Medical Design and Outsourcing

  • Home
  • Medical Device Business
    • Mergers & Acquisitions
    • Financial
    • Regulatory
  • Applications
    • Cardiovascular
    • Devices
    • Imaging
    • Implantables
    • Medical Equipment
    • Orthopedic
    • Surgical
  • Technologies
    • Supplies and Components Index
    • Contract Manufacturing
    • Components
    • Electronics
    • Extrusions
    • Materials
    • Motion Control
    • Prototyping
    • Pumps
    • Tubing
  • MedTech Resources
    • Medtech Events in 2025
    • The 2024 Medtech Big 100
    • Medical Device Handbook
    • MedTech 100 Index
    • Subscribe to Print Magazine
    • DeviceTalks
    • Digital Editions
    • eBooks
    • Educational Assets
    • Manufacturer Search
    • Podcasts
    • Print Subscription
    • Webinars / Digital Events
    • Whitepapers
    • Voices
    • Video
  • 2025 Leadership
    • 2024 Winners
    • 2023 Winners
    • 2022 Winners
    • 2021 Winners
  • Women in Medtech
  • Advertise
  • Subscribe

These common thermoplastics are ideal for medical device injection molding

November 15, 2019 By Nancy Crotti

The properties of certain polymers make them good choices for a variety of medical devices.

Raj Singh, BMP Medical

Injection molding manufacturing equipment (Image from BMP Medical)

Selecting the correct medical-grade plastic for a medical device or component is a critical decision in manufacturing the perfect part.

Polymers have long been considered to have a significant advantage over metals for medical applications. That’s because the isotonic saline solution that comprises the body’s extracellular fluid is extremely hostile to metals but is not normally associated with the degradation of many synthetic high-molecular-weight polymers.

Polymers are typically classified into three groups.

  • Thermoplastics — linear or branched polymers that can be melted and molded using conventional techniques. If reheated, wax can be molded into a different shape.
  • Thermosets — cross-linked polymers that are normally rigid and intractable. They consist of a 3D molecular network and cannot be re-melted. They degrade rather than melt upon heating.
  • Elastomers — rubbers that can be stretched to extension and will spring back when the stress is released.

By weight, thermoplastics represent 90% of all plastic used worldwide. Unlike most thermoset plastics, thermoplastics may be processed without any serious losses of properties. Here are some of the most common thermoplastics used in medical device injection molding:

Polyethylene

Also called polythene, polyethylene can be formulated in high or low densities. It is cost-effective, impact- and corrosion-resistant, absorbs little water and retains its overall performance and structural integrity after frequent sterilization cycles. A porous synthetic polymer, polyethylene is biologically inert, does not degrade in the body and is often used in medical implants.

Polypropylene

Polypropylene is a white, mechanically rugged material with a high chemical resistance. It is resistant to stress, cracking, impact and fatigue and has a high melting point. Polypropylene is commonly used to manufacture disposable syringes, membranes for membrane oxygenators, connectors, finger-joint prostheses, non-absorbable sutures, reusable plastic containers, pharmacy prescription bottles and clear bags.

Polymethyl methacrylate

Polymethyl methacrylate (PMMA) is a synthetic resin that offers transparency, toughness, rigidity and an almost perfect transmission of visible light. An ideal substitute for glass, it can keep a beam of light reflected within its surfaces and is frequently made into optical fibers for telecommunication and endoscopy.

Polyvinyl chloride

Polyvinyl chloride (PVC) is produced in two general forms, as a rigid or unplasticized polymer (RPVC), and as a flexible plastic. Flexible PVC is commonly used in areas where a sterile environment is a priority, and in some cases as a replacement for rubber. PVC is dense, inexpensive and readily available. Rigid PVC is very hard and has extremely good tensile strength. PVC is commonly used to manufacture disposable devices for hemodialysis or hemoperfusion, as well as tubing, cardiac catheters, blood bags and artificial limb materials.

Polyamide

Polyamide, or nylon, is a synthetic thermoplastic polymer that is often used as a substitute for weaker metals because of its strength, inflexible nature, temperature resilience and chemical compatibility. Polyamide is good for CNC machining, injection molding and 3D printing. It can be conditioned or combined with other materials to improve its overall strength and is a good option for parts that see a lot of wear and tear. It resists most chemicals but can be tricky to mold and is expensive.

Acrylonitrile butadiene styrene (ABS)

ABS is commonly used in part production and 3D-print manufacturing for OEMs. Its impact- and heat resistance and rigidity make it a good engineering plastic or substitute for metals in structural parts. It can be injection-molded, blow-molded, or extruded, melted and reshaped, and sterilized by gamma radiation or ethylene oxide (EtO). Common uses are non-absorbable sutures, tendon prostheses, drug-delivery systems and tracheal tubes.

Polycarbonate

Polycarbonate is naturally transparent and offers good UV protection. It is a good alternative to glass, relatively shatterproof, and medical grades can be sterilized using steam at 120 °C, gamma radiation or (EtO). Polycarbonate is lightweight, offers chemical-, electrical-, heat- and impact-resistance, stability and high performance.

Raj Singh is technical manager for BMP Medical.

The opinions expressed in this blog post are the author’s only and do not necessarily reflect those of Medical Design and Outsourcing or its employees.

Related Articles Read More >

A photo of a tiny micromolded medical device component on a fingertip.
Micromolding for surgical robotics can offer better functionality and lower costs
Accumold brings micro-optics expertise to Photonics West 2025
This image from ProMed Molded Products shows the Green Valley Park in Alajuela, Costa Rica, where ProMed plans a new facility.
ProMed Molded Products plans new manufacturing facility in Costa Rica
A photo of RenyMed's new building in Baldwin Park, California.
RenyMed expands manufacturing operations in California
“mdo
EXPAND YOUR KNOWLEDGE AND STAY CONNECTED
Get the latest medical device business news, application and technology trends.

DeviceTalks Weekly

See More >

MDO Digital Edition

Digital Edition

Subscribe to Medical Design & Outsourcing. Bookmark, share and interact with the leading medical design engineering magazine today.

MEDTECH 100 INDEX

Medtech 100 logo
Market Summary > Current Price
The MedTech 100 is a financial index calculated using the BIG100 companies covered in Medical Design and Outsourcing.
DeviceTalks

DeviceTalks is a conversation among medical technology leaders. It's events, podcasts, webinars and one-on-one exchanges of ideas & insights.

DeviceTalks

New MedTech Resource

Medical Tubing

MassDevice

Mass Device

The Medical Device Business Journal. MassDevice is the leading medical device news business journal telling the stories of the devices that save lives.

Visit Website
MDO ad
Medical Design and Outsourcing
  • MassDevice
  • DeviceTalks
  • MedTech100 Index
  • Medical Tubing + Extrusion
  • Medical Design Sourcing
  • Drug Delivery Business News
  • Drug Discovery & Development
  • Pharmaceutical Processing World
  • R&D World
  • About Us/Contact
  • Advertise With Us
  • Subscribe to Print Magazine
  • Subscribe to our E-Newsletter
  • Listen to our Weekly Podcasts
  • Join our DeviceTalks Tuesdays Discussion

Copyright © 2025 WTWH Media, LLC. All Rights Reserved. The material on this site may not be reproduced, distributed, transmitted, cached or otherwise used, except with the prior written permission of WTWH Media LLC. Site Map | Privacy Policy | RSS

Search Medical Design & Outsourcing

  • Home
  • Medical Device Business
    • Mergers & Acquisitions
    • Financial
    • Regulatory
  • Applications
    • Cardiovascular
    • Devices
    • Imaging
    • Implantables
    • Medical Equipment
    • Orthopedic
    • Surgical
  • Technologies
    • Supplies and Components Index
    • Contract Manufacturing
    • Components
    • Electronics
    • Extrusions
    • Materials
    • Motion Control
    • Prototyping
    • Pumps
    • Tubing
  • MedTech Resources
    • Medtech Events in 2025
    • The 2024 Medtech Big 100
    • Medical Device Handbook
    • MedTech 100 Index
    • Subscribe to Print Magazine
    • DeviceTalks
    • Digital Editions
    • eBooks
    • Educational Assets
    • Manufacturer Search
    • Podcasts
    • Print Subscription
    • Webinars / Digital Events
    • Whitepapers
    • Voices
    • Video
  • 2025 Leadership
    • 2024 Winners
    • 2023 Winners
    • 2022 Winners
    • 2021 Winners
  • Women in Medtech
  • Advertise
  • Subscribe