So that it is easy to impregnate into the fiber preform. Since the melting of reactive & epsilon] -caprolactam flakes is carried out in a single melting tank, energy consumption can be reduced, and a process of melting and mixing the reactive ? -Caprolactam flakes in two melting tanks is not necessary. The time can be greatly shortened. Therefore, the t-RTM method of the present invention has the effect of shortening the process time by about 15 minutes or more. Thus, the molding time can be shortened and the production amount can be greatly increased. In addition, the void ratio of the produced molded article is reduced, so that it is possible to produce a molded article having uniform quality and improved physical properties.

The present invention will be described in more detail with reference to the following examples and comparative examples. However, the technical scope of the present invention is not limited by the following embodiments.

In order to compare the void ratio and the molding time of the molded product manufactured by the conventional t-RTM molding method and the molded product produced by the t-RTM molding method of the present invention, a reactive ε- caprolactam was produced using a carbon fiber fabric preform Carbon fiber composites were fabricated.

(Examples 1, 2 and 3)

After melting the reactive ε- caprolactam in the single melting tank 20 of the t-RTM apparatus of the present invention, the reactive ε- caprolactam melt is injected into the reactor through the resin transfer pipe 70. At the same time, a catalyst and a reaction initiator are introduced into the reactor and mixed with the melt. At this time, 0.5 mol% of the catalyst and 0.4 mol% of the reaction initiator were mixed.

This? The molding mold of the t-RTM apparatus of the present invention is heated to 105 DEG C, a carbon fiber preform is placed in the molding mold, the mold is clamped, and the molten material is injected. Thereafter, polymerization is carried out and the product is demolded to complete the product. The injection pressure of the melt was 5 kgf / cm ² , and the degree of vacuum was maintained at 0.05 MPa. In order to prevent contact of the reactive ε- caprolactam melt with moisture during the molding process, the air was removed in each step.

Thereafter, polymerization is continued for a predetermined time, the product is cooled by natural cooling, and the upper mold 41 is opened by using a hydraulic cylinder to mold the molded product to complete the product.

Four carbon fiber preforms were prepared by laminating CK6252C (plain weave, weight per unit area of 315 g / m2, reinforcing fiber T700SC-12K) manufactured by Toray Industries, Inc.

The molding process was repeated three times in the same manner as described above, and the molded articles obtained in each were used in Examples 1 to 3.

(Comparative Examples 1, 2 and 3)

In Comparative Examples 1 to 3, the molding process was repeated three times using the conventional t-RTM apparatus in the same manner as in the above Examples, and the molded articles obtained in the respective Examples were used in Comparative Examples 1 to 3.

The void ratio and the molding time were measured from the molded articles of Examples 1 to 3 and Comparative Examples 1 to 3 and are shown in Table 1. In this case, the void ratio was measured by a test method of ASTM D 2734 (1997, Standard Test Methods for Void Content of Reinforced Plastics), and the molding time was measured by measuring the time required for one cycle of the molding process Respectively.

Example 1 Example 2 Example 3 Comparative Example 1 Comparative Example 2 Comparative Example 3 Void rate (%) 12 14 11 35 29 33 Molding time (min) 22 37

As shown in Table 1, the void ratio (%) of the molded product manufactured by the t-RTM method of the present invention is very small compared to the molded product manufactured by the conventional t-RTM molding method. This is because the t-RTM method of the present invention is injected into the molding mold as soon as the reactive ε- caprolactam, the catalyst and the reaction initiator are mixed with each other, so that the polymerization of the reactive ε- caprolactam proceeds, It is believed that voids are less likely to occur because impregnation is performed inside the fiber substrate when the viscosity is low and flow is easy.

In addition, the molding time of the t-RTM molding method of the present invention is 22 minutes, and it is found that the molding time of the comparative example is shortened by about 15 minutes than the molding time of 37 minutes. This is because the t-RTM method of the present invention has the effect of shortening the molding time as described above by increasing the polymerization reaction rate of the reactive ? -Caprolactam. As described above, by shortening the molding time and increasing the production amount by about two times, the mass production can be achieved.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it will be understood by those of ordinary skill in the art that various changes in form and details may be made therein without departing from the scope of the present invention. Accordingly, the true scope of the present invention should be determined by the technical idea of the appended claims.

20: Melting tank
21: first melting tank
22: second melting tank
30: Reactor
41: upper mold
42: Lower mold
40: Molding mold
80: Vacuum suction valve
50: fiber preform
31: catalyst inlet
32: reaction initiator inlet

Claims (6)

In a t-RTM molding method for reducing a void ratio of a molded body and shortening a molding time,
A first step in which the reactive? -Caprolactam flake is melted to form a reactive? -Caprolactam melt;
A second step of the reactive mixture of ε- caprolactone of toluene diisocyanate with a lactam melt, the catalyst sodium- ε -caprolactamate and initiator at the same time or in sequence;
Caprolactam melt in which the catalyst and the reaction initiator are mixed is injected into the molding space in which the upper shaping mold and the upper shaping mold which are complementarily joined to each other in the complementary shape on the upper side of the lower shaping mold are formed by meshing, ² ; < / RTI >
A fourth step of applying a vacuum of -0.1 MPa or less to the interior of the molding die;
A fifth step in which a reactive ε-caprolactam melt mixed with the catalyst and a reaction initiator is impregnated into a fiber preform, which is a molding, located inside the molding space;
A sixth step of polymerizing the reactive? -Caprolactam;
And removing air to prevent contact between the molten material and water during each of the steps;
≪ RTI ID = 0.0 > t-RTM <


delete delete delete delete A t-RTM molding apparatus for reducing a void rate of a molded article and shortening a molding time,
A single melting tank in which the reactive? -Caprolactam flake is melted;
A reactor for mixing the molten reactive ε- caprolactam and ε -caprolactamate sodium- catalyst and reaction initiator, toluene diisocyanate, either sequentially or at the same time;
A molding die having a lower molding die for forming a molding space and an upper molding die coupled in a complementary shape on the upper side of the lower molding die;
A fiber preform positioned inside the forming space;
A receiver inlet for injecting the molten reacted caprolactam by mixing the catalyst and the reaction initiator into the molding space;
And at least one vacuum suction valve installed to remove air inside the molding space.

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