medical-grade plastics for medical devices

10 Medical-Grade Plastics Used in Medical Device Injection Molding and Their Properties

When it comes to plastic injection molding of medical devices, not all plastics are created equal. Strict standards and a unique set of characteristics must be met, depending on the type of medical device or parts manufactured. In this article, we take a look at the ten most common medical-grade plastics and the properties that make them preferred choices for certain applications.

Key Takeaways

  • Medical-grade plastics are critical for ensuring patient safety, product reliability, and regulatory compliance in medical device manufacturing.
  • Material selection depends on four key criteria: Biocompatibility, mechanical & chemical properties, regulatory compliance, and application requirements.
  • Not all medical-grade plastics are suited for every application. Matching material properties to device requirements is key to performance, safety, and cost efficiency.

What Are Medical-Grade Plastics?

Medical-grade plastics are high-performance polymers that meet strict safety, durability, and biocompatibility standards. You’ll find them in implants, surgical tools, and diagnostic devices. These plastics resist chemicals, withstand sterilization, and remain stable under various conditions.

Using standard plastics where medical-grade is required can lead to product failure, contamination, or worse – patient risk. That’s why selecting the right material based on its heat resistance, chemical stability, strength, and numerous other factors is critical. When you use the right plastic, you don’t just meet specs – you protect lives.

4 Criteria for Selecting Medical-Grade Plastics

Choosing a plastic isn’t just about function. It’s about safety, performance, and compliance. So, how do you know what material is right for you?

1. Biocompatibility

Medical-grade plastics must be safe for the body and non-reactive with tissue or fluids. A truly biocompatible material should pass ISO 10993 and not trigger irritation, toxicity, or immune response. It also must mold cleanly without degrading. If you ignore biocompatibility, your device may cause swelling, infections, rejection, or even systemic reactions. That’s a risk that you obviously don’t want to take.

2. Mechanical and Chemical Properties

Not every product requires the same level of strength or flexibility. For surgical tools, you need tough, rigid materials. For tubing or implants, flexibility and chemical resistance are more important. For example, using a brittle material for a flexible catheter can lead to breakage. Ignoring mechanical needs can lead to failures, recalls, and increased costs.

3. Regulatory Compliance

Compliance isn’t optional – it protects your product, patients, and business. Medical device manufacturers need to use plastics that meet FDA standards and ISO certifications, like ISO 10993 for biocompatibility and ISO 13485 for quality systems. But that’s not all. Your injection molding partner must follow validated processes and meet clean room injection molding standards, such as ISO Class 7 or 8. Sourcing plastic materials from reputable suppliers ensures traceability and compliance.

4. Application Requirements

The application should always guide the material choice. For example, using polypropylene in a high-heat surgical instrument would be a mistake – it can’t handle autoclaving. But using PEEK in that same device would perform far better. On the other hand, for disposable parts, a high-cost resin isn’t ideal. Choose materials based on temperature, stress, exposure, cost, and lifecycle – no shortcuts.

Now let’s look at the most common plastics used in medical device plastic injection molding.

10 Medical-Grade Plastics Used in Medical Device Injection Molding

1. Polycarbonate (PC)

Property Tensile Strength Yield Strength Hardness (Rockwell) Melting Point Density
Value 55 – 75 MPa ~62 MPa M70 ~280 °C 1.20 – 1.22 g/cm³

Polycarbonate is a clear, tough thermoplastic used in many high-performance medical parts. Its moldability makes it a top choice for both disposable and reusable devices.

Key Properties of Polycarbonate

  • High Impact Resistance and Toughness: Polycarbonate can handle rough handling without cracking or breaking. It keeps its shape even under sudden impact.
  • Optical Clarity and Transparency: Its glass-like transparency makes it perfect for devices where visual monitoring or fluid control is key.
  • Sterilization Compatibility: It withstands repeated sterilization using autoclave, gamma radiation, and ethylene oxide (EtO) without degrading or losing clarity.

Applications

  • Surgical instruments
  • IV connectors
  • Blood filters
  • Oxygenators
  • Safety syringes
  • Diagnostic housings

2. Polyethylene (PE)

Property Tensile Strength Yield Strength Hardness (Shore D) Melting Point Density
HDPE 26 – 33 MPa ~26 MPa ~50 130 – 135 °C 0.94 – 0.97 g/cm³
UHMWPE 21 – 48 MPa ~23 MPa 62 – 66 130 – 152 °C 0.93 – 0.94 g/cm³

Polyethylene includes High-Density Polyethylene (HDPE) and Ultra-High Molecular Weight Polyethylene (UHMWPE) types. HDPE offers flexibility, low cost, and ease of molding. UHMWPE adds extreme wear resistance and implant-level biocompatibility. Both resist chemicals and absorb little moisture, making them reliable for various medical environments.

Key Properties of Polyethylene

  • Excellent Chemical Resistance: Withstands acids, bases, and solvents without degradation. Ideal for fluid-contact parts.
  • Biocompatibility (Especially UHMWPE): Proven for long-term implants like joint replacements without triggering immune reactions.
  • Flexibility and Impact Resistance: HDPE bends easily, and UHMWPE withstands wear and repeated stress.

Applications

  • Catheters
  • Tubing
  • Fluid containers
  • Joint prostheses
  • Orthopedic implants
  • Low-friction liners
  • Guide component

3. Polypropylene (PP)

Property Tensile Strength Yield Strength Hardness (Shore D) Melting Point Density
Values 35 – 40 MPa ~30 – 37 MPa ~95 R (Rockwell) 130 – 171 °C 0.895 – 0.92 g/cm³

Polypropylene is a lightweight, cost-effective thermoplastic widely used by medical parts injection molding service providers to produce disposable and reusable medical parts. PP is particularly suitable for precision plastic injection molding due to its excellent flow characteristics, allowing for the production of lightweight components with reduced wall thicknesses. It performs reliably in chemical-rich environments and remains stable through sterilization cycles. Its low density makes it ideal for producing lightweight medical products.

Key Properties of Polypropylene

  • Chemical Resistance & Sterilization Compatibility: PP withstands autoclaving and EtO, especially random copolymer grades.
  • Lightweight & Fatigue Resistant: It handles repeated flexing without cracking or weakening.
  • Clear Formulations Available: Special grades remain transparent after radiation sterilization.

Applications

  • Syringes
  • Medical fluid containers
  • Lab equipment
  • Diagnostic device housings
  • Disposable pipettes
  • Fluid delivery
  • Connectors

4. Polyetheretherketone (PEEK)

Property Tensile Strength Yield Strength Hardness (Shore D) Melting Point Density
Values 90 – 170 MPa ~100 – 114 MPa ~85 – 90 D ~343 °C ~1.31–1.32 g/cm³

Polyetheretherketone, or PEEK, is a high-performance thermoplastic valued in medical device molding. We turn to it when parts need strength, stiffness, and sterilization resilience. It excels under heat and pressure. Its mechanical stability and biocompatibility make it a go-to option for demanding medical components.

Key Properties of PEEK

  • High strength & stiffness: Tensile strength up to 170 MPa and Young’s modulus ~3.6 GPa.
  • Excellent biocompatibility: Proven safe for implants without causing toxicity.
  • High-temperature resistance & sterilization compatibility: Handles continuous service up to 250 °C and autoclaving, EtO, gamma, and steam.
  • Chemical & wear resistance: Stands firm against acids, bases, solvents, steam, and abrasion.
  • Radiolucent: Appears transparent in X-rays, allowing for improved imaging post-implantation.

Applications

  • Spinal fusion cages that match bone flexibility
  • Surgical instruments and endoscope handles
  • Trauma fixation plates and bone screws
  • Cardiovascular device parts
  • Custom fluid system components and connectors

Learn more about PEEK injection molding.

5. Polyvinyl Chloride (PVC)

Property Tensile Strength Yield Strength Hardness (Shore D) Melting Point Density
Values Flexible: ~24 MPa
Rigid: ~31–60 MPa
~10 – 25 MPa ~45 – 88 D ~100 – 114 °C Flexible: ~1.24 – 1.34 g/cm³
Rigid: 1.3 – 1.45 g/cm³

PVC stands out for medical molding due to its flexibility when plasticized, dependable chemical resistance, and cost efficiency. You’ll find PVC in many disposable and durable medical parts. It adapts to various sterilization methods and keeps your production costs under control.

Key Properties of PVC

  • Adjustable flexibility: Plasticizers make PVC soft, kink-resistant, and patient-friendly. You control rigidity.
  • Strong chemical resistance: Handles body fluids, alcohols, and cleaning agents. It resists degradation.
  • Sterilization ready: Tolerates steam, EtO, gamma, and electron beam methods.
  • Cost-effective & easy to process: PVC is abundant and simple to mold, weld, or bond.
  • High clarity: Clear grades help in visual fluid monitoring.

Applications

  • IV fluid containers
  • Tubing for IV, catheters, dialyzers, respiratory circuits
  • Feeding tubes
  • Oxygen masks
molded medical devices made of plastics

6. Thermoplastic Polyurethane (TPU)

Property Tensile Strength Yield Strength Hardness (Shore D) Melting Point Density
Values 30 – 50 MPa ~15 – 30 MPa ~35 A–70 A (≈40 D) ~160–220 °C 1.10 – 1.25 g/cm³

Thermoplastic polyurethane offers rubber-like elasticity with simple molding. Manufacturers use TPU when devices require soft, bendable parts that are both durable and flexible. It resists wear, oil, and chemicals. It suits parts that require tap flexibility, resilience, or patient comfort.

Key Properties of TPU

  • Rubber-like Flexibility and Elasticity: TPU offers excellent flexibility with elastic recovery. It resists cracking when bent or stretched, making it ideal for moving parts.
  • Biocompatibility and Patient Safety: Medical-grade TPU meets strict safety standards like USP Class VI and ISO 10993. It works well in both skin contact and internal applications.
  • Abrasion and Wear Resistance: TPU handles friction, surface wear, and repeated use without degrading. It’s reliable for high-contact medical parts.
  • Chemical and Fluid Resistance: This material resists oils, body fluids, and common cleaning agents. It holds up in real-world clinical environments.
  • Sterilization Compatibility: TPU tolerates EtO, gamma, and steam sterilization without losing strength or flexibility.

Applications

  • Medical and IV tubing
  • Catheter shafts
  • Overmolding connectors
  • Seals, gaskets, and flexible housings
  • Surgical instrument handles
  • Wearable sensor bands

7. Acrylonitrile Butadiene Styrene (ABS)

Property Tensile Strength Yield Strength Hardness (Shore D) Melting Point Density
Values 40 – 50 MPa ~30 – 40 MPa ~70 – 80 D Tg ~105 °C* 1.06 – 1.08 g/cm³

*ABS is amorphous; glass transition temperature instead of melting point.

ABS is ideal when you need a robust, easy-to-mold material with a good finish and shock resistance. It is widely used for medical-grade injection molding. We recommend this material for its lightweight yet durable properties, making it ideal for enclosures and instrument parts. It molds precisely and withstands various sterilization methods.

Key Properties of ABS

  • High Impact Strength and Toughness: ABS handles accidental drops, pressure, and external shocks well. Its structure absorbs energy without cracking.
  • Good Dimensional Stability and Surface Finish: It molds cleanly and holds shape under stress. This ensures tight fits and sleek, finished surfaces.
  • Compatible with Certain Sterilization Methods: ABS tolerates sterilization using gamma radiation or ethylene oxide. It’s not suitable for repeated autoclaving.

Applications

  • Enclosures for diagnostic devices (blood analyzers, ECG units)
  • Housings for portable surgical tools and lab instruments
  • Prototype models and single-use test kit parts
  • Handles, control panels, connectors, instrument covers

8. Polyethylene Terephthalate Glycol (PETG)

Property Tensile Strength Yield Strength Hardness (Shore D) Melting Point Density
Values 50 – 65 MPa ~40 – 55 MPa ~75 D ~230 – 260 °C 1.27 – 1.29 g/cm³

PETG hits the mark when you need transparent, rugged parts that ship pre-sterilized. It processes easily while offering a clean surface without stress marks. Its blend of clarity and toughness makes it a reliable option for fluid-focused parts.

Key Properties of PETG

  • High Clarity & Toughness: PETG delivers crystal-clear parts with strong impact resistance. It keeps transparency even after molding and handling.
  • Excellent Chemical Resistance: It resists a wide range of acids, bases, and cleaning agents. The material holds up in both laboratory and clinical settings.
  • Sterilization Compatibility: PETG tolerates gamma radiation, ethylene oxide, and electron-beam sterilization. It remains stable post-treatment.
  • Biocompatibility: Medical-grade PETG meets ISO 10993 and USP Class VI standards. It’s safe for parts that come into contact with skin or fluid.
  • Ease of Processing: It molds and thermoforms with minimal warpage. PETG works well in injection, sheet, or film formats.

Applications

  • Clear fluid delivery systems and connectors
  • Diagnostic instrument windows and covers
  • Vial caps, reservoir shields, labware components
  • Medical device housings requiring optical clarity

9. Polysulfone (PSU)

Property Tensile Strength Yield Strength Hardness (Shore D) Melting Point Density
Values ~75 – 85 MPa ~50 – 60 MPa ~80 D Tg: ~190 – 230 °C* ~1.24 g/cm³

*PSU is amorphous; glass transition temperature instead of melting point.

Polysulfone should be your choice when you need clear, heat-resistant, and chemically stable medical components. It lasts through heavy sterilization while keeping its shape and function.

Key Properties of PSU

  • High Heat & Mechanical Resistance: PSU stays strong and stable under steam and hot water. It resists warping at temperatures up to 150 °C.
  • Transparent yet Durable: It provides clear visibility while resisting impacts in laboratory and surgical settings.
  • Excellent Chemical Resistance: PSU resists acids, bases, and cleaning agents. It holds up well in clinical environments.
  • Autoclavable and Sterilization-Friendly: It withstands repeated autoclaving at 134°C without losing strength or clarity.
  • Biocompatibility: Medical-grade materials meet ISO 10993 and are suitable for short- to long-term bodily contact.

Applications

  • Dialysis filter housings and blood-contact parts
  • Surgical instrument handles
  • Filter enclosures and fluid connectors
  • Catheter hubs and transparent inspection windows

10. Polyamide (Nylon)

Property Tensile Strength Yield Strength Hardness (Shore D) Melting Point Density
Values 45 – 80 MPa ~30 – 60 MPa ~70 – 98 D ~215 – 265 °C ~1.01 – 1.15 g/cm³

Polyamide, or Nylon, is a strong, wear-resistant engineering plastic. Medical device manufacturers pick it when strength, toughness, and precision are required. With proper processing, it rivals metal in many uses. Its versatility suits both load-bearing parts and patient-contact components.

Key Properties of Polyamide

  • Durable Strength and Wear Resistance: Nylon offers high tensile strength of up to 80 MPa and resists abrasion. Reinforced grades deliver even more toughness.
  • High Chemical Resistance: It withstands many oils, hydrocarbons, and solvents. That makes it suitable for fluid contact and mechanical parts.
  • Heat & Sterilization Capability: Nylon works at temperatures up to 150 °C and tolerates autoclaving, EtO, and gamma sterilization.
  • Dimensional Precision: It molds with tight tolerances and minimal warping. Additives like glass fiber improve stability.
  • Low Friction & Fatigue Life: Nylon has low friction and resists wear. This makes it ideal for moving parts like gears or hinges.

Applications

  • Surgical instrument gears, hinges, and handles
  • Catheter hubs, threaded connectors, and prosthetic joints
  • Wear-resistant mechanical components and bushings
  • MRI-safe device parts and fluid-handling fittings

Medical-Grade Plastics Comparison Table

Material Strength Flexibility Clarity Biocompatible Cost
Polycarbonate (PC) High Low High Yes Moderate
Polyethylene (PE) Moderate (HDPE), High (UHMWPE) High (HDPE), Moderate (UHMWPE) Low Yes (especially UHMWPE) Low
Polypropylene (PP) Moderate High Moderate to High (some grades) Yes Low
Polyetheretherketone (PEEK) Very High Low Low Yes High
Polyvinyl Chloride (PVC) Low to Moderate High (Plasticized) High (Flexible grades) Yes Low
Thermoplastic Polyurethane (TPU) Moderate Very High Moderate Yes Moderate
Acrylonitrile Butadiene Styrene (ABS) Moderate Low Low Yes (short-term) Low
Polyethylene Terephthalate Glycol (PETG) High Low Very High Yes Moderate
Polysulfone (PSU) High Low Moderate Yes High
Polyamide (Nylon) High Moderate Low Yes Moderate

Conclusion

Each plastic covered in this guide serves a unique purpose in medical device design. Use PEEK or PSU for high-heat and high-strength applications. Choose TPU, PVC, or PE when flexibility and patient comfort are most important. For clear components, PETG or PC delivers strength and visibility. Material choice directly impacts product safety and reliability.

To get the best results, partner with a trusted medical device manufacturer. At PreciKam, we understand the importance of good resin selection for plastic injection molding, especially in the medical device manufacturing industry. This is why we buy our resins from reputable suppliers. We will work closely with you to understand your part requirements and guide you to the perfect medical-grade plastics that meet both your product requirements and your budget.

Learn more about our expertise in medical device plastic injection molding.