Peek injection is a process for manufacturing high-performance thermoplastics such as polyetheretherketone (PEEK). Peek is an extremely strong and durable material that can be molded using conventional injection molding equipment. The resulting parts have superior mechanical properties, which make them ideal for use in aerospace and automotive components, machine tools, semiconductors, and electrical and electronic machinery. Injection molded parts made from peek outperform metals in harsh environments and require fewer processing steps, which result in cost savings. Peek also resists corrosion better than many other plastics and is highly resistant to fatigue.
Injection molding is a highly automated process in which heated polymer is injected into a pre-formed mold at high pressure. After the injection process, the part is cooled and removed from the mold for further post-processing. This method of manufacture is ideal for producing large batches of identical plastic components with consistent quality.
However, the injection molding process requires precise temperature control to avoid processing defects such as warping and shrinkage. Moreover, the injected polymer must be properly cured to achieve its mechanical properties. When these requirements are not met, the resulting injection molded parts may have cold material points, silver streaks, porosity, and fusion marks.
The injection molding process can be difficult to master, especially with high-performance materials like PEEK. It requires high processing temperatures that are not easily controlled by standard injection molding machines. PEEK is a relatively expensive specialty plastic and is often used in aerospace and automobile applications, so it is critical that the injection molding process is carefully monitored to prevent these common errors.
To ensure the correct injection molding process for PEEK, operators must follow a series of best practices to prevent these common defects. First, the PEEK polymer should be dry before injection. Peek is supplied in pellet form and can absorb moisture from the air, so operators should dry the polymer on trays that circulate in a circulating oven for a maximum of 3 hours to reduce the moisture content.
Another important step is to ensure that the injection pressure is set correctly to avoid PEEK melt flow problems. This can be accomplished by adjusting the temperature of the injection molding machine and by minimizing the amount of gas generated during the injection process. PEEK polymers are typically manufactured with additives to improve their properties, such as glass, carbon, and graphite fibers for strength, PTFE to reduce friction, and silicon dioxide for heat resistance.
The mechanical tensile test experiment was designed and performed according to the GB/T 1040-2006 plastic tensile testing standard. The tensile tests were conducted on samples of PEEK injection molded parts that were produced by nine groups of different injection parameters. The tensile strengths of the PEEK parts were determined by stretching. The average values of the tensile data were used to evaluate the performance of each injection parameter. The experimental results proved that the photosensitive resin mould injection method is feasible to produce individualized PEEK parts with good mechanical properties in a short time.