Formula for chemical-resistant, flame-retardant polycarbonate

When developing medical equipment housings, medical device manufacturers often turn to chemical-resistant, flame-retardant materials. With a wide range of medical-grade materials, Covestro can help meet physical, chemical and environmental requirements for these applications.
The Cellfina® System utilizes Makroblend® M4000 FR PC+polyester blend and Makrolon® 2458 polycarbonate from Covestro. (Photo Credit: Merz)
The Cellfina® System utilizes Makroblend® M4000 FR PC+polyester blend and Makrolon® 2458 polycarbonate from Covestro. (Photo Credit: Merz)

One such material is Makroblend® M4000 FR PC+polyester blend, which offers flame retardancy of V-0 at 2.0 mm and 5VA at 3.0 mm and features superior chemical resistance appropriate for skin contact applications.

Additional benefits of Makroblend® M4000 FR PC+polyester blend include:

  • Biocompatible according to ISO 10993-5 (Cytotoxicity) and ISO10993-10 (Irritation and Sensitization)
  • High toughness
  • Reduced susceptibility to stress cracking
  • Good flowability
  • High tensile module

Merz, a global aesthetics and neurotoxin company headquartered in Frankfurt, Germany, recognized the potential of this polycarbonate grade for use in the motor module housing of its Cellfina® System. This system is the only FDA-cleared, minimally invasive procedure shown to improve the appearance of cellulite for up to three years. Covestro worked closely with Merz to select high-quality, proven materials for the Cellfina® System – providing chemical data, test plaques and custom order matching.

In between uses, the system’s motor module is disinfected with aggressive disinfectant wipes – calling for a material with superior chemical resistance. Makroblend® M4000 FR PC+polyester blend from Covestro met these requirements, and also offers flame retardance necessary for the product.

Additionally, Makrolon® 2458 polycarbonate is found in the sterilized disposable parts used with the Cellfina® system. This lightweight material is biocompatible according to many ISO 10993-1 test requirements, and features easy-release properties and low viscosity for ease of processing.


Both Makroblend® M4000 FR PC+polyester blend and Makrolon® 2458 polycarbonate provide durability needed to protect the device’s electronic components, yet are aesthetically pleasing. This collaboration with Merz demonstrates how Covestro can provide innovative solutions and technical support that meet the rigorous needs of the medical device industry.

For more information, email us: plastics@covestro.com.

Makroblend® and Makrolon® are registered trademarks of the Covestro group.

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