1. ABS (Acrylonitrile - Butadiene - Styrene) copolymer
Typical application scope
With its unique properties, ABS material has shown its capabilities in numerous fields. In the automotive industry, it is an indispensable and important material. The dashboard of a car needs to have a certain degree of strength and stability, as well as a good appearance. ABS material exactly meets these requirements and can provide a reliable and aesthetically pleasing operating interface for drivers. The tool compartment door needs to withstand frequent opening and closing. The impact resistance of ABS enables it to remain intact for a long time. The wheel cover not only needs to protect the wheel but also have a certain degree of decoration. ABS material can easily achieve various complex shapes through the injection molding process. The mirror housing needs to maintain stable performance in different environments. The chemical and thermal stability of ABS enable it to handle this task.
In daily life, ABS materials are also widely used in refrigerators. It can be used to manufacture the outer shell and some internal components of the refrigerator, which can not only ensure the overall strength of the refrigerator but also provide a good appearance. In the field of high-strength tools, such as hair dryers, blenders, food processors, and lawn mowers, materials with high strength and impact resistance are required. The high strength and toughness of ABS materials enable it to withstand various stresses generated by these tools during operation, ensuring the normal operation of the tools.
In terms of office supplies, telephone casings and typewriter keyboards often use ABS materials as well. Telephone casings need to have a good feel and appearance, and at the same time, they should also have a certain degree of drop resistance. ABS materials can meet these requirements. Typewriter keyboards need to have a certain degree of wear resistance and stability. The low creep and excellent dimensional stability of ABS materials enable them to ensure the long - term use of the keyboard.
In the entertainment field, ABS materials are also used in entertainment vehicles such as golf carts and jet sleds. Golf carts need to run on the grass and bear certain bumps and weights. The impact resistance and strength of ABS can ensure their normal use. Jet sleds are subjected to various external forces when running at high speed. The high strength and stability of ABS materials can provide reliable support for them.
Injection mold process conditions
Drying treatment: ABS material is hygroscopic, which means it must be dried before processing. Otherwise, moisture will affect the performance and processing quality of the material. It is recommended to dry the material at a temperature of 80 - 90°C for at least 2 hours to ensure that the moisture content in the material is less than 0.1%. This can ensure that the material can melt and flow evenly during the injection molding process, avoiding defects such as bubbles and cracks.
Melting temperature: The melting temperature range of ABS material is between 210 - 280°C, and the recommended temperature is 245°C. Within this temperature range, the material can be fully melted and has good fluidity, which facilitates injection molding. If the temperature is too low, the material may not be completely melted, resulting in defects in the injection-molded parts; if the temperature is too high, the material may decompose, affecting its performance.
Mold temperature: The mold temperature has a significant impact on the surface finish of plastic parts. The mold temperature ranges from 25 to 70°C. A lower temperature will result in a lower surface finish. Therefore, during the injection molding process, it is necessary to select an appropriate mold temperature according to the product requirements and material characteristics to ensure the surface quality of the plastic parts.
Injection pressure: The injection pressure is generally between 500 - 1000 bar. An appropriate injection pressure can ensure that the material fills the mold cavity, avoiding problems such as short shots and sink marks. In actual production, the injection pressure needs to be adjusted according to factors such as the structure of the mold, the size and shape of the plastic part.
Injection speed: A medium to high injection speed allows the material to flow quickly in the mold, reducing the cooling time of the material and improving production efficiency. Meanwhile, medium to high speed injection can also ensure the quality of plastic parts and avoid defects such as flow marks and bubbles.
Chemical and physical properties
ABS is a ternary copolymer synthesized from three chemical monomers: acrylonitrile, butadiene, and styrene. Each monomer brings unique properties to the ABS material. Acrylonitrile endows the material with high strength, thermal stability, and chemical stability, enabling it to maintain stable performance in different environments. Butadiene provides toughness and impact resistance, allowing the material to withstand relatively large external forces without damage. Styrene features easy processing, high surface finish, and high strength, which enables the ABS material to easily achieve various complex shapes through processes such as injection molding and also gives it a good appearance.
From a morphological perspective, ABS is a non-crystalline material. The polymerization of the three monomers results in a two-phase structure. One is the continuous phase of styrene - acrylonitrile, and the other is the dispersed phase of polybutadiene rubber. The properties of ABS mainly depend on the ratio of the three monomers and the molecular structures in the two phases. This provides great flexibility for product design. By adjusting the ratio of the monomers and the molecular structures, hundreds of different grades of ABS materials can be produced. These materials of different grades have different properties, such as medium to high impact resistance, low to high surface finish, and high-temperature distortion properties.
ABS material also has super easy processability, which enables it to be processed through various processes such as injection molding and extrusion to produce products of various shapes and sizes. It has good appearance characteristics and can obtain different colors and gloss through surface treatment and other methods. Low creep and excellent dimensional stability ensure that the product will not deform during long-term use and can maintain its original shape and size. High impact strength makes it less likely to be damaged when subjected to external impact, improving the reliability and service life of the product.
2. PA6 Polyamide 6 or Nylon 6
Typical application scope
Due to its good mechanical strength and stiffness, PA6 material is widely used in structural components. In fields such as mechanical manufacturing and aerospace, structural components need to withstand relatively large stresses and weights. The high strength and stiffness of PA6 enable it to meet these requirements. For example, in some mechanical equipment, PA6 can be used to manufacture components such as gears and bushings. These components need to maintain stable performance under high - speed operation and heavy loads.
At the same time, PA6 has excellent wear resistance properties, which makes it an ideal material for manufacturing bearings. Bearings need to withstand relatively large friction and pressure during operation. The wear resistance of PA6 can ensure the long - term use of bearings and reduce the occurrence of wear and failures.
Injection mold process conditions
Drying treatment: PA6 can easily absorb moisture, so the drying treatment before processing is crucial. If the material is supplied in waterproof packaging, the container should be kept sealed to prevent moisture from entering. If the humidity is greater than 0.2%, it is recommended to dry the material in hot air above 80°C for 16 hours to remove the moisture in the material. If the material has been exposed to the air for more than 8 hours, it is recommended to conduct vacuum drying at 105°C for more than 8 hours, which can remove the moisture more thoroughly and ensure the performance of the material.
Melting temperature: The melting temperature range of PA6 is between 230 - 280°C. For reinforced grades, the melting temperature is 250 - 280°C. An appropriate melting temperature can ensure that the material can be fully melted and flow during the injection molding process, avoiding problems such as cold slug marks and short shots. In actual production, the melting temperature needs to be adjusted according to the specific conditions of the material and the requirements of the product.
Mold temperature: The mold temperature has a great influence on the crystallinity of PA6, and the crystallinity directly affects the mechanical properties of plastic parts. For structural components, crystallinity is very important. Therefore, it is recommended that the mold temperature be 80 - 90°C. Within this temperature range, the material can form a better crystalline structure, improving the strength and stiffness of the plastic parts. For thin - walled plastic parts with a long flow path, it is also recommended to use a higher mold temperature to ensure that the material can fully fill the mold cavity. However, increasing the mold temperature will reduce the toughness of the plastic parts, so a trade - off needs to be made according to the specific requirements of the product. If the wall thickness is greater than 3mm, it is recommended to use a low - temperature mold at 20 - 40°C to avoid excessive crystallinity that may cause the plastic parts to become brittle. For glass - reinforced materials, the mold temperature should be greater than 80°C to ensure that the glass fibers can be evenly distributed in the material.
Injection pressure: The injection pressure is generally between 750 - 1250 bar, and the specific value depends on the material and product design. An appropriate injection pressure can ensure that the material can fill the mold cavity, avoiding problems such as material shortage and shrinkage marks. In actual production, the injection pressure needs to be adjusted according to factors such as the mold structure, the size and shape of the plastic part.
Injection speed: Generally, high-speed injection is used, but for reinforced materials, the injection speed should be slightly reduced. High-speed injection can fill the mold cavity with the material in a short time, reduce the cooling time of the material, and improve production efficiency. However, for reinforced materials, an excessively high injection speed may cause uneven distribution of additives such as glass fibers, affecting the performance of the product.
Runners and gates: Since the solidification time of PA6 is very short, the position of the gate is very important. The gate aperture should not be less than 0.5*t (where t is the thickness of the plastic part) to ensure that the material can smoothly enter the mold cavity. If a hot runner is used, the gate size should be smaller than that when using a conventional runner, because the hot runner can help prevent the material from solidifying prematurely. If a submarine gate is used, the minimum diameter of the gate should be 0.75mm to ensure smooth material flow.
Chemical and physical properties
The chemical and physical properties of PA6 are similar to those of PA66, but it also has some unique characteristics. It has a lower melting point and a wide range of processing temperatures, which gives it certain advantages during the processing. Its impact resistance and solvent resistance are better than those of PA66, but its hygroscopicity is also stronger. Hygroscopicity can affect many quality characteristics of plastic parts, such as dimensional stability and mechanical strength. Therefore, this should be fully considered when designing products using PA6.
To improve the mechanical properties of PA6, various modifiers are often added. Glass is the most common additive, which can enhance the strength and stiffness of the material. Sometimes, in order to improve the impact resistance, synthetic rubbers such as EPDM and SBR are also added. For products without additives, the shrinkage rate of PA6 ranges from 1% to 1.5%. Adding glass fiber additives can reduce the shrinkage rate to 0.3%, but it is slightly higher in the direction perpendicular to the flow path. The shrinkage rate of molded assemblies is mainly affected by the crystallinity and hygroscopicity of the material. The actual shrinkage rate is also a function of the plastic part design, wall thickness and other process parameters. This requires that these factors should be fully considered during product design and processing to ensure the dimensional accuracy and quality of the product.
3. PA12 Polyamide 12 or Nylon 12
Typical application scope
PA12 material has a wide range of applications in the fields of commercial equipment and machinery. Water meters need to measure water volume accurately, and some internal components of them require good corrosion resistance and dimensional stability. The chemical stability and low shrinkage rate of PA12 enable it to meet these requirements. Other commercial equipment, such as the casings and internal components of some instruments, also often use PA12 material to ensure the normal operation and appearance quality of the equipment.
In terms of cable sheaths, PA12 material has good flexibility and insulation properties, which can effectively protect cables and prevent them from being affected by the external environment. Mechanical cams and sliding mechanisms require materials with good wear resistance and self - lubrication. The wear - resistant characteristics and low friction coefficient of PA12 enable it to play an important role in these components. Bearings need to withstand relatively large friction and pressure during operation. The high strength and wear resistance of PA12 can ensure the long - term use of bearings and reduce the occurrence of wear and failures.
Injection mold process conditions
Drying treatment: Before processing, the moisture content of PA12 material should be kept below 0.1%. If the material is stored in the air, it is recommended to dry it in hot air at 85°C for 4 - 5 hours to remove the moisture in the material. If the material is stored in a sealed container, it can be used directly after 3 hours of temperature equilibrium. This can ensure that the material can be uniformly melted and flow during the injection molding process, avoiding defects such as bubbles and cracks.
Melting temperature: The melting temperature range of PA12 is between 240 - 300°C. For materials with ordinary properties, do not exceed 310°C to prevent material decomposition. For materials with flame-retardant properties, do not exceed 270°C to ensure the flame-retardant effect. An appropriate melting temperature can ensure that the material can be fully melted and flow during the injection molding process, avoiding problems such as cold slug marks and short shots.
Mold temperature: For unreinforced materials, the mold temperature is 30 - 40°C; for thin-walled or large-area components, the mold temperature is 80 - 90°C; for reinforced materials, the mold temperature is 90 - 100°C. Increasing the temperature will increase the crystallinity of the material. Precise control of the mold temperature is very important for PA12. A suitable mold temperature can ensure uniform crystallinity of the plastic parts and improve their mechanical properties and dimensional stability.
Injection pressure: The maximum can reach 1000 bar. It is recommended to use a low holding pressure and a high melting temperature. A low holding pressure can reduce the internal stress of the plastic part and avoid deformation and cracks. A high melting temperature can ensure the fluidity of the material and enable the material to fully fill the mold cavity.
Injection speed: High-speed injection is relatively suitable for PA12 materials, especially for materials with glass additives. High-speed injection can make the material fill the mold cavity in a short time, reduce the cooling time of the material, and improve production efficiency. At the same time, high-speed injection can also ensure the quality of plastic parts and avoid defects such as flow marks and air bubbles.
Runners and gates: For materials without additives, due to the low viscosity of the material, the runner diameter should be around 30mm to ensure smooth flow of the material. For reinforced materials, a large runner diameter of 5 - 8mm is required to meet the flow needs of the additives in the material. The runner shape should be all circular, and the injection port should be as short as possible to reduce the pressure loss of the material. Various forms of gates can be used, but small gates should not be used for large plastic parts to avoid excessive pressure or high shrinkage rate on the plastic parts. The gate thickness is preferably equal to the thickness of the plastic part to ensure uniform filling of the material. If a submarine gate is used, the minimum diameter is recommended to be 0.8mm. Hot runner molds are very effective, but precise temperature control is required to prevent the material from leaking or solidifying at the nozzle. If a hot runner is used, the gate size should be smaller than that of a cold runner.
Chemical and physical properties
PA12 is a linear, semi-crystalline to crystalline thermoplastic material derived from butadiene. Its properties are similar to those of PA11, but the crystal structures are different. PA12 is an excellent electrical insulator, and like other polyamides, its insulation performance is not affected by moisture. This gives it broad application prospects in the field of electronics and electrical engineering. It has good impact resistance and chemical stability, and can maintain stable performance in different environments.
PA12 has many improved varieties in terms of plasticizing properties and reinforcing properties. Compared with PA6 and PA66, these materials have lower melting points and densities, and a very high moisture regain rate. PA12 has no resistance to strong oxidizing acids, and contact with strong oxidizing acids should be avoided during use. The viscosity of PA12 mainly depends on humidity, temperature and storage time. It has good fluidity, which enables it to be easily processed into products of various shapes and sizes through processes such as injection molding. The shrinkage rate ranges from 0.5% to 2%, which mainly depends on the material variety, wall thickness and other process conditions. These factors need to be fully considered during product design and processing to ensure the dimensional accuracy and quality of the products.
4. PA66 Polyamide 66 or Nylon 66
Typical application scope
Compared with PA6, PA66 is more widely used in the automotive industry, instrument housings and other products that require impact resistance and high strength. In the automotive industry, components such as the engine hood and bumper of a car need to withstand relatively large impact forces and pressures. The high strength and impact resistance of PA66 enable it to meet these requirements. Instrument housings need to protect the internal instruments and equipment, and at the same time, they also need to have a certain degree of strength and stability. The performance of PA66 can provide reliable protection for instruments.
Injection mold process conditions
Drying treatment: If the material is sealed before processing, there is no need for drying. However, if the storage container is opened, it is recommended to dry the material in hot air at 85°C. If the humidity is greater than 0.2%, vacuum drying at 105°C for 12 hours is also required. This can ensure that the moisture content in the material meets the processing requirements and avoid the influence of moisture on the material properties and processing quality.
Melting temperature: The melting temperature range of PA66 is between 260 - 290°C. For products with glass additives, the melting temperature is 275 - 280°C. The melting temperature should be kept below 300°C to avoid material decomposition. An appropriate melting temperature can ensure that the material can be fully melted and flow during the injection molding process, preventing problems such as cold slug marks and short shots.
Mold temperature: It is recommended that the mold temperature be 80°C. The mold temperature will affect the crystallinity, and the crystallinity will affect the physical properties of the product. For thin-walled plastic parts, if a mold temperature lower than 40°C is used, the crystallinity of the plastic parts will change over time. To maintain the geometric stability of the plastic parts, annealing treatment is required. An appropriate mold temperature can ensure uniform crystallinity of the plastic parts and improve the mechanical properties and dimensional stability of the plastic parts.
Injection pressure: Usually between 750 - 1250 bar, and the specific value depends on the material and product design. An appropriate injection pressure can ensure that the material can fill the mold cavity, avoiding problems such as short shots and sink marks. In actual production, the injection pressure needs to be adjusted according to factors such as the structure of the mold, the size and shape of the plastic part.
Injection speed: High-speed injection is more suitable for PA66 materials, but it should be slightly lower for reinforced materials. High-speed injection can fill the mold cavity with the material in a short time, reduce the cooling time of the material, and improve production efficiency. However, for reinforced materials, an excessively high injection speed may lead to uneven distribution of additives such as glass fibers, affecting the performance of the product.
Runners and gates: Since the solidification time of PA66 is very short, the position of the gate is very important. The gate aperture should not be less than 0.5*t (where t is the thickness of the plastic part) to ensure that the material can smoothly enter the mold cavity. If a hot runner is used, the gate size should be smaller than that when using a conventional runner, because the hot runner can help prevent the material from solidifying prematurely. If a submarine gate is used, the minimum diameter of the gate should be 0.75mm to ensure smooth material flow.
Chemical and physical properties
PA66 has a relatively high melting point among polyamide materials. It is a semi-crystalline - crystalline material. This enables it to maintain strong strength and stiffness even at relatively high temperatures. In some high-temperature environments, such as components around the engine, PA66 can give full play to its advantages and ensure the normal operation of the components.
PA66 still has hygroscopicity after molding, and the degree mainly depends on the material composition, wall thickness, and environmental conditions. When designing the product, the influence of hygroscopicity on geometric stability must be considered. In order to improve the mechanical properties of PA66, various modifiers are often added. Glass is the most common additive, which can improve the strength and stiffness of the material. Sometimes, in order to improve the impact resistance, synthetic rubbers such as EPDM and SBR are also added.
5. PBT (Polybutylene Terephthalate)
Typical application scope
PBT (Polybutylene Terephthalate) has a wide and important range of applications in multiple fields. In the aspect of household appliances, it plays an indispensable role. Food processing blades made of PBT material can remain sharp for a long time thanks to their good mechanical properties, efficiently completing the cutting work of various food ingredients and bringing convenience to home cooking. Vacuum cleaner components using PBT can withstand high suction and frequent vibrations, ensuring the stable operation of the vacuum cleaner. The housings of electric fans and hair dryers are made of PBT, which not only has a certain strength to protect internal components but also can withstand the heat generated during long - term use. Coffee utensils made of PBT material can resist the heat and chemical corrosion of coffee, ensuring safe use.
In the field of electrical components, the application of PBT is also very crucial. Switches made of PBT material have good electrical insulation properties, which can effectively prevent the occurrence of electric leakage accidents and ensure electrical safety. Motor housings made of PBT can provide reliable protection for motors, and their good heat dissipation performance helps the motors operate stably. Fuse boxes made of PBT material can safely accommodate fuses when the circuit is overloaded, etc., to avoid the spread of danger. Computer keyboard keys made of PBT offer a comfortable touch, are wear - resistant and not easily deformed, meeting the needs of long - term and frequent use.
In the automotive industry, PBT also performs excellently. Using PBT materials for radiator grilles can ensure the heat dissipation function while withstanding the airflow impact during the vehicle's operation and the influence of the external environment. When PBT is used for body panels, it can reduce the vehicle's weight, and at the same time, it has good impact resistance and corrosion resistance to protect the vehicle's appearance. Selecting PBT for wheel covers can enhance the vehicle's aesthetic appeal and withstand the centrifugal force during high - speed driving and the impact of road splashes. When PBT is used for door and window components, it can ensure good sealing performance and durability, providing a comfortable environment inside the vehicle.
Injection mold process conditions
1. Drying treatment: The material PBT has a remarkable characteristic, that is, it is extremely prone to hydrolysis reactions in high - temperature environments. This makes the drying treatment a crucial process before its processing. If the drying is insufficient, the moisture in the material will react with PBT during the high - temperature processing, thus affecting the performance of the material and the quality of the products. It is recommended that when drying in the air, a temperature of 120°C can be selected for continuous drying for 6 - 8 hours; or a temperature of 150°C can be used for drying for 2 - 4 hours. At the same time, the humidity must be strictly controlled to be less than 0.03%. If a moisture - absorbing dryer is used for drying, the recommended conditions are 150°C for 2.5 hours, which can more effectively remove the moisture in the material and ensure the smooth progress of subsequent processing.
2. Melting temperature: The melting temperature range of PBT is between 225 - 275°C. However, it is recommended to set the temperature at 250°C. At this temperature, PBT can achieve good fluidity, which facilitates filling and molding in the mold. If the temperature is too low, the fluidity of the material will be insufficient, which may lead to problems such as material shortage and uneven surface of the product. If the temperature is too high, the material may degrade, affecting the performance of the product.
3. Mold temperature: For unreinforced PBT materials, the mold temperature should be controlled between 40 - 60°C. It is crucial to design the cooling channels of the mold reasonably, aiming to reduce the bending deformation of the plastic parts. During the injection molding process, the heat dissipation must be rapid and uniform. Otherwise, uneven cooling will cause internal stress in the plastic parts, resulting in bending. It is recommended that the diameter of the mold cooling channels be 12mm. This size can ensure the flow rate of the coolant and the cooling effect, keeping the mold temperature stable.
4. Injection pressure: When injecting PBT, the pressure is medium, with a maximum of up to 1500 bar. A moderate injection pressure can ensure that the material is fully filled in the mold, while avoiding defects such as mold damage or flash on the product caused by excessive pressure.
5. Injection speed: Since the solidification speed of PBT is very fast, the fastest possible injection speed should be used. Fast injection can completely fill all corners of the mold with the material before it solidifies, ensuring the molding quality of the product. If the injection speed is too slow, the material may start to solidify before completely filling the mold, resulting in problems such as voids and incomplete products.
6. Runners and gates: It is recommended to use circular runners because circular runners can increase the efficiency of pressure transmission. According to the empirical formula, the runner diameter is equal to the thickness of the plastic part plus 1.5 mm. Such a design can make the material flow smoothly in the runner and reduce pressure loss. Various types of gates can be used to meet the molding requirements of different products. Hot runners can also be used, but special attention should be paid to preventing material leakage and degradation. The gate diameter should be between 0.8 - 1.0 times the thickness of the plastic part, where t represents the thickness of the plastic part. If it is a submarine gate, the recommended minimum diameter is 0.75 mm to ensure that the material can smoothly enter the mold cavity.
Chemical and physical properties
PBT is an extremely tough engineering thermoplastic material and belongs to semi-crystalline materials. It has very excellent chemical stability, can maintain stable performance in various chemical environments, and is not easily corroded by chemical substances. Its mechanical strength is also quite considerable, and it can withstand relatively large external forces without damage. The electrical insulation characteristics enable PBT to be widely used in the electrical field, effectively preventing current leakage. In terms of thermal stability, it can maintain its performance within a certain temperature range and adapt to different working environments. These characteristics enable PBT to exhibit good stability under a wide range of environmental conditions.
PBT has very weak moisture absorption characteristics, which means it has a low ability to absorb moisture in a humid environment and will not experience performance degradation due to moisture absorption. The tensile strength of non-reinforced PBT is 50 MPa, while that of PBT with glass additives can reach 170 MPa. However, it should be noted that an excessive amount of glass additives will make the material brittle and reduce its toughness and impact resistance.
The crystallization speed of PBT is very fast. Although this is beneficial for improving production efficiency, it also brings some problems. Rapid crystallization may lead to bending and deformation due to uneven cooling. For materials with glass additives, the shrinkage rate in the flow direction can be reduced, but the shrinkage rate in the direction perpendicular to the flow is basically the same as that of ordinary materials. Generally, the shrinkage rate of materials is between 1.5% - 2.8%, and the shrinkage rate of materials containing 30% glass additives is between 0.3% - 1.6%.
The melting point of PBT is 225°C, and its high-temperature deformation temperature is also lower than that of PET material. The Vicat softening temperature is approximately 170°C, and the glass transition temperature ranges from 22°C to 43°C. Due to its high crystallization rate, its viscosity is very low, which is beneficial for rapid flow and mold filling during the injection molding process. Meanwhile, the cycle time for plastic part processing is generally short, which can improve production efficiency and reduce production costs.
6. PC (Polycarbonate)
Typical application scope
PC polycarbonate has a wide range of applications in multiple industries. In the field of electrical and commercial equipment, computer components such as motherboards and hard drive casings use PC materials. Due to their good electrical insulation and mechanical strength, they can protect internal electronic components from external interference and physical damage. Connectors are made of PC materials, which can ensure the stable transmission of signals and withstand the friction and stress during the plug - and - unplug process.
In terms of appliances, the food processor uses PC material to make the shell and some components. It can withstand the heat generated by high - speed rotation and friction, and meets food hygiene standards to ensure food safety. The refrigerator drawer is made of PC material, which has good low - temperature resistance and strength, and can withstand the frequent pushing and pulling of the drawer and the placement of heavy objects.
In the transportation industry, the front and rear lights of vehicles use PC materials, which have high transparency and good impact resistance. They can provide clear lighting effects and withstand the vibrations and collisions during the vehicle's operation. The dashboard is made of PC material, which not only has an aesthetically pleasing appearance but also can withstand high temperatures and sunlight, ensuring the normal display of the instruments and their service life.
Injection mold process conditions
1. Drying treatment: PC material is hygroscopic, which means it can absorb moisture from the air. If it is not sufficiently dried before processing, the moisture will form bubbles during the high - temperature processing, affecting the appearance and performance of the products. Therefore, drying before processing is very important. It is recommended that the drying conditions be 100℃ to 200℃ for 3 - 4 hours. Moreover, the humidity before processing must be strictly controlled to less than 0.02% to ensure that the dryness of the material meets the processing requirements.
2. Melting temperature: The melting temperature range of PC is between 260 - 340℃. Within this temperature range, PC can achieve suitable fluidity, facilitating the filling of molds. Different products and processing technologies may require the selection of an appropriate melting temperature according to the actual situation.
3. Mold temperature: The mold temperature should be controlled between 70 - 120°C. An appropriate mold temperature helps to improve the surface quality and dimensional accuracy of the products. If the mold temperature is too low, surface defects may occur on the products; if the temperature is too high, the products may deform or it may be difficult to demold them.
4. Injection pressure: When injection molding PC, high injection pressure should be used as much as possible. High injection pressure can ensure that the material is fully filled in the mold, especially for some products with complex shapes or thin walls. However, excessively high pressure may also cause problems such as mold damage or flash on the products. Therefore, adjustments need to be made according to the actual situation.
5. Injection speed: The selection of injection speed needs to be determined according to the type of gate. For smaller gates, low-speed injection should be used to avoid the jetting phenomenon of the material during high-speed flow, which may affect the quality of the product. For other types of gates, high-speed injection can be used to improve production efficiency and the molding quality of the product.