A method for integrally forming a high and low temperature resistant PEEK cable tie

Abstract

The application belongs to the technical field of plastic precision injection molding, and relates to an integrated forming preparation method of high and low temperature resistant PEEK cable ties. Through formula optimization, mold structure innovation and intelligent control fusion, the application completely eliminates the fusion mark defects of the PEEK cable ties, realizes one-time forming of long-size cable ties with a length greater than or equal to 300 mm, and simultaneously improves the consistency qualified rate of multi-cavity products to more than 98%, so as to meet the severe application requirements in the fields of aerospace, new energy vehicles, petroleum chemical industry and the like.

Description

Technical Field

[0001] This invention belongs to the field of precision injection molding technology for plastics, and relates to an integrated molding preparation method for high and low temperature resistant PEEK cable ties. The prepared high and low temperature resistant PEEK cable ties are suitable for harsh high and low temperature environments such as aerospace, new energy vehicles, and petrochemicals. Background Technology

[0002] Polyetheretherketone (PEEK), a semi-crystalline high-performance plastic, possesses characteristics such as a long-term operating temperature of 250℃, chemical corrosion resistance, excellent mechanical strength, and a flame retardant rating of V0, making it an ideal material to replace metal fasteners in high-end equipment applications. With the development of lightweight and integrated high-end equipment, stringent requirements have been placed on the length, strength, high and low temperature resistance, and batch consistency of PEEK cable ties. In particular, the aerospace field requires that cable ties retain at least 90% of their strength after 100 cycles of high and low temperatures from -60℃ to 250℃, with a dimensional accuracy deviation not exceeding ±0.1mm.

[0003] Currently, the molding technology for PEEK cable ties has made some progress. For example, patent CN113527834A discloses a high-temperature resistant PEEK self-locking plastic cable tie and its preparation method. This method improves the product's toughness by modifying PEEK with PTFE and embeds metal inserts inside the cable tie. However, stress concentration during molding leads to premature breakage, failing to meet the safety requirements of the aerospace field. Patent CN112795136A discloses a lightweight flame-retardant strapping for aviation and its preparation process, using one-time injection molding. While this reduces weld lines, it is only suitable for short cable ties ≤300mm in length, failing to address the problem of insufficient end filling for cable ties longer than 300mm. Furthermore, single-cavity production efficiency is extremely low, making industrial-scale mass production difficult.

[0004] In terms of multi-cavity molding and intelligent control, existing technologies generally suffer from the following insurmountable defects: (1) Weld lines cannot be completely eliminated: Multi-cavity molds often use multi-point injection or unbalanced runner design, and PEEK melt viscosity is extremely high (up to 10 at 380℃). 3 -10 4 (Pa·s), at the confluence point, the molecular chains are difficult to fully entangle, forming permanent weld line defects, which seriously reduces the tensile strength and fatigue resistance of the product; (2) Long dimensions are difficult to form: PEEK melt cools quickly and crystallization rate is sensitive. During long-distance flow, the viscosity rises sharply, which can easily lead to problems such as insufficient end filling and large dimensional accuracy deviation (above ±0.2mm), which cannot meet the precision assembly requirements of high-end equipment. (3) Poor consistency of multi-cavity molds: The temperature and pressure distribution of each cavity in traditional multi-cavity molds is uneven, with deviations of more than 5℃ and more than 15MPa, resulting in large performance dispersion of batch products, with a pass rate of only 70%-80%, and a large number of "hidden non-conforming products" that cannot be detected by random inspection, posing a major safety hazard. (4) Low level of intelligent control: Existing intelligent control systems for injection molding are mostly based on experience databases. They have not established a quantitative correlation model between the rheological properties of PEEK melt and process parameters. They rely on manual experience to adjust parameters and cannot adapt to changes in the state of different batches of raw materials, mold wear, etc. in real time. The parameter adjustment cycle is as long as 2-3 hours / batch, resulting in low production efficiency.

[0005] Therefore, an integrated molding and manufacturing method for PEEK cable ties is needed to solve the core technical problems of numerous weld lines, difficulty in filling long dimensions, and poor consistency of multiple cavities during the PEEK cable tie molding process, so as to achieve high consistency and high efficiency in the industrial production of long PEEK cable ties. Summary of the Invention

[0006] To address the shortcomings of existing technologies, this invention aims to provide an integrated molding method for high and low temperature resistant PEEK cable ties. This invention, through formula optimization, mold structure innovation, and intelligent control integration, completely eliminates weld line defects in PEEK cable ties, enabling one-time molding of long cable ties with a length ≥300mm. Simultaneously, it increases the consistency pass rate of multi-cavity products to over 98%, meeting the stringent application requirements in aerospace, new energy vehicles, petrochemical, and other fields.

[0007] To achieve the above objectives, the present invention adopts the following technical solution: A method for integrally molding and manufacturing high and low temperature resistant PEEK cable ties includes the following steps: Step 1, Raw material pretreatment: Mix all components evenly according to the proportion, and vacuum dry at 120-140℃ for 4-6 hours to make the moisture content of the raw materials ≤0.02%; Step 2, Mold Heating: The mold temperature controller uses an oil bath type zoned independent temperature control to heat the multi-cavity unidirectional injection mold, and controls the temperature of the cable tie mold cavity at 160-180℃, with the temperature deviation of each point in the cable tie mold cavity ≤±1℃; Step 3, Unidirectional Injection Molding: The pretreated raw material is added to the injection molding machine barrel. The injection molding machine controller controls the barrel temperature in three sections: Zone 1 340-360℃, Zone 2 360-380℃, Zone 3 380-400℃, and the nozzle temperature 370-390℃. A single-point unidirectional injection method is adopted, with the injection port set at the head of the cable tie. The raw material melt flows unidirectionally along the length of the cable tie to fill the cavity of the cable tie mold without confluence. The injection pressure is 120-150MPa, the holding pressure is 80-100MPa, and the holding time is 5-8s. Step 4, Cooling and Shaping: After injection molding, maintain the mold temperature at 160-180℃ for 10-15 seconds, then open the mold and remove the part; Step 5, Post-treatment: Anneal the formed cable ties at 180-200℃ for 2-3 hours to eliminate the internal stress of the forming process and obtain high and low temperature resistant PEEK cable ties.

[0008] Furthermore, in step 1, the components are specified by weight as follows: 80-90 parts of PEEK resin; 5-12 parts of short-cut carbon fibers with a surface treated with a silane coupling agent; 1-3 parts of nano-crystallization regulator; 0.5-2 parts of polytetrafluoroethylene powder; 0.2-0.5 parts of hindered phenolic antioxidants.

[0009] Furthermore, the intrinsic viscosity of the PEEK resin is 0.7-1.0 dL / g; the length of the chopped carbon fiber is 0.1-0.3 mm, which is obtained by cutting the original long carbon fiber into shorter carbon fibers to facilitate subsequent processing; the silane coupling agent is KH-550; and the nanocrystallization regulator is nano-silicon carbide or nano-boron nitride with a particle size of 50-100 nm.

[0010] Furthermore, in step 3, the injection speed is controlled in three stages: slow-fast-slow, 30-40mm / s, 60-80mm / s, and 20-30mm / s respectively. The first stage of the three-stage control is slow to ensure uniform filling of each flow channel and product cavity without flow lines. The second stage is fast to quickly fill the cable tie mold cavity. The third stage is slow to ensure uniform venting.

[0011] Furthermore, in step 2, the multi-cavity unidirectional injection mold includes a fixed mold and a moving mold. The fixed mold is fixed to the fixed mold mounting side of the injection molding machine and is connected to the injection molding machine nozzle. The moving mold is fixed to the moving mold mounting side of the injection molding machine and performs horizontal reciprocating motion with the machine tool opening and closing mechanism to realize the mold closing and opening actions.

[0012] The fixed mold includes a fixed mold fixing plate 2, a hot runner plate 3, and a fixed template 4; the moving mold includes a moving mold fixing plate 9, an ejector base plate 8, an ejector panel 7, two square iron pieces 6, and a moving template 5.

[0013] The fixed mold plate 2 is provided with a central through hole for installing the positioning ring 1. The fixed mold is installed on the injection molding machine and connected to the injection molding machine nozzle through the positioning ring 1. The hot runner plate 3 is provided with a hot runner 11 inside. A heating ring is installed in the hot runner 11 to control the melt temperature in the hot runner 11. The inlet of the hot runner 11 is connected to the central through hole of the fixed mold plate 2, and the outlet of the hot runner 11 is connected to a through hole provided on the fixed mold plate 4.

[0014] The fixed template 4 and the moving template 5 have corresponding grooves on their parting surfaces that match the size and shape of the cable tie product. The grooves fit together to form the cable tie mold cavity 14, which are arranged parallel to each other along the length of the parting surface. Each cavity corresponds to one cable tie product. The fixed template 4 and the moving template 5 also have corresponding grooves on their parting surfaces for forming cold runners 16. The grooves fit together to form cold runners 16. The inlet of the cold runner 16 is connected to the through hole on the fixed template 4, and the outlet is provided with multiple branch runners. The end of each branch runner is connected to a fan-shaped submerged injection port 15, which is located on the parting surface of the moving template 5. The fan-shaped submerged injection port 15 corresponds to the head side of the cable tie mold cavity 14. The melt passes through the cold runner 16 and then fills the cavity unidirectionally along its length through the fan-shaped submerged injection port 15.

[0015] Two square iron blocks 6 are fixed between the moving mold fixing plate 9 and the moving mold plate 5. The two square iron blocks 6 are respectively arranged on the inner edges of the moving mold fixing plate 9 and the moving mold plate 5, forming the central ejection mechanism receiving cavity. The ejector plate 7 is located on the upper surface of the ejector base plate 8. The lower part of the ejector pin 18 is clamped and fixed between the ejector plate 7 and the ejector base plate 8. An ejector pin 18 is arranged at the head and body positions of each cavity. The upper part of the ejector pin 18 slides into the moving mold plate 5. The top end face is flush with the bottom surface of the cavity. After the ejector plate 7, ejector base plate 8, and ejector pin 18 are fixed as one piece, they are placed in the ejection mechanism cavity. The whole can slide back and forth along the mold opening direction. The moving mold fixing plate 9 is fixed to the moving mold mounting side of the injection molding machine. The moving mold fixing plate 9 has a through hole for the injection molding machine ejector rod to pass through. After the mold is opened, the injection molding machine ejector rod pushes the ejector base plate 8 and ejector plate 7 forward, driving the ejector pin 18 to eject the formed cable tie product from the cavity.

[0016] The moving template 5 is equipped with a locking module 10 on its side, and the fixed template 4 is provided with a locking groove on its side. When the mold is closed, the locking module 10 cooperates with the locking groove to achieve lateral locking and positioning.

[0017] Each cable tie mold cavity 14 has an exhaust groove 17 at its end; the exhaust groove 17 extends outward along the length direction from the end edge of the cavity corresponding to the driven template 5, and the outer end of the groove extends to the outside of the mold, so as to discharge the gas in the cable tie mold cavity 14 to the atmosphere.

[0018] The fixed template 4 and the moving template 5 are provided with conformal cooling oil channels 19. Each cable tie mold cavity 14 corresponds to a set of independent conformal cooling oil channels 19. The conformal cooling oil channels 19 are connected to the circulation pipeline of the external oil bath mold temperature controller to adjust the temperature of each cable tie mold cavity 14 individually, ensuring the consistency of multi-cavity molding. The conformal cooling oil channels 19 extend along the length of the cavity, and the overall direction follows the contour of the cavity.

[0019] Each cable tie mold cavity 14 is equipped with a temperature sensor 12, which is embedded inside the moving template 5, near the middle of the cavity cable body. The detection end is close to the cavity wall, and is used to collect the actual temperature of the cavity in real time and feed it back to the intelligent control system.

[0020] Each cable tie mold cavity 14 is equipped with three pressure sensors 13, which are respectively arranged on the wall surface of the cavity head, cavity middle and cavity end corresponding to the moving template 5. The detection end face is flush with the inner wall of the cavity, and is used to collect pressure data at the three positions in real time during the melt filling process.

[0021] Furthermore, the temperature of the hot runner 11 is controlled at 380-390℃.

[0022] During the preparation process, an intelligent control system is used to regulate the temperature and pressure of the barrel and mold; the intelligent control system includes: The data acquisition unit includes a temperature sensor installed in each cable tie mold cavity, pressure sensors installed at the inlet, middle and end of each cable tie mold cavity, and a raw material melt viscosity sensor installed near the discharge port of the injection molding machine barrel, for collecting temperature, pressure and melt viscosity. The data processing unit is communicatively connected to the data acquisition unit to obtain the viscosity of the raw material melt and determine whether the product is qualified according to the qualification standard. The real-time control unit is communicatively connected to the data processing unit, the injection molding machine controller, and the mold temperature controller, and is used to control the barrel temperature, injection pressure, and mold temperature. The feedback correction unit is communicatively connected to the data processing unit, used to collect product performance data and optimize model parameters, and feed them back to the injection molding machine controller and the mold temperature controller; The intelligent control system can dynamically adjust the injection holding pressure, barrel temperature, and hot runner temperature based on real-time collected melt temperature, pressure, and viscosity data, thereby achieving closed-loop intelligent control of the multi-cavity molding process.

[0023] Preferably, the data processing unit incorporates a PEEK melt Cross-WLF rheological property model and a multi-cavity consistency evaluation model. The cross-WLF rheological property model of PEEK melt is as follows: in, The viscosity of the raw material melt. Zero shear viscosity For relaxation time, Non-Newtonian exponents The melting temperature is... For melt pressure, denoted as shear rate.

[0024] The multi-cavity consistency evaluation model uses the following criteria for qualification: temperature deviation ΔT ≤ 2℃, pressure deviation ΔP ≤ 5MPa, and filling time deviation Δt ≤ 0.5s for each mold cavity.

[0025] Preferably, the control logic of the real-time control unit is as follows: When the pressure at the end of a cable tie mold cavity falls below the standard value, the overall pressure holding pressure is automatically increased, with the pressure increase amount... ; When the viscosity of the raw material melt is higher than the standard value, the temperature of the three zones of the barrel is automatically increased, and the temperature increase range is as follows: ; When the filling time of a cable tie mold cavity exceeds the standard value by more than 0.5 seconds, the temperature of the hot runner corresponding to the cable tie mold cavity will be automatically increased by 2-3℃. Wherein, k1 and k2 are the pressure holding pressure and temperature control coefficients, respectively, with values ​​ranging from 0.1 to 0.5; and These are the standard value and the measured value of the holding pressure, respectively. and These are the standard and measured values ​​of the melt viscosity, respectively.

[0026] Preferably, after every 5 injection molding products, the feedback correction unit collects the dimensional accuracy and tensile strength data of each cable tie mold cavity product; if the product qualification rate is less than 98%, the coefficients of the Cross-WLF rheological model are automatically updated using the particle swarm optimization algorithm.

[0027] The high and low temperature resistant PEEK cable ties prepared by the method of this invention have no weld marks, a length ≥300mm, a dimensional accuracy deviation ≤±0.1mm, a tensile strength ≥500N, and can be used for a long time in an environment of -60℃~250℃.

[0028] Compared with the prior art, the present invention has the following significant advantages: (1) Significantly improved performance: The PEEK cable tie of the present invention has no weld lines and a tensile strength of ≥500N, which is more than 30% higher than the traditional multi-point glue injection process; the strength retention rate after 100 high and low temperature cycles is ≥92%, and it can be used for a long time in an environment of -60℃~250℃; it has excellent creep resistance, and the creep deformation is ≤0.5% after 1000h at 200℃ and 50% rated load.

[0029] (2) Breaking through the limitations of long-size molding: By optimizing the barrel temperature gradient, adopting high-temperature mold temperature control and unidirectional glue injection design, long-size PEEK cable ties with a length ≥300mm were formed in one step with a dimensional accuracy deviation ≤±0.1mm, solving the problem of insufficient filling of cable ties with large aspect ratio in traditional processes.

[0030] (3) Significantly improved consistency of multi-cavity products: The balanced flow channel design and zoned independent temperature control system are adopted, combined with intelligent control algorithm, to control the temperature deviation of each cavity within 2℃ and the pressure deviation within 5MPa. The product consistency qualification rate is ≥98%, which completely eliminates the safety hazards of "hidden non-conforming products".

[0031] (4) Production efficiency is greatly improved: the 4-8 cavity integrated mold design increases the output of a single mold by 4-8 times; the intelligent closed-loop control system does not require manual intervention, and the parameter adjustment time is shortened from 2-3 hours / batch to less than 5 minutes, improving the overall production efficiency by more than 40%.

[0032] (5) Extended mold life: The synergistic lubrication effect of PTFE powder and carbon fiber reduces mold wear. Combined with the automatic mold wear compensation function, the mold life is extended by more than 30%. Attached Figure Description

[0033] Figure 1 This is a schematic diagram of the overall structure of the multi-cavity unidirectional injection mold of the present invention; Figure 2 A schematic diagram of the fixed mold structure of a multi-cavity unidirectional injection mold; Figure 3 This is a schematic diagram of the moving mold structure of a multi-cavity unidirectional injection mold; Figure 4 A schematic diagram of the internal cooling oil channels of a multi-cavity unidirectional injection mold; Figure 5 This is a structural diagram of a PEEK cable tie; Figure 6 This is a diagram showing the overall architecture of the intelligent control system of the present invention.

[0034] In the diagram: 1. Positioning ring, 2. Fixed mold plate, 3. Hot runner plate, 4. Fixed mold plate, 5. Moving mold plate, 6. Square iron, 7. Ejector plate, 8. Ejector base plate, 9. Moving mold plate, 10. Locking module, 11. Hot runner, 12. Temperature sensor, 13. Pressure sensor, 14. Cable tie mold cavity, 15. Fan-shaped submerged sprue, 16. Cold runner, 17. Venting groove, 18. Ejector pin, 19. Conformal cooling oil channel, 20. Cable tie head, 21. Cable tie body, 22. Toothed structure, 23. Cable tie end. Detailed Implementation

[0035] The specific embodiments of the present invention will be further described below with reference to the accompanying drawings and technical solutions.

[0036] like Figure 1-4 As shown, the specific structure of the multi-cavity unidirectional injection mold of the present invention is as follows: The multi-cavity unidirectional injection mold includes a fixed mold and a moving mold. The fixed mold is fixed to the fixed mold mounting side of the injection molding machine and is connected to the injection molding machine nozzle. The moving mold is fixed to the moving mold mounting side of the injection molding machine and performs horizontal reciprocating motion with the machine tool opening and closing mechanism to realize the mold closing and opening actions.

[0037] The fixed mold includes a fixed mold fixing plate 2, a hot runner plate 3, and a fixed mold plate 4; the moving mold includes a moving mold fixing plate 9, an ejector base plate 8, an ejector panel 7, two square iron pieces 6, and a moving mold plate 5. All plates are circumferentially locked together using hexagonal socket head cap screws. In the closed mold state, the inner surface (parting surface) of the fixed mold plate 4 is tightly fitted with the inner surface (parting surface) of the moving mold plate 5, forming a closed molding cavity.

[0038] The fixed mold plate 2 is provided with a central through hole for installing the positioning ring 1. The fixed mold is installed on the injection molding machine and connected to the injection molding machine nozzle through the positioning ring 1. The hot runner plate 3 is provided with a hot runner 11 inside. A heating ring is installed in the hot runner 11 to control the melt temperature in the hot runner 11. The inlet of the hot runner 11 is connected to the central through hole of the fixed mold plate 2, and the outlet of the hot runner 11 is connected to a through hole provided on the fixed mold plate 4.

[0039] The fixed template 4 and the moving template 5 have corresponding grooves on their parting surfaces that match the size and shape of the cable tie product. These grooves align to form cable tie mold cavities 14. There are 4-8 cable tie mold cavities 14 in total, arranged parallel to each other along the length of the parting surface. Each cavity corresponds to one cable tie product. The fixed template 4 and the moving template 5 also have corresponding grooves on their parting surfaces for forming cold runner channels 16. These grooves align to form cold runner channels 16. The inlet of the cold runner channel 16 communicates with a through hole on the fixed template 4, and the outlet has multiple branch channels. Each branch channel... The length and cross-sectional dimensions of the runners are completely consistent, with a length deviation of ≤1mm. Each branch runner is connected to a fan-shaped submerged inlet 15 at its end, located on the parting surface of the moving mold plate 5. The fan-shaped submerged inlet 15 corresponds to the head side of the cable tie mold cavity 14, and its cross-section is fan-shaped, with a width of 4-6mm and a thickness of 2-3mm. The melt, after passing through the cold runner 16, fills unidirectionally along the cavity length direction through the fan-shaped submerged inlet 15, preventing melt confluence and eliminating weld lines at the source. This invention employs a combined balanced structure of "hot runner + cold runner" to ensure synchronous feeding and consistent pressure in each cavity.

[0040] Two square iron pieces 6 are fixed between the moving mold fixing plate 9 and the moving mold plate 5. The two square iron pieces 6 are respectively arranged on the inner edges of the moving mold fixing plate 9 and the moving mold plate 5, forming the central ejection mechanism receiving cavity. The ejector plate 7 is located on the upper surface of the ejector base plate 8. The lower part of the ejector pin 18 is clamped and fixed between the ejector plate 7 and the ejector base plate 8. An ejector pin 18 is arranged at the head and body positions of each cavity. The upper part of the ejector pin 18 slides into the moving mold plate 5, and the top end face is flush with the bottom surface of the cavity. After the ejector plate 7, the ejector base plate 8, and the ejector pin 18 are fixed as a whole, they are placed in the ejection mechanism receiving cavity, and the whole can slide back and forth along the mold opening direction. The moving mold fixing plate 9 is fixed to the moving mold mounting side of the injection molding machine. The moving mold fixing plate 9 has a through hole for the injection molding machine ejector rod to pass through. After the mold opens, the injection molding machine ejector rod pushes the ejector base plate 8 and the ejector plate 7 forward, driving the ejector pin 18. The formed cable tie product is ejected from the cavity.

[0041] The moving template 5 is equipped with a locking module 10 on its side, and the fixed template 4 is provided with a locking groove on its side. When the mold is closed, the locking module 10 cooperates with the locking groove to achieve lateral locking and positioning. When the injection molding machine installs or removes the mold, the locking module 10 prevents the mold from separating and falling off.

[0042] The cable tie mold cavity 14 has a cavity contour that perfectly matches the shape of the cable tie product, and is divided into a head receiving cavity, a body receiving cavity, and an end receiving cavity. The structure of the PEEK cable tie is as follows: Figure 5 As shown, it includes a cable tie head 20, a cable tie body 21, a toothed structure 22, and a cable tie end 23.

[0043] Each cable tie mold cavity 14 has an exhaust groove 17 at its end. The exhaust groove 17 extends outward along the length direction from the end edge of the cavity corresponding to the driven template 5. The groove is 0.02-0.03mm deep and 5-10mm long. The outer end of the groove extends to the outside of the mold, so as to discharge the gas in the cable tie mold cavity 14 to the atmosphere and avoid the formation of air bubbles due to trapped air.

[0044] The fixed template 4 and the moving template 5 are provided with conformal cooling oil channels 19. Each cable tie mold cavity 14 corresponds to an independent set of conformal cooling oil channels 19. The conformal cooling oil channels 19 are connected to the circulation pipeline of the external oil bath mold temperature controller to adjust the temperature of each cable tie mold cavity 14 individually, ensuring the consistency of multi-cavity molding. The conformal cooling oil channels 19 extend along the length of the cavity, and their overall direction follows the contour of the cavity. The oil channels corresponding to each cavity are independent of each other and are connected to the zoned temperature control circuit of the mold temperature controller, which can adjust the temperature of each cavity individually, further ensuring the consistency of multi-cavity molding. The vertical distance between the inner wall of the conformal cooling oil channel 19 and the inner wall of the cable tie mold cavity 14 is maintained at 8-10mm to ensure that the surface temperature of the cable tie mold cavity 14 is uniform and the temperature deviation at each point is ≤±1℃.

[0045] Each cable tie mold cavity 14 is equipped with a temperature sensor 12, which is embedded inside the moving template 5, near the middle of the cavity cable body. The detection end is close to the cavity wall, and is used to collect the actual temperature of the cavity in real time and feed it back to the intelligent control system.

[0046] Each cable tie mold cavity 14 is equipped with three pressure sensors 13, which are respectively arranged on the wall surface of the cavity head, cavity middle and cavity end corresponding to the moving template 5. The detection end face is flush with the inner wall of the cavity, and is used to collect pressure data at the three positions in real time during the melt filling process.

[0047] Experiments were conducted using the aforementioned multi-cavity unidirectional injection mold and the method of this invention (the intelligent control process of this invention is as follows). Figure 6 As shown), the details are as follows: (1) Experimental materials and equipment Experimental materials: PEEK resin: intrinsic viscosity 0.9 dL / g; short-cut carbon fiber: length 0.2 mm, surface treated with KH-550; nano-silicon carbide: particle size 80 nm; polytetrafluoroethylene powder; hindered phenolic antioxidant; Experimental equipment: Injection molding machine; mold temperature controller; capillary rheometer; universal testing machine; high and low temperature test chamber; (2) Calibration of Cross-WLF rheological property model Using a capillary rheometer, measurements were taken at four temperature points: 340℃, 360℃, 380℃, and 400℃, for 10 seconds. -1 50s -1 100s -1 500s -1 1000s -1 Viscosity data of PEEK melt were measured at five shear rates. Cross-WLF model parameters were obtained by fitting using the nonlinear least squares method. Zero shear viscosity =1.2×10 4 Pa·s (380℃) Relaxation time =0.08s Non-Newtonian exponent =0.35 Example 1 The raw materials, by weight, are formulated as follows: The composition consists of 85 parts PEEK resin, 8 parts carbon fiber, 2 parts nano silicon carbide, 1 part polytetrafluoroethylene powder, and 0.3 parts hindered phenolic antioxidant.

[0048] The integrated molding process is as follows: Step 1: After mixing the raw materials, vacuum dry them at 130℃ for 5 hours to ensure a moisture content of ≤0.02%. Step 2: Use a 4-cavity unidirectional glue injection mold with a total cable tie length of 367.6mm. Preheat the mold to 170℃, and ensure that the temperature deviation at each point in the cavity is ≤±1℃. Step 3: Injection molding machine barrel temperature: Zone 1 350℃, Zone 2 370℃, Zone 3 390℃, Nozzle temperature 380℃; Hot runner temperature 385℃; Injection speed: three-stage: 35mm / s, 70mm / s, 25mm / s; Injection pressure: 130MPa, Holding pressure: 90MPa, Holding time: 6s; Step 4: After holding the temperature for 12 seconds, open the mold and remove the part; Step 5: Anneal at 190℃ for 2.5 hours.

[0049] The intelligent control system monitors the parameters of each cavity in real time. When the pressure at the end of the cavity is detected to be 75MPa (standard value 80MPa), the system automatically increases the holding pressure by 5% to correct the pressure deviation.

[0050] Example 2 The raw materials, by weight, are formulated as follows: 90 parts PEEK resin, 7 parts carbon fiber, 2 parts nano silicon carbide, 0.5 parts polytetrafluoroethylene powder, and 0.5 parts hindered phenolic antioxidant.

[0051] The integrated molding process is as follows: Step 1: After mixing the raw materials, vacuum dry them at 130℃ for 5 hours to ensure a moisture content of ≤0.02%. Step 2: Use a 4-cavity unidirectional glue injection mold with a total cable tie length of 367.6mm. Preheat the mold to 180℃, and ensure that the temperature deviation at each point in the cavity is ≤±1℃. Step 3: Injection molding machine barrel temperature: Zone 1 350℃, Zone 2 370℃, Zone 3 390℃, Nozzle temperature 380℃; Hot runner temperature 385℃; Injection speed: three-stage: 40mm / s, 80mm / s, 30mm / s; Injection pressure: 140MPa, Holding pressure: 150MPa, Holding time: 8s; Step 4: After holding the temperature for 12 seconds, open the mold and remove the part; Step 5: Anneal at 190℃ for 2.5 hours.

[0052] The intelligent control system monitors the parameters of each cavity in real time. When the pressure at the end of the cavity is detected to be 75MPa (standard value 85MPa), the mold temperature is automatically increased by 6% to correct the temperature deviation.

[0053] Example 3 The raw materials, by weight, are formulated as follows: The composition consists of 80 parts PEEK resin, 12 parts carbon fiber, 3 parts nano silicon carbide, 2 parts polytetrafluoroethylene powder, and 0.5 parts hindered phenolic antioxidant.

[0054] The integrated molding process is as follows: Step 1: After mixing the raw materials, vacuum dry them at 140℃ for 4 hours to ensure a moisture content of ≤0.02%. Step 2: Use an 8-cavity unidirectional injection mold with a cable tie length of 367.6mm. Preheat the mold to 180℃, and ensure that the temperature deviation at each point in the cavity is ≤±1℃. Step 3: Barrel temperature: Zone 1 360℃, Zone 2 380℃, Zone 3 395℃, Nozzle temperature 390℃; Hot runner temperature 390℃; Step 4: The injection speed is in three stages: 40mm / s, 80mm / s, and 30mm / s; the injection pressure is 150MPa, the holding pressure is 100MPa, and the holding time is 8s. Step 5: After holding the temperature for 15 seconds, open the mold and remove the part; Step 6: Anneal at 200℃ for 3 hours.

[0055] When the intelligent control system detects that the melt viscosity is 1.1 dL / g (standard value 1.0 dL / g), it automatically raises the temperature of the three zones of the barrel to 400℃ to reduce the melt viscosity.

[0056] Comparative Example 1 (Traditional Multi-point Glue Injection Process) Using the same formula as in Example 1, PEEK cable ties were produced using a conventional 8-cavity multi-point injection mold. The cable tie length was 182mm, and the process parameters were the same as in Example 1.

[0057] Comparative Example 2 (without nanocrystal regulator) The formulation does not contain nano-silicon carbide, and the remaining components are the same as in Example 1, and the process parameters are the same as in Example 1.

[0058] Performance testing and comparison: Performance tests were conducted on the products of the examples and comparative examples according to national standards, and the results are shown in Table 1 below: Table 1 Performance test data of PEEK cable ties

[0059] The test results show that: (1) The tensile strength of the product in the embodiment of the present invention is increased by more than 47% compared with Comparative Example 1 (traditional multi-point glue injection), and the strength retention rate after high and low temperature cycling is increased by more than 24%, which fully demonstrates the superiority of the unidirectional glue injection design without weld lines. (2) The standard deviation of the strength of the multi-cavity product in the embodiment is only about 1 / 4 of that in Comparative Example 1, and the product consistency is significantly improved; (3) The high and low temperature performance and creep performance of Comparative Example 2 (without nano silicon carbide) decreased significantly, which proved the key role of nano crystallization regulator in refining grains and improving high and low temperature performance.

Claims

1. A method for integrally molding and preparing high and low temperature resistant PEEK cable ties, characterized in that, Includes the following steps: Step 1, Raw material pretreatment: Mix all components evenly according to the proportion, and vacuum dry at 120-140℃ for 4-6 hours to make the moisture content of the raw materials ≤0.02%; The components, by weight, are as follows: 80-90 parts of PEEK resin; 5-12 parts of short-cut carbon fibers with a surface treated with a silane coupling agent; 1-3 parts of nano-crystallization regulator; 0.5-2 parts of polytetrafluoroethylene powder; 0.2-0.5 parts of hindered phenolic antioxidant; Step 2, Mold Heating: The mold temperature controller uses an oil bath type zoned independent temperature control to heat the multi-cavity unidirectional injection mold, and controls the temperature of the cable tie mold cavity at 160-180℃, with the temperature deviation of each point in the cable tie mold cavity ≤±1℃; Step 3, Unidirectional Injection Molding: The pretreated raw material is added to the injection molding machine barrel. The injection molding machine controller controls the barrel temperature in three sections: Zone 1 340-360℃, Zone 2 360-380℃, Zone 3 380-400℃, and the nozzle temperature 370-390℃. A single-point unidirectional injection method is adopted, with the injection port set at the head of the cable tie. The raw material melt flows unidirectionally along the length of the cable tie to fill the cavity of the cable tie mold without confluence. The injection pressure is 120-150MPa, the holding pressure is 80-100MPa, and the holding time is 5-8s. Step 4, Cooling and Shaping: After injection molding, maintain the mold temperature at 160-180℃ for 10-15 seconds, then open the mold and remove the part; Step 5, Post-treatment: Anneal the formed cable ties at 180-200℃ for 2-3 hours to eliminate the internal stress of the forming process and obtain high and low temperature resistant PEEK cable ties.

2. The integrated molding preparation method of high and low temperature resistant PEEK cable ties according to claim 1, characterized in that, The intrinsic viscosity of the PEEK resin is 0.7-1.0 dL / g; the length of the chopped carbon fiber is 0.1-0.3 mm, which is obtained by cutting the original long carbon fiber into shorter carbon fibers; the silane coupling agent is KH-550; and the nanocrystallization regulator is nano-silicon carbide or nano-boron nitride with a particle size of 50-100 nm.

3. The integrated molding preparation method for a high and low temperature resistant PEEK cable tie according to claim 1, characterized in that, In step 3, the injection speed is controlled in three stages: slow-fast-slow, 30-40 mm / s, 60-80 mm / s, and 20-30 mm / s, respectively.

4. The integrated molding preparation method of high and low temperature resistant PEEK cable ties according to claim 1, characterized in that, In step 2, the multi-cavity unidirectional injection mold includes a fixed mold and a moving mold. The fixed mold is fixed to the fixed mold mounting side of the injection molding machine and is connected to the injection molding machine nozzle. The moving mold is fixed to the moving mold mounting side of the injection molding machine and performs horizontal reciprocating motion with the machine tool opening and closing mechanism to realize the mold closing and opening actions. The fixed mold includes a fixed mold fixing plate (2), a hot runner plate (3), and a fixed template (4); the moving mold includes a moving mold fixing plate (9), an ejector base plate (8), an ejector panel (7), two square iron pieces (6), and a moving template (5); The fixed mold fixing plate (2) is provided with a central through hole for installing a positioning ring (1). The fixed mold is installed on the injection molding machine and connected to the injection molding machine nozzle through the positioning ring (1). The hot runner plate (3) is provided with a hot runner (11) inside. A heating ring is provided in the hot runner (11) to control the melt temperature in the hot runner (11) separately. The inlet of the hot runner (11) is connected to the central through hole of the fixed mold fixing plate (2), and the outlet of the hot runner (11) is connected to a through hole provided on the fixed mold plate (4). The fixed template (4) and the moving template (5) are provided with grooves that are consistent with the size and shape of the cable tie product. The grooves are aligned to form the cable tie mold cavity (14). They are arranged in parallel along the length of the parting surface, and each cavity corresponds to one cable tie product. The fixed template (4) and the moving template (5) are provided with grooves for forming cold runners (16). The grooves are aligned to form cold runners (16). The inlet of the cold runner (16) is connected to the through hole on the fixed template (4). The outlet is provided with multiple branch runners. The end of each branch runner is connected to a fan-shaped submerged inlet (15). The fan-shaped submerged inlet (15) is located on the parting surface of the moving template (5). The fan-shaped submerged inlet (15) corresponds to the head side of the cable tie mold cavity (14). The melt passes through the cold runner (16) and fills the cavity unidirectionally along the length of the cavity through the fan-shaped submerged inlet (15). Two square iron pieces (6) are fixed between the moving mold fixing plate (9) and the moving template (5). The two square iron pieces (6) are respectively arranged on the inner edges of the moving mold fixing plate (9) and the moving template (5) to enclose the middle ejection mechanism receiving cavity. The ejector plate (7) is located on the upper surface of the ejector base plate (8). The lower part of the ejector (18) is clamped and fixed between the ejector plate (7) and the ejector base plate (8). An ejector (18) is arranged at the head and body positions of each cavity. The upper part slides into the moving template (5), and the top end face is flush with the bottom surface of the cavity. After the ejector plate (7), ejector base plate (8), and ejector (18) are fixed as one piece, they are placed in the ejection mechanism cavity. The whole can slide back and forth along the mold opening direction. The moving mold fixing plate (9) is fixed on the moving mold mounting side of the injection molding machine. The moving mold fixing plate (9) is provided with a through hole for the injection molding machine ejector rod to pass through. After the mold is opened, the injection molding machine ejector rod pushes the ejector base plate (8) and ejector plate (7) forward, and drives the ejector (18) to eject the formed cable tie product from the cavity. The moving template (5) is equipped with a locking module (10) on its side, and the fixed template (4) is provided with a locking groove on its side. When the mold is closed, the locking module (10) cooperates with the locking groove to achieve lateral locking and positioning. Each cable tie mold cavity (14) has an exhaust groove (17) at its end; the exhaust groove (17) extends outward along the length direction from the end edge of the cavity corresponding to the moving template (5), and the outer end of the groove extends to the outside of the mold, so as to exhaust the gas in the cable tie mold cavity (14) into the atmosphere. The fixed template (4) and the moving template (5) are provided with conformal cooling oil channels (19). Each cable tie mold cavity (14) corresponds to a set of independent conformal cooling oil channels (19). The conformal cooling oil channels (19) are connected to the circulation pipeline of the external oil bath mold temperature controller to adjust the temperature of each cable tie mold cavity (14) individually, ensuring the consistency of multi-cavity molding. The conformal cooling oil channels (19) extend along the length of the cavity, and the overall direction follows the contour of the cavity. Each cable tie mold cavity (14) is equipped with a temperature sensor (12), which is embedded inside the moving template (5) and close to the middle of the cavity body. The detection end is close to the cavity wall and is used to collect the actual temperature of the cavity in real time. Each cable tie mold cavity (14) is equipped with three pressure sensors (13), which are respectively arranged on the wall surface of the cavity head, cavity middle and cavity end corresponding to the moving template (5). The detection end face is flush with the inner wall of the cavity, and is used to collect pressure data at the three positions in real time during the melt filling process.

5. The integrated molding preparation method of high and low temperature resistant PEEK cable ties according to claim 1, characterized in that, The temperature of the hot runner (11) is controlled at 380-390℃.

6. The integrated molding preparation method for a high and low temperature resistant PEEK cable tie according to claim 1, characterized in that, During the preparation process, an intelligent control system is used to regulate the temperature and pressure of the barrel and mold; The intelligent control system includes: The data acquisition unit includes a temperature sensor installed in each cable tie mold cavity, pressure sensors installed at the inlet, middle and end of each cable tie mold cavity, and a raw material melt viscosity sensor installed near the discharge port of the injection molding machine barrel, for collecting temperature, pressure and melt viscosity. The data processing unit is communicatively connected to the data acquisition unit to obtain the viscosity of the raw material melt and determine whether the product is qualified according to the qualification standard. The real-time control unit is communicatively connected to the data processing unit, the injection molding machine controller, and the mold temperature controller, and is used to control the barrel temperature, injection pressure, and mold temperature. The feedback correction unit is communicatively connected to the data processing unit, used to collect product performance data and optimize model parameters, and feed them back to the injection molding machine controller and the mold temperature controller; The intelligent control system can dynamically adjust the injection holding pressure, barrel temperature, and hot runner temperature based on real-time collected melt temperature, pressure, and viscosity data, thereby achieving closed-loop intelligent control of the multi-cavity molding process.

7. The integrated molding preparation method of high and low temperature resistant PEEK cable ties according to claim 6, characterized in that, The data processing unit incorporates a PEEK melt Cross-WLF rheological property model and a multi-cavity consistency evaluation model. The cross-WLF rheological property model of PEEK melt is as follows: in, The viscosity of the raw material melt. Zero shear viscosity For relaxation time, Non-Newtonian exponents The melting temperature is... For melt pressure, Shear rate; The multi-cavity consistency evaluation model uses the following criteria for qualification: temperature deviation ΔT ≤ 2℃, pressure deviation ΔP ≤ 5MPa, and filling time deviation Δt ≤ 0.5s for each mold cavity.

8. The integrated molding preparation method of high and low temperature resistant PEEK cable ties according to claim 6, characterized in that, The control logic of the real-time control unit is as follows: When the pressure at the end of a cable tie mold cavity falls below the standard value, the overall pressure holding pressure is automatically increased, with the pressure increase amount... ; When the viscosity of the raw material melt is higher than the standard value, the temperature of the three zones of the barrel is automatically increased, and the temperature increase range is as follows: ; When the filling time of a cable tie mold cavity exceeds the standard value by more than 0.5 seconds, the temperature of the hot runner corresponding to the cable tie mold cavity will be automatically increased by 2-3℃. Wherein, k1 and k2 are the pressure holding pressure and temperature control coefficients, respectively, with values ​​ranging from 0.1 to 0.5; and These are the standard value and the measured value of the holding pressure, respectively. and These are the standard and measured values ​​of the melt viscosity, respectively.

9. The integrated molding preparation method of high and low temperature resistant PEEK cable ties according to claim 6, characterized in that, After each injection molding of 5 products, the feedback correction unit collects the dimensional accuracy and tensile strength data of each cable tie mold cavity product; if the product qualification rate is less than 98%, the coefficients of the Cross-WLF rheological model are automatically updated using the particle swarm optimization algorithm.

Images