A molding equipment for thermoplastic composite profiled sheets

Abstract

This invention discloses a molding equipment for thermoplastic composite material profiled sheets, belonging to the field of profiled sheet molding technology. It includes a preheating zone for flat composite material sheets, a gradient hot-pressing preforming zone for flat sheets, an integral hot-pressing forming zone, and a cooling and shaping zone arranged sequentially. The preheating zone for flat composite material sheets is equipped with a conveying device, and an infrared radiation preheating device is positioned above the conveying device. The gradient hot-pressing preforming zone for flat sheets is equipped with multiple sets of infrared radiation heating devices arranged sequentially, each set corresponding to a set of pressure preforming molds. The infrared radiation heating devices have multi-level temperature gradients, and the pressure preforming molds have multi-level curvature gradients. This equipment uses a heating and pressurizing preforming method with molds exhibiting localized multi-level curvature gradients to form a profiled cross-section with a certain curvature from the original flat composite material sheet. Then, through integral plasticizing and molding, a profiled composite material sheet product is finally formed.

Description

Technical Field

[0001] This invention belongs to the field of profiled sheet forming technology, specifically relating to a forming equipment for thermoplastic composite profiled sheets. Background Technology

[0002] The statements herein provide only background information in relation to this invention and do not necessarily constitute prior art.

[0003] Composite products made by reinforcing high-performance thermoplastic resin matrices with high-performance fibers, such as carbon fiber, glass fiber, and basalt fiber, have greater market application potential than traditional high-performance fiber-reinforced thermosetting resins due to the repeated plasticizing and molding characteristics of the resin matrix.

[0004] Currently, the molding of thermoplastic resin-based fiber composites generally involves hot pressing of thermoplastic prepreg fabrics through layering. Composite products produced by this method are generally regular in shape and are flat. However, for products with more complex shapes or irregular shapes with a certain curvature, the requirements for molding equipment and processes are higher. Moreover, thermoplastic resins have poor fluidity, and the impregnation and compounding process of resin and fiber is relatively slow in the molding of complex-shaped products. Traditional molding methods have low production efficiency. Summary of the Invention

[0005] To address the shortcomings of existing technologies, the purpose of this invention is to provide a molding equipment for thermoplastic composite profiled sheets. This equipment can utilize regular planar thermoplastic composite sheets and pre-form them by heating and pressurizing a molding die with local multi-level gradient curvature to form a profiled cross-section with a certain curvature. Then, through overall plasticizing and molding, a composite sheet product with a profiled cross-section as required by the design is finally formed.

[0006] To achieve the above objectives, the present invention is implemented through the following technical solution:

[0007] In a first aspect, the present invention provides a molding equipment for thermoplastic composite material profiled sheets, comprising a composite material planar sheet preheating zone, a planar sheet gradient hot pressing preforming zone, an integral hot pressing forming zone, and a cooling and shaping zone arranged sequentially; the composite material planar sheet preheating zone is provided with a conveying device, and an infrared radiation preheating device is provided above the conveying device; the planar sheet gradient hot pressing preforming zone is provided with multiple sets of infrared radiation heating devices arranged sequentially, the multiple sets of infrared radiation heating devices are arranged one-to-one with multiple sets of pressure preforming molds, the multiple sets of infrared radiation heating devices have multiple gradient temperatures, and the multiple sets of pressure preforming molds have multiple gradient curvatures.

[0008] As a further technical solution, the infrared radiation preheating device includes multiple sets of infrared radiation tubular heating components, which are arranged sequentially.

[0009] As a further technical solution, each set of infrared radiation heating devices is equipped with multiple sets of infrared radiation tubular heating components, and the multiple sets of infrared radiation tubular heating components are arranged in sequence.

[0010] As a further technical solution, the temperature settings of the infrared radiation tubular heating components of multiple infrared radiation heating devices are different, and the temperature values ​​change in a gradient.

[0011] As a further technical solution, multiple sets of pressure preforming molds all have curved forming surfaces, and the forming surfaces of each set of pressure preforming molds are different, forming multi-level gradients.

[0012] As a further technical solution, the preheating zone of the composite material planar sheet preheats and softens the planar sheet before transferring it to the gradient hot pressing preforming zone. The gradient hot pressing preforming zone pre-shapes the planar sheet by multi-stage heating and pressurization to pre-shape its curvature. Then, it is transferred to the overall hot pressing forming zone. The overall hot pressing forming zone performs overall hot pressing and melting composite bonding on the pre-shaped sheet. Finally, it is transferred to the cooling and shaping zone to cool the shaped composite material sheet and form the part.

[0013] As a further technical solution, the integral hot pressing forming area includes an inner mold with an irregular cavity, and an outer mold with electric heating is arranged outside the inner mold with an electric heating device.

[0014] As a further technical solution, the mold inside the irregular cavity has an irregular forming surface formed by multiple curves to form the sheet metal.

[0015] As a further technical solution, after the melt infiltration composite process is completed, the inner mold of the irregular cavity and the outer mold of the electric heating are separated, and the inner mold of the irregular cavity is transferred to the cooling and shaping area.

[0016] As a further technical solution, the cooling and shaping zone is equipped with a refrigeration device to rapidly cool the mold inside the irregular cavity.

[0017] The beneficial effects of the present invention are as follows:

[0018] The molding equipment of this invention includes a preheating zone for planar composite material sheets, which preheats and softens the planar thermoplastic composite material sheet to provide a preliminary basis for irregular shape processing; a gradient hot-pressing preforming zone for planar sheets, which pre-shapes the irregular shape by applying multi-stage heating and pressure; an overall heating and forming zone, which performs overall hot-pressing and melting composite bonding on the pre-shaped irregular sheet; and a cooling and shaping zone, which completes the cooling and shaping of the final irregular composite material sheet. This equipment can utilize regular planar thermoplastic composite material sheets, and through a localized multi-stage gradient curvature molding die, heat and pressurize the original planar composite material sheet to form an irregular cross-sectional shape with a certain curvature. Then, through overall plasticizing and compression molding, the final composite material sheet product with the designed irregular cross-section is formed.

[0019] The molding equipment of this invention uses planar thermoplastic composite material sheets as the original molding raw material. Through preheating, hot pressing preforming, overall hot pressing and cooling, it effectively avoids the layering and composite melting process of traditional thermoplastic prepreg fabrics, greatly reduces the product molding time and improves work efficiency.

[0020] The molding equipment of the present invention adopts a multi-level gradient irregular flat plate molding method, which can process irregular thermoplastic composite materials with various curvature shapes, effectively improving the process flexibility of part preparation. Attached Figure Description

[0021] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an improper limitation of the invention.

[0022] Figure 1 This is a schematic diagram of a molding equipment for thermoplastic composite profiled sheets according to one or more embodiments of the present invention;

[0023] In the diagram: the spacing or dimensions between parts have been exaggerated to show their positions; the diagram is for illustrative purposes only.

[0024] Among them, 1 is the preheating zone of composite material flat plate, 2 is the gradient hot pressing preforming zone of flat plate, 3 is the integral hot pressing forming zone, 4 is the cooling and shaping zone, 5 is the continuous metal track conveyor, 6 is the infrared radiation preheating device, 7 is the infrared radiation heating device, 8 is the pressure preforming mold, 9 is the irregular cavity inner mold, and 10 is the electric heating outer mold. Detailed Implementation

[0025] It should be noted that the following detailed description is illustrative and intended to provide further explanation of the invention. Unless otherwise specified, all technical and scientific terms used in this invention have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains.

[0026] In a typical embodiment of the present invention, such as Figure 1 As shown, a molding equipment for thermoplastic composite profiled sheets is proposed, comprising four parts: a preheating zone 1 for flat composite sheet, a gradient hot pressing preforming zone 2 for flat sheet, an integral hot pressing forming zone 3, and a cooling and shaping zone 4. The preheating zone 1 preheats and softens the planar thermoplastic composite sheet to provide a preliminary basis for profile processing; the gradient hot pressing preforming zone 2 pre-shapes the profiled areas through multi-stage heating and pressurization; the integral hot pressing forming zone 3 performs integral hot pressing and melting composite bonding on the pre-shaped profiled sheet; and the cooling and shaping zone 4 completes the cooling and final shaping of the profiled composite sheet.

[0027] The preheating zone 1 for the composite material planar sheet consists of a continuous metal conveyor belt 5 and an infrared radiation preheating device 6. The infrared radiation preheating device 6 is located above the continuous metal conveyor belt 5 and preheats the planar thermoplastic composite material sheet during its transport by the continuous metal conveyor belt 5. The infrared radiation preheating device 6 employs multiple sets of infrared radiation tubular heating components, arranged sequentially to preheat the planar thermoplastic composite material sheet within a certain radiation distance. The preheating temperature is flexibly designed based on the softening temperature of the resin matrix of the composite material sheet, and the preheating time is controlled within the range of 10-30 minutes, adjustable according to design requirements.

[0028] The infrared radiation tubular heating component can be designed and configured using halogen infrared lamps, carbon fiber far-infrared radiation tubular heating elements, or far-infrared ceramic heating elements. The thermal inertia time of the heater is controlled within the range of 1-10 seconds, and it has rapid heating and cooling functions.

[0029] The gradient hot-pressing preforming zone 2 for planar composite materials is located after the preheating zone 1 and is continuously connected by a metal conveyor belt. The conveyor belt transports the sheet material from the preheating zone 1 to the gradient hot-pressing preforming zone 2. The gradient hot-pressing preforming zone 2 consists of infrared radiation heating devices 7 and pressure preforming molds 8. Multiple sets of infrared radiation heating devices 7 are arranged sequentially to form multi-level temperature gradients. Each set of infrared radiation heating devices 7 is equipped with multiple sets of infrared radiation tubular heating components, which are arranged sequentially. The heating components are the same as those in the infrared radiation preheating device 6. The multiple infrared radiation heating devices 7 are arranged in multi-level temperature according to the preforming curvature hot-pressing process requirements. Generally, 2 to 4 heating temperature gradients can be set, that is, the temperature of the infrared radiation tubular heating components of each infrared radiation heating device 7 is set differently, and the temperature values ​​change in a gradient. The temperature of each temperature gradient is controlled within a temperature change range of 10 to 15°C, which can be flexibly adjusted according to design requirements.

[0030] Multiple sets of pressure preforming molds 8 are arranged sequentially, and each set of pressure preforming molds 8 corresponds to a set of infrared radiation heating devices 7. The mold is set with multi-level gradient curvature according to the curvature requirements of the final irregular cross-section plate. Generally, 2 to 4 irregular curvature pressing gradients can be set, which can be flexibly adjusted according to the curvature angle design requirements of the final irregular cross-section. Generally, the number of gradients of the irregular curvature pressure preforming mold components is consistent with the number of sets of temperature gradients of the heating components.

[0031] Each set of pressure preforming molds 8 has a curved forming surface to pre-press the overall planar thermoplastic composite material sheet. The forming surfaces of each set of pressure preforming molds 8 are different and form multi-level gradients. Each set of pressure preforming molds 8 can be equipped with upper and lower opposing mold bodies, and forming surfaces are formed between the mold bodies.

[0032] The processing pressure of multiple pressure preforming molds is controlled within the range of 1-10MPa and can be flexibly adjusted according to the preforming processing design requirements. The final pressurization time of each preforming stage is flexibly adjusted within the range of 2-20 seconds.

[0033] The integral hot pressing forming zone 3 is located after the preforming zone mentioned above. It is linked with a metal track conveyor to transport the sheet material from the flat sheet gradient hot pressing preforming zone 2 to the integral hot pressing forming zone 3. This hot pressing forming zone provides integral hot pressing and melting processing for the preformed sheet material, and performs integral forming processing on the preformed irregular sheet material. The heating element type and arrangement of the integral hot pressing forming zone are the same as those of the preforming zone. Its forming temperature is controlled within the range of the melting and melting temperature of thermoplastic resin. The integral part is formed by hot pressing mold. The forming time is controlled within the range of 5-20 seconds and the pressure is controlled within the range of 1-10 MPa.

[0034] The integral hot pressing mold for the integral heating and forming zone adopts a combined structure, including an inner mold 9 with an irregular cavity and an outer mold 10 with electric heating. The outer mold 10 with electric heating is arranged outside the inner mold 9 with a heating device. The inner mold provides integral melting and composite forming for the irregular sheet metal, and the outer mold provides heating for the inner mold. The outer mold with electric heating can also be equipped with an infrared radiation tubular heating component.

[0035] The mold 9 inside the irregular cavity has an irregular forming surface formed by multiple curves, which shapes the sheet metal.

[0036] After the melting and infiltration composite process is completed, the inner and outer molds are separated, and the inner mold is conveyed to the cooling and shaping zone 4 via a metal conveyor belt.

[0037] The cooling and shaping zone 4 is set after the overall heating and forming zone to complete the cooling and shaping of the final irregular composite material sheet. The cooling and shaping zone does not have heating components. The overall irregular inner mold of the previous process is rapidly cooled by natural cooling or forced cooling by a refrigeration device. The final cooling temperature is controlled within the range of 15-25℃.

[0038] The molding equipment of the present invention will be described below with specific embodiments.

[0039] Example 1:

[0040] In this embodiment, the preheating zone of the composite material planar sheet uses a halogen infrared lamp (thermal inertia time of 8 seconds) to heat the planar thermoplastic composite material sheet within a distance of 18cm. A polypropylene resin matrix is ​​used, and the preheating temperature is controlled at 160℃. The preheating time is within 10 minutes to preheat and soften the composite material planar sheet.

[0041] After preheating, the flat sheet material is conveyed into the gradient hot pressing preforming zone via a metal conveyor belt. The preheating zone is set with three heating temperature gradients: 200℃ / 210℃ / 220℃. A set of preforming molds is arranged in each gradient. The final curvature of this irregular cross-section is 90°, and the three curvature angle gradients are set to 160° / 120° / 90°. Heating in each gradient of the preheating zone is carried out within a 15cm range by carbon fiber far-infrared radiation tubular heating elements (thermal inertia time is 2 seconds). The forming pressure in each area of ​​the preforming zone is controlled at 3MPa, and the pressurization time is controlled at 12 seconds.

[0042] The pre-formed sheet is conveyed to the heating and forming zone via a metal conveyor belt. In the heating and forming zone, far-infrared ceramic heating elements (thermal inertia time of 7 seconds) are used to perform the final thermoplastic resin melting and infiltration within a 10cm range. The heating and forming zone uses a molding die with a combination structure of an inner mold with an irregular cavity and an outer mold with electric heating. The inner mold provides the overall melting and composite forming function between the irregular shapes, while the outer mold provides the heating function for the inner mold. The final heating temperature is controlled at 220℃, the processing and forming pressure is 5MPa, and the forming time is controlled at 20 seconds.

[0043] After the entire product is heated and formed, the inner and outer combined molds are opened, and the mold inside the irregular cavity is rapidly cooled using natural cooling or forced cooling by a refrigeration device, with the final cooling temperature controlled at 15℃. This completes the processing and forming of a sheet metal with an irregular cross-section curvature of 90°.

[0044] Example 2:

[0045] In this embodiment, the preheating zone of the composite material planar sheet uses a carbon fiber far-infrared radiation tubular heating element (thermal inertia time of 2 seconds) to heat the planar thermoplastic composite material sheet within a distance of 18cm. A polyethylene resin matrix is ​​used, and its preheating temperature is controlled at 80℃. The preheating time is within 10 minutes, which heats and softens the composite material planar sheet initially.

[0046] After preheating, the flat sheet is conveyed into the gradient hot pressing preforming zone via a metal conveyor belt. The preheating zone is set with two heating temperature gradients, 120°C and 135°C. A set of preforming molds is arranged in each gradient. The final curvature of this irregular cross section is 100°, and the three curvature angle gradients are set to 120° and 100°. Heating in each gradient of the preheating zone is carried out within a 15cm range by carbon fiber far-infrared radiation tubular heating elements (thermal inertia time is 2 seconds). The forming pressure in each area of ​​the preforming zone is controlled at 2MPa, and the pressurization time is controlled at 10 seconds.

[0047] The pre-formed sheet is conveyed to the heating and forming zone via a metal conveyor belt. In the heating and forming zone, carbon fiber far-infrared radiation tubular heating elements (thermal inertia time of 2 seconds) are used to perform the final thermoplastic resin melting and infiltration within a 10cm range. The heating and forming zone uses a molding die with a combination structure of an irregular cavity inner mold and an electrically heated outer mold. The inner mold provides the overall melting and composite forming function between the irregular shapes, while the outer mold provides the heating function for the inner mold. The final heating temperature is controlled at 140℃, the processing and forming pressure is 5MPa, and the forming time is controlled at 5 seconds.

[0048] After the entire product is heated and formed, the inner and outer combined molds are opened, and the mold inside the irregular cavity is rapidly cooled using natural cooling or forced cooling by a refrigeration device, with the final cooling temperature controlled at 25℃. This completes the processing and forming of the sheet metal with an irregular cross-section curvature of 100°.

[0049] Example 3:

[0050] In this embodiment, the preheating zone of the composite material planar sheet uses a far-infrared silicon carbide heating element (requiring the element's thermal inertia time to be 9 seconds) to heat the planar thermoplastic composite material sheet within a distance of 20cm. A polypropylene resin matrix is ​​used, and its preheating temperature is controlled at 160℃, with a preheating time within 15 minutes, to preheat and soften the composite material planar sheet.

[0051] After preheating, the flat sheet metal is conveyed into the gradient hot pressing preforming zone via a metal conveyor belt. The preheating zone is set with four heating temperature gradients: 180℃ / 200℃ / 210℃ / 220℃. A set of preforming molds is arranged in each gradient. The final curvature of this irregular cross-section is 90°, and the three curvature angle gradients are set to 160° / 140° / 120° / 90°. Heating in each gradient of the preheating zone is carried out within a 15cm range by far-infrared silicon carbide heating elements (requiring the thermal inertia time of the elements to be 9 seconds). The forming pressure in each area of ​​the preforming zone is controlled at 4MPa, and the pressurization time is controlled at 15 seconds.

[0052] The pre-formed sheet is conveyed to the heating and forming zone via a metal conveyor belt. In the heating and forming zone, far-infrared silicon carbide heating elements (requiring a thermal inertia time of 9 seconds) are used to perform the final thermoplastic resin melting and infiltration within a 10cm range. The heating and forming zone uses a molding die with a combination structure of an inner mold with an irregular cavity and an outer mold with electric heating. The inner mold provides the overall melting and infiltration composite forming function between the irregular shapes, while the outer mold provides the heating function for the inner mold. The final heating temperature is controlled at 220℃, the processing and forming pressure is 10MPa, and the forming time is controlled at 5 seconds.

[0053] After the entire product is heated and formed, the inner and outer combined molds are opened, and the mold inside the irregular cavity is rapidly cooled using natural cooling or forced cooling by a refrigeration device, with the final cooling temperature controlled at 20℃. This completes the processing and forming of a sheet metal with an irregular cross-section curvature of 90°.

[0054] Example 4:

[0055] In this embodiment, the preheating zone of the composite material planar sheet uses a halogen infrared lamp (thermal inertia time of 10 seconds) to heat the planar thermoplastic composite material sheet within a distance of 20cm. The polyether ether ketone resin matrix is ​​used, and the preheating temperature is controlled at 280℃. The preheating time is within 10 minutes to preheat and soften the composite material planar sheet.

[0056] After preheating, the flat sheet metal is conveyed into the gradient hot pressing preforming zone via a metal conveyor belt. The preheating zone is set with three heating temperature gradients: 280℃ / 290℃ / 315℃. A set of preforming molds is arranged in each gradient. The final curvature of this irregular cross-section is 90°, and the three curvature angle gradients are set to 160° / 120° / 90°. Heating in each gradient of the preheating zone is carried out by halogen infrared lamps (thermal inertia time is 10 seconds) within a distance of 20cm. The forming pressure in each area of ​​the preforming zone is controlled at 2MPa, and the pressurization time is controlled at 10 seconds.

[0057] The pre-formed sheet is conveyed to the heating and forming zone via a metal conveyor belt. In the heating and forming zone, far-infrared silicon carbide heating elements (thermal inertia time of 6 seconds) are used to perform the final thermoplastic resin melting and infiltration within a 10cm range. The heating and forming zone uses a molding die with a combination structure of an inner mold with an irregular cavity and an outer mold with electric heating. The inner mold provides the overall melting and composite forming function between the irregular shapes, and the outer mold provides the heating function for the inner mold. The final heating temperature is controlled at 320℃, the processing and forming pressure is 10MPa, and the forming time is controlled at 20 seconds.

[0058] After the entire product is heated and formed, the inner and outer combined molds are opened, and the mold inside the irregular cavity is rapidly cooled using natural cooling or forced cooling by a refrigeration device, with the final cooling temperature controlled at 15℃. This completes the processing and forming of a sheet metal with an irregular cross-section curvature of 90°.

[0059] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A forming apparatus for a thermoplastic composite profiled sheet material, characterised in that, It includes a preheating zone for composite material flat sheet, a gradient hot pressing preforming zone for flat sheet, an integral hot pressing forming zone, and a cooling and shaping zone arranged sequentially. The preheating zone for composite material flat sheet is equipped with a conveying device, and an infrared radiation preheating device is installed above the conveying device. The gradient hot pressing preforming zone for flat sheet is equipped with multiple sets of infrared radiation heating devices arranged sequentially. The multiple sets of infrared radiation heating devices are arranged one-to-one with multiple sets of pressure preforming molds. The multiple sets of infrared radiation heating devices have multiple gradient temperatures, and the multiple sets of pressure preforming molds have multiple gradient curvatures. Multiple infrared radiation heating devices are arranged in a multi-level temperature configuration according to the requirements of the preformed curvature hot pressing process. The temperature settings of the infrared radiation tubular heating components of each infrared radiation heating device are different, and the temperature values ​​change in a gradient. The temperature of each temperature gradient is controlled within a temperature change range of 10 to 15°C.

2. The forming apparatus for a thermoplastic composite profiled sheet material of claim 1, wherein The infrared radiation preheating device includes multiple sets of infrared radiation tubular heating components, which are arranged sequentially.

3. The forming apparatus for a thermoplastic composite profiled sheet material of claim 1, wherein, Each infrared radiation heating device is equipped with multiple sets of infrared radiation tubular heating components, which are arranged sequentially.

4. The forming apparatus for a thermoplastic composite profiled sheet material of claim 1, wherein, The infrared radiation tubular heating components of multiple infrared radiation heating devices are set to different temperatures, and the temperature values ​​change in a gradient.

5. The molding equipment for thermoplastic composite profiled sheets as described in claim 1, characterized in that, Multiple pressure preforming molds all have curved forming surfaces, and the forming surfaces of each pressure preforming mold are different, forming multiple levels of gradient.

6. The molding equipment for thermoplastic composite profiled sheets as described in claim 1, characterized in that, The preheating zone for composite planar panels preheats and softens the planar panels before transferring them to the gradient hot pressing preforming zone. The gradient hot pressing preforming zone pre-shapes the planar panels by applying multi-stage heating and pressure to pre-shape their curvature. The panels are then transferred to the overall hot pressing forming zone, where the pre-shaped panels are hot-pressed and melt-infiltrated together. Finally, the panels are transferred to the cooling and shaping zone, where the shaped composite panels are cooled and the parts are formed.

7. The molding equipment for thermoplastic composite profiled sheets as described in claim 1, characterized in that, The overall hot pressing forming area includes an inner mold with an irregular cavity, and an outer mold with electric heating is arranged outside the inner mold with an electric heating device.

8. The molding equipment for thermoplastic composite profiled sheets as described in claim 7, characterized in that, The mold inside the irregular cavity has an irregular forming surface formed by multiple curves, which shapes the sheet material.

9. The molding equipment for thermoplastic composite profiled sheets as described in claim 7, characterized in that, After the melt infiltration composite process is completed, the inner mold of the irregular cavity and the outer mold of the electric heating are separated, and the inner mold of the irregular cavity is transferred to the cooling and shaping area.

10. The molding equipment for thermoplastic composite profiled sheets as described in claim 9, characterized in that, The cooling and shaping zone is equipped with a refrigeration device to rapidly cool the mold inside the irregular cavity.

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