How PEEK Pellets Works?

Content Menu

● 1.The most common processing:PEEK injection molding

>> 1.1What are the features of the PEEK injection molding process?

● 2.Another common process of PEEK pellets:PEEK Extrusion

>> 2.1 Extrsuion PEEK sheets and PEEK rods

>>> 2.1.1 unfilled PEEK sheet/rods

>>> 2.1.2 glass fiber PEEK sheet/rod

>>> 2.1.3carbon finber reinforced PEEK sheet rods

>> 2.3PEEK 3D printing filaments

>>> 2.3.1how to use PEEK pellets to extrusion PEEK 3d printing filaments?

PRES is a company specializing in the production of PEEK materials. PEEK particles are our main product. 

We supply:

unfilled PEEK pellets

30% glass fiber reinforced PEEK pellets

30%carbon fiber reinforced PEEK pellets

Bearing grade PEEK pellets

The main types of PEEK particles process include injection molding, extrusion molding, and compression molding. These methods have their own characteristics and are suitable for manufacturing products with different shapes and performance requirements.

1.The most common processing:PEEK injection molding

PEEK injection molding is the most commonly used processing method for PEEK pellets, suitable for manufacturing PEEK parts with complex structures and high dimensional accuracy, and is suitable for mass production.

PEEK injection usually use injection grade PEEK which is easy flow.

1.1What are the features of the PEEK injection molding process?

PEEK (Polyetheretherketone) injection molding is a molding process that involves heating the particles to 380-400℃ for melting, then injecting them at high pressure and speed into a precise mold, followed by cooling and shaping to produce high-performance products. 

This process is highly efficient and is particularly suitable for mass production of complex-structured, precisely-sized, and highly-mechanically-performing engineering components, such as automotive gears, electronic connectors, medical implants, etc. 

Its core advantage lies in the fact that the products possess excellent mechanical strength, heat resistance (with a long-term use temperature of up to 260℃), and chemical corrosion resistance. 

During the processing, a dedicated high-temperature injection molding machine must be used, and the raw materials must undergo strict pre-drying treatment to prevent defects in the products. This is currently the main processing method for PEEK materials.

2.Another common process of PEEK pellets:PEEK Extrusion

PEEK extrusion is also a common method for processing PEEK particles. Mainly used for the production of continuous profiles such as PEEK rods, PEEK tubes, PEEK plates ,PEEK films or PEEK 3D printing filaments .

PEEK extrusion is the core process for manufacturing high-performance engineering plastic profiles.It usually use extrusion grade PEEK particles with a standard flow and high meltability.

It involves melting and plasticizing PEEK particles at high temperatures, then continuously extruding them through specific-shaped die molds. After cooling and shaping, it forms continuous products with a fixed cross-sectional shape (such as round rods or rectangular sheets). Finally, they are cut to the desired length as per requirements.

2.1 Extrsuion PEEK sheets and PEEK rods

PRES  has the capability to produce continuous extruded PEEK plates and PEEK rods, and the overall size of the plate has reached 620*1240MM,the biggest diameter of the PEEK rods can reach 200mm .And we provide many kinds of PEEK plate unfilled PEEK sheet/rods and modified PEEK sheet/rods.

2.1.1 unfilled PEEK sheet/rods

unfilled PEEK resin sheet  and PEEK resin rods can reach the biggest size than fiber reinforced PEEK sheet.At the same time, it's density is also lower, at only 1.3g/cm³.

Excellent impact resistance: The Izod impact strength of PEEK is usually around 80 - 100 J/m, and it is not sensitive to the notch. Even in low-temperature environments (such as -40℃), its toughness does not significantly decrease and it will not become brittle like ordinary plastics.

Fatigue resistance: PEEK exhibits excellent fatigue resistance, capable of withstanding millions of cycles of load without breaking. It is highly suitable for manufacturing parts that require long-term reciprocating motion (such as springs, gears)

2.1.2 glass fiber PEEK sheet/rod

Glass fiber reinforced PEEK sheet and rods (PEEK-GF30, with 30% glass fiber added) is the most rigid and dimensionally stable model in the PEEK series. By sacrificing some of the toughness of pure PEEK, it achieves extremely high structural strength and anti-rheological properties, making it the preferred material for manufacturing high-load structural components.

2.1.3carbon finber reinforced PEEK sheet rods

Carbon fiber reinforced PEEK (PEEK-CF30) is a high-performance material formed by adding carbon fibers (typically at a content of 20%-30%) to the PEEK resin matrix.

Through the effect of carbon fibers, it significantly enhances the rigidity, wear resistance and thermal conductivity of the material, making it the PEEK series with the most similar comprehensive performance to metals.

Ultra-high rigidity: The elastic modulus is as high as 15-20 GPa, which is 4-5 times that of pure PEEK. Under force, it hardly undergoes bending deformation.

Ultra-high strength: The tensile strength can reach 200-250 MPa, approaching or exceeding that of certain aluminum alloys.

Extremely low creep: Under long-term high temperature and high pressure conditions, the dimensional stability is excellent and there is almost no creep deformation.

Excellent thermal conductivity: The addition of carbon fibers significantly increases the thermal conductivity of the material, enabling rapid heat dissipation. It is suitable for manufacturing friction components that operate at high speeds.

Excellent wear resistance: Low friction coefficient, good self-lubrication properties, making it an ideal material for manufacturing oil-free bearings and gears.

Low thermal expansion coefficient: The thermal expansion rate is extremely low, perfectly matching that of metals, making it suitable for manufacturing metal inserts or precision mating parts.

2.3PEEK 3D printing filaments

Properties of PEEK 3D Printing Filament

PEEK (Polyether Ether Ketone) 3D printing filament properties primarily depend on the raw material grade and the printing process. As a high-performance engineering plastic, PEEK filament typically far surpasses common materials like PLA or ABS in performance, but there are significant variations between different grades.

Here are the core performance indicators and comparisons for PEEK 3D printing filament:

The properties of PEEK filament generally lie between those of standard PEEK injection-molded parts and pure resin. Due to the influence of interlayer bonding strength, the Z-axis (layer-to-layer) strength is typically lower than the XY-axis (in-plane) strength.

2.3.1how to use PEEK pellets to extrusion PEEK 3d printing filaments?

The production of PEEK (Polyetheretherketone) filament for 3D printing is a high-precision process. The core lies in high-temperature melt extrusion and precise dimensional control. As PEEK is a high-performance specialty engineering plastic, its manufacturing process is significantly more complex than that of standard PLA/ABS filaments. It demands extremely high requirements for equipment high-temperature resistance, temperature control accuracy, and cooling/solidification.

Below are the core process parameters and workflow for fabricating PEEK 3D printing filament:

1. Core Process Parameters

PEEK filament is typically produced via melt extrusion using a single-screw extruder, operating within a very narrow process window where temperature control is critical.

2. Detailed Fabrication Workflow

Step 1: Raw Material Drying

PEEK pellets are highly hygroscopic. Moisture content must be controlled below 0.02%. Typically, pellets are dried in an oven at 120-150°C for 3-4 hours. Inadequate drying leads to bubbles during high-temperature extrusion, resulting in rough filament surfaces or internal breakage.

Step 2: High-Temperature Extrusion

This is the most critical step. PEEK has a high melting point (~343°C) and high melt viscosity, requiring a heat-resistant alloy screw (e.g., 38CrMoAlA nitriding steel) and a specially designed die.

• Temperature Control: Zoned temperature control is essential. The rear section of the barrel is set lower (~350°C) to prevent premature melting and sticking; the front section and die head require temperatures of 380-400°C to ensure complete plasticization and optimal melt flow.

  
  

• Screw Speed: Low rotation speeds (e.g., 16-20 rpm) are typically used to reduce residence time in the high-temperature zone, preventing thermal degradation.

  
  

Step 3: Cooling & Solidification

As a semi-crystalline polymer, the cooling rate directly affects PEEK's crystallinity and filament properties.

• Air Cooling (Primary Method): This is the mainstream technique. Gradual cooling using hot or ambient air allows for orderly molecular chain arrangement, yielding higher crystallinity. The resulting filament has good toughness and is less prone to brittleness.

  
  

• Water Bath Cooling: If used, water temperature must be strictly controlled between 45-55°C. Water that is too cold causes rapid surface cooling, forming a "skin-core" structure with high internal stress, leading to bending or breakage. Water that is too warm provides insufficient cooling, causing deformation.

  
  

Step 4: Precision Drawing & Winding

• Dimensional Control: Standard PEEK filament diameters are 1.75mm or 2.85mm. A high-precision laser diameter gauge provides real-time monitoring, and the feedback controls the drawing speed to maintain a tolerance within ±0.05mm.

  
  

• Winding: A servo traverse winding system ensures the filament is wound neatly onto the spool without crossing or overlapping, preventing tangles during printing.

  
  

3. Key Equipment Requirements

• Extruder: Must be equipped with all-metal heaters capable of withstanding temperatures above 500°C, with uniform heating.

  
  

• Screw Design: A screw with a length-to-diameter (L/D) ratio of 20:1 or higher is recommended, with a moderate compression ratio to ensure uniform plasticization without generating excessive shear heat.

  
  

• Die: The die flow channel must be smooth and free of dead spots to prevent material stagnation and degradation.

  
  

4. Common Issues & Solutions

• Inconsistent Diameter: Check for screw wear, temperature fluctuations, or unstable drawing speed.

  
  

• Rough Surface/Bubbles: Insufficient raw material drying or excessively high extrusion temperature causing degradation.

  
  

• Brittle Filament: Cooling rate too fast (water temperature too low) or thermal-oxidative degradation of the material.