Medical Wire Insulations
Applying a flexible, non-conductive insulation to the bare conductor is a core MWS manufacturing capability, providing dielectric strength and electrical isolation. To support a wide range of medical device applications, MWS offers numerous insulated medical wire materials, colors, and build options, including single, heavy, triple, quad, and custom builds, each increasing insulation thickness and electrical protection.
Insulation is applied and cured using complex, part-specific manufacturing processes that ensure consistent performance and quality. MWS leverages a diverse portfolio of coating and curing equipment, combined with more than 50 years of expertise, to deliver insulation solutions ranging from traditional coatings to advanced extrusion and high-temperature insulation systems. This broad capability allows customers to select the insulation technology best suited to their application and performance requirements.
Medical Wire Insulation Guide
| Thermal Class | Insulation Type | MWS Product Code | NEMA Standard (MW 1000) | Insulation Characteristics |
|---|---|---|---|---|
| 155°C | Polyurethane 155 | P155 | MW 79 | Polyurethane-155 is a 155°C thermal class, solder-strippable insulation commonly used on fine-wire conductors. Its quick solder-through capability at approximately 390°C eliminates the need for mechanical or chemical stripping, helping streamline assembly processes and reduce handling of delicate wire during manufacturing. |
| Polyurethane Nylon 155 | PN155 | MW 80 | Polyurethane Nylon-155 combines a 155°C thermal class polyurethane insulation with a nylon overcoat. It is well suited for medical device applications requiring improved durability during assembly, routing, and repeated handling. This solder-strippable insulation supports efficient termination without the need for mechanical stripping, making it a practical choice for miniature medical components, sensors, coils, and other space-constrained electronic assemblies. | |
| 180°C | Polyurethane 180 | P180 | MW 82 | Polyurethane-180 provides the same characteristics as Polyurethane-155, with the added benefit of a 180°C thermal class. |
| Polyurethane Nylon 180 | PN180 | MW 83 | Polyurethane Nylon-180 provides the same characteristics as Polyurethane Nylon-155, with the added benefit of a 180°C thermal class. | |
| Solderable Polyester | SPT | MW 77 | Solderable Polyester is an ester-imide insulated wire that provides reliable solder-through termination at approximately 470°C. Its solderable insulation can help streamline assembly by eliminating the need for mechanical or chemical stripping prior to termination. This makes it a practical choice for medical device applications that utilize fine-gauge conductors, dense interconnects, or automated manufacturing processes where consistent wire preparation is critical. | |
| 200°C | Polyester 200 | PT200 | MW 74 | Polyester-200 is a modified theic-polyesterimide insulation that offers a 200°C thermal class, excellent thermal stability, and good chemical resistance. These properties make it well suited for medical device applications that require reliable performance in demanding environments, including exposure to elevated temperatures and harsh processing conditions. |
| Polyester A / I Topcoat | APT | MW 35 (RD) MW 36 (SQ & RECT) | Polyester-Amide-Imide wire features a modified polyester basecoat with an amide-imide overcoat, providing excellent heat-shock performance, mechanical durability, and chemical resistance. It is a durable insulation that is well suited for medical device applications requiring fine-gauge conductors, tight winding or forming, and reliable insulation integrity through soldering, thermal processing, and repeated handling during device assembly. | |
| 220°C | Polyamide-Imide | PAI | NEMA MW81-C | Polyamide-imide (PAI) insulation combines high strength, excellent thermal stability, abrasion resistance, and broad chemical resistance. Often applied over polyester enamel to increase thermal performance, PAI is well suited for medical device applications requiring durable insulation, reliable electrical performance, and resistance to demanding manufacturing and operating conditions. |
| 240°C | Polyimide – ML | ML | MW 16 (RD) MW 20 (SQ & RECT) | ML is a polyimide (PI) film insulation widely used in medical device applications where small diameter, high temperature performance, and durable electrical insulation are critical. Its thin-wall construction supports wire miniaturization and high conductor density, making it well suited for catheters, sensors, coils, and other space-constrained devices. With a 240°C thermal class and exceptional resistance to chemicals, solvents, abrasion, and burnout, ML helps maintain insulation integrity through demanding manufacturing and operating conditions. Its biocompatibility characteristics further support its use in medical device applications. |
Bond Coat Types
| Bonding Coat (Operating Temperature) | Solvent* |
|---|---|
| Polyvinyl Butyral (105°C) | Alcohol |
| Nylon (105°C) | None |
| Epoxy (130°C) | MEK or Acetone |
| Polyester (130°C) | None |
| Polyamide (165°C) | None |
| Polyimide (ML) (240°C) | None |