PTFE on the Advance
The High-Performance Plastic Finds a Steadily Increasing Field of Applications

In the field of life sciences, a wide range of plastics are used. Depending on the application, in addition to basic material properties, processing possibilities, service life (single use/re-usability), existing approvals and the associated costs are of paramount importance.

The amendment of the Medical Products Act (MPG) in Germany, in March 2010, places an even higher priority than before on patient safety. This has accelerated the need of improving component safety and traceability, not only for implants but also for equipment components. As a result, innovative forms of marking are becoming increasingly important, and developers are placing a stronger focus now on plastics which previously were used only for highly special applications.


1: Color-coded PTFE tubes for use in endoscopy

Which Factors Support the Use of PTFE?

Today, the polytetrafluoroethylene (PTFE) high-performance plastic, for example, is being used in endoscopy or analytics and similar fields due to its material properties. As a material for life science uses, PTFE is characterized in particular by the following special material properties:

  • Thermal resistance (-250°C to +300°C)
  • No water absorption and resistance to hot water vapor make PTFE suitable for autoclaving
  • Defined permeation of porous or expanded PTFE enables gas/liquid separation
  • Activation / passivation of the surface through doping or insertion of fillers. Examples   include the vitalization or drug elution of surfaces (doping) and antimicrobial properties   or X-ray contrast capability
  • Anti-adhesive and smooth surfaces allow gentle surgery with low shifting forces and low   adhesion of bio films
  • Application of markings such as logos, lettering or symbols using various printing   methods is possible
  • Physiological harmlessness and the resulting availability of important approvals for life   science uses such as ISO10993, EU1935/2004 or FDA
  • Attachment to other components can be achieved through adhesion-bonding or welding
  • Customization of compounds enables modification of the material properties to meet   specific requirements such as wear resistance, hardness, stiffness, color, flexibility,   electrical conductivity, elongation, light permeability
  • Light fastness and weather resistance contribute to component safety and reliability as
      storage, for example, does not impair the properties of the material
  • Very good chemical resistance allows the use of almost all cleaning agents and   disinfectants.

Using a Targeted Approach to Influence Properties

Through one- or multi-dimensional expansion in the unsintered state and possibly subsequent setting, the mechanical properties can be influenced in a targeted manner. The resulting expanded polytetrafluoroethylene (ePTFE) is characterized by very high flexibility and increased permeation compared to conventional PTFE. Applications for this material in the life sciences sector include vascular prosthetics and diaphragms, for example.

Suitable for Thermoplastic Processing

An innovative extension of the design options that exist when using PTFE is enabled by Moldflon™ 2, a material which is suitable for thermoplastic processing with a composition that largely corresponds to that of conventional modified PTFE and therefore offers advantages particularly with respect to component design. As a result, the material consumption compared to the traditional machining process used for PTFE components can be significantly reduced and parts costs drastically cut for large-volume production.
Compared to PTFE, which is produced in a compression/sintering process, Moldflon™  offers the following advantages:
- Minimal permeation
- Low cold flow tendency
- High transparency
- Excellent electrical properties
- Very good weldability

2: Wear characteristics of Moldflon™ compared to PTFE

Compounds Extend Fields of Application

Another modification, and thus the extension of the performance spectrum, can be achieved by the addition of fillers, a process known as compounding.
Even low percentages of polyetheretherketone (PEEK) significantly improve, for instance, the wear properties of PTFE and Moldflon™, but without exhibiting the critical properties which are typical for PEEK such as dulling in case of multiple sterilizations.
Another example of innovative compounds used in life sciences is the insertion of silver ions to improve the material’s antimicrobial properties. This is a step toward higher patient safety and thus reduces the risk of claims for damages, particularly with respect to the U.S. market.
These compounds have been awarded the crucial certifications according to ISO10993, EU1935/2004 or FDA regulations.

Despite these attractive properties for the life sciences sector PTFE is currently used in only a few areas there.
Typical applications for PTFE include:

  • Bellows for dialysis valves - 3
  • Tube module for high-performance liquid chromatography (HPLC) in the field of analytics
  • Endoscopy tubes, partially in multi-lumen versions with color coding such as connecting cables for FiAPC probes, hybrid knives or ERCP catheters
  • Various seals, e.g. for dental compressors, inhalers, (breast milk) pumps, lab dosing devices and endoscopes
  • Porous filter elements for gases, vapors and liquids
  • Trocar cannula for laparoscopic surgery
  • Friction bearings for operating tables or hinges in operating rooms


3: Double piston pump for use in home dialysis equipment

New processing technologies in combination with industry-specific compound development increasingly open up new fields of application such as:

  • Highly flexible endoscopy tubes from ePTFE which increase the user-friendliness and precision of endoscopes in surgical procedures
  • In-molding of components such as Moldflon™ housings for pacemakers
  • Intelligent connection to equipment components through combination of materials and free choice of design
  • Complex components such as function-integrated tube connectors
  • Moldflon™ bags for banked blood
  • Films/sheets and packaging for medical products - 4


4: Moldflon™ film

Solutions for Increasing Demands

In the high-volume life sciences market with its strong demand for consumption materials high-performance plastics play a minor role and are used only for highly special applications. However, due to its properties and modification options PTFE offers the possibility to create functional elements for high-tech applications with high levels of product safety. In view of the amendment of the German MPG and the resulting higher demands made on life science products an increasing number of new opportunities are opening up for the use of high-performance plastics.

Facts for Designers

  • Thermoplastically processable PTFE offers extended degrees of freedom for component design
  • Through compounding, material properties can be effectively modified to suit the respective application scenario

Facts for Buyers

  • Thermoplastically processable PTFE in high-volume production can be processed at clearly lower costs than standard PTFE

Facts for Quality Managers

  • PTFE is physiologically harmless and has been awarded important approvals for use in the life sciences sector such as ISO 10993, EU 1935/2004 or FDA
  • High-performance materials like PTFE offer interesting approaches to solutions in view of the amendment to the (German) MPG.