| HS Code | 846554 |
| Density | 1.01 g/cm³ |
| Melting Point | 178 °C |
| Tensile Modulus | 330 MPa |
| Tensile Strength At Yield | 25 MPa |
| Elongation At Break | 300% |
| Charpy Impact Strength At 23 C | No break |
| Flexural Modulus | 350 MPa |
| Water Absorption 24 H | 0.3% |
| Vicat Softening Temperature | 140 °C |
| Shore Hardness | D 54 |
As an accredited Evonik VESTAMID® Care ML67 Medical Grade Nylon 12 factory, we enforce strict quality protocols—every batch undergoes rigorous testing to ensure consistent efficacy and safety standards.
| Packing | Supplied as moisture-proof sealed polyethylene bags containing 25 kg of Evonik VESTAMID® Care ML67 medical grade nylon 12 pellets. |
| Container Loading (20′ FCL) | 20′ FCL: palletized drums of Evonik VESTAMID Care ML67 medical nylon 12, secured, full container load, no co-loading. |
| Shipping | VESTAMID® Care ML67 ships as non-hazardous medical-grade nylon 12 in sealed moisture-barrier bags or drums. Keep containers dry, avoid direct sunlight, and store below 30°C. No special hazmat requirements apply; however, use covered, clean transport to prevent contamination and protect product integrity. |
| Storage | Store VESTAMID® Care ML67 in its original, unopened packaging in a cool, dry, well-ventilated area. Protect from moisture, direct sunlight, and excessive heat. Avoid exposure to strong oxidizers. Keep container tightly sealed when not in use. Shelf life is typically two years under these conditions. |
| Shelf Life | Shelf life is typically 2 years when stored unopened in a dry, cool area, protected from moisture and light. |
Thin-wall intravascular catheter shafts and introducer sheaths require a polyamide with equilibrium water uptake no higher than 1.5 wt% at 23°C in water, because in-service dimensional change must remain below the outer diameter tolerance invoked by ISO 10555-1:2023. For biocompatibility screening, VESTAMID Care ML67 is qualified under ISO 10993-1:2018 within a risk-management file, with cytotoxicity per ISO 10993-5:2009, skin sensitisation per ISO 10993-10:2021, and systemic toxicity per ISO 10993-11:2017; USP Class VI chapter <88> testing covers intracutaneous reactivity and systemic injection. In a monolayer shaft the formulation addition ratio is 100 wt% VESTAMID Care ML67 as the polyamide matrix. In a tri-layer outer shaft the ML67 midlayer is coextruded at 35–60% of total wall thickness between a lubricious inner liner and a soft polyamide elastomer outer layer. Where radiopacity is required only in the distal tip, a barium sulfate masterbatch is compounded into the ML67 tip segment at 15–30 wt%, leaving the shaft matrix unfilled.
Pre-drying is performed at 80°C in a desiccant dryer with dew point ≤ −30°C for 4–8 h to residual moisture ≤0.10 wt%. Extrusion on a 25 mm single-screw line with L/D 24:1 or 30:1 barrier screw, melt pump, and crosshead die provides melt pressure stability; melt temperature is held at 230–250°C at the die exit, die temperature at 220–240°C, and water quench at 20–35°C. Draw-down ratio is controlled between 2.5:1 and 5.0:1; excessive draw-down freezes molecular orientation and raises axial shrink, while insufficient draw-down produces sag and ovality. On multi-lumen extrusion lines, melt-pressure variation exceeding ±2.0 bar at the melt pump inlet is sufficient to create visible outer diameter chatter in a 0.20 mm wall. Post-extrusion annealing at 100–110°C for 2 h in hot air relieves frozen stress. Terminal products include 3 Fr to 9 Fr introducer sheaths, PICC line shaft segments, neurovascular microcatheter outer jackets, and balloon catheter outer shafts. Moisture above 0.10 wt% at the feed throat causes hydrolysis, surface splay, and viscosity loss; melt temperature above 270°C should be avoided due to oxidative yellowing.
| Parameter | Monolayer 100 wt% ML67 | Tri-layer 35–60% ML67 midlayer |
|---|---|---|
| Melt temperature at die exit | 230–250°C | 235–245°C |
| Draw-down ratio | 2.5:1–5.0:1 | 3.0:1–6.0:1 |
| Water quench temperature | 20–35°C | 25–40°C |
| Residual moisture before extrusion | ≤0.10 wt% | ≤0.10 wt% |
| Annealing | 100°C for 2 h | 110°C for 2 h |
Luer-activated valve bodies and three-way stopcocks moulded from unfilled PA12 exhibit post-moulding dimensional recovery if annealing temperature is insufficient relative to service exposure, particularly after lipid emulsion contact. Fluid connectors intended for intravascular or hypodermic use must meet ISO 80369-7:2016; the material contributes to biocompatibility under ISO 10993-1:2018 and USP Class VI chapter <88> but does not replace device-level testing. In clear or natural connector bodies the formulation addition ratio is 100 wt% VESTAMID Care ML67 without internal additive packages. If the device requires improved thermal oxidation resistance through 1,000 autoclave cycles, a non-migrating heat stabilizer masterbatch is added at 0.2–0.5 wt%. External silicone oil is not compounded; it is applied post-moulding at 1–2 mg per component as a lubricant. Injection moulding uses a 16-cavity tool with clamp force ≥1,000 kN, melt temperature 240–255°C, mould temperature 60–80°C, injection velocity 30–60 mm/s, hold pressure 50–70 MPa for 3–5 s, and total cycle 25–40 s for wall thickness 2–4 mm. Post-moulding shrinkage of unfilled PA12 in Luer connectors is approximately 0.8–1.2% along the taper; if cooling time is trimmed below 25 s, recovery after annealing can shift the taper angle beyond go/no-go gauge limits. A valve gate diameter ≥0.8 mm reduces gate blush in the Luer taper area. Annealing at 110°C for 2 h in a circulating air oven after ejection reduces frozen stress and improves dimensional stability under ISO 80369-7 taper gauging. Terminal products include Luer-activated needleless connectors, 3-way stopcocks, extension set male and female Luer connectors, and high-pressure fluid management connectors rated at 300 psi (20.7 bar). Solvent-based cleaning agents with high xylene or alkylphenol content should be excluded from cleaning validation because polyamide swelling alters Luer taper engagement torque.
Because pressurized metered-dose inhaler actuators and dry-powder inhaler chassis generate a respirable aerosol cloud, extractables under ethanol and hydrofluoroalkane propellant exposure must remain below vehicle-specific limits in ISO 10993-12:2021 extraction studies. The applicable device standard is ISO 20072:2009 for aerosol drug delivery device design verification, supported by USP <87> and <88> Class VI biological reactivity and ISO 10993-5/10 endpoints. In this segment VESTAMID Care ML67 is used at 100 wt% of the actuator body, because unfilled PA12 avoids filler-loaded surfaces that can generate particulate extractables in the aerosol stream; for snap-fit closure features a medical-grade elastomeric modifier may be compounded at 10–20 wt% in a co-rotating twin-screw line to increase elongation at break. The downstream production route is injection moulding with dry-air purge, melt temperature 235–245°C, mould temperature 60°C, positive cavity pressure 60–80 MPa, and post-moulding vacuum drying at 80°C for 2 h to reduce retained moisture before actuator assembly. Terminal completed components include pMDI actuators, spacer bodies, DPI chassis and covers, and breath-actuated valve carriers. Mould release agents based on silicone should be excluded from mould maintenance because transfer to the aerosol path may appear as extractable siloxane in the drug product.
Cantilever snap-fit release buttons and dose-dial housings in autoinjector and pen injector systems fail drop-test requirements if the chosen PA12 resin cannot recover elastic strain after repeated engagement; the low moisture uptake of unfilled PA12 supports stable snap-fit force after ambient humidity conditioning. In a typical release-button specification, the snap arm is cycled 10 times and permanent set must remain ≤5% of arm deflection. The device class falls under ISO 11608-1:2022 for needle-based injection systems; material biocompatibility is screened under ISO 10993-1:2018, and US FDA 21 CFR Part 820 design controls apply to the assembled device. In a two-shot injection moulded chassis, the first shot is a glass-fibre reinforced PA12 or PC/ABS structural frame; VESTAMID Care ML67 is used as the second-shot unfilled material at 100 wt% of the overmoulded snap arm or dial wheel. Where wear-resistant gear teeth are required, a compounded blend of 70–85 wt% ML67 and 15–30 wt% medical-grade glass fibre is used, but only after confirming elongation at break remains above the device requirement. Rotary two-shot injection moulding uses platen diameter ≥800 mm; first shot barrel temperature 260–280°C, second shot ML67 barrel 230–245°C; mould temperature 90–110°C to preheat the first shot interface to ≥120°C for melt adhesion; injection velocity 80–120 mm/s; hold pressure 40–60 MPa; cooling time 20–30 s. Insufficient interface temperature causes delamination at the snap arm root. Terminal products include autoinjector chassis, pen injector dose-dial housings, snap-fit release buttons, and drive-gear carriers. Pre-drying at 80°C for 4 h to ≤0.10 wt% moisture remains mandatory; moisture above 0.10 wt% at the overmoulding interface generates steam porosity and reduces bond strength.
Surgical instrument handles that must tolerate ≥500 autoclave cycles at 134°C impose oxidative and hydrolytic stress on the polymer matrix. The relevant sterilization compatibility pathway is ISO 17665-1:2024 for moist heat sterilization, supported by AAMI TIR17:2017 for material compatibility and ISO 10993-1:2018 biocompatibility endpoints. For reusable handles and housings, VESTAMID Care ML67 is processed at 100 wt% of the polymer matrix; a heat stabilizer masterbatch at 0.2–0.3 wt% is incorporated only where the IFU demands ≥500 steam cycles. Published comparative data for this specific grade at >1,000 cycles is limited, so cycle-life validation must be performed per ISO 17665-1:2024. Injection moulding of thick-wall handle bodies 6–10 mm uses melt temperature 240–250°C, mould temperature 70°C, injection speed 20–50 mm/s, and gas-assisted packing with nitrogen supply pressure 10–15 MPa to reduce sink marks; post-mould annealing at 110°C for 2 h in a circulating air oven stabilizes dimensions before steam exposure. Flame-retardant additives are excluded because extractables can be released during steam sterilisation. Terminal completed devices include laparoscopic grasper handles, powered orthopedic drill housings, ultrasonic dissector handle bodies, and reusable biopsy instrument frames.
Polypropylene and polycarbonate alternatives fail repeated ethylene oxide cycles due to stress cracking; PA12 manifolds are selected for dimensional stability after 3 successive EO cycles at 55°C and 70% RH. ISO 10993-7:2008 provides residue limits for ethylene oxide and ethylene chlorohydrin; ISO 10993-1:2018 and USP Class VI chapter <88> cover biological evaluation. Device-level leakage testing follows ISO 80369-1:2018 and the applicable part-specific small-bore connector standard. The manifold body uses VESTAMID Care ML67 at 100 wt% of the polyamide phase; where a clear window is required, a transparent copolyester is overmoulded at 10–15% of part volume, but the structural manifold remains PA12. Silicone O-rings are inserted post-moulding rather than overmoulded to avoid contaminating the polyamide with platinum-cure residues. Injection moulding uses cold runner or hot-runner valve gates, melt temperature 240–255°C, mould temperature 60–80°C, packing pressure 50–70 MPa, and total cycle 30–50 s for walls 3–5 mm. After moulding, forced-air post-cure at 70°C for 4 h reduces retained EO uptake before terminal sterilisation. Terminal products include fluid sampling manifolds, stopcock rotor bodies, anaesthesia gas sampling blocks, and renal dialysis machine valve housings.
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VESTAMID® Care ML67 is a plasticizer-free polyamide 12 medical-grade resin supplied by Evonik Industries as a low-viscosity pellet for injection molding and melt extrusion. The molecular structure is based on an aliphatic long-chain semicrystalline polyamide backbone, which provides flexibility without the addition of low-molecular-weight flexibilizers. In the dry-as-molded condition, representative mechanical data include a tensile modulus of 400–500 MPa per ISO 527-1/-2:2012, nominal strain at break greater than 200% under ISO 527-1/-2:2012, and Shore D hardness of 60–65 per ISO 868:2003. The density is approximately 1.01 g/cm³ per ISO 1183-1:2019, and the melting peak is approximately 176 °C per ISO 11357-3:2018. These values distinguish ML67 from higher-stiffness PA12 grades and from plasticized polyvinyl chloride compounds.
The equilibrium moisture uptake of PA12 remains lower than that of short-chain polyamides. Saturation water absorption is typically 1.3–1.5% by mass after immersion at 23 °C per ISO 62:2008, compared with approximately 9–10% for PA6 and 8–9% for PA66 under the same standard. This lower amide density reduces the degree of moisture-induced plasticization and improves dimensional stability in humid environments relative to PA6 and PA66. The result is particularly relevant for catheter shaft components exposed to aqueous media for extended periods, where mechanical performance must be assessed in the conditioned state rather than the dry-as-molded state.
| Property | Test standard | Unit | Typical range or value |
|---|---|---|---|
| Density | ISO 1183-1:2019 | g/cm³ | 1.01 |
| Tensile modulus, dry | ISO 527-1/-2:2012 | MPa | 400–500 |
| Tensile stress at yield, dry | ISO 527-1/-2:2012 | MPa | 25–30 |
| Nominal strain at break, dry | ISO 527-1/-2:2012 | % | >200 |
| Shore D hardness | ISO 868:2003 | Shore D | 60–65 |
| Melting temperature, DSC | ISO 11357-3:2018 | °C | 176 |
| Water absorption, saturation | ISO 62:2008 | % | 1.3–1.5 |
These values are representative manufacturer-published ranges; final lot-specific certificates of analysis govern the production specification. Conditioning history, moisture content, and processing temperature can shift the measured values, and device-level testing is required for design verification.
The low-viscosity melt character of ML67 is the primary processing distinction from medium-viscosity VESTAMID® Care PA12 grades. Melt volume-flow rate measured under ISO 1133-1:2022 conditions is a lot-specific value, but the grade is positioned for thin-wall flow and high-speed extrusion. In injection molding, melt temperatures of 220–250 °C and mold temperatures of 40–80 °C are used for initial process development. Hot-runner systems with valve gates provide gate vestige control in small-lumen connectors; cold-runner tools with positive shutoff nozzles reduce drooling from the low-viscosity melt. Screw backpressure is commonly set in the 0.2–0.6 MPa range, and screw rotation speeds below 150 min⁻¹ are selected for PA12 to limit shear heating. These parameters are starting conditions, not universal fixed values.
Drying is required before processing when ambient relative humidity exceeds 60% or when pellet storage has been open for more than 4 h. A desiccant-air dryer with a dew point at or below −30 °C is recommended. Residual moisture must be brought below 0.10% by mass before extrusion or injection molding; typical drying conditions are 80 °C for 4–8 h. Higher drying temperatures can cause pellet bridging and surface oxidation. The low-viscosity melt is sensitive to hydrolytic degradation; moisture above the stated limit produces silver streaks in molded parts and foam or ovality defects in extruded tubing.
For single-screw extrusion, general-purpose polyamide screws with 25:1–30:1 L/D, a compression ratio of 2.5:1–3.0:1, and a grooved feed section are employed in production-scale tubing lines. For compounding operations involving color or radiopacifier masterbatch, a co-rotating twin-screw extruder with 40:1 L/D and vacuum venting is used to remove trace volatiles. Measured melt temperature should not exceed 260 °C for extended periods; thermal-oxidative chain scission and discoloration are the primary failure modes. If melt temperature exceeds 260 °C, residence time is minimized and the screw may be reconfigured to reduce shear input.
In tubing extrusion, barrel profiles typically begin at 180–200 °C in the feed zone and rise to 220–240 °C at the die. Melt temperature is measured with an insertion thermocouple at the die head and controlled within ±5 °C. Vacuum calibration tanks with closed-loop water temperature control are used to maintain outer diameter and wall thickness; inadequate vacuum or water temperature variation above ±2 °C can produce lumen collapse or ovality. Published process data for all ML67 tubing configurations are limited; each die and calibrator combination requires a design-of-experiments study because the low-viscosity melt does not tolerate the same drawdown ratios as higher-viscosity PA12 grades.
Shear-viscosity data for ML67 are best generated by capillary rheometry per ISO 11443:2021 because low-viscosity melts are sensitive to moisture and residence time. At processing shear rates typical of injection molding, apparent viscosity depends on temperature and shear rate; no single viscosity value is suitable for all tool designs. For thin-wall flow simulation, the Cross-WLF or Carreau viscosity model is fitted to shear-sweep data from a capillary die with L/D 20:1 and entrance-angle correction. The melt-density data used for process simulation should be taken from ISO 1183-1:2019 at 23 °C and corrected for pressure-volume-temperature behavior with high-pressure dilatometry. Lot-to-lot variation in melt flow is normally small when pellet moisture is held below 0.10% and hopper residence is minimized; however, regrind addition can shift melt viscosity and should be controlled by the device manufacturer’s validation.
Production-scale conversion of low-viscosity PA12 has recorded specific failure modes. In injection molding, inadequate drying shows as moisture splay at the gate and weld-line brittleness in parts with wall sections below 0.5 mm. In extrusion, melt-temperature variation of more than ±5 °C across the die circumference produces lumen ovality and wall-thickness eccentricity after vacuum calibration. Nonuniform pellet feed into the screw is a common root cause of surge; gravimetric feed systems and dry-air hopper purges are therefore specified when ambient relative humidity exceeds 60%. Frequent screw recovery time checks and nozzle temperature measurement with a surface pyrometer are used to maintain batch-to-batch consistency. Process capability studies for tube dimensions should follow ISO 9001:2015 statistical methods, but the specific tolerance bands are set by the device design and by extrusion tooling verification.
Chemical interaction testing of VESTAMID® Care ML67 follows the usual PA12 profile. Immersion tests per ISO 175:2010 at 23 °C and 37 °C may show limited swell in physiological saline, phosphate-buffered saline, and isotonic glucose. The material is not compatible with concentrated mineral acids, cresol, formic acid, or strong oxidizing acids, which attack the amide bond under sustained contact. Resistance to aliphatic hydrocarbons, oils, and many dilute alkaline solutions is consistent with long-chain aliphatic polyamides. Each fluid-contact claim must be validated on the finished device under the actual temperature, strain, and exposure duration because molded-in stress accelerates chemical attack.
Sterilization selection modifies the material state. Steam autoclave at 121–134 °C introduces water uptake and may cause temporary plasticization; repeated autoclave cycles can hydrolyze the polymer and reduce molecular weight. Ethylene oxide processing at 55–60 °C is used for heat-sensitive tubing, but aeration must meet ISO 10993-7:2008 residual limits before patient contact. Gamma and electron-beam irradiation in the 25–50 kGy range can cause free-radical oxidation, yellowing, and loss of elongation. No resin-level sterilization claim applies; the final medical device manufacturer validates the sterilization process under ISO 11135 for ethylene oxide or ISO 11137 for radiation, and then re-verifies function after worst-case processing.
Substitution of plasticized PVC with VESTAMID® Care ML67 is evaluated when plasticizer migration and humid aging are design constraints. Plasticized PVC compounds depend on low-molecular-weight plasticizers that can migrate into contacting fluids; their use in medical devices is regulated under Regulation (EU) 2017/745 and REACH (EC) No 1907/2006. ML67 contains no intentionally added flexibilizer. The density of ML67 at 1.01 g/cm³ per ISO 1183-1:2019 is lower than typical plasticized PVC compounds between 1.16 g/cm³ and 1.35 g/cm³, which can reduce tube mass when dimensions remain fixed. However, plasticized PVC is available in a wide durometer range; a one-to-one wall-thickness substitution is not automatically acceptable because the two material classes have different tensile stress-strain responses and thermal expansion.
In comparison with polyether block amide elastomers, ML67 has a homopolyamide backbone and higher Shore D hardness. Polyether block amides can be formulated to Shore D values below 40, while ML67 is approximately 60–65 Shore D per ISO 868:2003. The polyether-free structure modifies solvent partitioning and water uptake; PA12 generally has lower equilibrium water absorption than many hydrophilic polyether block amide grades, but quantitative comparisons against a specific PEBA formulation require side-by-side conditioning per ISO 62:2008. The higher amide character of ML67 also provides a different extractables profile that must be assessed under ISO 10993-18:2020 rather than assumed from PA12 class data.
Within the VESTAMID® Care PA12 family, ML67 is distinguished from lower-flow PA12 grades by its melt viscosity and from higher-flexibility polyamide elastomers by its Shore D range. The alphanumeric suffix does not correspond directly to a single standardized property; grade selection should be based on the full datasheet and lot certificate rather than nomenclature. Compared with general-purpose VESTAMID® PA12, the Care designation indicates a controlled healthcare formulation with supporting documentation, not a change in the fundamental polymer backbone.
Material-level documentation for ML67 may include biological test summaries, resin composition disclosure, and change notification commitments. The legal manufacturer of the finished device is responsible for demonstrating that the material and processes comply with the applicable medical device regulation. The matrix below identifies assessment routes commonly applied to PA12 medical components; inclusion in this matrix does not state that every production lot has been tested to every standard unless the supplier certificate explicitly confirms it.
| Standard/Regulation | Assessment scope |
|---|---|
| ISO 10993-1:2018 | Biological evaluation planning, chemical characterization, toxicological risk assessment, and final device testing obligations |
| ISO 10993-5:2009 | In vitro cytotoxicity of polymer extracts |
| ISO 10993-10:2010 | Skin sensitization and irritation potential |
| USP <88> Class VI | Pharmacopeial plastic material classification based on systemic injection, intracutaneous reactivity, and implantation |
| ISO 13485:2016 | Quality management system for medical device manufacturing; resin supplier documentation is not a substitute for device QMS |
| Regulation (EU) 2017/745 | European medical device regulation; general safety and performance requirements, chemical information in technical documentation |
In the United States, the resin may fall under 21 CFR 177.1500(b) as a nylon resin for repeated food-contact articles, but this citation is not a substitute for medical device clearance. For medical use, the device manufacturer’s 21 CFR Part 820 quality system and ISO 13485:2016 controls apply. If the device is marketed in the European Union, the technical documentation must satisfy Regulation (EU) 2017/745 Annex II; this includes chemical characterization, biological evaluation, and clinical evaluation where required. The resin supplier’s material declarations support these activities but do not transfer regulatory responsibility.
Chemical characterization of ML67 per ISO 10993-18:2020 should include extraction in polar and nonpolar media and identification of residual laurolactam, oligomers, stabilizers, and processing aids. PA12 differs from PA6 and PA66 in monomer chemistry; residual monomer is laurolactam rather than caprolactam or adipic acid analogues. The long-chain aliphatic structure reduces amide group density, which influences oligomer polarity and extraction behavior. Because final devices may introduce color concentrates, radiopacifiers, lubricants, adhesives, and sterilization residues, resin-level extractables data cannot be directly equated to device-level leachables. Toxicological risk assessment follows ISO 10993-17:2002 or newer risk-management practice, using chemical characterization data as input.
Extractables testing for PA12 medical grades is typically performed using extraction ratios and times derived from ISO 10993-12:2021. A common design uses polar and nonpolar solvents, such as water, ethanol/water, and hexane or isopropanol, under reflux or at 37–70 °C for 24–72 h. The analytical methods include liquid chromatography-mass spectrometry, gas chromatography-mass spectrometry, and inductively coupled plasma-mass spectrometry for elements. The goal is to characterize oligomers, residual monomer, processing aids, and potential metal residues. Published data for ML67 in this specific extraction configuration is limited; the manufacturer’s test summary should be requested and compared with the final device’s clinical exposure duration.
Mechanical performance of ML67 at low temperatures near −40 °C is relevant to cryogenic storage and transport applications. PA12 retains impact resistance below 0 °C better than many rigid amorphous thermoplastics; however, the specific notched impact value for ML67 at −30 °C per ISO 179-1/1eA:2010 should be read from the current lot certificate. The grade may not be suitable where sustained service above 100 °C is required, because the semicrystalline phase softens near the melting point and oxidative stabilizers are consumed over time. Continuous exposure to hot aqueous environments above 80 °C may accelerate hydrolysis; the device manufacturer should perform aging studies under ASTM F1980-21 accelerated aging or equivalent protocols where applicable.
For extrusion of catheter shafts, single-screw machines with 24:1–30:1 L/D and screen packs of 100–200 mesh are typical. The melt enters a crosshead die and is sized in vacuum water. Dry-air purge of the hopper is maintained when ambient relative humidity is above 60%, and storage of open pellets should not exceed 4 h under those conditions. The material is not intended for long-term implantable load-bearing components unless the manufacturer has completed device-specific biocompatibility, mechanical reliability, and clinical evaluation. Avoid contact with concentrated formic acid, cresol, and strong oxidizing acids; sustained exposure to these media causes surface attack and molecular weight reduction.
