Polyetheretherketone occupies a performance tier that no other injection-moldable polymer reaches — a sustained service temperature approaching 260 °C, strength-to-weight ratio rivaling aluminum, resistance to virtually every industrial chemical except concentrated sulfuric and nitric acids, inherent biocompatibility validated for long-term implant use, and the ability to replace metal in precision components that must withstand 100 million fatigue cycles without measurable dimensional change.
The challenge is not finding a reason to specify PEEK plastic. The challenge is executing the specification correctly. PEEK injection molding operates at barrel temperatures of 370–420 °C — higher than most precision machines are configured for. Mold temperatures of 160–200 °C require specialized hot-oil or electric heating systems. Crystallinity management determines whether a PEEK part achieves its rated mechanical properties or underperforms by 30–40%. And the material cost — typically 30–80× that of ABS — means that every processing failure is expensive.
This guide covers both the material science and the manufacturing discipline required to deliver PEEK plastic programs that perform to specification. It draws on Dimud’s experience processing PEEK across medical device components, semiconductor handling equipment, automotive precision bearing seats, and robotics joint components — providing the technical foundation for engineers who need to understand the material before committing to tooling.
What Is PEEK Plastic?
PEEK plastic — polyetheretherketone — is a semi-crystalline high-performance thermoplastic belonging to the polyaryletherketone (PAEK) family, characterized by a repeating unit of two ether (E) linkages and one ketone (K) group connecting aromatic phenylene rings. This 2:1 ether-to-ketone ratio is not incidental — it creates the specific balance of chain flexibility and interchain attraction that gives PEEK its unique combination of melt processability, thermal stability, and mechanical performance.
The polymer was first commercialized by ICI (now Victrex) in 1978 under the Victrex® PEEK brand, and it remains the reference standard against which all competing high-performance thermoplastics are measured. The molecular architecture explains the properties:
The aromatic backbone (phenylene rings in the main chain) provides the thermal stability and rigidity that defines PEEK’s performance ceiling. Unlike aliphatic backbone polymers (PE, PP, PA) that soften progressively above their glass transition temperature, PEEK’s aromatic rings restrict chain mobility up to 143 °C (Tg) — and the semi-crystalline domains formed during controlled cooling maintain structural integrity to within 30–40 °C of the 343 °C crystalline melting point.
The ether linkages provide chain flexibility that enables PEEK to be melt-processed in injection molding equipment (at 370–420 °C barrel temperature) — a processability advantage over other aromatic polymers like PPS or PPSU that require more restrictive processing conditions.
The ketone carbonyl groups create interchain dipole interactions that contribute to PEEK’s wear resistance, chemical barrier properties, and fatigue performance under cyclic loading.
What PEEK plastic delivers that no other injection-moldable thermoplastic matches:
- Continuous service temperature: 240–260 °C (versus PC’s 130 °C, PA66’s 180 °C, PPS’s 220 °C)
- Tensile strength at 200 °C: > 100 MPa in 30% carbon fiber grades — performance that metals require special alloys to match
- Chemical resistance: withstands > 95% of all industrial solvents, acids, and bases; exceptions are concentrated H₂SO₄ and HNO₃
- Hydrolytic stability: retains mechanical properties after continuous immersion in steam at 260 °C for thousands of hours
- Inherent biocompatibility: non-cytotoxic, non-hemolytic, compliant with ASTM F2026 for surgical implant applications
- Radiolucency: X-ray and MRI transparent — critical for implant-adjacent medical applications
- Radiation resistance: maintains properties after gamma sterilization doses up to 2,000 kGy
What PEEK plastic costs:
- Raw material: $80–$400/kg depending on grade versus $3–8/kg for ABS or PP
- Processing equipment: barrel temperatures of 370–420 °C require upgraded or dedicated injection molding machines
- Mold tooling: elevated mold temperatures (160–200 °C) require hot-oil or electric heating systems not used for commodity polymers
- Crystallinity management: process discipline requirements exceed those for any other commercial injection-molded thermoplastic
В Димуд, PEEK plastic programs are reserved for applications where this performance-cost equation is genuinely favorable — where the alternative is a metal component that adds mass, corrodes, or requires secondary machining, or where no other polymer survives the service environment.
Grade Landscape: Unfilled, Reinforced, and Implant-Grade PEEK
Unfilled PEEK (Natural / Standard Grade)
The base homopolymer: semi-crystalline, natural light amber color, providing the full chemical resistance and biocompatibility profile of PEEK without filler contributions to mechanical properties. Key commercial grades include Victrex® PEEK 450G (Victrex), KetaSpire® KT-820 (Solvay), and Vestakeep® 4000G (Evonik).
Unfilled PEEK is specified where:
- Chemical resistance is the primary driver (fillers can open pathways for chemical penetration)
- Biocompatibility certification is required (implant-grade unfilled PEEK to ASTM F2026)
- Electrical insulation performance must be maintained (carbon fiber grades are conductive)
- Optical inspection through the part is required
Glass Fiber Reinforced PEEK (GF-PEEK)
10–30% short glass fiber increases flexural modulus by 2–3× and HDT by 20–30 °C versus unfilled grade, at the cost of reduced chemical resistance at fiber-matrix interfaces and increased abrasive tool wear in injection molding:
- 10% GF-PEEK: Modest property improvement; good balance for food-contact and semiconductor applications
- 30% GF-PEEK: Maximum structural performance without carbon fiber cost; standard for automotive bearing seats and industrial wear components
Carbon Fiber Reinforced PEEK (CF-PEEK)
10–30% short carbon fiber provides the highest stiffness and strength available in any injection-moldable thermoplastic:
| Grade | Tensile Strength | Flexural Modulus | HDT | Specific Notes |
|---|---|---|---|---|
| 10% CF-PEEK | 175–200 MPa | 14,000–17,000 MPa | 310 °C+ | Electrically conductive |
| 30% CF-PEEK | 210–240 MPa | 18,000–22,000 MPa | 315 °C+ | Metal replacement tier |
CF-PEEK is the specification for aerospace structural brackets, robotic joint components, and any application where maximum stiffness-to-weight ratio is the design objective. The electrical conductivity of CF-PEEK disqualifies it from electrical insulation applications but enables ESD-dissipative use in semiconductor handling.
Wear-Grade PEEK (PTFE/Graphite/CF Hybrid)
Formulated with PTFE (10–15%), graphite (10%), and carbon fiber (10%) for self-lubricating wear applications — bearing surfaces, seal rings, piston components, and any sliding-contact application where dry lubrication is required:
- PV limit (pressure × velocity): 2–5× higher than unfilled PEEK
- Dynamic friction coefficient: 0.10–0.20 (versus 0.35–0.45 for unfilled PEEK)
- Wear rate: 10–50× lower than unfilled PEEK under equivalent PV conditions
Wear-grade PEEK is the dominant specification for pump components, compressor valve seats, and medical instrument bushings at Dimud.
Implant-Grade PEEK
The most stringent grade category. Implant-grade PEEK meets:
- ASTM F2026: Standard Specification for PEEK Polymers for Surgical Implant Applications — purity criteria, molecular weight minimums, mechanical property thresholds
- ISO 10993: Biological evaluation of medical devices — full biocompatibility series
- USP Class VI: Systematic injection test, intracutaneous reactivity, implantation test
- Virgin resin only; no colorants, fillers, or processing aids not covered by the specification
Commercial implant grades include Victrex® PEEK-OPTIMA® и Invibio® Biomaterial Solutions products — segregated manufacturing environments, lot traceability from monomer synthesis to finished pellet, and Certificate of Compliance to ASTM F2026 as standard supply chain documents.
Other Specialty PEEK Grades
| Grade | Modification | Key Benefit | Заявка |
|---|---|---|---|
| ESD/Conductive PEEK | Carbon black or CF | Static dissipation | Semiconductor wafer trays, IC test sockets |
| High-flow PEEK | Lower MW | Thin-wall moldability | Miniature connectors, precision instruments |
| PEEK/PTFE compound | PTFE blend | Enhanced chemical resistance + lubricity | Chemical pump components |
| Ceramic-filled PEEK | ZrO₂ or TiO₂ | Radiopacity (bone-matching opacity) | Dental implant abutments |
| Food-contact PEEK | FDA/EU 10/2011 certified | Food safety | Food processing equipment components |
Key Physical and Mechanical Properties
| Недвижимость | Unfilled PEEK | 30% GF-PEEK | 30% CF-PEEK | Wear-Grade PEEK | Test Standard |
|---|---|---|---|---|---|
| Плотность | 1.30–1.32 g/cm³ | 1.49–1.54 g/cm³ | 1.40–1.44 g/cm³ | 1.32–1.40 g/cm³ | ISO 1183 |
| Tensile Strength (23 °C) | 100–110 MPa | 160–190 MPa | 210–240 MPa | 90–120 MPa | ISO 527 |
| Tensile Strength (200 °C) | 50–60 MPa | 90–110 MPa | 120–150 MPa | 45–60 MPa | ISO 527 |
| Flexural Modulus | 3,600–4,100 MPa | 10,000–13,000 MPa | 18,000–22,000 MPa | 3,200–4,000 MPa | ISO 178 |
| Notched Izod Impact | 50–85 J/m | 60–90 J/m | 50–80 J/m | 40–70 J/m | ISO 180 |
| Heat Deflection Temp (1.82 MPa) | 152–160 °C | 280–300 °C | 305–315 °C | 150–158 °C | ISO 75 |
| Continuous Service Temp | 240–260 °C | 240–260 °C | 240–260 °C | 240–260 °C | UL 746B |
| Glass Transition Temp (Tg) | 143 °C | 145 °C | 145 °C | 140–143 °C | DSC |
| Melting Point (Tm) | 343 °C | 343 °C | 343 °C | 340–343 °C | DSC |
| Mold Shrinkage (flow) | 1.2–1.8 % | 0.5–1.0 % | 0.4–0.8 % | 1.0–1.5 % | ISO 294-4 |
| Water Absorption (23 °C, sat.) | 0.50 % | 0.30 % | 0.20 % | 0.30 % | ISO 62 |
| Химическая стойкость | Exceptional | Превосходно | Превосходно | Exceptional | — |
| Flammability | UL 94 V-0 | UL 94 V-0 | UL 94 V-0 | UL 94 V-0 | UL 94 |
| Limiting Oxygen Index | 35 % | 40 % | 43 % | 35 % | ISO 4589 |
| Dielectric Strength | 19–24 kV/mm | 16–20 kV/mm | Conductive | 18–22 kV/mm | IEC 60243 |
| Biocompatibility | ASTM F2026 / ISO 10993 | Limited (filler) | Limited (CF) | Limited | — |
| Radiation Resistance (gamma) | Excellent (to 2,000 kGy) | Хорошо | Хорошо | Хорошо | — |
Dimud Engineering Note — The 30% CF-PEEK Metal Replacement Threshold
30% CF-PEEK’s flexural modulus of 18,000–22,000 MPa and tensile strength of 210–240 MPa places it within the performance range of aluminum alloy 6061-T6 (flexural modulus ~69,000 MPa; tensile strength 276 MPa) at approximately 55% of the density. For components where stiffness is proportional to the cube of thickness (as in bending-loaded structural elements), designing in CF-PEEK with appropriate geometry optimization frequently achieves equivalent or greater component stiffness versus aluminum at 30–50% mass reduction. At Dimud, CF-PEEK metal replacement feasibility is assessed at DFM stage using FEA (Finite Element Analysis) as a standard deliverable for structural PEEK programs.
PEEK Injection Molding: Process Parameters and Critical Controls
PEEK injection molding is among the most technically demanding standard injection molding processes commercially practiced. The barrel temperatures required (370–420 °C) exceed the processing temperature of virtually every other commercial thermoplastic and approach the thermal limits of standard injection molding equipment. Mold temperatures of 160–200 °C require heating systems beyond standard water cooling infrastructure. And PEEK’s semi-crystalline solidification behavior means that crystallinity — and therefore mechanical properties — are directly determined by the thermal history the part experiences during and immediately after molding.
Machine Requirements for PEEK Injection Molding
Before process parameters, machine qualification is the prerequisite:
- Barrel and screw: Bimetallic barrel with corrosion- and wear-resistant liner (PEEK at 400 °C is aggressive); screw with controlled compression ratio (2.0–2.5:1 recommended); screw diameter sized for ≥ 25% barrel utilization to minimize residence time
- Maximum barrel temperature capability: 420–450 °C minimum; standard machines rated to 380 °C are insufficient for PEEK
- Nozzle: Hardened and insulated; open-tip design (reverse taper causes cold slug accumulation that produces black specks in PEEK parts)
- Clamping force: 0.4–0.6 T/cm² of projected area (similar to standard engineering polymers)
- Mold temperature controller: Hot-oil or electric cartridge controllers capable of 160–200 °C; standard water coolers cannot reach the required mold temperature range
Drying Protocol
PEEK’s water absorption (0.50% saturation) is moderate, but at 370–420 °C barrel temperature, any residual moisture causes hydrolytic chain scission that permanently reduces molecular weight and mechanical performance:
| Параметр | Unfilled PEEK | GF/CF-PEEK | Implant-Grade PEEK |
|---|---|---|---|
| Dryer type | Dehumidifying hopper (dew point ≤ −40 °C) | Same | Same; dedicated dryer |
| Temperature | 150–160 °C | 150–160 °C | 150 °C |
| Duration | 4–6 hours minimum | 4–6 hours | 5–8 hours |
| Target moisture | < 0.02 % | < 0.02 % | < 0.02 % |
| Verification | Karl Fischer titration | Karl Fischer | Karl Fischer (mandatory) |
| Max regrind | 10 % maximum | 5 % maximum | 0 % (virgin only, absolutely) |
Barrel and Melt Temperature
| Zone | Unfilled PEEK | 30% GF-PEEK | 30% CF-PEEK | Notes |
|---|---|---|---|---|
| Rear (Feed) | 340–360 °C | 350–370 °C | 355–375 °C | Controlled entry; avoid cold plugs |
| Middle (Compression) | 360–390 °C | 375–400 °C | 375–405 °C | Primary melt zone |
| Front (Metering) | 375–400 °C | 385–415 °C | 390–415 °C | Final melt temp |
| Nozzle | 370–395 °C | 380–405 °C | 380–405 °C | Open-tip; insulated; avoid cold slug |
Degradation ceiling: PEEK begins to degrade above 420–430 °C, producing discoloration and molecular weight reduction. At Dimud, barrel temperature is verified by calibrated thermocouple at machine qualification, with ±5 °C tolerance as the production standard. Residence time is calculated and documented for every PEEK machine configuration — short-residence purging protocols are mandatory when production is interrupted.
Mold Temperature — The Crystallinity Determinant
Mold temperature for PEEK injection molding: 160–200 °C
This is the single most impactful process parameter for PEEK mechanical properties. See Section 6 for full crystallinity management detail. The consequence in brief:
- Mold temperature < 160 °C: Amorphous or low-crystallinity PEEK; HDT drops from 152 °C to < 50 °C; strength, modulus, and chemical resistance all reduced 20–40% versus optimally crystallized parts
- Mold temperature 160–180 °C: Target range for engineering-grade crystallinity (30–35%) in most unfilled and reinforced PEEK programs
- Mold temperature 180–200 °C: Maximum crystallinity development; for demanding applications with continuous service > 200 °C
Achieving 160–200 °C uniform mold temperature requires dedicated hot-oil temperature controllers (not water units). Dimud’s PEEK programs use oil-type temperature controllers with ±3 °C stability as standard.
Injection Speed and Pressure
- Injection pressure: 100–160 MPa for unfilled PEEK; 130–180 MPa for 30% CF-PEEK (highest fill pressure among standard commercial thermoplastics)
- Hold pressure: 60–80% of injection pressure; extended hold critical for dimensional stability
- Back pressure: 5–10 MPa — very low; PEEK at 400 °C is sensitive to shear heating from back pressure
- Injection speed: Moderate to slow — fast injection of PEEK causes excessive shear at gate, producing weld-line weakness and surface discoloration; fill over 3–10 seconds is typical for precision components
Post-Mold Annealing
For applications requiring maximum crystallinity, dimensional stability, or thermal performance, post-mold annealing is standard practice:
- Temperature: 200–220 °C in a circulating air oven (above Tg but well below Tm)
- Duration: 2–4 hours for standard parts; 4–8 hours for thick-section or precision bearing components
- Fixturing: Parts annealed in precision fixtures to prevent distortion during crystallization completion
- Result: Crystallinity increases from 30–35% (as-molded) to 38–45% (annealed); HDT improves 10–20 °C; dimensional shrinkage completes, reducing post-assembly dimensional variation
Common Defects and Corrective Actions
| Дефект | Основная причина | Corrective Action |
|---|---|---|
| Black specks / contamination | Degraded material in barrel dead zones | Purge thoroughly; check nozzle tip; eliminate cold slug |
| Yellow/brown discoloration | Barrel overheating; long residence time | Reduce temp; purge; rightsize barrel for shot volume |
| Low mechanical properties | Low crystallinity from insufficient mold temp | Raise mold temp to 160°C+; verify temperature controller |
| Warpage (flat parts) | Non-uniform cooling; differential crystallinity | Balance cooling; uniform wall; anneal in fixture |
| Короткий удар | High viscosity; insufficient pressure/temp | Raise barrel temp; increase injection pressure; widen gate |
| Вмятины от раковины | Thick sections; insufficient hold | Core out thick areas; extend hold time |
| Weld lines (weak) | Low melt temp; multiple gates | Raise melt temp; consolidate gate; raise mold temp |
| Moisture-related splay | Inadequate drying | Extend drying; verify Karl Fischer; check hopper seal |
Mold Design Considerations for PEEK Plastic Components
PEEK injection molding imposes the most demanding mold design requirements of any standard commercial thermoplastic — elevated temperature operation (160–200 °C), high injection pressures (up to 180 MPa), and PEEK’s abrasive reinforced grades combine to require steel selection, heating system design, and gate engineering that differs fundamentally from ABS or PA tooling.
Steel Selection
| Steel | Заявка | Shot Life | Notes |
|---|---|---|---|
| H13 hardened (50–54 HRC) | Standard unfilled PEEK; GF-PEEK | 300,000–500,000 | Minimum acceptable for PEEK; gate wear monitoring required |
| S7 tool steel (air-hardened) | High-impact PEEK programs | 400,000–600,000 | Better thermal fatigue resistance at elevated mold temps |
| D2 (62–64 HRC) | CF-PEEK and wear-grade programs | 400,000–700,000 | High wear resistance for abrasive CF grades |
| H13 + PVD coating (TiN/TiAlN) | CF-PEEK high-volume programs | 600,000–1,000,000 | PVD coating essential for gate inserts on CF-PEEK |
P20 is not acceptable for PEEK programs under any conditions. PEEK’s processing temperature (370–420 °C) causes P20 to temper and lose hardness at operating mold temperature (160–200 °C), resulting in rapid parting line wear, flash generation, and dimensional drift within the first 50,000 shots.
Heating System Design
Achieving 160–200 °C uniform mold temperature requires an integrated heating system:
- Hot-oil channels: Primary heating method; oil temperature controllers at 170–210 °C supply channels sized 10–12 mm diameter, spaced 25–35 mm from cavity surface
- Cartridge heaters: Secondary option for compact tools or local temperature boost in areas where oil channels cannot be routed
- Insulation plates: Thermal insulation plates between the mold and platen are mandatory to prevent heat loss to the machine — without insulation, maintaining 180 °C mold temperature requires excessive heater capacity and produces non-uniform surface temperature
Dimud’s PEEK tool designs include thermal FEA simulation of the heating system before construction to verify temperature uniformity within ±5 °C across the cavity surface — a requirement that directly determines crystallinity uniformity and part-to-part mechanical consistency.
Конструкция ворот
PEEK’s high viscosity at injection conditions and sensitivity to shear degradation at gate regions requires careful gate sizing:
- Direct (sprue) gates: Preferred for single-cavity PEEK parts where gate size can be maximized; minimal shear, maximum packing efficiency
- Edge and fan gates: Used for flat PEEK structural components; gate thickness minimum 80% of wall to prevent freeze-off during extended hold
- Hot-runner valve gates: Recommended for multi-cavity PEEK programs — eliminates cold runners, enables precise valve timing to control fill dynamics, and avoids cold slug contamination. Hot-runner manifold must be rated for 420 °C service with PEEK-compatible seal materials
- Gate land: 0.5 mm maximum for unfilled PEEK; 0.3 mm for GF and CF grades
Ejection System
PEEK’s high stiffness and elevated processing temperatures create specific ejection requirements:
- Generous draft angles (1.5°–3° per side) — PEEK’s high modulus and thermal contraction from 180 °C mold temperature onto the core generates high ejection forces
- Blade ejectors or sleeve ejectors preferred for cylindrical and tubular PEEK parts
- Ejection force calculated by FEA at DFM stage for complex PEEK geometries
- Post-ejection fixturing recommended for PEEK parts with tight flatness tolerances
Crystallinity Control: The Property Multiplier in PEEK Programs
Crystallinity management in PEEK injection molding is not a refinement — it is the foundational requirement that determines whether a PEEK part delivers its rated performance or fails to justify its material cost. Engineers new to PEEK who treat it as a commodity amorphous polymer — molding it at low mold temperatures for fast cycles — consistently produce parts that disappoint.
What Crystallinity Determines in PEEK Parts
| Недвижимость | Amorphous PEEK (< 5% crystallinity) | Semi-crystalline PEEK (30–35%) | High-crystallinity PEEK (40–45%) |
|---|---|---|---|
| HDT (1.82 MPa) | < 50 °C | 152–160 °C | 155–165 °C |
| Tensile Strength | 80–90 MPa | 100–110 MPa | 105–115 MPa |
| Химическая стойкость | Significantly reduced | Full rated resistance | Full + slight improvement |
| Dimensional stability | Poor (creep above Tg) | Превосходно | Превосходно |
| Optical appearance | Transparent / amber clear | Opaque white/beige | Opaque white |
The critical failure mode: An engineer molds PEEK at low mold temperature (80 °C) to achieve fast cycle time. The part passes initial dimensional inspection. It passes room-temperature mechanical testing. It enters service at 120 °C — well within PEEK’s rated continuous temperature. The part creeps, deforms, and fails within 100 operating hours. Root cause: low mold temperature produced amorphous PEEK with HDT below 50 °C, not the 152 °C of correctly crystallized material.
The Mold Temperature — Crystallinity Relationship
| Температура пресс-формы | Resulting Crystallinity | Practical Consequence |
|---|---|---|
| 40–80 °C (water cooling) | 2–8% (amorphous) | Transparent; HDT < 50 °C; avoid for all engineering use |
| 80–120 °C | 10–20% (partial) | Hazy; variable properties; avoid for engineering use |
| 120–150 °C | 20–28% | Approaching target; marginal for demanding applications |
| 160–180 °C (target) | 30–35% | Full mechanical properties; rated HDT achieved |
| 180–200 °C | 35–45% | Maximum properties; use for highest-demand programs |
Post-Mold Annealing Protocol
Dimud’s standard post-mold annealing protocol for precision PEEK programs:
- Ejection at mold temperature: Parts ejected at 160–180 °C and placed immediately in pre-heated fixtures at 200 °C
- Annealing oven: Circulating air oven at 200–220 °C; temperature verified with calibrated probes; parts supported in stress-free orientation
- Duration: 2 hours minimum for wall thickness ≤ 3 mm; 4 hours for 3–8 mm; 6+ hours for > 8 mm
- Controlled cooling: Oven cooling at maximum 2 °C/minute to 80 °C before removal — prevents thermal shock crystalline cracking in thick sections
- Dimensional inspection: CMM inspection after annealing cooling to confirm shrinkage completion before any secondary machining operations
Metal Replacement with PEEK Plastic
Metal replacement is one of the primary commercial drivers for PEEK plastic programs — and one of the most technically and economically compelling value propositions in precision manufacturing. Understanding where PEEK wins the metal replacement argument, and where it does not, is essential for engineers evaluating the material.
Where PEEK Beats Metal
| Application Parameter | Steel / Stainless | Алюминий 6061 | 30% CF-PEEK |
|---|---|---|---|
| Плотность | 7.8–8.0 g/cm³ | 2.70 g/cm³ | 1.40–1.44 g/cm³ |
| Specific strength | Низкий | Средний | Высокий |
| Corrosion resistance | Stainless only | Хорошо | Exceptional |
| Electrical insulation | None | None | Full (CF grades conductive) |
| Magnetic interference | Significant | Minimal | None |
| MRI compatibility | Incompatible | Incompatible | Fully compatible |
| Secondary machining cost | Высокий | Средний | Reduced (net-shape molding) |
| Mass reduction vs steel | — | 65% | 82% |
| Mass reduction vs aluminum | — | — | 47% |
PEEK wins the metal replacement argument when: corrosion resistance is required without coating; electrical or magnetic insulation must be integrated into the component; MRI compatibility is specified; component geometry justifies injection molding economics (> 500 units annually); and mass reduction is a design objective.
Metal remains the better specification when: service temperatures exceed 260 °C; compressive load bearing exceeds PEEK’s compressive strength (> 120–170 MPa); impact energy absorption requires metallic ductility; or the production volume is too low to amortize PEEK tooling cost.
Net-Shape Advantage
Unlike metal components requiring extensive CNC machining from billet or forging, PEEK injection molding produces near-net-shape components in a single operation — eliminating the machining cost, material waste, and lead time that characterize metal part production for complex geometries. For precision PEEK bearing cages, impeller components, and manifold bodies, the net-shape advantage versus machined PEEK or machined metal frequently justifies the tooling investment at production quantities above 200–500 annual units.
Industry Applications
Medical and Implantable Devices
Medical is the application domain where PEEK plastic’s combination of biocompatibility, radiolucency, and bone-matched modulus creates a performance profile that no metal or ceramic achieves simultaneously. Dimud processes implant-adjacent PEEK components under ISO 13485-compatible quality systems with full material traceability from resin lot to finished part.
Spinal cage implants and bone fixation components (implant-grade PEEK): PEEK’s elastic modulus (3,600–4,100 MPa for unfilled grade) closely approximates cortical bone (7,000–25,000 MPa range) — significantly closer than titanium (110,000 MPa) or stainless steel (200,000 MPa). This modulus matching reduces the stress-shielding effect that causes bone resorption around metal implants. Combined with PEEK’s MRI and CT compatibility (radiolucency allows imaging of the implant site without artifact), implant-grade PEEK has become the dominant material for interbody spinal fusion cages, fracture fixation plates, and orthopedic reconstruction components globally.
Surgical instrument housings and reusable device components (standard PEEK): PEEK’s compatibility with steam autoclaving (121–134 °C, repeated cycles), gamma sterilization (up to 25 kGy), and EO sterilization — combined with chemical resistance to all standard surgical disinfectants — makes it the specification standard for reusable surgical instrument handles, endoscope components, and precision instrument guide components.
Diagnostic equipment bearing and wear components (wear-grade PEEK): High-cycle bearing surfaces in diagnostic imaging equipment (CT gantry bearings, MRI table drive components) where PEEK’s self-lubrication, wear resistance under continuous operation, and MRI compatibility combine to create a material specification that metal bearings requiring lubrication cannot match in clean-room environments.
Наш сайт Medical & Healthcare injection molding capabilities support PEEK medical programs with dedicated production cells, clean manufacturing protocols, and full regulatory documentation.
Semiconductor and Electronics
Wafer handling and process equipment components (unfilled and ESD-PEEK): PEEK plastic is the dominant material for semiconductor wafer carrier rings, end-effector contact components, and process chamber components in front-end semiconductor fabrication. Requirements driving PEEK specification: zero ionic contamination of ultra-pure process environments, dimensional stability under repeated thermal cycling between room temperature and 200 °C process temperatures, chemical resistance to process chemicals (HF, H₂SO₄, H₂O₂), and low outgassing at elevated temperatures.
IC test socket inserts and burn-in board components (unfilled PEEK): PEEK’s combination of dimensional stability at 150–175 °C burn-in temperatures, electrical insulation across the frequency range of high-speed IC testing, and resistance to cleaning solvents makes it the standard specification for precision test socket insulators, burn-in board carriers, and handling tray inserts in semiconductor packaging.
High-voltage connector insulation components (unfilled and GF-PEEK): Power electronics operating at voltages above 1,000 V require connector insulation materials that maintain dielectric strength (19–24 kV/mm for unfilled PEEK) and dimensional stability at continuous service temperatures above 150 °C — performance that eliminates most engineering thermoplastics and makes PEEK plastic the practical specification in high-power industrial and EV power electronics.
For our full semiconductor manufacturing capabilities, see our Electronics & Semiconductor industry page.
Автомобили
Transmission and engine components (30% GF/CF-PEEK): Gear elements, bearing cages, pump impellers, and valve seats in automotive transmission systems. PEEK’s continuous service temperature of 240–260 °C enables service in direct contact with transmission fluid at operating temperatures (typically 140–160 °C) and peak thermal excursions, replacing sintered metal components at equivalent structural performance with 50–60% mass reduction.
EV powertrain insulation components (unfilled and GF-PEEK): High-voltage bus bar insulators, motor slot liner components, and inverter insulation structures in EV powertrains. PEEK’s combination of dielectric strength (19–24 kV/mm), continuous service temperature (240 °C accommodates motor hot-spot temperatures), and chemical resistance to thermal runaway off-gases in battery-adjacent environments makes it the engineered choice for next-generation EV power electronics.
Fuel system precision components (chemical-resistant PEEK): Fuel pump components, injector nozzle insulators, and fuel filter housings in direct-injection engine systems. PEEK resists all fuel types including E10/E85 ethanol blends and biodiesel formulations that degrade many engineering polymers over 10-year vehicle service life.
Робототехника и хранение энергии
Robot joint bearing and bushing components (wear-grade PEEK): Self-lubricating PEEK bearing bushings in robot joint assemblies replace oil-lubricated metal bearings in collaborative robots deployed in food-processing, cleanroom, and outdoor environments where lubrication maintenance is impractical. Wear-grade PEEK’s dynamic friction coefficient (0.10–0.20) and PV limit provide dry-running service life exceeding 10,000 operating hours in moderate-load joint designs.
Robotic arm structural brackets (30% CF-PEEK): Carbon fiber PEEK structural components in robot link assemblies where the design objective is maximum stiffness-to-weight ratio for rapid-acceleration servo-driven axes. CF-PEEK link covers and brackets at 1.42 g/cm³ density deliver equivalent structural performance to aluminum at 47% mass reduction — directly improving servo-motor acceleration response and reducing joint drive train loading.
Fuel cell and electrolyzer stack components (chemical-resistant PEEK): Bipolar plate frames, cell spacers, and manifold components in hydrogen fuel cell and electrolyzer stacks. PEEK’s resistance to concentrated sulfuric acid (with limitations), hydrogen fluoride at moderate concentrations, and electrochemical oxidation at stack operating potentials makes it one of the few thermoplastics that survives the combined chemical and thermal environment of PEM (proton exchange membrane) electrolyzer operation.
Battery pack precision structural components (GF-PEEK): High-precision cell registration frames and module alignment components in automotive battery packs where dimensional stability at continuous elevated temperatures (battery pack operating temperature: 40–80 °C continuous; 120 °C peak) over 15-year vehicle life eliminates thermal creep issues that affect lower-HDT engineering polymers.
PEEK Plastic vs. Competing High-Performance Materials
| Недвижимость | PEEK | PPS | PAI (Torlon) | PPSU | PEI (Ultem) | Titanium |
|---|---|---|---|---|---|---|
| Continuous Service Temp | ★★★★★ (260 °C) | ★★★★☆ (220 °C) | ★★★★★ (260 °C) | ★★★★☆ (180 °C) | ★★★★☆ (170 °C) | ★★★★★ |
| Mechanical Strength | ★★★★★ | ★★★★☆ | ★★★★★ | ★★★☆☆ | ★★★★☆ | ★★★★★ |
| Химическая стойкость | ★★★★★ | ★★★★☆ | ★★★★☆ | ★★★★☆ | ★★★★☆ | ★★★★☆ |
| Biocompatibility (implant) | ★★★★★ | ★★☆☆☆ | ★★★☆☆ | ★★★★☆ | ★★★☆☆ | ★★★★☆ |
| Radiolucency (MRI/X-ray) | ★★★★★ | ★★★★☆ | ★★★★☆ | ★★★★☆ | ★★★★☆ | ★☆☆☆☆ |
| Processing Ease | ★★★☆☆ | ★★★☆☆ | ★★☆☆☆ | ★★★☆☆ | ★★★☆☆ | N/A (machining) |
| Raw Material Cost | $$$$ | $$$$ | $$$ | $$$$ | ||
| Mass Advantage vs Metal | Высокий | Высокий | Высокий | Высокий | Высокий | — |
PEEK vs. PPS: PPS is less expensive (roughly 40–60% of PEEK’s raw material cost) and processes more easily (lower barrel temperature: 300–330 °C). PPS wins for applications requiring good chemical resistance and moderate thermal performance (continuous: 220 °C) without PEEK’s cost premium. PEEK wins when service temperature exceeds 220 °C, biocompatibility is required, or impact resistance (PEEK: 50–85 J/m vs PPS: 25–50 J/m) is a design factor.
PEEK vs. PAI (Torlon): PAI achieves comparable continuous service temperature and mechanical performance to PEEK, but with significantly more complex processing (cure cycles required post-molding) and higher raw material cost. PEEK’s processing accessibility and available implant-grade certification make it the dominant choice when both materials are technically qualified.
PEEK vs. PEI (Ultem): PEI provides inherent UL 94 V-0 at 0.8 mm, good chemical resistance, and reasonable cost at 40–60% of PEEK’s price. PEI is specified when 170 °C continuous service temperature is sufficient and PEEK’s cost premium is not justified. For applications requiring > 170 °C continuous service or implant-grade certification, PEEK is non-substitutable.
For a comprehensive view of Dimud’s complete materials portfolio, see the injection molding materials guide.
DFM Guidelines for PEEK Plastic Parts
PEEK’s material cost ($80–$400/kg) makes DFM failures significantly more expensive than equivalent failures in commodity polymers. A rejected PEEK part represents not only the material cost but the machine time at 400 °C, the elevated mold maintenance burden, and potentially the loss of a single-cavity tool run. DFM discipline is proportionally more important in PEEK programs than in any other commercial injection molding material.
Димудс Product Design & DFM service includes FEA structural analysis, crystallinity simulation, and metal replacement feasibility assessment as standard deliverables for PEEK programs.
Толщина стенок
Recommended range: 1.5–6.0 mm for injection-molded PEEK. Thin walls (< 1.5 mm) require high-flow grades and high injection pressures that increase shear-induced crystallinity suppression near the gate. Thick walls (> 6 mm) create differential crystallinity gradients between surface (high crystallinity, fast-cooling skin) and core (potentially lower crystallinity, slower cooling) that reduce dimensional predictability.
For PEEK programs replacing metal components, minimum wall thickness should be determined by structural analysis (FEA) rather than empirical rules — PEEK’s high specific stiffness often allows wall thickness reductions of 30–50% versus the metal component being replaced.
Corner Radii
Minimum internal corner radius: 1.0 mm. Recommended: 1.5–2.0 mm.
This is a more stringent requirement than for ABS or PS. PEEK’s moderate notched impact strength (50–85 J/m) combined with high stiffness means stress concentration at sharp corners under service loading can initiate brittle fracture at stress levels below those that would cause visible deflection. For implant applications subject to cyclic loading, all internal corners are specified at minimum 1.5 mm radius in Dimud’s PEEK DFM standard.
Углы наклона
- Standard surfaces: 1.5°–3° per side minimum (higher than for ABS; PEEK contracts strongly against the core on cooling from 180 °C mold temperature)
- Polished bearing surfaces: 2°–3° per side; polished PEEK on polished steel at 180 °C generates high ejection force
- Filled grades (GF/CF): 2°–4° per side; reinforced grades are stiffer and contract less, but abrasive wear on draft surfaces increases with insufficient draft angle
Achievable Tolerances
PEEK plastic’s dimensional precision in injection molding depends on grade and crystallinity control:
- Unfilled PEEK (well-crystallized): ±0.05–0.10 mm on dimensions ≤ 50 mm
- 30% GF-PEEK (flow direction): ±0.03–0.08 mm
- 30% CF-PEEK: ±0.03–0.06 mm (lowest shrinkage of all PEEK grades)
- Post-mold annealed parts: Tighter tolerances achievable as shrinkage completion is verified before secondary operations
For precision bearing bores (h6/H7 tolerance class) and precision seating surfaces, Dimud specifies post-mold CMM inspection followed by single-pass precision boring or grinding where injection molding tolerance is insufficient — a standard workflow for PEEK bearing seat programs.
Dimud's PEEK Plastic Injection Molding Capabilities
PEEK injection molding requires a manufacturing partner with specialized equipment, material expertise, and quality systems calibrated for the most demanding engineering applications. Димуд provides PEEK plastic injection molding as part of a vertically integrated system — three coordinated manufacturing plants for mold development, CNC machining, and precision assembly — serving medical, semiconductor, automotive, and robotics customers in Europe, North America, and the Middle East.
| Service Stage | Dimud Capability | Customer Benefit |
|---|---|---|
| DFM & Grade Review | Grade recommendation; FEA metal replacement analysis; crystallinity simulation; tolerance feasibility | Eliminate the most expensive PEEK program failures before tooling |
| Rapid Prototyping | CNC-machined PEEK samples from stock + aluminum soft tools for low-volume PEEK samples | Engineering and regulatory samples in 10–15 working days |
| Machine Qualification | PEEK-capable machines (420 °C barrel rated); Karl Fischer verification; residence time documentation | Validated PEEK processing baseline before production commitment |
| Mold Development | H13/D2/S7 hardened tool steel; hot-oil temperature control 160–200 °C; PVD-coated gate inserts for CF grades; Moldflow pre-validated | Production-ready PEEK tooling; guaranteed shot life with maintenance schedule |
| Production Molding | Dedicated PEEK cells; oil temperature controllers; annealing ovens with fixture inventory; 50T–800T machines | Controlled crystallinity from pilot to production volume |
| Post-Mold Operations | Precision annealing with CMM verification; secondary boring/grinding for bearing tolerances; clean-room assembly | Net-shape and precision-machined PEEK sub-assemblies |
| Quality Documentation | PPAP Level 3; CoC with resin lot documentation; Karl Fischer records; DSC crystallinity verification; CMM bore mapping | Audit-ready for medical OEM, automotive Tier-1, and semiconductor OEM customers |
| Supply Chain | Victrex/Solvay/Evonik resin sourcing; lot-segregated storage; incoming lot verification; DDP logistics | Implant-grade traceable supply from resin producer to finished part |
Часто задаваемые вопросы
PEEK injection molding requires barrel temperatures of 370–420 °C — significantly higher than any other standard commercial thermoplastic. This exceeds the rated operating temperature of many standard injection molding machines (typically 380 °C maximum). For PEEK programs, Dimud uses machines with upgraded bimetallic barrels, high-temperature screw seals, and temperature controllers verified to ±5 °C accuracy at 400 °C. Engineers evaluating PEEK programs should confirm machine capability before tooling is committed — not all contract manufacturers claiming PEEK capability have equipment appropriately configured for the material.
Both PEEK and PPS are semi-crystalline high-performance thermoplastics with excellent chemical resistance and high thermal stability. PPS processes at lower barrel temperatures (300–330 °C) and costs approximately 40–60% less per kilogram than PEEK. PPS is the appropriate specification when continuous service temperature up to 220 °C is sufficient, biocompatibility certification is not required, and impact resistance requirements are moderate (PPS notched Izod: 25–50 J/m). PEEK is specified when service temperature exceeds 220 °C, biocompatibility or implant certification is required, impact resistance above PPS's capability is needed, or hydrolytic stability in continuous steam or hot water exposure is a service requirement. Dimud processes both materials and provides grade selection analysis as part of DFM review.
Yes — PEEK is one of the most sterilization-compatible engineering thermoplastics available. It is compatible with: gamma radiation (up to 25 kGy for standard programs; up to 2,000 kGy total without significant property degradation in specialized grades), ethylene oxide (EO/EtO) sterilization, steam autoclaving at 121–134 °C (repeated cycles without hydrolytic degradation — a unique advantage versus most thermoplastics), and hydrogen peroxide vapor-phase sterilization. This multi-method compatibility makes PEEK the preferred material for reusable surgical instruments and device components where sterilization method flexibility is valued. Dimud provides sterilization validation support documentation as part of medical PEEK program qualification.
PEEK is a semi-crystalline polymer — its final properties depend not just on composition but on the degree of crystalline domain formation during solidification. At low mold temperatures (< 100 °C), PEEK solidifies too rapidly for crystalline domains to form, producing amorphous PEEK with HDT below 50 °C — a part that will deform at temperatures well below PEEK's rated 240–260 °C service temperature. At the target mold temperature of 160–180 °C, controlled crystallization produces 30–35% crystallinity with full rated properties. This is not a subtle effect — the HDT difference between amorphous and correctly crystallized PEEK is greater than 100 °C, and the difference is invisible to visual or dimensional inspection of the finished part. This is why mold temperature control, verification, and documentation are mandatory quality requirements in all Dimud PEEK programs.
PEEK raw material costs $80–$400/kg versus $3–8/kg for ABS — a raw material cost ratio of 10–100×. The program cost premium is partially offset by PEEK's density advantage (1.30–1.32 g/cm³ versus ABS's 1.03–1.06 g/cm³ — approximately 25% more parts per kilogram), net-shape molding eliminating machining costs, and the elimination of metal component finishing and corrosion protection. The commercial justification is application-specific: in medical implants, no alternative material achieves PEEK's combination of biocompatibility, bone-matched modulus, and radiolucency at any cost. In semiconductor process equipment, PEEK's contamination-free performance is not replaceable by lower-cost alternatives. In automotive transmission components at production volumes above 50,000 units annually, PEEK's mass reduction and elimination of machining frequently produces a total system cost advantage over machined metal. Dimud provides total cost of ownership analysis as part of PEEK program feasibility review.
Заключение
PEEK plastic is not a general-purpose material that happens to perform well under demanding conditions. It is an engineered polymer whose molecular architecture was designed for a specific performance tier — one that no other injection-moldable thermoplastic occupies. When the application genuinely requires continuous service above 200 °C, implant-grade biocompatibility, metal-level strength at polymer-level density, or resistance to virtually every industrial chemical in simultaneous combination, PEEK is not a premium choice. It is the only choice.
The execution discipline required to deliver that performance reliably — mold temperatures above 160 °C, barrel temperatures approaching 420 °C, Karl Fischer moisture verification, DSC crystallinity confirmation, and a quality system that traces material provenance from resin producer to finished part — is not exceptional. It is the standard operating procedure for a PEEK program done correctly.
Димуд brings that operational standard to PEEK injection molding programs across medical, semiconductor, automotive, and robotics applications — for customers in Europe, North America, and the Middle East who need the material’s performance delivered with the documentation rigor their industries require.
