A rapid hot-pressing punching forming composite board and a method for combining with plastic

Abstract

The application provides a rapid hot-pressing punching forming composite board and a method for combining with plastic, which is applied to a mold with a rapid temperature rising and falling pipeline system, an in-mold cutting mechanism and a plastic injection mechanism, and the method comprises the following steps: placing a board; adjusting the temperature of the mold; making the temperature of the mold reach between Tg and Tm of thermoplastic plastic in the composite board; first-stage mold closing; heating the composite board; second-stage mold closing; heating and pressing the composite board to form; first-stage temperature falling; the temperature of the mold falls to a range of 30 DEG C above and below the Tg, and the mold is used for plastic injection; second-stage temperature falling; after the temperature falls below the HDT of the composite board, the product material head is punched; third-stage temperature falling; the composite board is cooled and shaped; and taking out the finished product; after the mold falls to normal temperature, the mold is opened and the finished product is taken out. The application can save work sections, reduce pollution, and the combined part of the composite board and the plastic is not prone to produce a step difference.

Description

[Technical Field]

[0001] This invention relates to the field of composite sheet forming technology, and in particular to a method for rapidly hot-pressing and punching composite sheets and bonding them with plastics. [Background Technology]

[0002] Composite sheets have a wide range of applications, with products combining composite sheets and plastics being particularly prevalent in production and daily life. The production process for these products typically involves first heating the composite sheet in a furnace outside the mold before placing it inside, or heating it with an infrared heating plate inserted into a thermoforming mold, followed by thermoforming. The thermoformed product is then transferred to a punching section where the sheet is punched. Finally, the punched composite sheet is moved to the next stage where it is used as an insert for plastic injection molding, bonding the composite sheet with the plastic to obtain the finished product. This production process is not only complex and involves many stages, but it is also prone to the following problems:

[0003] 1. The following problems may occur when composite boards are externally heated or hot-pressed into a mold using an infrared baking pan:

[0004] (1) Difficult to clamp and position: When the heating furnace heats the composite board to above Tg (glass transition temperature), the material softens, making clamping and positioning difficult and unable to be used for more precise products;

[0005] (2) Poor temperature reproducibility: The temperature of the composite board continues to drop during the process of moving it from the heating furnace to the mold after heating, and it is easily affected by the external environment, resulting in large temperature variations of the board during hot pressing. In particular, the heat loss of thinner composite boards is faster, and the impact on hot pressing is greater.

[0006] (3) Product quality decline: When high Tg (glass transition temperature) composite boards are heated to high temperatures, the resin and additives in the boards will volatilize, resulting in resin loss, which in turn leads to a decline in the mechanical properties and surface appearance quality of the hot-pressed products.

[0007] (4) Environmental pollution: When composite boards with high Tg (glass transition temperature) are heated to high temperatures, the resin and additives that volatilize will produce dense smoke, polluting the production environment.

[0008] 2. When the hot-pressed composite sheet is moved to the punching section for punching, the high dimensional accuracy of the product makes it difficult for the punching section to accurately position the hot-pressed composite sheet, thus reducing the product yield.

[0009] 3. When the hot-pressed and punched composite sheet is transferred to the next stage mold for plastic injection molding, problems such as step difference and poor bonding force are prone to occur at the joint.

[0010] In view of this, the present invention provides a method for rapidly hot-pressing and punching composite sheet material and bonding it with plastic to solve the above problems. [Summary of the Invention]

[0011] The technical problem this invention aims to solve is as follows: To address the issues arising from hot-pressing composite sheets by external heating before placing them into a mold or using an infrared baking pan inside the mold, which results in difficulties in clamping and positioning the product, poor temperature reproducibility, decreased product quality, and environmental pollution, and furthermore, the difficulty in accurately positioning the hot-pressed composite sheet at the die-cutting head in the die-cutting section, leading to defective products, and the potential for poor bonding due to step differences when moving it to the plastic injection molding section, this invention provides a method for rapidly hot-pressing and die-cutting composite sheets and bonding them with plastic to solve these problems.

[0012] The solution to the technical problem of this invention is: a method for rapidly hot-pressing and punching composite sheet metal and bonding it with plastic, applied in a mold with a rapid heating and cooling mold piping system, an in-mold cutting mechanism, and a mold capable of plastic injection, comprising the following steps:

[0013] S1: Inserting the board material: Place the cut composite board material into the mold;

[0014] S2: Adjust mold temperature: Select the corresponding medium to enter the mold pipeline to adjust the mold temperature. The mold temperature depends on factors such as the Tg (glass transition temperature) and Tm (melting temperature) of the thermoplastic in the composite board and the product pressing shape, so that the mold temperature reaches between the Tg (glass transition temperature) and Tm (melting temperature) of the thermoplastic in the composite board.

[0015] S3: First stage mold closing: Control the distance between the mold and the composite material. This distance depends on factors such as the product pressing shape. Utilize the temperature of the mold to heat the composite material through thermal radiation and convection.

[0016] S4: Second stage mold closing: The mold closing speed in this stage is adjusted according to the thickness of the composite material and the shape of the product. The mold closes while simultaneously heating the composite material using heat conduction and pressing it into shape.

[0017] S5: First stage cooling: Select the corresponding medium to enter the mold pipeline and start the first stage cooling. When the mold temperature drops to Tg-30 to Tg+30℃, the mold will inject plastic to make the composite board and plastic better bonded.

[0018] S6: Second stage cooling: After the mold continues to cool down to below the HDT (heat distortion temperature) of the composite material, the product head is punched using the in-mold cutting mechanism;

[0019] S7: Third stage cooling: The mold continues to cool down and cool the composite material until the mold closing pressure slowly decreases to zero. The composite material cools in the mold and is pressed and shaped under the mold pressure.

[0020] S8: Remove the finished product: After the mold has cooled to room temperature, open the mold and remove the finished product.

[0021] Preferably, the thermoplastic in the composite sheet is PC (polycarbonate), with a Tg (glass transition temperature) of 100-150°C and a Tm (melting temperature) of 220°C. The medium passing through the mold pipeline in S2 is water vapor at 160-170°C, and the medium passing through the mold pipeline in S5 is water at 15-30°C.

[0022] Preferably, the thermoplastic in the composite board is PSU (polysulfone), with a Tg (glass transition temperature) of 190°C and a Tm (melting temperature) of 288°C. In S2, the mold pipeline can first pass water vapor at 160-170°C. When the mold temperature rises to 150°C, hot kerosene at 250-280°C is then used to pass through the mold pipeline to achieve rapid heating. In S5, the medium passing through the mold pipeline is water at 15-30°C.

[0023] Preferably, the distance between the mold and the composite material in S3 is 1mm to 5mm.

[0024] Preferably, the mold closing speed in S4 is 0.1 mm / sec to 3 mm / sec.

[0025] Preferably, in step S6, when the mold is cooled to HDT-50 to HDT-30℃, the punching effect on the product material head is better.

[0026] Preferably, before changing the medium in the mold pipeline, the mold pipeline can be dried with air to drain the medium from the mold pipeline, so as to prevent the mold pipeline from bursting due to the reaction between different media when changing the medium in the mold pipeline.

[0027] The beneficial effects of this invention are that it saves processing steps, avoids defective products caused by poor positioning accuracy when transferring the hot-pressed composite sheet to the punching section, and can quickly and stably process thin parts and composite sheets with high surface precision requirements. At the same time, it avoids the diffusion of harmful gases and dust into the production environment. Furthermore, the injection of the plastic bonded to the composite sheet within a 30°C range above and below the Tg (glass transition temperature) of the thermoplastic in the composite sheet can enhance the bonding force between the two and reduce the likelihood of step differences. [Attached Image Description]

[0028] Figure 1This is a flowchart illustrating the steps of a rapid hot-pressing and punching process for forming composite sheets and its bonding with plastics according to the present invention.

[0029] Figure 2 This is a flowchart of the steps in Embodiment 1 of the present invention.

[0030] Figure 3 This is a flowchart of the steps in Embodiment 2 of the present invention.

[0031] Figure 4 This is a schematic diagram of the composite board placed in a mold and awaiting hot pressing.

[0032] Figure 5 This is a schematic diagram showing the combination of the plastic injected by the injection molding machine and the composite material inside the mold.

[0033] Figure 6 This is a schematic diagram of the in-mold cutting mechanism punching the product material head.

[0034] Figure 7 This is a schematic diagram of the finished product structure.

Detailed Implementation Methods

[0035] To further illustrate the technical means and effects of the present invention, the following detailed description is provided in conjunction with the embodiments of the present invention and their accompanying drawings.

[0036] This invention provides a method for rapidly hot-pressing and punching composite sheet metal and bonding it with plastic. It is applied to a mold 1 with a rapid heating and cooling mold piping system, an in-mold cutting mechanism 5, and a mold 1 that can be connected to an injection molding machine 6 for plastic injection. The mold 1 can inject plastic using the composite sheet metal 3 as an insert during the cooling process, thus bonding the two together. The rapid heating and cooling mold piping system connects to the inlet 20 and outlet 21 of the existing mold piping 2 with external pipes (not shown in the figure) for the medium entering the mold piping 2, which can be controlled by valves (not shown in the figure). The valves (not shown in the figure) control the medium entering the mold piping 2, such as steam, hot kerosene, air, or water, according to the required temperature of the mold 1, to achieve rapid heating and cooling of the mold 1. The in-mold cutting mechanism 5 can punch the material head inside the mold 1 after the composite sheet metal 3 has cooled below its HDT (heat distortion temperature), obtaining a finished product 4 of the correct dimensions.

[0037] The thermoplastic in the composite sheet 3 can be PC (polycarbonate), PMMA (polymethyl methacrylate), PPS (polyphenylene sulfide), PA series such as PA6 (nylon 6) or PA66 (nylon 66) or PA12 (nylon 12)..., PSU (polysulfone) and other thermoplastics. The following describes the rapid hot-pressing and die-cutting of the composite sheet and the method of bonding it with plastic in conjunction with Examples 1 and 2.

[0038] Example 1

[0039] In Example 1, the thermoplastic in the composite sheet 3 is PC (polycarbonate), with a Tg (glass transition temperature) of 100-150°C and a Tm (melting temperature) of 220°C. The method for rapidly hot-pressing and die-cutting the composite sheet and bonding it with plastic includes the following steps:

[0040] S110: Inserting the board material: Place the cut composite board material 3 into the mold 1;

[0041] S120: Adjust mold temperature: Use 160-170℃ water vapor to enter mold pipe 2 to adjust the mold temperature so that the mold temperature reaches between the Tg (glass transition temperature) of PC (polycarbonate) of 100-150℃ and the Tm (melting temperature) of 220℃.

[0042] S130: First stage mold closing: The distance between the composite plate 3 and the mold 1 is controlled between 1mm and 5mm. The temperature of the mold 1 is used to heat the composite plate 3 through heat radiation and convection.

[0043] S140: Second stage mold closing: The mold closing speed of the mold 1 in the second stage is controlled at 0.1mm / sec to 3mm / sec. While the mold 1 is closing, it uses heat conduction to heat the composite board 3 and press the composite board 3 into shape.

[0044] S150: First stage cooling: Select water at 5-30℃ to enter the mold pipe 2 to start the first stage cooling. When the mold temperature drops to 70-180℃, the injection molding machine 6 connected to the mold 1 will inject plastic to make the composite board 3 better bond with the plastic.

[0045] S160: Second stage cooling: The mold 1 continues to cool down. When the mold 1 is cooled down to HDT-50 to HDT-30℃ of the composite board 3, the product head is punched by the in-mold cutting mechanism 5.

[0046] S170: Third stage cooling: Mold 1 continues to cool down and cool the composite board 3 until the mold closing pressure slowly decreases to zero. The composite board 3 is cooled in mold 1 and pressed into shape under mold pressure.

[0047] S180: Remove the finished product: After the mold 1 is cooled to room temperature, open the mold and remove the finished product 4.

[0048] Example 2

[0049] In Example 2, the thermoplastic in the composite sheet 3 is PSU (polysulfone), with a Tg (glass transition temperature) of 190°C and a Tm (melting temperature) of 288°C. The method for rapidly hot-pressing and die-cutting the composite sheet and bonding it with plastic includes the following steps:

[0050] S210: Inserting the board material: Place the cut composite board material 3 into the mold 1;

[0051] S220: Adjusting the mold temperature: First, use 160-170℃ steam to enter the mold pipe 2 to adjust the mold temperature and make the mold temperature rise rapidly. When the mold temperature rises to 150℃, replace it with air to blow the mold pipe 2 dry. Then replace it with hot kerosene at 250-280℃ to make the mold temperature reach between the Tg (glass transition temperature) of PSU (polysulfone) of 190℃ and the Tm (melting temperature) of 288℃.

[0052] S230: First stage mold closing: The distance between the composite plate 3 and the mold 1 is controlled between 1mm and 5mm. The temperature of the mold 1 is used to heat the composite plate 3 through heat radiation and convection.

[0053] S240: Second stage mold closing: The mold closing speed of the mold 1 in the second stage is controlled at 0.1mm / sec to 3mm / sec. While the mold 1 is closing, it uses heat conduction to heat the composite board 3 and press the composite board 3 into shape.

[0054] S250: First stage cooling: Select water at 5-30℃ to enter the mold pipe 2 to start the first stage cooling. When the mold temperature drops to 160-220℃, the injection molding machine 6 connected to the mold 1 will inject plastic to make the composite board 3 better bond with the plastic.

[0055] S260: Second stage cooling: The mold 1 continues to cool down. When the mold 1 is cooled down to HDT-50 to HDT-30℃ of the composite board 3, the product head is punched by the in-mold cutting mechanism 5.

[0056] S270: Third stage cooling: Mold 1 continues to cool down and cool the composite board 3 until the mold closing pressure slowly decreases to zero. The composite board 3 is cooled in mold 1 and pressed into shape under mold pressure.

[0057] S280: Remove the finished product: After the mold 1 is cooled to room temperature, open the mold and remove the finished product 4.

[0058] Before changing the medium in the mold pipe 2, the mold pipe 2 can be dried with air to remove the medium from the mold pipe 2, so as to prevent the mold pipe 2 from bursting due to the reaction between different media when changing the medium in the mold pipe 2.

[0059] The beneficial effects of this invention are that it saves processing steps, avoids defective products caused by poor positioning accuracy when transferring the hot-pressed composite sheet to the punching section, and can quickly and stably process thin parts and composite sheets 3 with high surface precision requirements. At the same time, it avoids the diffusion of harmful gases and dust into the production environment. Furthermore, the injection of the plastic bonded to the composite sheet 3 within a temperature range of 30°C above and below the Tg (glass transition temperature) of the thermoplastic in the composite sheet 3 can enhance the bonding force between the two and reduce the likelihood of step differences.

[0060] It should be noted that the present invention is not limited to the above embodiments. Any simple modifications, equivalent changes and alterations made by those skilled in the art to the above embodiments based on the technical solutions of the present invention shall fall within the protection scope of the present invention.

Claims

1. A method for rapidly hot-pressing and punching composite sheet metal and bonding it with plastic, applied in a mold with a rapid heating and cooling mold piping system, an in-mold cutting mechanism, and a mold capable of plastic injection, characterized in that, Includes the following steps: S1: Inserting the board material: Place the cut composite board material into the mold; S2: Adjust mold temperature: Select the appropriate medium to enter the mold pipeline to adjust the mold temperature. The factors that determine the mold temperature include the Tg (glass transition temperature) and Tm (melting temperature) of the thermoplastic in the composite sheet and the product pressing shape, so that the mold temperature reaches between the Tg (glass transition temperature) and Tm (melting temperature) of the thermoplastic in the composite sheet. S3: First stage mold closing: Controlling the distance between the mold and the composite material, which depends on factors including the product pressing shape, and using the temperature of the mold to heat the composite material through heat radiation and convection. S4: Second stage mold closing: The mold closing speed in this stage is adjusted according to the thickness of the composite material and the shape of the product. The mold closes while simultaneously heating the composite material using heat conduction and pressing it into shape. S5: First stage cooling: Select the corresponding medium to enter the mold pipeline and start the first stage cooling. When the mold temperature drops to Tg -30 to Tg +30 ℃, the mold will inject plastic to make the composite board and plastic better bonded. S6: Second stage cooling: After the mold continues to cool down to below the HDT (heat distortion temperature) of the composite material, the product head is punched using the in-mold cutting mechanism; S7: Third stage cooling: The mold continues to cool down and cool the composite material until the mold closing pressure slowly decreases to zero. The composite material cools in the mold and is pressed and shaped under the mold pressure. S8: Remove the finished product: After the mold has cooled to room temperature, open the mold and remove the finished product.

2. The rapid hot-pressing and punching forming composite sheet and the method for bonding it with plastic as described in claim 1, characterized in that: The thermoplastic in the composite board is PC (polycarbonate), with a Tg (glass transition temperature) of 145-150℃ and a Tm (melting temperature) of 230-240℃. The medium passing through the mold pipeline in S2 is water vapor at 160-170℃, and the medium passing through the mold pipeline in S5 is water at 15-30℃.

3. The rapid hot-pressing and punching forming composite sheet and the method for bonding it with plastic as described in claim 1, characterized in that: The thermoplastic in the composite board is PSU (polysulfone), with a Tg (glass transition temperature) of 190°C and a Tm (melting temperature) of 288°C. In S2, the mold pipeline first passes through water vapor at 160-170°C. When the mold temperature rises to 150°C, hot kerosene at 250-280°C is then passed through the mold pipeline to achieve rapid heating. In S5, the medium passing through the mold pipeline is water at 15-30°C.

4. The rapid hot-pressing and die-cutting method for forming composite sheets and bonding them with plastics as described in claim 1, characterized in that: The distance between the mold and the composite plate in S3 is 1mm to 5mm.

5. The rapid hot-pressing and die-cutting method for forming composite sheets and bonding them with plastics as described in claim 3, characterized in that: The mold closing speed in S4 is 0.1 mm / sec to 3 mm / sec.

6. The rapid hot-pressing and die-cutting method for forming composite sheets and bonding them with plastics as described in claim 1, characterized in that: In step S6, when the mold is cooled to HDT-50 to HDT-30 ℃, the punching effect on the product material head is better.

7. The rapid hot-pressing and die-cutting method for forming composite sheets and bonding them with plastics as described in claim 1 or 3, characterized in that: Before changing the medium in the mold pipeline, the mold pipeline is first dried by air to drain the medium from the mold pipeline, so as to prevent the mold pipeline from bursting due to the reaction between different media when changing the medium in the mold pipeline.

Images