ePTFE Coating

PTFE (polytetrafluoroethylene) is a linear polymer composed of fluorine and carbon molecules. ePTFE is an expanded version of PTFE, and its microporous structure is formed by the expansion process of ePTFE. ePTFE has high strength-to-weight ratio, biocompatibility, high heat resistance, low friction, long-term stability and chemical inertness, and is most suitable for the medical device industry. ePTFE can be stretched, deformed and formed into a variety of geometric shapes, such as: strips, membranes, films, tubes, fibers and sheets. ePTFE has a microporous structure and is well suited as a porous coating material that can both seal and promote tissue growth, thereby potentially preventing migration.

01. Biocompatible polymers for stent coatings
Biocompatibility is defined as “the ability of a material to react appropriately with the host in a specific application.” The medical device industry quickly adopted ePTFE, and it is now commonly used for stent coating in many medical markets; from gastric self-expanding stents to vascular abdominal aortic aneurysm devices. ePTFE is also commonly used in cardiology, such as heart valves in structural heart applications, ventricular septal occluders, left atrial appendage implants, mitral valve clips, etc.

02. ePTFE coating technology
One disadvantage of using ePTFE is that it is usually applied to the stent by suturing technology. Suturing is a manual, time-consuming process that is less reproducible and difficult to scale up compared to automated processes. Although suturing only requires a layer of ePTFE to be covered, the suture itself creates another “micro layer” and creates stress in the suture area. This is a disadvantage in terms of compression profile.
Another coating technology using ePTFE is lamination. ePTFE can be laminated to the inner diameter, outer diameter, or inner and outer diameter of the stent. Lamination technology uses temperature and pressure to connect the coating material to the metal stent. The lamination of two layers can produce a “sandwich-like” coating material because the two coating layers are tightly connected in the overlapping area. This is very effective when the increase in thickness and compression profile is not a problem.

03. Sintering technology
The sintering process is another form of double-layer lamination, in which two layers of ePTFE sleeves are sintered to each other and then adhered to the metal stent. This process requires higher temperatures than the usual lamination process, between 340℃ and 400℃. Before using this process, carefully consider its impact on the thermal properties of the nitinol stent. Compared with single-layer sutureless lamination, this technology involves high temperatures and requires two layers of material, which increases the compression profile.

04. Innovative sutureless lamination technology
Overcome the difficulty of covering only one layer of ePTFE without sutures, while maintaining strong adhesion between the polymer cover and the metal stent. This unique sutureless lamination technology is based on a unique adhesion platform. This platform was developed to improve the adhesion between the metal stent and the polymer cover, two materials that do not usually adhere together. The adhesion platform activates the metal surface and then wraps the stent struts with an encapsulation coating, resulting in strong adhesion between the stent and the cover. The strong bond created between the stent and the cover allows engineers to replace the previous suture technology with a new, automated, repetitive, high-capacity technology, allowing for fast, easy, high-capacity mass production. Since the “micro-layer” of sutures is no longer required, the cover thickness and compression profile can be reduced.

ePTFE coating technology
Sintering, suture lamination, fusion, etc.

ePTFE coating is suitable for:
Aortic valve, mitral valve, tricuspid valve, pulmonary valve and other products, left atrial appendage coating occluder, ventricular septum coating occluder

ePTFE Coating - Stent Coating Systems for Drug Coatings

Cheersonic provides a variety of ultrasonic coating equipment and solutions for manufacturing industry of implantable, in interventional medical devices, the drug-eluting stents and balloon catheters. Our ultrasonic coating systems have been used to spray anti-restenosis drug eluting polymer solutions onto implantable stents. Compared to conventional two-fluid nozzles, ultrasonic nozzles can spray a more uniform drug coating that completely covers the stent without the orange peel and adhesion to a complex stent. And the coatings are much thinner than can be achieved with dip coating, saving spray material.

  • Ideal for R&D and low-volume production
  • Compact desktop design that is easy to move
  • The material usage ratio > 95%
  • Reliable, repeatable and consistent coating, uniformity of ±5%
  • Max. length 100mm, max. diameter 60mm

About Cheersonic

Cheersonic is the leading developer and manufacturer of ultrasonic coating systems for applying precise, thin film coatings to protect, strengthen or smooth surfaces on parts and components for the microelectronics/electronics, alternative energy, medical and industrial markets, including specialized glass applications in construction and automotive.

Our coating solutions are environmentally-friendly, efficient and highly reliable, and enable dramatic reductions in overspray, savings in raw material, water and energy usage and provide improved process repeatability, transfer efficiency, high uniformity and reduced emissions.

Chinese Website: Cheersonic Provides Professional Coating Solutions