Blended PPA / PPS plastic processing control method

Abstract

The invention discloses a processing control method for blended PPA / PPS plastic, and relates to the technical field of plastic processing, and the processing control method comprises the following steps: locking the range of processed materials, pretreating main materials and auxiliary materials, and blending the pretreated materials; according to the invention, PPA resin with a melting range similar to that of PPS is selected, the melting temperature is within 305 DEG C, the alloy material retains rigidity and toughness of PPA and high rigidity and ultralow water absorption of PPS, perfect combination is achieved, and non-uniform material flow and phase separation are reduced by utilizing complementary characteristics of PPA and PPS; a multifunctional auxiliary is introduced, a special compatilizer improves the compatibility of PPA and PPS, a hindered phenol antioxidant and a phosphite antioxidant synergist synergistically inhibit oxidative degradation, adverse reaction of the auxiliary is avoided, and the oxidation resistance and the overall performance of the material are improved; during blending, according to the melting characteristics of PPA and PPS, the co-rotating twin-screw extruder is used for precisely controlling the temperature and the speed, and a high-precision weightlessness type feeding system is used for ensuring the blending ratio, improving the product quality and the production efficiency and promoting the development of plastic products with special purposes.

Description

Technical Field

[0001] The present invention relates to the technical field of plastic processing, and particularly to a control method for processing blended PPA / PPS plastics. Background Art

[0002] In the technical field of plastic processing, when blending PPA (polyphthalamide) and PPS (polyphenylene sulfide) to prepare special-purpose plastic products, a series of key problems in the existing processing technologies urgently need to be solved.

[0003] Due to the significant differences in properties such as the melt viscosity and crystallization temperature between PPA and PPS. For example, PPA shows high pseudoplasticity in the melt viscosity at a specific temperature and is sensitive to changes in the shear rate, while the melt viscosity of PPS is less sensitive to temperature. This makes the material flow inconsistent during the blending process, easily causing local concentration unevenness, and further leading to phase separation, seriously affecting the uniformity and performance stability of the final material. Based on this, the existing technologies only simply select conventional types of PPA and PPS, without fully considering the complementarity of material properties, and it is difficult to meet the performance requirements of special-purpose plastic products.

[0004] The problem of material property matching further leads to the dilemma of additive selection and synergy. Because additives are crucial for achieving special applications. However, on the premise that it is difficult to match the material properties of PPA and PPS, the interaction between different additives and these two base materials becomes more complex and unpredictable. Taking the commonly used plasticizer as an example, when used alone for PPA, it can effectively improve its flexibility, but when added to the PPS / PPA blend system, it may damage the crystal structure of PPS, resulting in a decrease in the overall rigidity and heat resistance of the material. Due to the lack of in-depth research on the complex chemical reactions and physical interactions between additives and the two base materials in the existing technologies, it is difficult for those skilled in the art to avoid these adverse reactions based on conventional experience or simple tests.

[0005] When there are problems with both material property matching and additive selection and synergy, precise control of the production method also faces huge challenges. Even if the ratios of the main material, auxiliary material, and additive are determined, parameters such as temperature, pressure, and mixing time during the production process still have a decisive impact on the performance of the final product. The thermal performance parameters such as the thermal decomposition temperature and melting enthalpy of PPA and PPS are different. During high-temperature processing, PPA may thermally degrade prior to PPS, greatly affecting the high-temperature resistance of the material. Moreover, the thermal behavior and other characteristics of the blend of the two materials are very different from those of single materials, and the common parameter adjustment methods in the existing technology simply cannot achieve precise control of the production process of this blend system. In addition, during the blending process, PPA and PPS may form a special supramolecular structure. Although this structure can improve the initial strength of the material, it will slowly decompose during long-term use, resulting in a sharp decline in material performance. Since the formation and change of the supramolecular structure involve complex interactions at the molecular level, there is little research in the existing technology, and it is difficult for those skilled in the art to solve this problem through conventional means.

[0006] Due to the problem of material property matching in the existing PPA / PPS blend plastic processing technology, a series of problems such as additive selection and synergy and precise control of the production method have been caused, severely restricting the performance improvement and wide application of special-purpose plastic products. There is an urgent need for a new processing control method to solve these problems and improve product quality and production efficiency.

[0007] In view of this, a processing control method for blending PPA / PPS plastics is provided to overcome the above problems. Summary of the Invention

[0008] The purpose of the present invention is to provide a processing control method for blending PPA / PPS plastics to solve the problems raised in the above background technology.

[0009] To solve the above technical problems, a processing control method for blending PPA / PPS plastics provided by the present invention includes the following steps:

[0010] Lock the range of materials to be processed, select a PPA model with high toughness and chemical stability and a PPS model with high thermal stability and dimensional stability as the main materials, add carbon fiber chemically coated with a silicon-containing coupling agent as the auxiliary material, and introduce a multifunctional additive composed of a hindered phenol antioxidant, a phosphite antioxidant synergist, and a special compatibilizer;

[0011] Pretreat the main material and the auxiliary material. Place PPA in a vacuum drying oven at 120 °C for 8 hours, place PPS in a vacuum drying oven at 10 - 120 °C, and select the drying time according to the water removal rate result. Immerse the carbon fiber in a 5% coupling agent solution in an ultrasonic bath for 30 minutes and then dry it in an oven at 80 °C for 2 hours;

[0012] Blend the pre-treated materials. First, stir them in a high-speed mixer at 1,200 revolutions per minute for 15 minutes for preliminary mixing. Then, use a co-rotating twin-screw extruder for twin-screw extrusion blending. The temperatures of the screws from the feed inlet to the discharge outlet are set as

[0013] 280 °C, 290 °C, 310 °C, 320 °C, 310 °C, and the rotation speed is controlled at 350 revolutions per minute. Ensure that each component enters the extruder at a stable flow rate through a loss-in-weight feeding system;

[0014] Mold according to product requirements. For small precision parts, use injection molding. Set the barrel temperature to 300 - 320 °C. Adjust the injection pressure according to the shape and size of the product, ranging from 80 - 120 MPa. The holding pressure time is 1 - 2 seconds, and the cooling time is 3 - 6 seconds. For large flat products, use compression molding. Place the material in a mold press mold preheated to 300 °C, hold the pressure at 10 MPa for 3 - 5 minutes, and then cool to room temperature and demold.

[0015] Furthermore, PPA remains flexible at 250 °C, and the dimensional change rate of PPS is less than 0.3% at 205 °C.

[0016] Furthermore, the diameter of carbon fiber treated with a silicon-containing coupling agent chemical coating is 5 - 8 μm after conventional processing, and in special cases, it is converted to 50 - 65 nanometers. The length of the carbon fiber is controlled between 200 - 300 μm according to product requirements after processing.

[0017] Furthermore, for the automotive engine intake manifold, the mass ratio of PPA:PPS:carbon fiber:auxiliary is 40%:35%:20%:5%.

[0018] Furthermore, during the twin-screw extrusion blending process, the residence time of the material in the screw is 3 - 5 minutes, and the accuracy of the loss-in-weight feeding system is ±0.5%.

[0019] Furthermore, during injection molding, according to the Hagen-Poiseuille formula:

[0020]

[0021] where Q is the volume flow rate, R is the runner radius, ΔP is the pressure difference, η is the melt viscosity, and L is the runner length. Analyze the melt flow situation to adjust parameters including but not limited to the injection pressure.

[0022] Furthermore, during compression molding, use the internal circulating water cooling system in the mold to precisely control the cooling rate with an accuracy of ±1 °C.

[0023] Furthermore, the temperature control accuracy of the vacuum drying oven is ±1°C, the stirring speed range of the high-speed mixer is 0 - 3000 revolutions per minute, the co-rotating twin-screw extruder has a multi-segment independent temperature control function, the temperature control accuracy is ±2°C, the barrel temperature control accuracy of the injection molding machine is ±3°C, and the maximum pressure of the molding press is 20 MPa.

[0024] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0025] Precise material selection, laying the foundation for performance: Aiming at the problem that the characteristics of PPA and PPS are significantly different and conventional material selection is difficult to meet the requirements of special applications, the present invention precisely selects PPA models with high toughness and chemical stability at 250°C, and PPS models with a dimensional change rate of less than 0.3% at 205°C, high thermal stability and dimensional stability. This material selection method based on the complementary characteristics of materials reduces the problem of inconsistent material flow caused by differences in characteristics such as melt viscosity and crystallization temperature from the source, effectively reducing the probability of local concentration non-uniformity and phase separation during the blending process, laying a solid foundation for improving material uniformity and performance stability, and meeting the strict requirements of special-purpose plastic products for material performance. At the same time, carbon fibers with a diameter of 5 - 8 μm after conventional processing (converted to 50 - 65 nm in special cases) and a length controlled between 200 - 300 μm according to product requirements, which are treated with a chemical coating of a silicon-containing coupling agent, are added as auxiliary materials, enhancing the chemical bonding with PPA and PPS, improving the dispersibility and bonding force, and further optimizing the basic performance of the material.

[0026] Innovative additives, breaking through the synergy dilemma: On the basis of solving the problem of material characteristic matching, aiming at the dilemma of additive selection and synergy, the present invention introduces self-developed multifunctional additives. Among them, the special compatibilizer, based on the principle of like dissolves like, has chain segments in its molecular structure that are similar to the molecular structures of PPA and PPS respectively, which can effectively improve the compatibility of PPA and PPS, and solve the problem of complex interactions between additives and base materials caused by difficult material characteristic matching. The hindered phenol antioxidant and phosphite antioxidant synergistically act. According to the principle of antioxidant synergy, the hindered phenol antioxidant captures free radicals to terminate the oxidation chain reaction, and the phosphite antioxidant reduces the quinone structure generated by the hindered phenol antioxidant, thereby more effectively capturing free radicals and inhibiting the oxidation degradation reaction, avoiding adverse reactions such as damage to the PPS crystal structure that may occur after the addition of additives, greatly improving the antioxidant performance and overall performance of the material, and further consolidating the performance advantages of the material.

[0027] Precise control to ensure product quality: After solving the problems of material property matching and additive selection coordination, the present invention focuses on precise control of the production method. In the blending stage, according to the melting characteristics of PPA and PPS, a co-rotating twin-screw extruder is used. The temperature of the screw from the feed inlet to the discharge outlet is set to 280°C, 290°C, 310°C, 320°C, and 310°C in sequence, the rotation speed is controlled at 350 revolutions per minute, and a loss-in-weight feeding system with an accuracy of ±0.5% is used to ensure that each component enters the extruder at a stable flow rate. Combining with the residence time of the material in the screw for 3 - 5 minutes, it is ensured that the blending of the material is completed within an appropriate time, avoiding problems such as thermal degradation of the material during the processing, and ensuring that each component is blended in precise proportions. In the molding stage, when injection molding small precision parts, according to the molding temperature range of the blended material, the barrel temperature is set to 310 - 330°C, and the melt flow is analyzed according to the Hagen-Poiseuille formula. The injection pressure is adjusted between 80 - 120 MPa according to the shape and size of the product, and the holding pressure time is controlled at 1 - 2 seconds, and the cooling time is 3 - 6 seconds to ensure the molding quality and dimensional accuracy; when compression molding large flat products, the material is placed in a mold preheated to 300°C, and the pressure is held at 10 MPa for 3 - 5 minutes. The cooling rate is precisely controlled by the internal circulating water cooling system of the mold to avoid internal stress and deformation of the product. Through these precise parameter controls, precise control of the production process of the blending system is achieved, improving the stability and consistency of the material properties, ensuring product quality, effectively solving the problem of unstable product performance caused by difficult-to-precisely-control production parameters in the prior art, avoiding the adverse effects of possible thermal degradation of PPA and PPS during high-temperature processing and the slow decomposition of the special supramolecular structure on the material properties, improving product quality and production efficiency, and promoting the performance improvement and wide application of special-purpose plastic products. Brief Description of the Drawings

[0028] Figure 1 It is a schematic diagram of a processing control method for blending PPA / PPS plastics according to the present invention. Detailed Embodiments

[0029] The following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0030] Please refer to Figure 1 , the present invention provides a technical solution:

[0031] Refer to Figure 1As shown below, an embodiment of a processing control method for blended PPA / PPS plastics:

[0032] Taking the production of an automotive engine intake manifold as an example, this embodiment elaborates on "a processing control method for blended PPA / PPS plastics". In the field of plastic processing technology, this method proposes an innovative solution to the problems existing in the prior art and has significant practical value.

[0033] In the field of plastic processing, when blending PPA (polyphthalamide) and PPS (polyphenylene sulfide) to prepare special-purpose plastic products, there are many bottlenecks in the prior art that are difficult to break through.

[0034] Difficulty in matching material properties: The melt viscosity, crystallization temperature and other properties of PPA and PPS are significantly different. For example, PPA shows high pseudoplasticity in melt viscosity at a specific temperature and is sensitive to changes in shear rate; while the melt viscosity of PPS is less sensitive to temperature. During the blending process, this difference causes inconsistent material flow, easily resulting in uneven local concentration, and further triggering phase separation, seriously affecting the uniformity and performance stability of the final material. Moreover, the prior art simply selects conventional types of PPA and PPS without fully considering the complementarity of material properties, making it difficult to meet the performance requirements of special-purpose plastic products.

[0035] Problems in selecting and synergizing additives: Additives are crucial for achieving special applications, but the interactions between different additives and PPA and PPS are extremely complex and difficult to predict. For example, common plasticizers can effectively improve the flexibility of PPA when used alone, but when added to the PPS / PPA blend system, they may damage the crystal structure of PPS, resulting in a decrease in the overall rigidity and heat resistance of the material. Due to the lack of in-depth research on the complex chemical reactions and physical interactions between additives and the two base materials in the prior art, it is difficult for those skilled in the art to avoid these adverse reactions based on conventional experience or simple tests.

[0036] Precision control problems in the production method: Even if the ratios of the main materials, auxiliary materials, and additives are determined, parameters such as temperature, pressure, and mixing time during the production process still have a decisive impact on the performance of the final product. The thermal performance parameters such as the thermal decomposition temperature and melting enthalpy of PPA and PPS are different. During high-temperature processing, PPA may undergo thermal degradation prior to PPS, greatly affecting the high-temperature resistance of the material. Moreover, the thermal behavior and other characteristics of the blend of the two materials are very different from those of single materials. The common parameter adjustment methods in the existing technology simply cannot achieve precise control of the production process of this blend system, and there is an urgent need for new ideas and a large number of experiments to explore. In addition, during the blending process, PPA and PPS may form a special supramolecular structure. Although this structure can improve the initial strength of the material, it will slowly decompose during long-term use, resulting in a sharp decline in material performance. Since the formation and change of the supramolecular structure involve complex interactions at the molecular level and there is little research in the existing technology, it is difficult for those skilled in the art to solve this problem through conventional means.

[0037] I. Locking the range of materials to be processed

[0038] Main materials: Select PPA models with high toughness and good chemical stability, which are still flexible at 250 °C, and the molecular chain structure endows them with impact resistance; adopt PPS models with high thermal stability and dimensional stability, and the dimensional change rate is less than 0.3% at 205 °C, and the crystalline structure helps to maintain shape stability at high temperatures. The working environment of the intake manifold of an automotive engine is extremely harsh, and it needs to withstand high temperatures above 200 °C, pressure fluctuations of 5 - 10 MPa, and high-speed air flow impacts of 50 - 100 m / s. Based on this working condition, these models of PPA and PPS can perfectly meet the requirements of the intake manifold for high-temperature impact resistance and shape stability. By carefully selecting these two specific models of PPA and PPS, the complementary advantages of their characteristics are fully utilized, successfully overcoming the problem of material characteristic matching, significantly improving the comprehensive performance of the intake manifold material, and ensuring its reliability and stability under complex working conditions.

[0039] Auxiliary materials: Add carbon fibers chemically coated with a silicon-containing coupling agent. The diameter of the carbon fibers is, after conventional processing, this size is between 5 - 8 μm, and in special cases, it is transformed to 50 - 65 nm; the length of the carbon fibers is, according to the product requirements, this size is controlled between 200 - 300 μm after processing, enhancing the chemical bonding with PPA and PPS, improving the dispersibility and bonding force, and not affecting the processing fluidity. Carbon fibers have a tensile strength of up to 3 - 5 GPa and an elastic modulus of 200 - 300 GPa. Adding them to the PPA / PPS blend system can greatly enhance the mechanical properties. The specially treated carbon fibers greatly enhance the mechanical properties of the blend material, laying a solid foundation for subsequent blending, and ensuring that the material has good processing performance while meeting the mechanical property requirements.

[0040] Auxiliary agent: A multifunctional auxiliary agent developed independently is introduced, which is composed of a hindered phenol antioxidant, a phosphite antioxidant synergist, and a special compatibilizer. The compatibilizer improves the compatibility between PPA and PPS, and the antioxidant and the antioxidant synergist jointly inhibit oxidative degradation. According to the principle of antioxidant synergism, the hindered phenol antioxidant terminates the oxidative chain reaction by capturing free radicals, while the phosphite antioxidant synergist reduces the quinone structure generated by the hindered phenol antioxidant, so as to capture free radicals more effectively and inhibit the oxidative degradation reaction. The special compatibilizer contains chain segments similar to the molecular structures of PPA and PPS respectively in its molecular structure. According to the principle of like dissolves like, the compatibility between PPA and PPS can be improved. The problems of auxiliary agent selection and synergy are successfully solved, avoiding the possible adverse reactions between the auxiliary agent and the two base materials, greatly improving the antioxidant performance and compatibility of the material, and comprehensively enhancing the overall performance of the material.

[0041] II. Pretreatment steps

[0042] Material drying: When PPA and PPS are processed at high temperatures, moisture will trigger hydrolysis reactions. Taking PPA as an example, the amide bonds in its molecular chain will break under the action of high temperature and water, resulting in a decrease in molecular weight, which will seriously affect the mechanical properties and thermal stability of the material. Place PPA in a vacuum drying oven at 120°C for 8 hours, and place PPS in a vacuum drying oven at 10 - 120°C. The drying time is selected according to the water removal rate results. Using a vacuum environment (the pressure can reach 10-2 - 10-3 Pa) and an appropriate temperature can accelerate the water evaporation rate, and the moisture can be completely removed. In a vacuum environment, the saturated vapor pressure of moisture decreases, making it easier to escape from the material. Combining with an appropriate temperature can accelerate the water evaporation process. This ensures the stability of the material properties during the subsequent processing, avoids the decline of material properties caused by moisture, and effectively improves the product quality.

[0043] Carbon fiber pretreatment: Immerse the carbon fiber in a 5% coupling agent solution in an ultrasonic bath for 30 minutes. The ultrasonic action (the frequency is generally 20 - 40 kHz) can accelerate the diffusion and adsorption of the coupling agent molecules to the carbon fiber surface. Then dry it in an oven at 80°C for 2 hours to cause a chemical bonding reaction of the coupling agent on the carbon fiber surface, forming a uniform and stable chemical bonding layer, enhancing the bonding force between the carbon fiber and the main material. The cavitation effect of ultrasound generates local high temperature and high pressure when the tiny bubbles burst, promoting the chemical reaction between the coupling agent and the carbon fiber surface and improving the firmness of the chemical bonding. Further enhancing the bonding force between the carbon fiber and the main material, and improving the mechanical properties of the blended material.

[0044] III. Blending stage

[0045] Initial mixing: Set the mixing ratio according to the product performance requirements. For example, the mass ratio of PPA:PPS:carbon fiber:auxiliary agent for the intake manifold of an automotive engine is 40%:35%:20%:5%. This is determined based on a large number of experimental studies and the comprehensive material performance requirements of the intake manifold of an automotive engine. Stir in a high-speed mixer at 1200 revolutions per minute for 15 minutes. According to the principles of stirring dynamics, appropriate stirring speed and time can enable each component to be fully dispersed under the action of mechanical force, achieving initial uniform mixing. The linear speed of the stirring paddle can reach 10 - 15 m / s at this rotational speed, and the shear force and convective action generated are sufficient to overcome the cohesive force and frictional force between the materials, making each component uniformly dispersed. This lays a good foundation for subsequent twin-screw extrusion blending, ensuring that each component can be evenly distributed during subsequent processing and improving the consistency of material properties.

[0046] Twin-screw extrusion blending: Use a co-rotating twin-screw extruder. The temperatures of the screws from the feed inlet to the discharge outlet are set as 280°C, 290°C, 310°C, 320°C, 310°C in sequence. This is determined according to the melting characteristics of PPA and PPS and the requirements for the movement and interaction of molecular chain segments during the blending process. The melting point of PPA is generally between 290 - 330°C, and 290°C, which is close to the melting point of PPS, is selected. The melting point of PPS is between 285 - 290°C. Starting from the feed inlet, the temperature gradually increases. First, it reaches 280°C, which is close to the lower limit of the melting point of PPS, to preliminarily melt PPS; then it is heated to 290°C to prompt PPA to start melting. At this time, both materials are in the initial state of melting, creating conditions for uniform mixing; continue to heat to 310°C. A higher temperature can enhance the activity of molecular chain segments, accelerating their mutual diffusion and mixing; then heat to 320°C to further improve the mixing effect, allowing molecular chain segments to fully move and interact; finally, cool to 310°C. Under the condition of slightly lower than the highest mixing temperature, the blending system tends to be stable, which is conducive to forming a stable eutectic system and ensuring the quality and performance of the blend. The rotational speed is controlled at 350 revolutions per minute. Combining the residence time of the material in the screw (generally 3 - 5 minutes) and the conveying capacity of the screw (related to parameters such as the pitch and diameter of the screw) can ensure that the material completes blending within an appropriate time. The loss-in-weight feeding system has an accuracy of ±0.5%, ensuring that each component enters the extruder at a stable flow rate. According to the law of conservation of mass, the accuracy of the blending ratio is guaranteed. It effectively solves the problem of precise control of the production method, avoids problems such as thermal degradation of materials during processing, ensures that each component is blended in precise proportion, and improves the stability and consistency of material properties.

[0047] IV. Eutectic zone product category

[0048] Analysis by differential scanning calorimetry (DSC) and scanning electron microscopy (SEM) found that a homogeneous eutectic system is formed between PPA and PPS at 285 - 300 °C. In this system, the molecular chain segments of the two materials penetrate and entangle with each other, forming stable chemical bonds and physical entanglements. The characteristic peaks of the newly formed chemical bonds can be detected by Fourier transform infrared spectroscopy (FT-IR) analysis, proving the formation of chemical bonds. This eutectic zone structure endows the material with both the high thermal stability and dimensional stability of PPS and the high toughness of PPA. When manufacturing the intake manifold of an automotive engine, by utilizing the characteristics of this eutectic zone, the heat resistance of the product is increased by 20 °C, and the impact strength is increased by 30%, effectively extending the service life of the product.

[0049] V. Determination of the blending modification ratio range

[0050] Through a large number of experimental studies, the mass ratio range of PPA / PPS blending modification is determined to be 30%:70% - 70%:30%.

[0051] In the process of exploring the blending modification of PPA / PPS, a large number of experimental studies are the key to determining the optimal ratio range. For different application scenarios, we conducted multiple groups of experiments on the blending ratio, the addition amount of carbon fiber and additives. The following table (Table 1) details the key data of each experiment and the performance of the corresponding products. These data intuitively show the impact of different formulations on the product performance, providing a solid basis for determining the blending modification ratio range.

[0052] Table 1: Experimental data of the blending modification ratio range

[0053]

[0054]

[0055] Within this range, the ratio can be adjusted according to the product performance requirements. For products with high heat resistance requirements, such as heat dissipation components of electronic devices, the proportion of PPS can be increased to 60% - 70%, and the proportion of PPA can be correspondingly reduced because the high thermal stability of PPS can better play its role in high-temperature environments; for products that require high toughness, such as aircraft interior parts, the proportion of PPA can be increased to 50% - 70%. The addition amount of carbon fiber is 15% - 25% by mass, and the addition amount of additives is 3% - 8% by mass, which can effectively enhance the material performance and ensure good processing performance. In the production of the intake manifold of an automotive engine, a PPA / PPS ratio of 40%:35% is adopted, combined with an addition amount of 20% carbon fiber and 5% additives, achieving the optimization of material performance.

[0056] VI. Molding stage

[0057] Injection molding: For small and precise parts such as automotive engine intake manifolds, the blended material is injected into the barrel of an injection molding machine. The barrel temperature is set at 310 - 330 °C, which is determined according to the molding temperature range of the blended material. The injection pressure is adjusted between 80 - 120 MPa according to the shape and size of the product, the holding pressure time is 1 - 2 seconds, and the cooling time is 3 - 6 seconds. These parameters are determined through theoretical analysis of processes such as melt flow, mold filling, pressure holding and compensation, and cooling and shaping during the injection molding process, combined with practical production experience and a large number of tests. For example, according to the Hagen - Poi seu i l l e formula:

[0058]

[0059] where Q is the volume flow rate, R is the runner radius, ΔP is the pressure difference, η is the melt viscosity, and L is the runner length. The flow situation of the melt during injection molding can be analyzed, so as to reasonably adjust parameters such as injection pressure to ensure the molding quality and dimensional accuracy. For the intake manifold with complex shape, the runner radius and length will be calculated according to the specific structure, and the injection pressure is adjusted to ensure that the melt can fill the mold cavity. Meet the high - precision requirements of automotive engine intake manifolds, ensure the molding quality and dimensional accuracy, reduce product defects, and improve the product qualification rate.

[0060] Compression molding: For large flat products, such as some large plastic parts of automotive bodies, the material is placed into the mold of Haitian MA3000 / 12000 compression molding machine preheated to 300 °C, held under pressure at 10 MPa for 3 - 5 minutes, and then slowly cooled to room temperature for demolding. The internal circulating water cooling system of the mold is used to precisely control the cooling rate with an accuracy of ±1 °C to avoid internal stress and deformation of the product. This process is based on the molding characteristics of polymer materials at a certain temperature and pressure. By precisely controlling the temperature and pressure, the material is fully molded in the mold, and the temperature drops evenly during the cooling process to prevent internal stress generation and deformation caused by uneven temperature changes. This method ensures the dimensional accuracy and physical properties of large flat products, meeting the quality requirements of the automotive industry for large plastic products.

[0061] VII. Processing control and equipment and instruments

[0062] Vacuum drying oven: The DHG - 9070A vacuum drying oven is selected. The temperature control accuracy can reach ±1 °C, which can accurately meet the drying temperature requirements of PPA and PPS. The vacuum environment is used to accelerate the evaporation of moisture to ensure the full removal of moisture. The vacuum system of this equipment can effectively reduce the air pressure in the oven, enabling moisture to evaporate rapidly at a lower temperature. The temperature control system adopts the PID control algorithm to ensure the stability of the drying temperature and meet the requirements of the material drying process.

[0063] High-speed mixer: The JCT-500 high-speed mixer is adopted. The mixing speed ranges from 0 to 3,000 revolutions per minute and can be accurately adjusted to 1,200 revolutions per minute. Its reasonable design with double-layer blades (the upper layer is a dispersion blade and the lower layer is a mixing blade) can fully disperse the materials, avoid agglomeration, and ensure preliminary uniform mixing. The shape and angle of the mixing blades are optimized. When rotating at high speed, the shear force and convection generated make each component evenly distributed in a short time, providing good initial conditions for subsequent blending.

[0064] Co-rotating twin-screw extruder: The SHJ-65 co-rotating twin-screw extruder has the function of independent multi-zone temperature control. The temperature control accuracy can reach ±2°C, which can meet the setting requirements of different temperature zones. The screw speed can be accurately adjusted within the range of 0 - 600 revolutions per minute, and the accuracy of the loss-in-weight feeding system reaches ±0.5%, ensuring accurate blending ratio. The multi-zone temperature control function can accurately adjust the temperature according to different processing stages of the materials in the screw, promoting material melting, mixing, and reaction. The loss-in-weight feeding system accurately controls the feeding speed of each component by real-time monitoring of the material weight change, using high-precision weighing sensors and a closed-loop control system, ensuring the stability of the blending ratio.

[0065] Injection molding machine: The JM200-MK6 injection molding machine is selected. The barrel temperature control accuracy can reach ±3°C, the injection pressure can be accurately adjusted within the range of 0 - 200 MPa, and the holding pressure time and cooling time have high control accuracy, which can meet the injection requirements of different products and ensure product quality. The advanced temperature and pressure control system adopts PLC control technology, and can accurately set and adjust injection parameters according to the process requirements of different plastic products, ensuring the molding quality and dimensional accuracy of the products.

[0066] Press: The MA3000 / 12000 type press is selected. The maximum pressure can reach 20 MPa, which can meet the molding pressure requirement of 10 MPa. The internal circulating water cooling system of the mold can accurately control the cooling water temperature, with an accuracy of ±1°C, effectively avoiding internal stress and deformation of the products. The powerful pressure output system is hydraulically driven, ensuring the stable operation of the mold under high pressure. The circulating water cooling system accurately controls the water temperature through a high-precision temperature controller and flow regulating valve, enabling the products to dissipate heat evenly during the cooling process and preventing internal stress and deformation caused by temperature gradient.

[0067] VIII. Test and production data

[0068] In order to more intuitively and comprehensively demonstrate the excellent effectiveness of the method of the present invention in actual production, the following presents the performance test results of the intake manifold of an automotive engine and the heat dissipation component of an electronic device through a detailed data table (Table 2). These data are all from rigorous tests and actual production verifications, strongly supporting the reliability and stability of the processing control method of the present invention.

[0069] Table 2: Test and Production Verification Data of Intake Manifold of Automobile Engine and Heat Dissipation Components of Electronic Equipment

[0070]

[0071]

[0072] During the R & D process, a large number of tests and actual production verifications were carried out. Taking the production of 1,000 intake manifolds of automobile engines as an example, for the products produced by the method of the present invention, after testing, the heat resistance performance was increased by 18 °C on average. This is based on the test results of a thermogravimetric analyzer (TGA) heating from room temperature to 500 °C at a heating rate of 10 °C / min in a nitrogen atmosphere, recording the mass change, determining that the thermal decomposition temperature has increased compared with before, and thus obtaining the data of the improved heat resistance performance. The average impact strength reaches 58 kJ / m 2 , and the standard deviation is 3 kJ / m 2 . This is because when testing the notched impact strength of the sample using a cantilever beam impact tester in accordance with ISO179 standard, the average value is taken after multiple tests, and considering the certain fluctuations in material properties during the production process, the standard deviation is calculated based on statistical principles. In the actual working conditions of the intake manifold of an automobile engine, the material is required to have good impact resistance. Referring to the impact strength range of the same type of high-performance plastic materials in this application scenario, it is generally 50 - 52 kJ / m 2 , and the impact strength of the products produced by the method of the present invention reaches 55 kJ / m 2 , meeting and exceeding the industry standard, and the standard deviation of 3 kJ / m 2 also indicates that the product performance has high stability. The dimensional accuracy error is controlled within ±0.08 mm, and the product qualification rate is close to 100%. The three-coordinate measuring instrument is used to measure the dimensional accuracy to ensure compliance with the design requirements. Due to the precise control of equipment accuracy and process parameters during the production process, as well as the stability of raw material properties, the dimensional accuracy of the products is effectively guaranteed, thus achieving a high qualification rate.

[0073] When manufacturing heat dissipation components for electronic devices, after 500 high and low temperature cycle tests (-20°C - 150°C), the performance retention rate of the material remains above 92% (when exceeding the usage conditions). The high and low temperature cycle tests are carried out using a high and low temperature test chamber in accordance with the GJB150.3A - 2009 standard. Each cycle includes maintaining at -20°C for 2 hours, maintaining at 150°C for 2 hours, and then quickly switching the temperature. Heat dissipation components of electronic devices will frequently experience temperature changes during use, and have extremely high requirements for the heat resistance cycle performance of the material. Through the processing control method of the present invention, the structural stability and performance consistency of the material under different temperature conditions are ensured. In actual tests, compared with materials of the same type used for heat dissipation components of electronic devices on the market, after the same high and low temperature cycle tests, the performance retention rate is mostly between 85% - 90%, while the performance retention rate of the material produced by the method of the present invention reaches above 92%, fully demonstrating the advantages of this method in meeting the strict requirements of heat resistance cycle performance of materials for heat dissipation components of electronic devices. Through the statistical analysis of the performance test data of different batches of products, it is fully proved that the processing control method of the present invention can ensure the consistency and stability of product performance, providing reliable data support for actual production.

[0074] IX. Summary

[0075] Select PPA and PPS models with specific complementary properties, use carbon fiber with special surface treatment and self-developed multifunctional additives to improve material compatibility and comprehensive performance. For the working conditions of the intake manifold, select PPA with flexibility still at 250°C and PPS with a dimensional change rate less than 0.3% at 205°C, as well as carbon fiber with specific dimensions treated with a silicon-containing coupling agent and composite multifunctional additives, ensuring product performance from the raw material level.

[0076] Determine that the mass ratio range of PPA / PPS blend modification is 30%:70% - 70%:30%, the mass ratio of carbon fiber addition is 15% - 25%, and the mass ratio of additive addition is 3% - 8%, which can be adjusted according to product performance. This ratio range is obtained through a large number of experimental studies and can meet the diverse requirements of different products for material performance, providing a key basis for customized production of products.

[0077] Utilize the unique microstructure of the PPA / PPS eutectic zone to improve the comprehensive performance of the material and apply it to the manufacture of products in different fields. Through analysis means such as DSC, SEM, and FT-IR, the formation conditions and structural characteristics of the eutectic zone are clarified, providing a theoretical basis for its application in products such as automotive engine intake manifolds and heat dissipation components of electronic devices, and broadening the application fields of the material.

[0078] The unique temperature distribution of the twin-screw extruder, screw speed, feeding system, and the precise pressure, temperature, and time control parameters during the injection molding and compression molding processes ensure stable processing and product quality. The temperatures of the twin-screw extruder from the feed inlet to the discharge outlet are set successively as

[0079] 280 °C, 290 °C, 310 °C, 320 °C, 310 °C, and the rotational speed is controlled at 350 revolutions per minute. Combined with the loss-in-weight feeding system, the accuracy of the blending ratio is guaranteed. The precise parameter control in each molding stage ensures the high-quality production of products.

[0080] Specific equipment such as a vacuum drying oven, high-speed mixer, twin-screw extruder, injection molding machine, and compression molding machine are selected, and corresponding precise parameters are set to ensure the feasibility of processing control. The temperature control accuracy of the DHG-9070A vacuum drying oven can reach ±1 °C, and the JCT-500 high-speed mixer can be precisely adjusted to 1200 revolutions per minute, etc. The precise selection of equipment and parameter setting are the hardware basis for realizing process control.

[0081] The reliability and stability of the method of the present invention are verified through a large number of tests and production data, providing a basis for actual production. In the production of automotive engine intake manifolds and electronic device heat dissipation components, strict performance tests and data analysis show that this method can ensure the consistency and stability of product performance, providing solid data support for large-scale industrial production.

[0082] X. Application Expansion and Prospect

[0083] With the rapid development of industries such as the automotive industry and the electronic device manufacturing industry, the demand for high-performance plastic materials continues to grow. The blending PPA / PPS plastic processing control method of the present invention is not only applicable to automotive engine intake manifolds and electronic device heat dissipation components, but also can be extended to other fields with demanding material performance requirements. For example, in the aerospace field, this material can be used to manufacture interior components of aircraft, components around the engine, etc., taking advantage of its high heat resistance, high toughness, and dimensional stability to meet the usage requirements of aerospace components in extreme environments. In the field of high-end medical devices, it can be used to manufacture some components that come into contact with the human body and require good chemical stability and mechanical properties, such as the outer shell of surgical instruments, the outer packaging of implants, etc.

[0084] From the perspective of the market prospect, the blended materials produced by this method have a broad market space. On the one hand, its high-performance characteristics can meet the needs of the upgrading of existing products, improving product quality and competitiveness; on the other hand, it provides the possibility for the development of new high-performance plastic products, creating new market demands. It is expected that in the next 5 - 10 years, with the further maturity of technology and the reduction of production costs, the market share of this blended material will gradually expand and is expected to become an important development direction in the field of high-performance plastic materials.

[0085] XI. Potential Challenges and Countermeasures

[0086] Although the present invention has achieved remarkable results, it may still face some challenges in actual popularization and application. First is the issue of raw material costs. The procurement costs of special types of PPA and PPS, as well as specially treated carbon fiber and additives, are relatively high, which may limit the large-scale application of the product. The countermeasure is to establish long-term cooperative relationships with raw material suppliers and reduce procurement costs through methods such as bulk purchasing and technical cooperation. At the same time, continuously research and develop new materials or optimize material formulations, and find more cost-effective alternative materials on the premise of ensuring performance.

[0087] Secondly, the investment cost of production equipment is high. A complete set of processing equipment, including vacuum drying ovens, high-speed mixers, twin-screw extruders, injection molding machines, and molding presses, etc., requires a large initial investment, which may pose financial pressure on some small and medium-sized enterprises. It is possible to consider cooperating with equipment manufacturers to develop leasing models or provide equipment installment payment plans to lower the financial threshold for enterprises. In addition, continuously optimize the production process, improve the production efficiency and product qualification rate of the equipment, and reduce the equipment depreciation cost per unit product.

[0088] Finally, the shortage of technical talents is also a potential problem. The present invention involves complex knowledge of materials science and processing technology, and requires professional technical talents for operation and management. Strengthen cooperation with universities and research institutions, carry out talent cultivation programs, and deliver professional talents to the enterprise. At the same time, establish an in-enterprise training system, regularly conduct technical training and skill improvement for employees, and ensure that the enterprise has sufficient technical strength to implement and optimize this processing control method.

[0089] In summary, the blend PPA / PPS plastic processing control method of the present invention has significant innovations in aspects such as material selection, processing technology, and equipment application, effectively solves the problems in the prior art, and has broad application prospects and industrial value. Subsequently, it is possible to further study the influence of new additives or different processing technologies on material properties to meet the continuously developing industrial needs. At the same time, with the continuous progress of equipment technology, timely update the equipment selection and parameter settings to further improve production efficiency and product quality.

Claims

1. A blended PPA / PPS plastic processing control method, characterized in that: The following steps are involved: Lock the range of materials to be processed, select PPA models with high toughness and chemical stability and PPS models with high thermal stability and dimensional stability as the main materials, add carbon fiber treated with chemical coating of silicon-containing coupling agent as auxiliary materials, and introduce multifunctional additives composed of hindered phenol antioxidants, phosphite antioxidant synergists and special compatibilizers; Pre-treat the main material and auxiliary material, place PPA in a vacuum drying oven at 120°C for 8 hours, place PPS in a vacuum drying oven at 10-120°C for 8 hours, and the drying time is selected according to the water removal rate result. Soak the carbon fiber in an ultrasonic bath of a 5% coupling agent solution for 30 minutes and then dry it in an oven at 80°C for 2 hours. The pretreated materials were blended, first stirred in a high-speed mixer at 1200 rpm for 15 minutes for preliminary mixing, and then extruded and blended using a co-rotating twin-screw extruder. The screw temperatures from the feed port to the discharge port were set to 280°C, 290°C, 310°C, 320°C, and 310°C, respectively, and the speed was controlled at 350 rpm. A loss-in-weight feeding system was used to ensure that each component entered the extruder at a stable flow rate. Molding is carried out according to product requirements. Injection molding is used for small precision parts. The barrel temperature is set to 300-320℃, and the injection pressure is adjusted between 80-120MPa according to the shape and size of the product. The holding time is 1-2 seconds and the cooling time is 3-6 seconds. For large flat products, compression molding is used. The material is placed in a molding machine mold preheated to 300℃, and the pressure is maintained at 10MPa for 3-5 minutes, then cooled to room temperature and demolded.

2. A blended PPA / PPS plastic processing control method as claimed in claim 1, characterized in that: PPA is still flexible at 250°C, and the dimensional change rate of PPS is less than 0.3% at 205°C.

3. A blended PPA / PPS plastic processing control method as claimed in claim 1, characterized in that: The diameter of the carbon fiber treated with a silicon-containing coupling agent chemical coating is 5-8um after conventional processing, and can be converted to 50-65 nanometers in special cases; the length of the carbon fiber is controlled between 200-300um after processing according to product requirements.

4. A blended PPA / PPS plastic processing control method as claimed in claim 1, characterized in that: For automobile engine intake manifold, the mass ratio of PPA:PPS:carbon fiber:additive is 40%:35%:20%:5%.

5. A blended PPA / PPS plastic processing control method as claimed in claim 1, characterized in that: During the twin-screw extrusion blending process, the material residence time in the screw is 3-5 minutes, and the loss-in-weight feeding system has an accuracy of ±0.5%.

6. A blended PPA / PPS plastic processing control method as claimed in claim 1, characterized in that: During injection molding, according to the Hagen-Poiseuille formula: Where Q is the volume flow rate, R is the flow channel radius, ΔP is the pressure difference, η is the melt viscosity, and L is the flow channel length. The melt flow conditions are analyzed to adjust parameters including but not limited to the injection pressure.

7. A blended PPA / PPS plastic processing control method as claimed in claim 1, characterized in that: During compression molding, the cooling speed is precisely controlled by the mold's internal circulating water cooling system with an accuracy of ±1°C.

8. A blended PPA / PPS plastic processing control method as claimed in claim 1, characterized in that: The temperature control accuracy of the vacuum drying oven is ±1°C, the stirring speed range of the high-speed mixer is 0-3000 rpm, the co-rotating twin-screw extruder has multi-stage independent temperature control function, the temperature control accuracy is ±2°C, the injection molding machine barrel temperature control accuracy is ±3°C, and the maximum pressure of the molding machine is 20MPa.

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