Wood fiber injection molding intelligent production line

Abstract

The application discloses a kind of wood fiber injection molding intelligent production line, belong to environmental protection composite material intelligent manufacturing equipment field.The production line integrates automatic counterweight and visual identification fixed-length cutting feeding system, six-axis robot and quick-change end effector, double-machine-position injection molding machine, adaptive feeding control system, hot air slow cooling conveying device and curing oven and safety protection system and other modules, realizes the automation and intelligentization of raw material automatic feeding, in-mold real-time monitoring and dynamic feeding, product slow cooling curing and other key processes.Using visual measurement and weighing to ensure the accuracy of batching, eliminating the filling defects by adaptive control feeding, using hot air slow cooling and constant temperature and humidity curing to avoid product deformation, thereby significantly improving production efficiency and product quality.

Description

Technical Field

[0001] This invention relates to intelligent production line technology for wood fiber injection molding, belonging to the field of intelligent manufacturing equipment for environmentally friendly composite materials. Background Technology

[0002] Wood fiber / thermosetting polymer composites are widely used in automotive interiors, building formwork, and appliance housings due to their green, environmentally friendly, and recyclable properties.

[0003] Existing wood fiber injection molding processes typically rely on manual operation or semi-automated equipment for raw material preparation, feeding, and product handling, resulting in low production efficiency and inconsistent product quality. Furthermore, insufficient precision in raw material proportioning and inadequate control of process parameters frequently lead to defects such as uneven product density, cracking, and bulging. In addition, the molded parts still contain significant residual moisture, easily causing bulging and deformation. Existing wood fiber injection molding equipment also suffers from the following drawbacks: 1. Manual loading and unloading is labor-intensive; 2. The cycle time of a single machine is greater than 40 seconds, resulting in low efficiency and isolated equipment. 3. The product temperature is high after molding, and there is a risk of burns when handling the parts manually; 4. The material filling status cannot be monitored in real time during the injection process, which can easily lead to defects such as underfilling and air bubbles; 5. Lack of information interfaces makes it impossible to trace quality data.

[0004] There is an urgent need for a high-speed, unmanned, highly efficient, and real-time quality closed-loop intelligent production line for wood fiber injection molding, which can realize automatic feeding, precise material batching, real-time process monitoring, and continuous production to improve product quality and production efficiency. Summary of the Invention

[0005] To address the problems of low automation, unstable molding quality, and low production efficiency in existing wood fiber injection molding technologies, this invention proposes an intelligent production line for wood fiber injection molding. This invention integrates functional modules such as an automatic counterweight and visual recognition cutting and feeding system, a six-axis robot with rapidly switchable end effectors, an adaptive feeding control system, a hot air slow cooling conveying device, and a curing oven. This achieves automation and intelligentization of key processes such as automatic raw material feeding, real-time in-mold monitoring and dynamic feeding, and slow product cooling. Specific technical solutions include: A wood fiber injection molding intelligent production line, comprising, in sequence along the material flow direction: a) An automatic counterweight and visual recognition fixed-length cutting and feeding system is used for online measurement, weighing, quantitative cutting and conveying of cylindrical wood fiber raw materials; b) A six-axis industrial robot and quick-change end effector for gripping raw materials and feeding them into an injection molding die, and for removing the molded parts after the die is opened; c) A dual-position injection molding machine, used to perform thermosetting injection molding of the raw material under mold temperature of 160℃~200℃ and pressure of 10MPa~25MPa; d) An adaptive feeding control system is used to monitor the temperature, pressure and steam concentration in the mold cavity in real time, and dynamically adjust the feeding amount and feeding frequency according to the deviation; e) Hot air slow cooling conveyor and curing oven, used for slow cooling and constant temperature and humidity curing of the molded products; f) Safety protection system, used to monitor the status of the safety door and cut off the power and shut down the machine in case of abnormality.

[0006] As a preferred embodiment of the present invention, the automatic counterweight and visual recognition fixed-length cutting and feeding system includes a horizontal conveyor belt, an industrial camera and a strip LED light source, a servo cutter, a weighing sensor and a pneumatic pusher. The industrial camera measures the length L of the raw material online. The servo cutter cuts the raw material according to the preset target weight M0 and material density so that the weight of each segment of raw material reaches a predetermined value (error ±5g). The weighing sensor weighs the cut raw material and feeds the weight back to the control system. The pneumatic pusher is used to send the cut raw material to the second pallet position of the double-layer cross pallet.

[0007] As a preferred embodiment of the present invention, the double-layer cross pallet has upper and lower pallet positions, and completes 90° rotation and exchange within 2.1 seconds through the built-in servo rotating shaft, realizing the alternation of loading and unloading, and the pallet positioning accuracy is ±0.1mm.

[0008] As a preferred embodiment of the present invention, the six-axis industrial robot can switch the end effector within 30 seconds via a quick-change flange interface; the robot is equipped with a contour-following dual gripper with a gripping force of 80-250N (adjustable), and a high-temperature resistant silicone pad is provided on the vertical surface, used to grip cylindrical raw materials and put them into the injection molding die, and to remove the high-temperature molded parts after the mold is opened; the vacuum suction cup has an adsorption force of -20 to -85kPa (adjustable), used to grip flat molded products.

[0009] As a preferred embodiment of the present invention, the adaptive feeding control system includes a temperature sensor, a pressure sensor, and a steam concentration sensor arranged in the mold cavity for real-time acquisition of the temperature T, pressure P, and steam concentration C in the mold cavity; the system also includes a controller for calculating the feeding index I (I=k1·ΔT+k2·ΔP+k3·ΔC) based on the set target values ​​and real-time deviations ΔT, ΔP, and ΔC, and automatically adjusting the feeding amount (0~500g) and the feeding frequency (0~3 times) according to the I value, so as to ensure that when the mold cavity parameters are lower than the preset values, raw materials are added to the mold cavity through the injection mechanism to fully fill the product and achieve the best curing effect; the feeding coefficients k1, k2, and k3 can be set and switched through the touch screen human-machine interface.

[0010] As a preferred embodiment of the present invention, the hot air slow cooling conveying device includes a chain conveyor located at the outlet of the injection molding machine. The conveyor is equipped with three axial flow fans and a PTC heater. The hot air generated by the fans is controlled by PID to maintain the outlet air temperature within the range of 50℃ to 90℃, and the air volume is continuously adjustable between 800 and 1500 m³ / h, which is used to slowly cool the molded parts. The rear end of the chain conveyor is connected to the curing oven.

[0011] As a preferred embodiment of the present invention, the curing oven is equipped with a temperature sensor and a humidity sensor to control the indoor temperature at 65℃~75℃ and the relative humidity at 35%~45%. The finished product stays in this environment for about 4 hours to allow the residual moisture inside the product to evaporate further and release internal stress, thereby avoiding cracking and deformation.

[0012] As a preferred embodiment of the present invention, the safety protection system includes a safety fence and a safety door with a power-off switch. When the safety door is opened, the system cuts off all power supply and stops operation within 0.3 seconds. When the safety door is closed, the system automatically resets and resumes operation.

[0013] (1) Automatic counterweight and visual recognition fixed-length cutting and feeding system: This system includes a horizontal conveyor belt, an industrial camera and strip LED light source, a servo cutter, a weighing sensor, and a pneumatic push rod. The industrial camera measures the length L of the long strip of wood fiber material online, calculates the target cutting length L0 based on the preset target weight M0 and material density, and when the conveyor belt stops, the servo cutter cuts the material according to L0, so that the weight of each segment of material after cutting reaches the predetermined value (error ±5g). The weighing sensor monitors the weight of the material online and feeds it back to the control system to ensure accurate feeding. The cut material is sent to the second pallet position of the double-layer cross pallet through the pneumatic push rod. The double-layer pallet has two pallet positions, which can complete a 90° rotation exchange within 2.1 seconds through the built-in servo rotating shaft, realizing the alternation of feeding and picking, and improving the continuity of feeding and forming. The pallet positioning accuracy is up to ±0.1mm, ensuring accurate robot gripping.

[0014] (2) Six-axis industrial robot and quick-change end effector: A six-axis industrial robot is used, with a quick-change flange interface at the end that can be exchanged within 30 seconds, allowing connection to end effectors with different functions. The two main actuators include: a contour-following dual gripper (gripping force continuously adjustable from 80 to 250 N, with a high-temperature resistant silicone pad in the vertical direction of the gripper) for gripping cylindrical raw materials and placing them into the injection molding die, while simultaneously removing the high-temperature molded parts after the die is opened; and a vacuum suction cup (adsorption force continuously adjustable from -20 to -85 kPa) for gripping flat molded products. The robot alternately operates the two injection molding machines through a preset program to ensure unmanned continuous production.

[0015] (3) Dual-position injection molding machine: includes two injection molding machines, used to thermo-cur the raw material under the conditions of mold temperature of 160~200℃ and pressure of 10~25MPa.

[0016] (4) Adaptive feeding control system: Composed of temperature sensor, pressure sensor and steam concentration sensor installed in the mold cavity, it collects the temperature T, pressure P and steam concentration C in the mold cavity in real time and feeds the data back to the controller. Based on the set target value and real-time deviations ΔT, ΔP and ΔC, the system calculates the feeding index I (I = k1·ΔT + k2·ΔP + k3·ΔC, where k1, k2 and k3 are adjustable coefficients), and automatically adjusts the feeding amount (0~500g) and feeding times (0~3 times) according to the I value. When the parameters in the mold cavity are lower than the preset value, the control system adds raw materials to the mold cavity through the injection mechanism to ensure that the product is fully filled and achieves the best curing effect. Each feeding coefficient can be set and switched through the touch screen human-machine interface (HMI).

[0017] (5) Hot air slow cooling conveyor and curing oven: After molding, the robot takes out the product and places it on the chain conveyor located at the outlet of the injection molding machine. The chain conveyor is equipped with three axial flow fans and PTC heaters. The hot air generated by the fans is regulated by PID to maintain the outlet temperature in the range of 50~90℃, and the air volume is continuously adjustable between 800~1500m³ / h. The product cools down slowly in the hot air environment to reduce thermal stress. Then, the product enters the curing oven connected to the conveyor. The oven is equipped with temperature and humidity sensors to control the indoor temperature at 65~75℃ and the relative humidity at 35~45%. The total residence time is about 4 hours, which allows the residual moisture inside the product to evaporate further and release internal stress, avoiding cracking and deformation.

[0018] (6) Safety protection system: The production line is surrounded by safety fences and safety doors with power-off switches. When the safety door is opened, the system cuts off all power supply and stops the machine in an emergency within 0.3 seconds to protect the safety of the operators; after the safety door is closed, the system automatically resets and resumes operation.

[0019] The beneficial effect of the present invention is that, through the above technical solution, the production line of the present invention achieves a high degree of automation and intelligence in the wood fiber injection molding process, which can significantly improve production efficiency and product quality. Attached Figure Description

[0020] Figure 1 This is an overview perspective view of the intelligent production line for wood fiber injection molding of the present invention; Figure 2 This is a schematic diagram of the automatic counterweight and visual recognition fixed-length cutting and feeding system of the present invention; Figure 3This is a schematic diagram of the six-axis industrial robot and its quick-change end effector of the present invention; Figure 4 This is a flowchart illustrating the adaptive feeding control system of the present invention. Figure 5 This is a schematic diagram of the hot air slow cooling conveying device and curing oven of the present invention; Figure 6 This is a schematic diagram of the safety protection system of the present invention.

[0021] In the diagram: 1. Automatic counterweight and vision recognition fixed-length cutting and feeding system; 2. Double-layer cross-feeding assembly; 3. Six-axis robot; 4. Injection molding machine; 5. Hot air slow cooling conveyor; 6. Curing oven; 7. Safety fence; 8. Industrial camera; 9. Servo cutter; 10. Pneumatic push rod; 11. Double-layer cross-pallet; 12. Horizontal conveyor belt; 13. Quick-change flange interface; 14. Contouring double gripper; 15. Vacuum suction cup; 16. Chain conveyor; 17. Axial flow fan; 18. Mobile rack. 19. Insulated room body 20. Safety door. Detailed Implementation

[0022] Reference Figures 1-6 The intelligent production line for wood fiber injection molding described in this embodiment mainly includes modules such as an automatic counterweight and visual recognition fixed-length cutting and feeding system, a six-axis industrial robot and quick-change end effector, a dual-position injection molding machine, an adaptive feeding control system, a hot air slow cooling conveying device and a curing oven, and a safety protection system.

[0023] A wood fiber injection molding intelligent production line, comprising, in sequence along the material flow direction: a) Automatic counterweight and visual recognition fixed-length cutting and feeding system 1, used for online measurement, weighing and quantitative cutting and conveying of cylindrical wood fiber raw materials; b) A six-axis robot 3 and a quick-change end effector, used to grab raw materials and put them into the injection molding die, and to remove the molded parts after the die is opened; c) A dual-position injection molding machine 4, used to perform thermosetting injection molding of the raw material under mold temperature of 160℃~200℃ and pressure of 10MPa~25MPa; d) An adaptive feeding control system is used to monitor the temperature, pressure and steam concentration in the mold cavity in real time, and dynamically adjust the feeding amount and feeding frequency according to the deviation; e) Hot air slow cooling conveyor 5 and curing oven 6 are used for slow cooling and constant temperature and humidity curing of the molded products. f) Safety protection system, used to monitor the status of the safety door and cut off the power and shut down the machine in case of abnormality.

[0024] The automatic counterweight and visual recognition fixed-length cutting and feeding system 1 includes a horizontal conveyor belt 12, an industrial camera 8 and a strip LED light source, a servo cutter 9, a weighing sensor and a pneumatic pusher 10. The industrial camera 8 measures the length L of the raw material online. The servo cutter 9 cuts the raw material according to the preset target weight M0 and material density so that the weight of each piece of raw material reaches the predetermined value (error ±5g). The weighing sensor weighs the cut raw material and feeds the weight back to the control system. The pneumatic pusher 10 is used to send the cut raw material to the second tray position of the double-layer cross-type feeding assembly 2.

[0025] The double-layer cross pallet 11 has two pallet positions: an upper layer (first pallet position) and a lower layer (second pallet position). It can complete a 90° rotation exchange within 2.1 seconds through a built-in servo shaft, realizing the alternation of loading and unloading. The pallet positioning accuracy is ±0.1mm.

[0026] The six-axis robot 3 can switch its end effector within 30 seconds via the quick-change flange interface 13. The end effector includes a contouring dual gripper 14 and a vacuum suction cup 15, which can be installed on the quick-change flange interface 13 respectively. The contouring dual gripper 14 equipped with the robot has a gripping force of 80-250N (adjustable) and a high-temperature resistant silicone pad on its vertical surface. It is used to grip cylindrical raw materials and put them into the injection molding die, as well as to remove high-temperature molded parts after the mold is opened. The vacuum suction cup 15 has an adsorption force of -20 to -85kPa (adjustable) and is used to grip flat molded products. The six-axis robot 3 is located within a safety fence 7.

[0027] The adaptive material replenishment control system includes temperature sensors, pressure sensors, and steam concentration sensors arranged inside the mold cavity to collect the temperature T, pressure P, and steam concentration C inside the mold cavity in real time. The system also includes a controller to calculate the replenishment index I (I=k1·ΔT+k2·ΔP+k3·ΔC) based on the set target values ​​and real-time deviations ΔT, ΔP, and ΔC, and automatically adjust the replenishment amount (0~500g) and replenishment frequency (0~3 times) according to the I value to ensure that when the mold cavity parameters are lower than the preset values, raw materials are added to the mold cavity through the injection mechanism to fully fill the product and achieve the best curing effect. The replenishment coefficients k1, k2, and k3 can be set and switched through the touch screen human-machine interface.

[0028] The hot air slow cooling conveying device 5 includes a chain conveyor 16 located at the outlet of the injection molding machine 4. The conveyor is equipped with three axial flow fans 17 and a PTC heater. The hot air generated by the fans is controlled by PID to maintain the outlet air temperature within the range of 50℃ to 90℃, and the air volume is continuously adjustable between 800 and 1500 m³ / h, which is used to slowly cool the molded parts. A movable rack 18 is set at the rear end of the chain conveyor, which can be moved into the curing oven 6.

[0029] The curing oven 6 is equipped with temperature and humidity sensors to control the indoor temperature at 65℃~75℃ and the relative humidity at 35%~45%. The finished products stay in this environment for about 4 hours to allow residual moisture inside the products to evaporate further and release internal stress, thus preventing cracking and deformation. The exterior of the curing oven 6 is an insulated chamber 19.

[0030] The safety protection system includes a safety fence 7 and a safety door with a power-off switch. When the safety door is opened, the system cuts off all power supply and stops operation within 0.3 seconds. When the safety door is closed, the system automatically resets and resumes operation.

[0031] The specific implementation process is as follows: the raw materials are first placed on the horizontal conveyor belt 12 for conveying, such as... Figure 2 As shown, the industrial camera 8 measures the length L of the long strip of wood fiber raw material online and calculates the target cutting length L0 based on the preset target weight M0 and material density. After the conveyor belt stops, the servo cutter 9 cuts the raw material according to L0, ensuring that the weight of each segment reaches the predetermined value (allowing an error of ±5g). The cut raw material is then conveyed to the second pallet position of the double-layer cross pallet 11 via the pneumatic pusher 10. The upper and lower layers of the double-layer pallet are used alternately, and the built-in servo shaft completes a 90° rotation switch within 2.1 seconds, realizing the alternation of feeding and picking, improving the continuity of feeding; the pallet positioning accuracy is ±0.1mm, ensuring accurate robot gripping.

[0032] like Figure 3 As shown, this production line uses a six-axis robot 3, equipped with a quick-change flange interface 13 at the end, allowing for rapid end effector replacement within approximately 30 seconds. A contouring double gripper 14 or a vacuum suction cup 15 can be installed as needed. The gripping force of the contouring double gripper 14 is adjustable within the range of 80–250 N, and the vertical surface of the gripper is equipped with a high-temperature resistant silicone pad for grasping and holding cylindrical raw materials, placing them into the injection molding die, or grasping high-temperature molded parts after mold opening. The suction force of the vacuum suction cup 15 is adjustable within the range of -20–-85 kPa, used for grasping flat products after molding. The six-axis robot 3 alternately operates two dual-position injection molding machines according to a pre-programmed sequence, achieving unmanned continuous production.

[0033] The dual-position injection molding machine 4 is located in the center of the production line, such as... Figure 1 As shown, two injection molding machines 4 are used to thermoset the input wood fiber raw materials. The mold temperature is controlled between 160℃ and 200℃, and the injection pressure is controlled between 10MPa and 25MPa. After heating and pressurizing, the injection molding machines 4 hold the pressure for curing. After mold opening, the product is removed by a six-axis robot 3. At this time, temperature sensors, pressure sensors, and steam concentration sensors located inside the mold cavity collect the parameters T, P, and C within the mold cavity in real time and feed them back to the controller. Figure 4As shown, the controller calculates the replenishment index I based on the deviations ΔT, ΔP, and ΔC between the preset target values ​​and the collected values, according to the formula I = k1·ΔT + k2·ΔP + k3·ΔC. Based on the I value, the system automatically adjusts the replenishment strategy: if the parameters within the mold cavity are lower than the preset values, additional material is added to the mold cavity through the injection mechanism. The replenishment amount is 0–500g, and 0–3 replenishment operations can be performed to ensure the product is fully filled and achieves optimal curing. The replenishment coefficients k1, k2, and k3 are set and switched via a touchscreen HMI, ensuring the flexibility and reliability of the replenishment control.

[0034] After injection molding, a six-axis robot 3 places the product on a chain conveyor for slow cooling, such as... Figure 5 As shown, the chain conveyor is equipped with three axial flow fans and a PTC heater. The hot air blown out by the fans is controlled by PID to maintain the outlet air temperature within the range of 50℃ to 90℃, and the air volume is continuously adjustable between 800 and 1500 m³ / h. The products cool down slowly during conveying, releasing some thermal stress. Subsequently, the products enter a curing oven 6 connected to the conveyor for further processing. The curing oven 6 is equipped with temperature and humidity sensors to maintain a constant indoor temperature between 65℃ and 75℃ and a relative humidity between 35% and 45%. The products are cured in this temperature and humidity environment for approximately 4 hours, allowing residual internal moisture to evaporate further and releasing internal stress, thereby preventing cracking or deformation.

[0035] like Figure 6 The entire production line is surrounded by safety fences 7 and safety doors 20 with power-off switches. When any safety door 20 is opened, the system will cut off all power supply and shut down the machine in an emergency within 0.3 seconds to ensure the safety of the operators. After the safety door 20 is closed, the system will automatically reset and resume normal operation.

[0036] In summary, the intelligent production line for wood fiber injection molding shown in this embodiment achieves a high degree of automation and intelligence in the wood fiber injection molding process through technologies such as automatic feeding, online detection, dynamic replenishment, and slow cooling curing, which significantly improves product quality and production efficiency.

Claims

1. A smart production line for wood fiber injection molding, characterized in that, Along the logistics direction, the following are included in sequence: a) An automatic counterweight and visual recognition fixed-length cutting and feeding system is used for online measurement, weighing, quantitative cutting and conveying of cylindrical wood fiber raw materials; b) A six-axis industrial robot and quick-change end effector for gripping raw materials and feeding them into an injection molding die, and for removing the molded parts after the die is opened; c) A dual-position injection molding machine, used to perform thermosetting injection molding of the raw material under mold temperature of 160℃~200℃ and pressure of 10MPa~25MPa; d) An adaptive feeding control system is used to monitor the temperature, pressure and steam concentration in the mold cavity in real time, and dynamically adjust the feeding amount and feeding frequency according to the deviation; e) Hot air slow cooling conveyor and curing oven, used for slow cooling and constant temperature and humidity curing of the molded products; f) Safety protection system, used to monitor the status of the safety door and cut off the power and shut down the machine in case of abnormality; The automatic counterweight and visual recognition fixed-length cutting and feeding system includes a horizontal conveyor belt, an industrial camera and a strip LED light source, a servo cutter, a weighing sensor and a pneumatic pusher. The industrial camera measures the length L of the raw material online. The servo cutter cuts the raw material according to the preset target weight M0 and material density to ensure that the weight of each segment of raw material reaches the predetermined value with an error of ±5g. The weighing sensor weighs the cut raw material and feeds the weight back to the control system. The pneumatic pusher is used to send the cut raw material to the second tray position of the double-layer cross-type tray. The adaptive material replenishment control system includes temperature sensors, pressure sensors, and steam concentration sensors arranged within the mold cavity to collect real-time temperature T, pressure P, and steam concentration C within the mold cavity. The system also includes a controller to calculate the replenishment index I based on set target values ​​and real-time deviations ΔT, ΔP, and ΔC, where I = k1·ΔT + k2·ΔP + k3·ΔC. The controller automatically adjusts the replenishment amount and replenishment frequency based on the I value. The replenishment amount is 0–500g, and the replenishment frequency is 0–3 times, ensuring that when mold cavity parameters are lower than preset values, additional material is added to the mold cavity via the injection mechanism, allowing the product to be fully filled and achieve optimal curing. The replenishment coefficients k1, k2, and k3 are set and switched via a touchscreen human-machine interface.

2. The intelligent production line for wood fiber injection molding according to claim 1, characterized in that, The double-layer cross pallet has two pallet positions, upper and lower, and can complete a 90° rotation exchange within 2.1 seconds through a built-in servo shaft, realizing alternating loading and unloading, with a pallet positioning accuracy of ±0.1mm.

3. The intelligent production line for wood fiber injection molding according to claim 1, characterized in that, The six-axis industrial robot can switch end effectors within 30 seconds via a quick-change flange interface; the six-axis industrial robot is equipped with a contour-following dual gripper with a gripping force of 80-250N, and a high-temperature resistant silicone pad on the vertical surface, used to grip cylindrical raw materials and put them into the injection molding die, and to remove high-temperature molded parts after mold opening; the vacuum suction cup of the six-axis industrial robot has an adsorption force of -20 to -85kPa, used to grip flat molded products.

4. The intelligent production line for wood fiber injection molding according to claim 1, characterized in that, The hot air slow cooling conveying device includes a chain conveyor located at the outlet of the injection molding machine. The chain conveyor is equipped with three axial flow fans and a PTC heater. The hot air generated by the fans is controlled by PID to maintain the outlet air temperature within the range of 50℃ to 90℃, and the air volume is continuously adjustable between 800 and 1500 m³ / h, which is used to slowly cool the molded parts. The rear end of the chain conveyor is connected to the curing oven.

5. The intelligent production line for wood fiber injection molding according to claim 1, characterized in that, The curing oven is equipped with temperature and humidity sensors to control the indoor temperature at 65℃~75℃ and the relative humidity at 35%~45%. The molded product stays in this environment for 4 hours to allow the residual moisture inside the product to evaporate further and release internal stress, thus preventing cracking and deformation.

6. The intelligent production line for wood fiber injection molding according to claim 1, characterized in that, The safety protection system includes a safety fence and a safety door with a power-off switch. When the safety door is opened, the system cuts off all power supply and stops operation within 0.3 seconds. When the safety door is closed, the system automatically resets and resumes operation.

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