What is PEEK Material? | The Definitive Guide

There is a high demand for rigid engineering thermoplastics for making high-end engineering goods for the automotive and aerospace industries. Let’s check some detailed information about one of the most in-demand thermoplastics in the manufacturing sector.

What is PEEK Material?

Polyetheretherketone, better known as PEEK, is a semi-crystalline, high-performance, rigid engineering thermoplastic material with various beneficial properties and excellent resistance to harsh chemicals.

PEEK material has been commercially available since the 1980s; after that, there’s no looking back. Remarkable mechanical properties, resistance to wear, fatigue, and high temperature up to 260°C make PEEK one of the most resilient and highly utilized thermoplastic materials in plastic industries.

It is one of the smoothest materials for processing in almost every vertical; however, it is mostly utilized in industries like oil and gas, aerospace, automotive, electrical, biomedical, and semi-conductor applications because of its resilient properties.

Polyetheretherketone can be processed in traditional plastic manufacturing methods like injection molding, extrusion molding, compression molding, etc

Properties of Polyetheretherketone 

PEEK

Here are the specific properties of PEEK:

Property Unit Value
Physical Properties
Density g mL-1 1.33
Melting Point °C 343 – 387
Coefficient of Thermal Expansion x 10-5 cm / (cm °C) 4.5 – 5.5
Thermal Conductivity W / mK 0.29
Heat Deflection Temperature, 1.8 MPa °C 152 – 172
Rockwell Hardness, M Scale M100 – M124
Mechanical Properties
Tensile Modulus at 23 C MPa 3725
Tensile Strength, Yield at 23 C MPa 100 – 115
Tensile Strength, Break at 23 C MPa
Compressive Strength MPa 120
Flexural Modulus MPa 4065 – 4275
Break Elongation % 15 – 45
Yield Elongation %
Izod Unnotched kJ / m2 No breaking
Electrical Properties
Dielectric Strength V/mm x 104 2.5 – 3.3
Volume Resistivity Ohm-cm
Dielectric Constant @ 1 MHz 2.8 – 3.3
Dissipation Factor @ 1 MHz 0.001 – 0.005
Other Properties
Mold Shrinkage % 1.0 – 1.3
Processing Temperature °C 370 – 400
Water Absorption, 24 hr. Immersion % 0.05 – 0.2
  1. PEEK showcases magnificent creep resistance. When reacted with flexural and tensile capabilities, it gives a great balance of several mechanical properties that can withstand high loadings for an extended period without residual damage.
  2. PEEK also boasts impressive tensile strength even in high temperatures up to 299°C. The polymer should be reinforced with carbon fibers to achieve maximum results with retained properties. Uplifting the tensile strength somewhere between 25000psi to 30000 is quite achievable.
  3.  The polymer can show good insulating properties in different temperatures and environments.
  4.  The polymer’s crystalline structure supports high resistance with multiple ranges of liquid and fabulous fatigue performance.
  5. The polymer’s spiral geometry helps it with reinforcing glass or carbon reinforcement, which will improve the polymer’s thermal conductivity.
  6. Besides being manufacturer-friendly, it is also environment-friendly, with a V0 flammability rating of 1.45 mm and an LOI of 35%. Compared to other mainstream thermoplastic materials, its generation of toxic gases and smoke is quite low.

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Key Benefits of PEEK

key benefits of PEEK

  1. PEEK’s toughness, rigidity, and excellent fatigue resistance make its strength comparable to alloys.
  2. It has great sliding properties making it suitable for rigorous applications with low coefficient of friction and abrasion.
  3. Terrefic chemcial and corrosion resistance.
  4. PEEK boasts one of the best flame resistance properties of most other thermoplastics, with a size of 1.45mm; it doesn’t need any flame retardants.
  5. Peeling resistance also increases PEEK’s applicability in harsh conditions and makes it easy to make with these wires and magnet wires.

Limitations of PEEK

limitation of PEEK

As discussed above, everything about PEEK seems perfect, but that’s not the case. It has great properties and multiple applications and has some limitations that need to be discussed.

  1. Processing at high temperatures may not be suitable for everyone.
  2. UV light resistance is quite low.
  3. The mechanical properties make the polymer expensive and applicable for high-tech applications. PEEK even may prove a drag for manufacturing simple components.

How is PEEK Material Manufactured?

Bisphenolate salts are the main ingredient for PEEK. A process called step-growth polymerization using dialkylation is responsible for manufacturing PEEK.

4,4’-difluorobenzophenone is blended with hrdrocloroquinone and alkali carbonates. After the reaction is completed, PEEK is secluded by removing alkali metal fluoride and the polymerization solvent.

The stiff aromatic polymer backbone is the prime reason for possessing such high thermal transitions and mechanical propertiesThus, the polymer can be used at temperatures such as 240°C.

Popular Applications of Polyetheretherketone (PEEK) 

PEEK Plastic is one of the most utilized thermoplastic materials in industries like aerospace, automotive, biomedical, electrical, etc. Its might and vigor make it suitable for manufacturing bearings, insulation cables, safety gears, pumps, heavy machine parts, valves, compressors, semiconductors, etc.

Let’s dive into some of the applications in detail.

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Aerospace 

Products and components made up of PEEK are steadily replacing aluminum and other metals in the aerospace industry. There are many components in the aerospace market with acceptable tolerances manufactured more cost-effectively.

  1. Crucial engine parts can be produced with intricate designs, as Polyetheretherketone can withstand high temperatures. Elements with the need for high lubrication and inter-biological reactions to different scenarios.
  2. The polymer can heavily reduce smoke and gas emissions for the interior part. Fire resistance will also play a major part in providing safety.
  3. PEEK will benefit the exterior as it can provide great rain erosion. Even here, wear and tear resistance properties will come in handy to protect the plane’s exterior part for the long term.

Healthcare 

Healthcare products are about safety, comfort, and mobility. Polyetheretherketone can manufacture cost-effective, wear, tear, chemical, and heat-resistant products. Its applications include dental instruments, safety guards, endoscopes, thermometers, and dialyzers.

  1. Out of many products that PEEK has replaced, dental syringes, which PEEK manufactures, have become lighter and more cost-effective than aluminum and metal.
  2. Sterile boxes, mechanical limbs, tooth, and load-bearing implants are other products that PEEK actively manufactures.
  3. PEEK offers excellent resistance to stress crack and mechanical strength to deal with chemicals, steam, water, and other available solvents at hospitals and clinics.

Electronics

PEEK plastic already has a significant presence in the electronics market. Household products like Mobile phones, cables, setup boxes, refrigerators, ACs, washing machines, computers, laptops, and electronic wearables. In some way, all these products or parts of their assembled components are produced using PEEK.

  1. It can be utilized for making products with temperature, frequency, and pressure fluctuations.
  2. Great mechanical properties will maximize safety and comfort while handling silicon wafers.

Apart from those applications, PEEK also takes over other markets like FMCG, hospitality, chemicals, packaging, transportation, and logistics.

Processing of PEEK Material 

PEEK plastic can be processed in injection molding, extrusion, and compression molding; however, molding conditions can heavily affect its mechanical properties.

Before processing it, drying for at least 3 hours at 150°C is recommended. By doing that, we can avoid molding defects.

Let’s check on PEEK’s processing with the injection molding method –

Injection Molding 

  1. The advisable mold temperature is 60-190°C for good crystallization and eliminates warping.
  2. Tweaking with a temperature of 200°C after crystallization is possible, but only when the proceeding component requires high dimensional stability.
  3. We advise using injection molding only to manufacture tiny components with very tight dimensional tolerances for near-perfect production quality.
  4. The advised injection pressure is 70-140 Mpa.
  5. The advised mold shrinkage is Unfilled – 1.2-2.4%, Filled – 0.1-1.1%.

Let’s check on PEEK’s processing with the extrusion method –

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Extrusion 

  1. The cooling temperature would be crucial in guiding the crystallinity and performance.
  2. When it to comes to sheet extrusion for cooling cylinders, the temperature should be 50°C for amorphous material.
  3. For crystalline and opaque materials cooling cylinder temperature should be 170°C.

The Future of PEEK Material 

Global PEEK market share by Application, 2018
Chart by Visualizer
Source: GrandWireResearch.com

According to a study by Grand View Research, the global Polyetheretherketone market was estimated at 684.8 million in 2018. And pegged to have a CAGR of 7.2% from 2019 to 2026. Surely, things will change drastically because of the Covid-19 pandemic.

However, the medical industry’s push (due to the pandemic) and impressive growth in the automotive segment are due to an increase in demand for lightweight, fuel-efficient, and less-pollution-creating vehicles.

North America, Europe, and Asia-pacific are the biggest consumers of PEEK and will further push the growth. Asia-pacific is the fast-growing region for plastic processing, let alone Polyetheretherketone, because of increased manufacturing spending and FDI.

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FAQs 

Below are the frequently asked questions on PEEK material properties and PEEK tensile strength. Let’s dive deep to learn more.

Why is PEEK plastic so expensive?

Often manufacturers get surprised by the high price point of the material. The price is said to be high compatibility with CNC milling machines.

Is PEEK used in food applications?

All the PEEK grades are compliant with FDA regulation 21 CFR 177.2415. So it is safe and secure for repeated food contact.

Can we 3D print from PEEK?

PEEK can be 3D printed in the temperature range of 370°C to 450°C. The bed temperature is standard at 120°C. It should be noted that it takes a bit more time with PEEK 3D printing than with other materials, but if enough time is spent, the quality of the products will not disappoint.

How strong is peek?

PEEK is a strong material with a GPa of 3.6 and a tensile strength of 90 to 100 MPa.

What is the melting point of PEEK?

343°C – the melting point of PEEK.

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Final Words 

Thus, was my knowledge and insights on PEEK material. Although expensive, PEEK’s outstanding mechanical properties surely put a lot on the table for the price. The thermoplastic’s fantastic machining capabilities also come as a boon for a manufacturer looking to speed up production without hampering the quality of the product.

I hope you liked the article. I would really appreciate it if you shared our reviews in the comment box.

Have a wonderful week.

1 thought on “What is PEEK Material? | The Definitive Guide”

  1. PEEK is certainly impressive at high temperatures, but how does the strength go down with temperature? Is there a Strength vs Temperature graph? All the way to 250 C?
    TIA

    Reply

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