METHOD FOR THE PRODUCING THERMOPLASTIC COMPOSITE PLASTICS

Description

[0001] The present invention relates to a molding apparatus, a system for manufacturing thermoplastic composites and a method of manufacturing thermoplastic composites.

[0002] Current processes for manufacturing thermoplastic composites from thermoplastic prepreg textiles are based on the principle of thermocompression. Thermocompression involves pressurizing thermoplastic prepreg textiles at high temperatures. However, the thermocompression process has the disadvantage of low productivity, due in particular to a long cycle time. Indeed, the temperature rise and fall rate in this process is very slow.

[0003] It is known to heat thermoplastic prepreg textiles using tools. Different heating techniques can be used, including conduction, convection, and radiation heating. Conduction heating includes ceramic and electrical resistance heating. This type of heating can be used, for example, to heat press plates. Convection heating can be achieved using a heat transfer fluid. Radiant heating can be achieved using infrared, microwave, or induction heating.

[0004] In recent decades, various manufacturing processes, such as thermoplastic injection or stamping, of thermoplastic composites have been developed.

[0005] Generally, a first step consists of manufacturing a plate or laminate by consolidating textiles impregnated with a thermoplastic resin or matrix. In other words, the plate or laminate is formed once the thermoplastic resin or matrix has penetrated the core of the textiles. The stamping process then consists of shaping the plate or laminate under high pressure and at high temperature in a press and then cooling it to obtain an appropriate crystalline structure that determines the mechanical properties of the composite material part. However, stamping has the disadvantage of being expensive and energy-intensive. In addition, the demolding of the composite material is carried out hot, which creates a risk of burns for the user, and the cooling is carried out outside the tooling, which makes it difficult to control and repeat.

[0006] Document EP2349667 discloses a molding device for transforming a material, comprising: a lower mold body, or die, made of an electrically conductive material and comprising a molding zone intended to be in contact with the material to be transformed; an upper mold body, or punch, made of an electrically conductive material; and comprising a molding zone intended to be in contact with the material to be transformed; a removable intermediate part, or core, made of an electrically conductive material, and interposed between the die and the punch; inductive means capable of generating a magnetic field enveloping the die, the punch and the intermediate part;these three elements being electrically insulated two by two, so that the facing faces of the intermediate part and the die on the one hand, and of the intermediate part and the punch on the other hand, delimit two air gaps in which circulates the magnetic field which induces currents on the surface of the molding zones, the die and the punch, thus making it possible to localize the action of the inductors on the surface of the molding zones. ;

[0007] The process disclosed in document EP2349667 using induction heating is energy-intensive and complex to implement. Furthermore, the structure of the molding device, and in particular of the intermediate part, does not allow control of the dimensions of the material to be transformed, the reduction of these temperature cycles and causes heterogeneity of the material to be transformed. Indeed, the diffusion of heat in the molding device is heterogeneous. Thus, the quality of thermoplastic composites can be degraded. Finally, only thin parts made of thermoplastic composites can be manufactured.

[0008] US 5,139,407 A describes a method of manufacturing thermoplastic composites using a system for manufacturing thermoplastic composites comprising: a molding apparatus comprising a first thermally conductive flange and a second thermally conductive flange, said first and second thermally conductive flanges defining a cavity configured to receive thermoplastic prepregs, a thermoconductive and thermoregulated mold by a heat transfer fluid comprising an upper cavity and a lower cavity, said upper and lower cavities being configured to receive said first and second thermally conductive flanges, and a press comprising an upper press plate on which the upper cavity of the thermoregulated and thermally conductive mold is fixed and a lower press plate on which the lower cavity of the thermoregulated and thermally conductive mold is fixed the method for manufacturing thermoplastic composites comprising the following steps: Provision of thermoplastic prepreg mats comprising fibers and a thermoplastic matrix,inserting the thermoplastic pre-impregnated textiles into first and second heat-conducting plates, transferring the heat-conducting plates into a press comprising an insulating mold and supports thermoregulated by a heat transfer fluid, preheating the heat-conducting plates by means of a direct heating system for the plates, pressing the heat-conducting plates, transferring the heat-conducting plates into a press comprising a heat-conducting mold and thermoregulated by a heat transfer fluid, cooling the heat-conducting plates in said press, - pressing the heat-conducting plates in said press, extracting the heat-conducting plates from said press and demolding the thermoplastic composites.

[0009] The invention aims to overcome the aforementioned drawbacks by proposing a molding apparatus, a system for manufacturing quasi-finished parts made of thermoplastic composites and a method for manufacturing quasi-finished parts made of thermoplastic composites facilitating the shaping of thermoplastic pre-impregnated textiles. Furthermore, the invention aims to propose a molding apparatus, a system for manufacturing quasi-finished parts made of thermoplastic composites making it possible to optimize the energy efficiency of the method for manufacturing quasi-finished parts made of thermoplastic composites.Finally, the invention aims to propose a molding apparatus, a system for manufacturing almost finished parts in thermoplastic composites and a method for manufacturing almost finished parts in thermoplastic composites ensuring control of the dimensions of the parts in thermoplastic composites, allowing acceleration of the temperature rise, homogenization of the temperature of the thermoplastic pre-impregnated textiles, while maintaining a high quality of the thermoplastic composites and limiting the production of waste.

[0010] The subject of the invention is a molding apparatus comprising: A first thermally conductive flange and a second thermally conductive flange, said first and second thermally conductive flanges defining a cavity configured to receive thermoplastic pre-impregnated textiles, A thermally conductive mold and thermoregulated by a heat transfer fluid and comprising an upper imprint and a lower imprint, said upper and lower imprints being configured to receive said first and second thermally conductive flanges.

[0011] The molding apparatus according to the invention makes it easier to shape thermoplastic pre-impregnated textiles. In fact, the stacking of thermoplastic pre-impregnated textiles is carried out in the cavity delimited by a first and a second lightweight heat-conducting flanges whose thermal conductivity is optimized. Furthermore, the energy efficiency of the thermoplastic composite manufacturing process is improved. In fact, the molding apparatus makes it possible to reduce the energy required for its use on the one hand, thanks to the combination of the first and second heat-conducting flanges with the thermoregulated and thermoconductive mold and on the other hand, thanks to the fact that the mold is thermoregulated and thermoconductive. The mold is thermoregulated unlike the devices of the prior art in which the press is generally thermoregulated.This has the effect of concentrating the heat more quickly and more efficiently around the first and second heat-conducting plates, avoiding heating the thick press plates which only diffuse part of the heat. The thermoregulated mold has the effect of ensuring the recrystallization of the thermoplastic composites. In addition, the heat-conducting plates, being removable, are independent of the thermoregulated and heat-conducting mold and the press, which has the advantage of better consolidation of the thermoplastic pre-impregnated textiles while facilitating the thermoplastic composite manufacturing process. The thermoplastic composite manufacturing process can then be implemented on an industrial scale, particularly continuously.In addition, the first and second thermally conductive flanges and the thermoregulated and thermally conductive mold have compatible thermal expansions to ensure control of the dimensions of the thermoplastic composites.

[0012] In one embodiment, said first and second thermally conductive plates have a thermal conductivity greater than 30 W·m -1< ·K -1< and said thermally conductive and thermoregulated mold by a heat transfer fluid has a thermal conductivity greater than 30 W·m -1< ·K -1< . Preferably, said first and second thermally conductive plates have a thermal conductivity greater than 49 or greater than 55W·m -1< ·K -1< . In this embodiment, the first and second thermally conductive plates and the thermally conductive and thermoregulated mold make it possible to ensure optimal heat transfer and guarantee temperature homogeneity within them while maintaining optimal quality of the thermoplastic composites.

[0013] In one embodiment, said first and second thermally conductive flanges are made of burnished steel, aluminum or a thermoset composite. For example, said first and second thermally conductive flanges are made of a composite comprising long carbon fibers and a thermoplastic matrix made of BMI or a composite comprising chopped carbon fibers and a thermoplastic matrix made of BMI such as Hextool ®<. Preferably, said first and second thermally conductive flanges are made of burnished steel. In this embodiment, the thermal conductivity of the first and second thermally conductive flanges is optimized.

[0014] In one embodiment, said first and second thermally conductive plates have a thickness of between 1 and 15 mm. Preferably, said first and second thermally conductive plates have a thickness of between 1 and 10 mm and advantageously between 1 and 5 mm. In this embodiment, the heat transfer is improved due to the low thickness of the thermally conductive plates.

[0015] In one embodiment, said first and second thermally conductive flanges comprise removable assembly means. For example, the removable assembly means are stop screws. In this embodiment, the assembly of the first and second thermally conductive flanges makes it possible to ensure the maintenance and the properties of the thermoplastic pre-impregnated textiles.

[0016] In one embodiment, the assembly means define an air gap between said first and second heat-conducting flanges. In this embodiment, it appears that the thermoplastic pre-impregnated textiles occupy the cavity defined by the heat-conducting flanges so as to obtain a thermoplastic composite part having the desired dimension without the need for cutting. This arrangement ensures complete filling of the cavity defined by the two flanges because the air gap is erased during the press-pressing step.

[0017] In one embodiment, the thermoregulating mold is made of steel.

[0018] In one embodiment, the heat transfer fluid is chosen from: water or oil.

[0019] The invention also relates to a system for manufacturing thermoplastic composites comprising: The molding apparatus according to the invention and a press comprising an upper press plate on which the upper impression of the thermoregulated and thermoconductive mold is fixed and a lower press plate on which the lower impression of the thermoregulated and thermoconductive mold is fixed.

[0020] The system for manufacturing thermoplastic composites according to the invention makes it possible to increase the energy efficiency of the thermoplastic composite manufacturing process while ensuring high quality of the thermoplastic composites. Indeed, the heating of the heat-conducting plates is carried out by means of the heat-conducting and thermoregulated mold, which makes it possible to avoid energy losses and optimize the diffusion of heat in the heat-conducting plates.

[0021] The invention finally relates to a method for manufacturing thermoplastic composites using the system for manufacturing thermoplastic composites according to the invention comprising the following steps: A. Provision of thermoplastic pre-impregnated textiles comprising fibers and a thermoplastic matrix, B. Insertion of the thermoplastic pre-impregnated textiles into first and second heat-conducting plates, C. Transfer of the heat-conducting plates into a press comprising a heat-conducting mold and thermoregulated by a heat transfer fluid, D. Preheating of the heat-conducting plates by means of the mold in said press, E. Pressing of the heat-conducting plates, F. Transfer of the heat-conducting plates into an infrared oven, G. Heating of the heat-conducting plates under infrared to melt the thermoplastic matrix, H. Transfer of the heat-conducting plates into a press comprising a heat-conducting mold and thermoregulated by a heat transfer fluid, I. Cooling of the heat-conducting plates in said press, J. Pressing of the heat-conducting plates in said press, K.Extraction of the heat-conducting plates from the said press and L. Demolding of thermoplastic composites.

[0022] The method according to the invention makes it possible to increase the energy efficiency thereof while reducing the manufacturing cycle time of thermoplastic composites. The productivity of the process is then improved. Indeed, the molding apparatus and the system for manufacturing thermoplastic composites make it possible to optimize the heating and cooling cycles. During the preheating carried out in step D), the heat-conducting plates and the thermoregulated and heat-conducting mold cooperate so as to increase and homogenize the diffusion of heat. During the heating carried out in step G), the heat-conducting plates are heated under infrared to promote the melting of the thermoplastic matrix of the thermoplastic pre-impregnated textiles.The molding apparatus allows expansion phenomena to be controlled and also optimizes the cooling carried out in step I) and thus the crystallization of the thermoplastic matrix of thermoplastic composites. During step L), demolding is carried out at a temperature allowing the part to be handled without risk of burning the user. Furthermore, the process offers almost finished parts in ready-to-use thermoplastic composites, i.e. requiring little or no cutting. Indeed, the heat-conducting flanges are previously sized to obtain the desired thermoplastic composite part. In addition, the press(es) used in the process are conventional presses, which reduces production costs. In addition, a wide variety of thermoplastic composites can be produced quickly and efficiently.Indeed, thermally conductive flanges can easily vary in terms of thickness, shape and patterns. The method according to the invention ensures the reproducibility of the parts, is inexpensive and allows for the optimization of the shaping of almost finished parts.

[0023] For example, in step A), the thermoplastic prepreg textiles comprise fibers selected from: short or continuous fibers, natural fibers, organic or mineral fibers, For example, the fibers are selected from: basalt fibers, carbon fibers, glass fibers. For example, in step A), the thermoplastic matrix is ​​composed of: polyolefins, polycarbonates, polyamides, polystyrenes, polyesters and / or polyaryletherketones. For example, the thermoplastic matrix is ​​made of polyphenylene sulfide, a thermoplastic matrix is ​​made of polyethylene, a thermoplastic matrix is ​​made of poly(ethylene terephthalate).

[0024] In one embodiment, in step D), the preheating of the mold is carried out by convection or by conduction. Conduction heating includes ceramic heating and electrical resistance heating. Convection heating can be carried out using a heat transfer fluid. In this embodiment, thermal diffusion is improved.

[0025] In one embodiment, in step D), the preheating of the mold is carried out at a temperature between 50 and 150°C. Unlike the prior art in which the presses are generally heated to temperatures around 350°C, it seems that in this embodiment the heat-conducting flanges and the heat-conducting and thermoregulated mold manage to optimize the energy efficiency, in particular by considerably reducing the preheating temperature. Indeed, the heat-conducting mold is heated so as to diffuse the heat towards the heat-conducting flanges, which has the effect of increasing the heat transfer without energy loss.

[0026] In one embodiment, in step D), the preheating is carried out for 1 to 10 min. In this embodiment, it appears that the diffusion of heat with the molding apparatus is efficient, which has the effect of reducing the heating time and thus increasing productivity while optimizing energy efficiency.

[0027] In one embodiment, in steps E) and / or J), the pressing is carried out at a pressure of between 10.10 6< and 60.10 6< Pa.

[0028] In one embodiment, the method comprises a step M) carried out after step E) or after step J) including the evacuation of the first and second heat-conducting plates. In this embodiment, the evacuation makes it possible to improve the penetration of the molten thermoplastic matrix into the fibers. Furthermore, the evacuation makes it possible to maintain the orientation of the fibers included in the thermoplastic pre-impregnated textiles, to avoid oxidation of the thermoplastic matrix, to remove any contamination and to avoid delamination of the thermoplastic pre-impregnated textiles during shaping. Finally, the evacuation keeps the thermoplastic matrix fluidized.

[0029] In one embodiment, a gasket is inserted between said first and second heat-conducting flanges. For example, the gasket is heat-resistant. For example, the gasket has a compression factor of between 0.1 and 10 mm, preferably between 0.1 and 5 mm, and advantageously between 0.1 and 3 mm.

[0030] In one embodiment, in step G), the first and second heat-conducting plates are heated to the melting temperature of the thermoplastic matrix of the thermoplastic pre-impregnated textiles.

[0031] In one embodiment, in step G), the heating of the first and second heat-conducting plates is carried out for 5 to 15 min. In this embodiment, the preheating step D) and the heat-conducting plates make it possible to reduce the heating time.

[0032] In one embodiment, in step I), the first and second thermally conductive plates are cooled to a temperature at least 10°C lower than the glass transition temperature of the thermoplastic matrix. In this embodiment, the user can handle the first and second thermally conductive plates without any risk of burning.

[0033] In one embodiment, in step I), the cooling is carried out for 1 to 10 min.

[0034] In one embodiment, the thermoplastic prepreg textiles comprise electronic components based on inorganic compounds or organic compounds. For example, the electronic components are selected from: a near-field communication tag or a radio-identification tag. In this embodiment, the thermoplastic composites can be easily traced by the user.

[0035] In one embodiment, only one press is used in steps C) and H). In other words, the same press is used in steps C) and H).

[0036] In one embodiment, two separate presses are used during steps C) and H). In other words, a first press is used during step C) and a second press is used during step H). In this embodiment, the method makes it possible to manufacture parts continuously on an industrial scale.

[0037] The invention will be better understood from the following description, which relates to one or more embodiments according to the present invention, given as non-limiting examples and explained with reference to the appended schematic drawings, in which: [ Fig. 1 ] is an overview of a system for manufacturing thermoplastic composites according to the invention, [ Fig. 2 ] is a side view of a system for manufacturing thermoplastic composites according to the invention, [ Fig. 3 ] is a schematic view of the process for manufacturing thermoplastic composites according to the invention, [ Fig. 4 ] is an overview of part of the process for manufacturing thermoplastic composites according to the invention, [ Fig. 5 ] is an overview of part of the process for manufacturing thermoplastic composites according to the invention, [ Fig. 6 ] is an overview of part of the process for manufacturing thermoplastic composites according to the invention, [ Fig. 7 ] is an overview of part of the process for manufacturing thermoplastic composites according to the invention, [ Fig. 8 ] is an overview of part of the process for manufacturing thermoplastic composites according to the invention, [ Fig. 9 ] is an overview of part of the process for manufacturing thermoplastic composites according to the invention, [ Fig. 10 ] is an overview of part of the process for manufacturing thermoplastic composites according to the invention, [ Fig. 11 ] is an overview of part of the process for manufacturing thermoplastic composites according to the invention, [ Fig. 12 ] is an overview of part of the process for manufacturing thermoplastic composites according to the invention and [ Fig. 13 ] is an overview of part of the process for manufacturing thermoplastic composites according to the invention.

[0038] THE Figures 1 et 2 illustrate a system 1 for manufacturing thermoplastic composites comprising: A molding apparatus 2 and a press 3 comprising an upper press plate 31 and a lower press plate 32.

[0039] The molding apparatus 2 comprises a first thermally conductive flange 21 and a second thermally conductive flange 22, said first 21 and second 22 thermally conductive flanges defining a cavity configured to receive thermoplastic pre-impregnated textiles. The first 21 and second 22 thermally conductive flanges have a thermal conductivity greater than 30 W m -1< K -1< and preferably greater than 49 or greater than 55 W m -1< K -1< .

[0040] The first 21 and second 22 thermally conductive plates are for example made of burnished steel, aluminum or thermoset composite. Preferably, said first and second thermally conductive plates are made of burnished steel, which has the effect of increasing the thermal conductivity.

[0041] The molding apparatus 2 further comprises a thermoregulated and thermally conductive mold 23 comprising an upper cavity 24 and a lower cavity 25 and having a thermal conductivity greater than 30 W·m -1< ·K -1< , said upper 24 and lower 25 cavities being configured to receive said first 21 and second 22 thermally conductive flanges.

[0042] For example, the first 21 and second 22 thermally conductive plates have a thickness of between 1 and 15 mm. Thus, the thermally conductive plates are lightweight and have improved thermal conductivity.

[0043] The first 21 and second 22 heat-conducting flanges may comprise removable assembly means. For example, the removable assembly means are stop screws 26.

[0044] The thermoregulated and thermally conductive mold 23 is preferably made of steel. The thermoregulated and thermally conductive mold 23 is preferably regulated by means of a heat transfer fluid, for example water.

[0045] The upper imprint 24 of the thermoregulated and thermoconductive mold 23 is fixed on the upper press plate 31 of the press 3 and the lower imprint 25 of the thermoregulated and thermoconductive mold 23 is fixed on the lower press plate 32. The first 21 and second 22 thermoconductive flanges are removable, that is to say independent of the thermoregulated and thermoconductive mold 23 and of the press 3.

[0046] In this example, the system 1 comprises a vacuum device 11.

[0047] In this example, the system 1 further comprises a transfer frame 12 which makes it possible to transfer the first 21 and second 22 thermally conductive plates, lateral guide supports 13 on which guide rails 14 are fixed which make it possible to guide the first 21 and second 22 thermally conductive plates and the transfer frame 12.

[0048] The method of manufacturing thermoplastic composites using system 1 for manufacturing thermoplastic composites comprises a step A) in which thermoplastic prepreg textiles comprising fibers and a thermoplastic matrix are provided.

[0049] THE Figures 3 And 4illustrate step B) in which the thermoplastic pre-impregnated textiles 4 are inserted into first 21 and second 22 thermally conductive flanges. For this purpose, the thermoplastic pre-impregnated textiles 4 can be deposited on the second thermally conductive flange 22. The first flange 21 can then be deposited on the second thermally conductive flange 22 so as to delimit a cavity configured to receive the thermoplastic pre-impregnated textiles 4. The first 21 and second 22 thermally conductive flanges can then be assembled with stop screws 26 ( Figure 5 ).

[0050] For example, in step A), the thermoplastic pre-impregnated textiles 4 comprise fibers chosen from: short or continuous fibers, natural fibers, organic or mineral fibers. For example, the fibers are chosen from: basalt fibers, carbon fibers, glass fibers. For example, in step A), the thermoplastic matrix is ​​composed of: polyolefins, polycarbonates, polyamides, polystyrenes, polyesters and / or polyaryletherketones. For example, the thermoplastic matrix is ​​made of polyphenylene sulfide, a thermoplastic matrix is ​​made of polyethylene, a thermoplastic matrix is ​​made of poly(ethylene terephthalate).

[0051] There Figure 6 illustrates step C) in which the first 21 and second 22 heat-conducting plates are transferred into the press 3. For this purpose, the first 21 and second 22 heat-conducting plates are arranged on the rails 14.

[0052] THE Figures 3 And 7illustrate step D) in which the first 21 and second 22 heat-conducting flanges are preheated by means of the mold 23 in said press 3. The preheating of the mold 23 can be carried out by convection or by conduction at a temperature between 50 and 150°C and for example at a temperature of 100°C. The preheating can be carried out for 1 to 10 min and for example, for 5 min.

[0053] THE Figures 3 And 7 also illustrate step E) in which the first 21 and second 22 heat-conducting flanges are pressed. The pressing can be carried out at a pressure of between 10.10 6< and 60.10 6< Pa and for example at a pressure equal to 15.10 6< Pa.

[0054] There Figure 7 also illustrates step M) which can be carried out after step E) including the evacuation of the first 21 and second 22 heat-conducting plates using the vacuum device 11. For example, a heat-resistant seal is inserted between said first 21 and second 22 heat-conducting plates. The seal can have a compression factor of between 0.1 and 3 mm and for example a compression factor of 1.5 mm.

[0055] There Figure 8 illustrates the opening of the press 3. The first 21 and second 22 heat-conducting flanges can then be placed on the transfer frame 12 ( Figure 1 ). In a step F), the first 21 and second 22 heat-conducting plates are transferred into an infrared IR oven.

[0056] THE Figures 3 And 9illustrate step G) in which the first 21 and second 22 heat-conducting plates are heated in an infrared IR oven. For example, the first 21 and second heat-conducting plates are heated to the melting temperature of the thermoplastic matrix of the thermoplastic pre-impregnated textiles. The heating of the first 21 and second 22 heat-conducting plates can be carried out for 5 to 15 min or for example for 8 min.

[0057] There Figure 10 illustrates the opening of the press 3. The first 21 and second 22 heat-conducting flanges can then be placed on the transfer frame 12 ( Figure 1 ). In a step H), the first 21 and second 22 heat-conducting plates are transferred into the press 3.

[0058] THE Figures 3 And 11illustrate step I) in which the first 21 and second 22 heat-conducting plates are cooled. For example, the first 21 and second 22 heat-conducting plates are cooled to a temperature at least 10°C lower than the glass transition temperature of the thermoplastic matrix. The cooling can be carried out for 1 to 10 min or for example for 6 min.

[0059] THE Figures 3 And 11 also illustrate step J) in which the first 21 and second 22 heat-conducting flanges are pressed. The pressing can be carried out at a pressure of between 10.10 6< and 60.10 6< Pa and for example at a pressure equal to 15.10 6< Pa.

[0060] There Figure 11 also illustrates step M) which can be carried out after step J) including the evacuation of the first 21 and second 22 heat-conducting plates using the vacuum device 11. For example, a heat-resistant seal is inserted between said first 21 and second 22 heat-conducting plates. The seal can have a compression factor of between 0.1 and 3 mm and for example a compression factor of 1.5 mm.

[0061] There Figure 12 illustrates the opening of press 3 when cooling is complete.

[0062] There Figure 13illustrates step K) in which the first 21 and second 22 heat-conducting flanges are extracted from the press 3. After removing the first heat-conducting flange 21, the thermoplastic composites 41 can be demolded. For example, the thickness of the thermoplastic composite part is between 1 and 50 mm, preferably between 1 and 10 mm and is for example 2 mm.

[0063] When implementing the method according to the invention, two separate presses can be used during steps C) and H).

[0064] The molding apparatus according to the invention facilitates the shaping of thermoplastic pre-impregnated textiles. Furthermore, the energy efficiency of the thermoplastic composite manufacturing process is improved. In addition, the removable thermally conductive plates allow for better consolidation of the thermoplastic pre-impregnated textiles while facilitating the thermoplastic composite manufacturing process. The thermoplastic composite manufacturing process can be implemented on an industrial scale, particularly continuously. In addition, the first and second thermally conductive plates and the thermoregulated and thermally conductive mold have compatible thermal expansions to ensure control of the dimensions of the thermoplastic composites.Finally, the first and second thermally conductive plates ensure optimal heat transfer and guarantee temperature homogeneity within them while maintaining optimal quality of the thermoplastic composites.

Claims

1. A method for manufacturing thermoplastic composites (41) using a system (1) for manufacturing thermoplastic composites comprising: - a molding apparatus (2) comprising a first thermo-conductive flange (21) and a second thermo-conductive flange (22), said first (21) and second (22) thermo-conductive flanges delimiting a cavity configured to receive thermoplastic pre-impregnated textiles (4), and a mold (23), thermo-conductive and thermo-regulated by a heat transfer fluid, comprising an upper imprint (24) and a lower imprint (25), said upper (24) and lower (25) imprints being configured to receive said first (21) and second (22) thermo-conductive flanges, and - a press (3) comprising an upper press plate (31) on which the upper imprint (24) of the thermo-regulated and thermo-conductive mold (23) is fixed and a lower press plate (32) on which is fixed the lower imprint (25) of the thermo-regulated and thermo-conductive mold (23) the method for manufacturing thermoplastic composites comprising the following steps: A. Provision of thermoplastic pre-impregnated textiles (4) comprising fibers and a thermoplastic matrix, B. Insertion of the thermoplastic pre-impregnated textiles (4) into first (21) and second (22) thermo-conductive flanges, C. Transfer of the thermo-conductive flanges (21, 22) into a press (3) comprising a mold (23) which is thermo-conductive and thermo-regulated by a heat transfer fluid, D. Preheating of the thermo-conductive flanges (21, 22) by means of the mold in said press, E. Pressing of the thermo-conductive flanges (21, 22), F. Transfer of the thermo-conductive flanges (21, 22) into an infrared oven (IR), G. Heating of the thermo-conductive flanges (21, 22) under infrared to melt the thermoplastic matrix, H. Transfer of the thermo-conductive flanges (21, 22) into a press (3) comprising a mold (23) which is thermo-conductive and thermo-regulated by a heat transfer fluid, I. Cooling of the thermo-conductive flanges (21, 22) in said press (3), J. Pressing of thermo-conductive flanges (21, 22) in said press (3), K. Extraction of the thermo-conductive flanges (21, 22) from said press (3) and L. Demolding of the thermoplastic composites (41).

2. The method for manufacturing thermoplastic composites according to claim 1, wherein in step D), the preheating of the mold (23) is carried out by convection or by conduction.

3. The method for manufacturing thermoplastic composites according to claim 1 or 2, wherein in step D), the preheating of the mold (23) is carried out at a temperature comprised between 50 and 150°C.

4. The method for manufacturing thermoplastic composites according to any one of claims 1 to 3, wherein in steps E) and / or J), the pressing is carried out at a pressure comprised between 10.106 and 60.106 Pa.

5. The method for manufacturing thermoplastic composites according to any one of claims 1 to 4, comprising a step M) carried out after step E) or J), including the vacuuming of the first and second (21, 22) thermo-conductive flanges.

6. The method for manufacturing thermoplastic composites according to claim 5, wherein a seal is inserted between said first (21) and second (22) thermo-conductive flanges.

7. The method for manufacturing thermoplastic composites according to any one of claims 1 to 6, wherein in step G), the first (21) and second (22) thermo-conductive flanges are heated to the melting temperature of the thermoplastic matrix of the thermoplastic pre-impregnated textiles (4).

8. The method for manufacturing thermoplastic composites according to any one of claims 1 to 7, wherein in step I), the first (21) and second (22) thermo-conductive flanges are cooled to a temperature at least 10°C lower than the glass transition temperature of the thermoplastic matrix.

9. The method for manufacturing thermoplastic composites according to any one of claims 1 to 8, wherein the thermoplastic pre-impregnated textiles (4) comprise electronic components based on inorganic compounds or organic compounds.

10. The method for manufacturing a thermoplastic composite according to any one of claims 1 to 9, wherein said first (21) and second (22) thermo-conductive flanges have a thermal conductivity greater than 30 W.m-1.K-1 and said mold (23), which is thermo-conductive and thermo-regulated by a heat transfer fluid, has a thermal conductivity greater than 30 W·m-1·K-1.

11. The method for manufacturing a thermoplastic composite according to any one of claims 1 to 10, wherein said first (21) and second (22) thermo-conductive flanges are made of burnished steel, aluminum or thermoset composite.

12. The method for manufacturing a thermoplastic composite according to any one of claims 1 to 11, wherein said first (21) and second (22) thermo-conductive flanges comprise removable assembly means.