PEEK-Evonik Vestakeep i4G
To secure permanent bone-anchored biostability and eliminate stress-shielding effects in long-term human implants, Evonik’s Vestakeep i4G offers an unreinforced, high-viscosity polyetheretherketone (PEEK) matrix with unparalleled high purity. Featuring a density of 1.30 g/cm³ and compliance with ASTM F2026 and USP Class VI, this implantable grade exhibits a mechanical modulus close to cortical bone. Jucheng Precision, operating under strict ISO 13485 medical device certified systems, specializes in cleanroom molding of Vestakeep i4G. Using mirror-polished, rust-resistant S136 tool steel cavities, we ensure zero particulate contamination and optimal crystallinity, delivering high-purity medical implants verified by Zeiss CMM.
Vestakeep i4G Medical & Biocompatibility Compliance Profile
VESTAKEEP® i4 G is a natural-colored, high-viscosity PEEK resin engineered by Evonik, certified to meet the absolute highest biological and quality safety standards for long-term surgical implants:
| Surgical Regulatory Standard | Vestakeep i4G Certification Spec | Implication for Permanent Implants |
|---|---|---|
| Surgical Implant Polymers | ASTM F2026 Compliance | Officially designated and fully approved as safe for long-term surgical implants permanently contacting bone and soft tissue in the human body. |
| Systemic Toxicity & Irritation | ISO 10993-3, 5, 6, 10, 11 / USP Class VI | Extensively tested to prove zero genotoxicity, zero cytotoxicity, zero local tissue irritation, and zero subchronic systemic toxicity. |
| Pharmaceutical master file | US FDA Device Master File (MAF) | Simplifies the regulatory approval and validation path for medical device developers targeting the North American and global MedTech markets. |
Biocompatible Process & Implant Configurations for Vestakeep i4G
With high viscosity and outstanding biostability, Vestakeep i4G is highly suited for dynamic, long-term human implants:
| Molding Technology Class | Molding Compatibility & Operational Focus |
|---|---|
| Spinal Fusion Cages | Excellent. Run inside our ISO Class 7/8 cleanrooms to mold highly complex load-bearing spinal cages with customized bony-interlocking micro-features. |
| Bone Suture Anchors | Excellent. High shear-strength of the unreinforced matrix supports micro-injection molding of tiny suture screws with wall thicknesses down to 0.15mm. |
| Facial & Cranial Implants | Excellent. Ideal for molding thin-walled maxillo-facial orbital plates, cardiovascular access ports, heart valves, and joint spacer blocks. |
PEEK-Evonik Vestakeep i4G Cleanroom Tooling & Processing Guide
Molding an ultra-pure, high-viscosity implantable polymer like Vestakeep i4G requires absolute prevention of micro-particulate contamination and precise temperature controls:
Enclosed Cleanroom Molding (ISO Class 7/8)
Implant-grade PEEK must be protected from any airborne particulates or dust. Jucheng operates dedicated injection molding machines inside fully enclosed, positive-pressure ISO Class 7/8 cleanrooms. Raw material feeding, plastication, and robot part-ejection are completely automated and isolated.
Mirror-Polished S136 Tooling (Purity Preservation)
To prevent tissue irritation from microscopic surface micro-roughness, we build molds using high-chromium S136 stainless steel. Cavities are mirror-polished to a high level using clean diamond paste, ensuring non-porous biocompatible part surfaces with no dynamic release drag marks.
Pressurized Oil Mold Heating (Crystallization Control)
Crystallinity governs the biostability of PEEK. We maintain mold temperatures continuously at 160°C–200°C (preferably 180°C/356°F) using pressurized oil temperature controllers. Slower, uniform thermal crystallization ensures the optimal opaque-beige bone-mimicking strength is attained.
Extended Desiccant Pre-Drying Protocol
Moisture causes hydrolytic polymer chain cleavage, making surgical parts brittle. We pre-dry Vestakeep i4G resin in desiccant hopper dryers at 150°C (302°F) for 4 hours, keeping internal moisture below 0.02% to ensure flawless structural density.
Key Application Fields for PEEK-Evonik Vestakeep i4G
- Spine Surgery & Orthopedics (ISO 13485): Spinal fusion cages, bone suture anchors, orthopedic targeting blocks, bone plates, interference screws, and joint spacers.
- Cranio-Maxillo-Facial (CMF): Patient-specific orbital plates, facial implants, cranial bone reconstruction plates, and temporary dynamic fixation clips.
- Cardiovascular & General Surgery: Biocompatible catheter tips, cardiovascular access ports, heart valves, vascular stents, and dynamic surgical instrument components.
Properties
| Density | 1.3 g/cm³ |
| Water Absorption (Saturation) | 0.4 % |
| Moisture Absorption | 0.12 % |
| Tensile Modulus | 3,500 MPa |
| Tensile Stress at Yield | 96 MPa |
| Tensile Stress at Break | 76 MPa |
| Tensile Strain at Yield | 5 % |
| Tensile Strain at Break | 30 % |
| Charpy Notched Impact Strength (23°C) | 5 kJ/m² |
| Melting Temperature (DSC) | 340 °C |
| Glass Transition Temperature (Onset) | 143 °C |
| Biocompatibility Compliance | ISO 10993 / ASTM F2026 - |
| Linear Mold Shrinkage | 1.00 - 1.30 % |
| Maximum Part Size (Cleanroom limit) | 600 x 400 mm |
| Minimum Part Size (Micro Implant limit) | 0.1 x 0.1 mm |