PEEK vs. ULTEM vs. PPS-GF20

Which high-performance polymer is suitable for my application?

Ein Bauteil aus PPS-GF. Hergestellt mittels FGF (Granulatdruck).

Introduction: Three materials, one crucial choice

Anyone wanting to manufacture highly stressed plastic components using 3D printing will sooner or later face the same question: PEEK, ULTEM (PEI) or PPS? All three are considered high-performance thermoplastics – but there are significant differences in processability, cost, thermal stability and application profile.

This article provides a technically sound, practical comparison of the three materials, including actual characteristic values from datasheets and clear recommendations for typical industrial application scenarios. Malping processes all three materials using both FFF and FGF pellet printing on the AIM3D ExAM 510.

The three materials in profile

1. PEEK – the undisputed king of high performance

Polyetheretherketone (PEEK) is the highest-performing polymer readily available for 3D printing. It combines excellent mechanical properties, exceptional chemical resistance, biocompatible special grades, and a continuous operating temperature of up to 250 °C, all at a comparatively low weight.

Malping's portfolio includes PEEK in three variants: natural (unfilled), GF20 (glass fiber reinforced), and CF30 (carbon fiber reinforced) . For high-volume production and large components, Malping relies on FGF pellet printing, which uses granules instead of filament – reducing material costs from €500–700/kg (filament) to €80–150/kg (granules).

Challenge: PEEK requires printing temperatures of 380–420 °C as well as a heated build chamber and places the highest demands on printer hardware and process parameters.

2. ULTEM 9085 (PEI) – the strong PEEK alternative

Polyetherimide (PEI), specifically the ULTEM 9085 variant, is the standard for additive manufacturing in the aerospace industry. The material meets the FAR 25.853 standard for Flame, Smoke and Toxicity (FST) – a certification that is virtually indispensable in aircraft construction. Like all PEI types, ULTEM 9085 is amorphous and has no defined melting point.

Compared to ULTEM 1010, 9085 has a lower glass transition temperature of ~186 °C (vs. ~217 °C) and no FDA approval for food contact – but it does have the FST certification, crucial for industrial 3D printing, and higher impact strength. It is by far the most widely used PEI material in industrial FFF manufacturing.

Challenge: ULTEM 9085 is sensitive to aggressive solvents, halogenated compounds, and concentrated acids. Its mechanical properties—especially stiffness and tensile strength—are significantly lower than those of PEEK, limiting its use in structurally highly stressed components. Furthermore, its water absorption (~1.1%) is higher than that of PEEK and PPS-GF20.

3. PPS-GF20 – the underestimated cost winner

Polyphenylene sulfide (PPS) with 20% glass fiber reinforcement is the most underrated material in this trio. PPS offers inherent chemical resistance comparable to PEEK in certain media (e.g., strong acids) and achieves UL94 V-0 at a wall thickness of just 1.5 mm.

The printing temperature, at 310–350 °C, is significantly lower than that of PEEK or ULTEM, making the process more accessible and saving energy. Water absorption is exceptionally low at 0.11% (equilibrium value at 70% RH, 23 °C) – an advantage in humid or wet environments.

For automotive and electronics applications where electrical insulation (surface resistance > 10¹² Ω, dielectric strength 6.05 kV/mm) and dimensional accuracy are paramount, PPS-GF20 is often the most economical choice.

Challenge: PPS-GF20 is not biocompatible and is unsuitable for medical applications. Furthermore, its HDT (heat transfer temperature) of 1.8 MPa (125.8 °C after annealing at 130 °C) is significantly lower than that of PEEK. Post-annealing at 230 °C can increase the HDT to up to 219.6 °C. The glass fiber requires wear-resistant dies (steel or PCD-tipped).

Key performance indicator comparison at a glance

The following table is based on manufacturer data sheets (Ensinger TECAFIL, 3DXTech FibreX, Fiberon PPS-GF20) and Malping's internal test results. All values refer to 3D-printed test specimens (XY plane, annealed).

Characteristic	PEEK (CF30)	ULTEM 9085 (PEI)	PPS-GF20
density	1.30–1.43 g/cm³	1.34 g/cm³	1.36 g/cm³
Glass transition temperature (Tg)	~143 °C	~186 °C	95 °C
Melting point	~343 °C	-	279.6 °C
HDT (0.45 MPa)	~250–280 °C	~153 °C	236.3 °C*
HDT (1.8 MPa)	~200–230 °C	~130 °C	125.8 °C*
Tensile strength (XY)	~150–200 MPa	~71 MPa	64.1 MPa
Traction E-modulus (XY)	~13,000 MPa	~2,540 MPa	4,552 MPa
Flexural strength (XY)	~220–260 MPa	~115 MPa	102.3 MPa
Bending modulus (XY)	~12,000 MPa	~2,690 MPa	4,111 MPa
Charpy (XY, notched)	~10–15 kJ/m²	~5–8 kJ/m²	7.3 kJ/m²
Water absorption	<0.1%	~1.1%	0.11%
Flame retardant	UL94 V-0	UL94 V-0 + FAR 25.853	UL94 V-0
Chemical resistance	Excellent	Medium	Very good
Biocompatibility	Yes	No	No
Pressure temperature	380–420 °C	350–390 °C	310–350 °C
Filament price level	High	Medium-High	Medium
FGF granules available	Yes	Yes	Yes

* PPS-GF20: HDT values after annealing at 130 °C. After annealing at 230 °C, HDT (0.45 MPa / 1.8 MPa) rises to 248.9 °C / 219.6 °C.

Application profile: When which material?

Material selection depends on three key factors: continuous thermal stress, mechanical requirements, and regulatory framework. The following decision matrix provides initial guidance.

Application scenario	PEEK	ULTEM 9085	PPS-GF20
Continuous operating temperature > 200 °C	✅ First choice	❌ Not suitable	⚠️ Only glowed
High mechanical load (CF variant)	✅ First choice	➖ Average	➖ Average
Medical technology / Implants	✅ Best option	❌ Not suitable	❌ Not suitable
Chemical environment / solvents	✅ Excellent	⚠️ Restricted	✅ Very good
Electrical Insulation (UL94 V-0)	✅ Yes	✅ Yes	✅ Yes
Aerospace (FAR 25.853 FST)	⚠️ Possible	✅ First choice	❌ Not certified
Large-volume components (FGF)	✅ Ideal	✅ Well suited	✅ Well suited
Cost-sensitive serial parts	❌ Expensive	⚠️ Medium	✅ Cheapest option
Automotive / Electronics	✅ Possible	✅ Possible	✅ First choice

Detailed analysis by industry

Mechanical engineering and plant engineering

High-temperature applications with static and dynamic loads are the core area of expertise for PEEK CF30. Bearings, sliding rings, guide elements, and housing components that are continuously operated above 150 °C cannot be covered by PPS-GF20. ULTEM is borderline suitable for structural components in this context.

For voluminous machine components with a component volume of approximately 300 cm³ or more, Malping's FGF technology is clearly economically advantageous: The cost benefit from pellet granules adds up considerably for larger production runs.

Electrical engineering and electronics

All three materials achieve UL94 V-0. PPS-GF20 is often the first choice here: low printing temperature, very good electrical insulation (dielectric strength 6.05 kV/mm, surface resistance > 10¹² Ω), low moisture absorption, and comparatively low material costs make PPS the efficiency champion in this segment. ULTEM 9085 is the mandatory solution as soon as FAR 25.853 FST compliance is required.

For applications involving extreme temperatures or aggressive cleaning media, PEEK remains the only option.

Medical technology

PEEK (natural color) is a standard material in medical technology: It is biocompatible, sterilizable (steam, EtO, gamma radiation), and proven in applications near implants. ULTEM 9085 is not suitable for this segment – those requiring medical approvals should use ULTEM 1010 (FDA/NSF approved) or PEEK medical grade. PPS-GF20 is completely unsuitable for this segment.

Chemical industry and laboratory technology

PPS-GF20 exhibits excellent resistance to most acids, alkalis, and organic solvents – making it almost on par with PEEK. For components subjected to high chemical stress where extreme temperatures are not present, PPS-GF20 is the more economical choice. ULTEM is significantly more susceptible to concentrated acids and halogenated solvents – this should be taken into account when selecting the material.

Printability and process requirements

The processability differs considerably and affects not only the part quality but also the economic costs.

PEEK

• Printing temperature: 380–420 °C

• Heated build chamber required (> 100 °C)

• Abrasive CF/GF variants require wear-resistant nozzles

• FGF printing possible: AIM3D ExAM 510 (510×510×400 mm build volume)

• Drying: essential (< 0.1% moisture before printing)

ULTEM 9085 (PEI)

• Printing temperature: 350–390 °C

• Heated build chamber recommended (≥ 70 °C)

• Amorphous – low warpage, but no chemical resistance to solvents

• FAR 25.853 FST certification – prerequisite for aerospace use

• No annealing required for standard applications

PPS-GF20

• Printing temperature: 310–350 °C

• Print bed: 80–90 °C, room temperature build chamber possible

• Wear-resistant nozzle (steel/ruby) absolutely necessary

• Drying: 100 °C / 10 h before printing; < 20% relative humidity during storage

• Glow heating at 130 °C / 10 h recommended; at 230 °C for maximum HDT

• Shrinkage: XY approx. 0.35–0.49%, Z approx. 0.25–0.28% (after annealing)

Economic efficiency: Cost overview

Material costs are only one part of the overall calculation. Processing costs, scrap rates, and rework also play a role.

PEEK filament: 500-700 €/kg | PEEK granules (FGF): 80-120 €/kg

ULTEM 9085 filament: €150–280/kg | Granules: €30–100/kg, limited availability

PPS-GF20 filament: €110–150/kg | cheaper than ULTEM and significantly cheaper than PEEK

For large-volume components (> 300 cm³), Malping's FGF granulate printing with the AIM3D ExAM 510 offers the greatest economic advantage. With PEEK granulate, the pure material costs are around 80% lower than the filament price – while simultaneously offering a significantly larger build volume (104 liters vs. ~27 liters for FFF systems).

→ You can read more about the economic viability of FGF here .

Conclusion: No material is universal

PEEK, ULTEM and PPS-GF20 are not interchangeable alternatives – they are complementary materials with clearly defined strengths.

• PEEK is the first choice when maximum thermal, mechanical and chemical resistance is required – and in medical technology there is no alternative.

• ULTEM 9085 is an aerospace-certified material (FAR 25.853 FST) and is the industrial FFF standard for aerospace and transportation applications with flame retardancy requirements.

• PPS-GF20 is the economic champion for automotive, electronics and chemically stressed environments – with excellent electrical insulation and lowest pressure temperature in a trio.

Malping processes all three materials in series – using FFF for precise small components and FGF pellet printing for bulky components up to 510×510×400 mm. We offer free consultation on material selection.

Submit your inquiry now: Contact

Our PEEK 3D printing guide: Guide

More information about FGF granule printing: Granules

FAQ – Frequently Asked Questions

Can PPS-GF20 replace PEEK?

For applications with continuous temperatures up to approximately 120 °C and without biocompatibility requirements, PPS-GF20 is an economically viable alternative. Above this limit or in cases of extreme mechanical demands, PEEK remains the better choice.

Is ULTEM 9085 better than PEEK?

Not generally. ULTEM 9085's decisive advantage lies in its FAR 25.853 certification for aerospace applications and its easier processing. PEEK is superior in almost all mechanical and thermal properties and remains the only option for high-temperature and biocompatibility requirements. ULTEM 9085 is not a thermal alternative to PEEK. Its operating temperature of approximately 170 °C is significantly lower than that of PEEK (approximately 260 °C).

Which material has the best chemical resistance?

PEEK and PPS-GF20 perform at a comparably high level. PPS-GF20 can even have an advantage with certain concentrated alkalis or organic solvents. ULTEM is more susceptible to halogenated solvents and concentrated acids.

Why do I need a wear-resistant nozzle for FGF printing with PPS-GF20?

The glass fibers in PPS-GF20 are highly abrasive. Standard brass nozzles are significantly worn down within a few hours, leading to dimensional deviations and quality problems. For all glass fiber and carbon fiber reinforced materials, Malping recommends only hardened steel nozzles or PCD-tipped nozzles.

PEEK 3D printing vs. CNC manufacturing

When does 3D printing become worthwhile?

by Dr.-Ing. Bastian Gaedike, Malping GmbH, #MATERIALPINGUIN

The most important points in 30 seconds

PEEK can be processed using both CNC milling and 3D printing – both methods have their place.

CNC excels at tight tolerances and smooth surfaces.

3D printing is winning in terms of complex geometries, short lead times and material efficiency.

The decision depends on geometry, quantity, tolerance, and budget.

Malping GmbH is proficient in both processes and will advise you neutrally.

Ein additiv gefertigtes PEEK-Bauteil mit nachbearbeiteter Oberfläche.

Introduction

PEEK (polyetheretherketone) is one of the world's highest-performing high-performance plastics. It withstands temperatures up to 250 °C in continuous operation, is chemically resistant, biocompatible, and significantly lighter than metal. No wonder it is in such high demand in the chemical, medical technology, aerospace, and mechanical engineering industries.

Anyone wanting to have a PEEK component manufactured faces a fundamental question: CNC milling or 3D printing? Both methods can process PEEK – but they differ significantly in their strengths. This article provides you with an honest, practical comparison.

The two procedures explained briefly

CNC milling of PEEK

CNC milling involves removing material from a PEEK semi-finished product (rod, sheet). The tool follows a computer-controlled path and "subtracts" material until the desired component is created. The result: very high dimensional accuracy, smooth surfaces, and complete isotropy. This means the component has the same mechanical properties in all directions because it is made from a homogeneous raw material.

Challenge: Complex internal geometries, undercuts, or internal channels are difficult or even impossible to achieve. Furthermore, material removal occurs, which is particularly problematic with expensive PEEK blanks.

PEEK 3D printing (FFF / FGF)

In 3D printing (FFF = Fused Filament Fabrication or FGF = Fused Granulate Fabrication), PEEK is applied layer by layer. A print head heats the material to over 400 °C and builds the component from the bottom up. The result: maximum design freedom, minimal material consumption, and short lead times.

Challenge: The layered structure leads to anisotropic properties (different strength depending on the direction) and somewhat rougher surfaces. Tight tolerances below 0.05 mm require CNC post-processing.

Malping GmbH uses, among other things, the ExAM 510 from AIM3D for PEEK 3D printing – an FGF granule printer that works directly with PEEK granules, thus significantly reducing material and process costs.

Direct comparison

criterion	CNC milling	PEEK 3D printing
geometry	Complex is possible, but more time-consuming.	Complex geometries without problems
Tooling costs	High (milling cutter, clamping)	No tooling costs
Dimensional tolerance	±0.02 mm typical	±0.1–0.3 mm typical
surface	Very smooth (Ra < 1 µm)	Layer texture visible
Quantity	Economical from 1 piece	Economical from 1 piece
Material utilization	Machining, high material removal	Additive, minimal waste
Lead time	1–3 days	1–2 days
Internal structures	Not possible	Possible (grates, channels)

When which procedure?

CNC is better if...	3D printing is better if...
Very tight tolerances (< 0.05 mm)	Complex internal geometries / channels
Smooth sealing surfaces are needed.	Lightweight construction through lattice structures
Small details (< 1 mm)	One-off pieces / prototypes quickly
Custom rework required	Cost-effective design iterations
High production volume with tolerance	Save on material when using expensive PEEK blanks

My tip: Many components benefit from a combination – 3D printing for the basic shape, CNC post-processing for critical fits and sealing surfaces. Malping GmbH offers precisely this hybrid approach.

3 practical examples from everyday machine use

1. Chemical & Process Industry: Pump Housing Cover

Task: A lid for a chemical pump must be made of PEEK: aggressive media, 180 °C operating temperature, pressure tightness.

• CNC milling would be the classic choice: tight tolerances, dense surface.

• In this specific case, 3D printing helped: integrated internal flow channel, fewer parts, faster availability.

• Result: 10 days instead of 6 weeks delivery time, 40% lower costs.

2. Medical technology: Instrument holder in the sterilization area

Task: Holder for surgical instruments, autoclavable, dimensionally accurate fits.

• CNC was the right choice here: tolerance ±0.02 mm required, surface Ra < 0.8 µm.

• The geometry was simple enough to be milled economically.

• Result: Standard-compliant parts, economical from a quantity of 5.

3. Mechanical and plant engineering: Guide element with lightweight grid

Task: Guide element for a linear drive – PEEK for abrasion resistance, but as light as possible.

• 3D printing with internal grid: same load-bearing capacity, 35% less weight.

• CNC machining would not have been possible here at all (internal structure).

• Result: Functional integration that was not achievable with conventional machining.

Frequently Asked Questions

Is PEEK 3D printed as good as milled PEEK?

Mechanically: almost. Strength is lower in the Z-direction (perpendicular to the layers). This isn't a problem for many applications – the values are very good for tensile and compressive loads in the plane. Ask us about load-optimized compression orientation.

What tolerances can PEEK 3D printing achieve?

Typical tolerances are ±0.1–0.2 mm. With CNC post-processing of critical surfaces: ±0.02 mm and better. This is perfectly adequate for most housings, brackets, and functional components.

At what quantity does CNC become more cost-effective than 3D printing?

It's impossible to give a general answer – it depends heavily on the geometry. Simple turned parts are often more cost-effective with CNC machining for quantities as low as 10. Complex geometries with undercuts remain more economical with 3D printing, regardless of the quantity. Contact us – we'll calculate both options for you.

Conclusion

There is no universally "better" method. CNC milling and PEEK 3D printing are tools – and like any tool, they only reach their full potential when used correctly. As material penguins – exotic yet highly adapted – we know both worlds and can help you make the right decision.

Your component deserves the right process. Not just the next best one.

Free initial consultation

Are you planning to use a PEEK component?

We analyze your requirements and recommend the appropriate manufacturing process – without sales pressure.

Contact: info@malping.de | www.malping.de | #MATERIALPENGUIN

author

Dr.-Ing. Bastian Gaedike

Founder & Managing Director, Malping GmbH

Neuhausen auf den Fildern | malping.de | #MATERIALPENGUIN

What is PEEK? Properties & applications in industrial 3D printing

Introduction

In the world of high-performance plastics , PEEK (polyetheretherketone) has established itself as one of the most versatile and efficient materials. Particularly in additive manufacturing, i.e., industrial 3D printing, PEEK opens up numerous possibilities for companies in mechanical engineering, chemicals, medical technology, and many other sectors. In this article, we will show you what distinguishes PEEK, what properties make it so special, and in which applications 3D printing of PEEK components offers decisive advantages.

Eine Demo-Baugruppe aus PEEK-Bauteilen.

What is PEEK?

PEEK is a thermoplastic, semi-crystalline, high-performance polymer belonging to the polyaryletherketone (PAEK) family. Developed in the late 1970s, it is distinguished by its excellent combination of mechanical, chemical, and thermal properties. Due to its versatility, PEEK is now used in the most demanding industrial sectors.

Key properties of PEEK

1. High temperature resistance

PEEK can be used continuously at temperatures up to 250 °C and retains its mechanical stability even under short-term loads up to 300 °C.

2. Excellent chemical resistance

PEEK resists aggressive chemicals such as acids, bases and organic solvents – a clear advantage in the chemical and process industries.

3. High mechanical strength

With a tensile strength of up to 100 MPa and high stiffness, PEEK remains dimensionally stable even under load.

4. Low friction & wear resistance

PEEK exhibits excellent tribological properties, making it ideal for bearings, guides and sliding components.

5. Biocompatibility & Sterilizability

PEEK is biocompatible and sterilizable, which is why it is also used in medical technology (e.g. implants, surgical instruments).

6. Electrical insulation & flame retardancy

Thanks to its electrical insulation properties and inherent flame retardancy (UL 94 V-0), PEEK is also in demand in the electronics industry.

PEEK in 3D printing: Opportunities & Challenges

With the advent of specialized 3D printers for high-temperature materials, PEEK has established itself as a key material in industrial 3D printing. In particular, the Fused Deposition Modeling (FDM) process is used for processing PEEK.

Advantages of PEEK in 3D printing

• Design freedom : Complex geometries and functional components can be realized.

• Rapid availability : Components can be produced within a few days.

• Cost efficiency for small series & prototypes : No expensive tools required.

• Individualization : Components can be adapted to specific requirements.

challenges

• High printing temperatures : Extruder up to 400 °C, heated print bed & closed build chamber required.

• Anisotropy : Mechanical properties can be direction-dependent.

• Material costs : PEEK filament is more expensive than standard plastics.

  
  

Typical applications of 3D-printed PEEK

• Mechanical engineering : Functional components, bearings, gears, guide elements

• Chemical industry : Chemical-resistant seals, pipes, pump parts

• Medical technology : Prototypes for implants, surgical instruments, cleanroom components

• Aerospace & Automotive : Lightweight components, structural elements

• Electronics industry : insulators, housings, connectors

  
  

Conclusion

PEEK uniquely combines temperature resistance, chemical resistance, strength, and processability – properties that make it the ideal material for industrial 3D printing. With modern manufacturing facilities like those at Malping GmbH, companies can benefit from customized PEEK components – quickly, economically, and reliably.