PEEK Injection Molding: A Comprehensive Guide

PEEK injection molding is a manufacturing process that involves melting pellets of polyetheretherketone (PEEK) resin and injecting the molten material into a mold cavity under high pressure. PEEK is a high-performance thermoplastic with excellent mechanical, thermal and chemical properties, making it a popular choice for a variety of applications in industries such as aerospace, medical and electronics. PEEK injection molding can create complex shapes and sizes with high precision and consistency. Injection molding of PEEK is different from the injection molding of other plastics. This article discusses some of the peculiarities associated with this. In doing so we also get to explore its properties, applications, and some of its special features. Here you’ll have a good insight into how injection molding of PEEK stands out from that of other plastics.

What is PEEK?

PEEK(Polyether Ether Ketone) is a high-performance thermoplastic material that is known for its exceptional mechanical, thermal, and chemical properties. It is a semi-crystalline polymer commonly used in applications where extreme conditions exist, such as high temperature, high pressure and exposure to harsh chemicals. PEEK has a high strength-to-weight ratio, excellent dimensional stability, wear resistance and fatigue resistance. It is also biocompatible and has been approved for use in medical implants and devices. PEEK is used in various industries such as aerospace, medical, oil and gas, automotive, and electronics, and is processed using various techniques such as injection molding, extrusion, and machining.

PEEK Categories

PEEK is a versatile material for injection molding, as it offers a range of properties that can be applied to diverse manufacturing projects. PEEK is available in four major categories, which include the natural grade and reinforced varieties. These categories offer a broad range of properties that can be tailored to meet specific project requirements.

• Natural PEEK

Natural PEEK is an unreinforced general-purpose grade that is highly wear-resistant and has the highest levels of elongation and toughness of all PEEK grades. This makes it an excellent choice for instrument components that require aesthetic appeal. Additionally, Natural PEEK is well-suited for plastic parts that require high levels of ductility and inertness.

• GF30 PEEK

GF30 PEEK is a type of PEEK resin that contains 30% glass fibers. The addition of glass fibers significantly reduces the expansion rate and increases the flexural modulus of the resin. This makes GF30 PEEK an excellent choice for structural applications that require high levels of strength, stiffness, and dimensional stability, particularly at temperatures exceeding 148ºC / 300ºF.

• CF30 PEEK

CF30 PEEK is a PEEK resin that contains 30% carbon fibers. The inclusion of carbon fibers significantly reduces its expansion rate and improves the compressive strength and stiffness of PEEK. This grade of PEEK is particularly advantageous as it offers enhanced thermal conductivity compared to natural PEEK, allowing for greater heat dissipation from surfaces.

• PVX Black PEEK

PVX Black PEEK is a type of PEEK that is reinforced with graphite and PTFE lubricants. This grade of PEEK offers the lowest coefficient of friction and the best machinability out of all PEEK grades. It is an excellent choice for plastic parts that are exposed to extreme environmental conditions, as it offers a combination of low friction, low wear, high LPV, low mating part wear, and ease of machining.

Properties of PEEK Material

PEEK (Polyether Ether Ketone) is a high-performance thermoplastic material that possesses several exceptional properties, which make it well-suited for use in demanding industrial applications. Some of the key properties of PEEK material include:

• 1.High Temperature Resistance:PEEK can withstand high temperatures up to 250°C (482°F) without losing its strength or dimensional stability.
• 2.Chemical Resistance:PEEK is highly resistant to various chemicals, including acids, bases, and organic solvents, making it suitable for use in harsh chemical environments.
• 3.Excellent Mechanical Properties:PEEK has a high strength-to-weight ratio, excellent fatigue and wear resistance, and good dimensional stability, making it ideal for use in applications that require high strength and durability.
• 4.Biocompatibility:PEEK is biocompatible and has been approved for use in medical implants and devices.
• 5.Hydrolysis Resistance:PEEK has good hydrolysis resistance, making it suitable for use in water and steam environments.
• 6.Electrical Insulation:PEEK has excellent electrical insulation properties, making it suitable for use in electrical and electronic applications.
• 7.Low Flammability:PEEK has a low flammability, which makes it suitable for use in applications that require resistance to fire.

PEEK’s combination of high temperature and chemical resistance, excellent mechanical properties, biocompatibility, and electrical insulation makes it a versatile material that can be used in various industries, including aerospace, medical, oil and gas, automotive, and electronics.

What is PEEK Injection Molding?

PEEK (polyetheretherketone) injection molding is a manufacturing process used to produce high-performance thermoplastic components using PEEK resin.The injection molding process involves melting PEEK resin pellets and injecting the molten material into a mold cavity at high pressure. The mold is then cooled, and the solidified part is ejected from the mold. This process allows for the production of complex, precise, and repeatable parts with a high degree of accuracy and consistency.
PEEK injection molding is often used to produce parts with high strength, stiffness, and dimensional stability, making it suitable for applications where high performance and reliability are required. Some common applications of PEEK injection molded parts include connectors, electrical components, medical instruments, and aerospace components.

Advantages of PEEK Injection Molding

There are several advantages of PEEK injection molding, including:

• 1.Excellent mechanical properties: PEEK has excellent mechanical properties, including high strength, stiffness, and toughness, making it ideal for demanding applications where high performance is required.
• 2.High-temperature resistance: PEEK can withstand high temperatures and maintain its mechanical properties, making it suitable for use in high-temperature applications.
• 3.Chemical resistance: PEEK is highly resistant to chemicals, including acids, bases, and solvents, making it ideal for use in harsh chemical environments.
• 4.Dimensional stability: PEEK has excellent dimensional stability and maintains its shape and size even at high temperatures, making it suitable for applications where tight tolerances are required.
• 5.Good wear resistance: PEEK has good wear resistance, making it suitable for use in applications where parts are subject to high levels of friction and wear.
• 6.Biocompatibility: PEEK is biocompatible, making it suitable for use in medical applications, such as implantable medical devices, where biocompatibility is essential.

Disadvantages of PEEK Injection Molding

Compared with other resins：

• 1.PEEK resin is generally more expensive.
• 2.PEEK is characterized by its low resistance to UV light.
• 3.PEEK requires high processing temperatures.
• 4.When used in medical applications, the hydrophobic and non-polar nature of PEEK results in limited cell adhesion.

Applications of PEEK Injection Molding

PEEK injection molding is used in a variety of applications across different industries. Here are some common applications of PEEK injection molded parts:

• 1.Aerospace: PEEK is used in aerospace applications where high performance and reliability are required. For example, engine components, electrical connectors, and structural components.
• 2.Automotive: PEEK is used in automotive applications where high strength, stiffness, and temperature resistance are required. Some examples include engine components, fuel systems, and electrical connectors.
• 3.Medical: PEEK is used in medical applications due to its biocompatibility and high chemical resistance. For example, surgical instruments, implantable devices, and dental instruments.
• 4.Electronics: PEEK is used in electronics applications due to its high temperature resistance, electrical insulation properties, and chemical resistance. Some examples include electronic connectors, PCB components, and semiconductor manufacturing.
• 5.Oil and gas: PEEK is used in oil and gas applications due to its high temperature and chemical resistance. For example, downhole tools, chemical processing equipment, and subsea components.
• 6.Industrial: PEEK is used in industrial applications due to its high strength, stiffness, and chemical resistance. Some examples include gears, bearings, and bushings.

PEEK injection molding is used in applications where high performance, reliability, and durability are required. Its unique combination of mechanical, thermal, and chemical properties make it suitable for use in a wide range of industries and applications.

PEEK Injection Molding Process

The PEEK injection molding process involves several steps, including:

• Material preparation: PEEK resin pellets are loaded into the injection molding machine hopper and heated to a specified temperature to melt the resin.
• Mold preparation: The mold is prepared by cleaning and inspecting it to ensure it is free from defects and damage. The mold is then preheated to the specified temperature.
• Injection: The molten PEEK resin is injected into the mold cavity at high pressure. The mold is filled with the molten resin, and the pressure is maintained until the resin cools and solidifies.
• Cooling: The mold is cooled to a specified temperature to solidify the PEEK resin. The cooling time depends on the part geometry and the thickness of the material.
• Ejection: Once the part has cooled and solidified, the mold is opened, and the part is ejected from the mold.
• Post-processing: The part is inspected and trimmed to remove any excess material or flash. The part may also undergo additional post-processing, such as machining, surface finishing, or assembly.

The PEEK injection molding process requires precision and skill to produce high-quality parts consistently. The process parameters, such as temperature, pressure, and cooling time, must be carefully controlled to ensure the part meets the required specifications.

Factors to Consider When Moulding PEEK

When molding PEEK, there are several factors to consider to ensure a successful process and high-quality parts. Here are some of the key factors:

• 1.Temperature: PEEK has a high melting temperature, typically between 340-400°C (644-752°F), and requires a high processing temperature to melt and flow properly. The processing temperature should be carefully controlled to avoid overheating or underheating, which can result in poor quality parts.
• 2.Pressure: PEEK requires high injection pressure to fill the mold cavity completely. The injection pressure should be carefully controlled to ensure the proper filling of the mold and prevent defects such as voids or sink marks.
• 3.Mold design: The mold design should be carefully considered to ensure proper filling of the mold cavity and prevent defects such as warpage or flashing. The mold should be designed with sufficient cooling channels to ensure proper cooling and prevent overheating.
• 4.Material handling: PEEK resin is sensitive to moisture, and exposure to moisture can affect the material properties and lead to defects. The material should be stored in a dry environment and handled carefully to avoid moisture contamination.
• 5.Post-processing: PEEK parts may require additional post-processing, such as machining or surface finishing, to achieve the desired specifications. Careful consideration should be given to the post-processing techniques to avoid damaging the part and to ensure the proper finish.
• 6.Equipment: PEEK requires specialized equipment, such as high-temperature injection molding machines, to process the material properly. The equipment should be properly maintained and calibrated to ensure consistent processing and high-quality parts.

Overall, careful consideration of these factors is critical to the successful molding of PEEK and the production of high-quality parts with the desired properties.

Some Common Challenges When Molding PEEK

Molding PEEK can present some challenges due to its unique material properties. Here are some common challenges when molding PEEK:

• High processing temperature: PEEK has a high melting temperature, typically between 340-400°C (644-752°F), and requires a high processing temperature to melt and flow properly. This high temperature can cause issues with mold and machine parts, and can require specialized equipment and expertise.
• Sensitivity to moisture: PEEK is sensitive to moisture, and exposure to moisture can affect the material properties and lead to defects such as bubbles, voids, or surface imperfections. Proper material handling and storage are critical to minimize moisture absorption.
• Warpage: PEEK has a low coefficient of thermal expansion, which can make it prone to warpage or distortion during cooling. Proper mold design, cooling, and ejection can help prevent warpage.
• Sink marks: PEEK has a high viscosity, which can cause sink marks or depressions on the surface of the molded part. Proper processing parameters, such as temperature and pressure, and mold design can help prevent sink marks.
• Part sticking: PEEK can be prone to sticking to the mold, which can cause damage to the part or the mold. Proper mold release agents and ejection systems can help prevent sticking.
• Tool wear: Due to the high processing temperature and abrasive nature of PEEK, molds and machine parts can experience increased wear and tear over time. Proper maintenance and replacement of worn parts are important to ensure consistent quality and prevent downtime.

Proper mold design, processing parameters, material handling, and maintenance are critical to successfully overcome the challenges of molding PEEK and produce high-quality parts.

Choose PEEK Injection Molding Service Manufacturer—Sungplastic

Sungplastic is a PEEK injection molding service manufacturer that can provide a range of services to help with PEEK parts manufacturing. Our company has many years of experience in the plastic molding industry, specializing in the production of high-precision complex parts. We offer a range of injection molding services including design, engineering, tooling, and production. Here are some ways Sungplastic can help:

• 1.Experience: Sungplastic is a manufacturer with a track record of producing high quality PEEK parts. An experienced manufacturer will have the expertise and knowledge to handle the unique properties and requirements of PEEK.
• 2.Capabilities: Consider the manufacturer’s capabilities, such as their ability to produce complex parts with tight tolerances and their ability to handle large production runs. Sungplastic has the necessary equipment and technology to produce PEEK parts that meet the required specifications.
• 3.Material selection: Sungplastic can help with material selection, including selecting the appropriate grade of PEEK resin for the specific application and requirements.
• 4.Design and engineering: Sungplastic can provide design and engineering services to help optimize the part design for successful molding and efficient production.
• 5.Mold design and fabrication: Sungplastic can design and fabricate molds for PEEK injection molding, ensuring proper gating and venting, as well as adequate cooling and ejection.
• 6.Injection molding: Sungplastic can perform PEEK injection molding using its state-of-the-art equipment and experienced technicians to produce high-quality parts with tight tolerances and complex geometries.
• 7.Quality control: Sungplastic has a robust quality control system in place to ensure that PEEK parts meet the required specifications and quality standards.
• 8.Post-processing: Sungplastic can perform post-processing operations such as machining, polishing, and coating to achieve the desired dimensions, surface finish, and functionality of the PEEK parts.
• 9.Logistics: Sungplastic can handle logistics such as packaging, shipping, and inventory management to ensure that PEEK parts are delivered on time and in the required quantities.

Sungplastic’s expertise and capabilities in plastic injection molding help ensure the successful manufacture of PEEK parts, from material selection to final delivery. At Sungplastic, we offer dependable service and ensure that you have a great experience with a seamless manufacturing process. When choosing a PEEK manufacturer, Sungplastic can be a great choice for you.

If you need custom PEEK injection molded parts, please send us an online quote and we will do our best to answer your questions.

FAQ:About PEEK Injection Molding

• Q:What are some post-processing techniques for PEEK parts?

A:Post-processing techniques for PEEK parts can include machining, polishing, and coating. These techniques can be used to achieve the desired dimensions, surface finish, and functionality of the part.

• Q:What are some design considerations for PEEK parts?

A:Design considerations for PEEK parts include the part geometry, wall thickness, draft angles, and gating and venting. Proper design can help ensure successful molding and high-quality parts.

• Q: Can you manufacture other plastics?

A: Yes, such as ABS, PP, PC, Nylon, PMMA, etc. To better understand how Sungplastic can serve you for your injection molding project, contact us or request a quote today.