In the PEEK injection molding process, suitable injection molding equipment is the key to ensuring product quality and production efficiency. Due to the special physical and chemical properties of PEEK material, it has high and unique requirements for various aspects of injection molding equipment.
The injection molding of PEEK material requires screws with special design. The length to diameter ratio (L/D) of the screw is generally between 20:1-24:1. A longer aspect ratio can provide sufficient plasticizing length for the material, allowing PEEK to be fully heated and mixed evenly in the barrel. The compression ratio is usually set between 2.5-3.5, which can effectively compress and shear the material, ensuring that PEEK material forms a good melt during the plasticization process to meet the requirements of injection molding.
Accurate temperature control of the material barrel is crucial for PEEK injection molding. The temperature of the material barrel usually needs to be set at 360-390 ℃, and the temperature near the nozzle can be slightly lower, about 350-370 ℃, to prevent the material from solidifying prematurely at the nozzle. Due to the narrow processing temperature range of PEEK, the fluctuation range of temperature in each section of the barrel should be controlled within ± 5 ℃. Advanced temperature control system, equipped with high-precision thermocouples and intelligent temperature control instruments, can monitor and adjust the temperature of the material barrel in real time, ensuring that the material is always in the best melting state, guaranteeing the stability of the injection molding process and the consistency of product quality.
Injection molding machines need to have sufficient injection pressure and a wide speed adjustment range. The injection pressure is generally between 100-140MPa to overcome the high melt viscosity of PEEK material and ensure that the material can quickly and completely fill the mold cavity. The adjustment of injection speed is crucial for products of different shapes and sizes. For example, thin-walled products require a high injection speed, usually around 50-100mm/s, to prevent defects such as short shots caused by rapid cooling of the melt during the filling process; For thick walled products, the injection speed can be controlled between 20-50mm/s to avoid problems such as trapped gas and internal stress concentration caused by excessive speed.
Reliable drying equipment is essential to ensure that PEEK materials meet the water content standards before injection molding. The hot air circulation drying oven is a commonly used drying equipment that can dry materials in an environment of 150-180 ℃ for 3-4 hours, reducing the moisture content to below 0.02%. In addition, for some application scenarios that require extremely high moisture content, vacuum drying equipment can also be used to achieve efficient drying at lower temperatures, better protecting the performance of PEEK materials.
Due to the high mold temperature required for PEEK injection molding, generally between 160-190 ℃, the role of mold temperature control equipment should not be underestimated. Oil temperature machine or electric heating mold temperature controller can accurately stabilize the mold temperature within the required range. A stable mold temperature helps improve the crystallinity of the product, enhance its dimensional stability and mechanical properties, and reduce issues such as deformation and cracking caused by temperature fluctuations.
Mold Temperature Machine Driven by water
In summary, the requirements for PEEK injection molding equipment cover the core components of injection molding machines as well as various auxiliary equipment. Only by selecting equipment that meets the requirements and accurately setting and maintaining its parameters can high-quality PEEK injection molding production be achieved, meeting the growing market demand for PEEK products. In actual production, continuously optimizing equipment performance and process parameters is an important way to improve production efficiency and product quality.
