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.