Trelleborg Supports Engineers Developing Drug-eluting Devices

Trelleborg Supports Engineers Developing Drug-eluting Devices

Trelleborg Sealing Solutions releases two whitepapers focused on the combination of silicone with Active Pharmaceutical Ingredients (API) that will support healthcare & medical device engineers and designers involved in the development of drug-eluting devices.

Drew Gaillard, Global Director Healthcare & Medical for Trelleborg Sealing Solutions, says: “The Healthcare market is driven by trends such as an aging population, increasing chronic disease, and global healthcare concerns related to obesity, diabetes and infectious diseases.

HM Whitepaper Drug Eluting Devices

With these trends comes other struggles for the medical community, such as an increase in catheter associated infections or the challenge of ensuring patient compliance with their medications. These trends and challenges have in turn led to the rapid innovation in drug device combination products, in particular those that elute regular, controlled doses of drugs precisely and consistently to a treatment area.”

Drug-eluting devices can be produced in and by a variety of materials and processes. One of the most successful materials in the design and production of combination products, in particular implantable ones, is silicone.

Gaillard continues: “Trelleborg Sealing Solutions is at the forefront of silicone drug-eluting product innovation and has studied the different methods of combining silicone with an API. The results of testing on the immersion method are now available to engineers and designers working in the healthcare & medical field.”

In the whitepaper Supporting the Advancement of Drug-Eluting Devices, two methods of adding Active Pharmaceutical Ingredients (API) to silicone, the addition of API to raw silicone and the impregnation of vulcanized silicone with API by immersion, are discussed.

The traditional method of adding API to uncured silicone is proven and effective. However, it is limited to API that are resistant to a vulcanization process and exposure to heat. A newer method of impregnation of vulcanized silicone by API, potentially broadens the APIs that can be used in drug-eluting silicone devices. This whitepaper presents test results that prove the effectiveness of this method, potentially opening drug-eluting devices to delivery of a wider range of API.

The second whitepaper, Fighting Hospital Acquired Infection, focuses on Healthcare-Associated Infections (HAI). Although combatting hospital-acquired infections has been a focus for the medical community, they still remain a significant issue. In particular, catheter-associated infections are difficult to prevent due to a catheter’s inherent positioning: part in and part out of the body.

Silicone is often used for the catheter tubes and though the material is biocompatible and biostable, it is not immune to bacterial colonization. Techniques exist that can reduce this colonization including coating, addition of antibiotic API to raw silicone and the impregnation of vulcanized silicone with API through immersion. In this whitepaper the three techniques are evaluated and Trelleborg shares its results from an effectiveness study of the impregnation methodology.

The two whitepapers, Supporting the Advancement of Drug-Eluting Devices and Fighting Hospital Acquired Infection, are the latest additions to the Trelleborg Sealing Solutions technical area that contains valuable resources for the engineer and designer. Registration and access to all resources is free. Go to for further information and to download the whitepapers.

Nano Scale Seal-Glide Coating

Nano Scale Seal-Glide Coating

Seal-Glide®, an innovative surface treatment from Trelleborg Sealing Solutions, significantly improves friction and stick-slip properties of elastomer seals while having little or no effect on the performance of the compounds the seals are made from. The coating is just a few hundred nanometers, ten to 50 times less than typical coating thicknesses. Even though it is so thin, the coating significantly reduces the friction coefficient of elastomer seals and improves their stick-slip properties considerably, facilitating effective automated assembly.

Nano Scale Seal-Glide Coating

Seal-Glide® is suited for coating classic O-Rings and complex molded parts for a wide range of applications and is available in two versions: Seal-Glide® Nano for automotive and industrial uses and Seal-Glide® Medical. Typically Seal-Glide® coatings are less than 450 nanometers. It therefore imparts the benefits of a surface coating, without affecting the bulk properties of the seals. As a result, the original elastic properties of the elastomers are virtually unaltered but the seals have a higher service life due to reduced wear when in motion or on start-up.

Andreas Schmiedel, Technical Manager for Healthcare and Medical in Europe at Trelleborg Sealing Solutions, says: “The Seal-Glide® Medical coating is ideal for use in healthcare and medical applications as the new process has a very high level of stability. This makes it resistant against sterilization with gamma radiation, ethylene oxide and hot steam, which is essential for the multiple use of medical devices, valves or syringes.

“To this end, the coating process satisfies the strict requirements for medical, bio-technology and pharmaceutical applications as prescribed by the authorities such as the American FDA (Food and Drug Administration) or European standards such as DIN EN ISO 10993 for the biological evaluation of medical devices.”

In automotive or industrial applications, Seal-Glide® Nano gives distinct advantages in high volume automated assembly lines.

Gordon Micallef, Operations Director at Trelleborg Sealing Solutions in Malta, where Seal-Glide® Nano was developed, says: “The strong surface tackiness of elastomer seals is an inherent property, which can cause issues such as the creation of high assembly forces, disruptions in automatic assembly lines as well as reduced performance in dynamic applications.

“On many assembly lines, overall speed is limited by the elastomer parts feed rate. Due to the reduction in co-efficient of friction, the use of the Seal-Glide® Nano coating will result in significant efficiency gains, by considerably improving the feed rate in automatic assembly lines.”

Elastomers without a surface treatment tend to stick, either to each other during automatic assembly or to counter surfaces in dynamic use. A particular issue is after periods of rest, when due to an elastomer’s inherent stickiness, there can be a stick-slip-effect. In this, the elastomer seal sticks to its counterpart and when moved elastomer is pulled off the seal reducing seal life. In addition, extra energy is required to move the seal from a stationary position.

This stick-slip effect can be minimized or even virtually eradicated through effective surface treatment of a seal. This is also important in healthcare and medical applications.

Schmiedel continues: “When coated, O-Rings or complex molded parts can be installed more easily and securely in components due to better separation of the seals. Using the friction-reducing coating, the components can be assembled smoothly and without damage so that the entire assembly process is completed simply and securely. Feed issues are minimized, reducing the probability of production stops.”

Another advantage of Seal-Glide® is that due to its thinness, the coating has a high level of transparency and does not cover the original color of the elastomer. The color of seals can play a central role in assembly. O-Rings are mostly black, but are often dyed in order to visually highlight differences in composition, diameter, thickness or positioning within a component. With our innovative coating, this color coding is retained, even after the coating.

Seal-Glide® is suitable for many types of elastomer and thermoplastic seal material types. These include LSR (Liquid Silicone Rubber), Ethylene Propylene Diene Monomer Rubber (EPDM), Fluorocarbon (FKM), Fluorosilicone (FVMQ), Nitrile Butadine rubber (NBR), Hydrogenated Nitrile Butadiene Rubber (HNBR), Ethylene Acrylate Rubber (AEM), and silicone rubber (VMQ) as well as thermoplastic polyurethane (TPU).



Trelleborg Sealing Solutions unveils a pioneering product that could “radically improve the reliability” of rotary wing aircraft.


The Turcon® Varilip® PDR RT rotary shaft seal, which has already been proven to out perform other similar seal products, was developed to meet the ever-growing demand to provide seal integrity at increasingly higher rotational wing speeds.

Torben Andersen, Trelleborg Sealing Solutions Director of Aerospace, said: “This project started several years ago, when we wanted to find a seal that would provide a better performance at very high speeds, specifically for rotary wing aircraft.

“We knew that at high surface speeds, ensuring that essential lubrication is maintained was a major challenge and any leakage would compromise the operation of the aircraft. That’s why designing a seal that out performs anything that’s currently out there was so vital.”

During the development of the Turcon® Varilip® PDR RT rotary shaft seal, Trelleborg designed and commissioned bespoke high speed test equipment capable of running at speeds of up to 24,000 rpm and a test programme that closely followed the way rotary wing aircraft gearboxes work. This allowed developers to ensure that the seal met highly demanding application requirements. The team experimented with a number of different lip materials, marrying them to various seal designs and investigating the best lip geometries and lip features to select the correct profile and material.

Torben added: “This is a breakthrough. We’ve developed a process that facilitates a seal with less torque, friction and heat to reduce maintenance; one that will radically improve the reliability and boost the performance of rotary wing aircrafts.

“Though initially designed for this specific application, the work we’ve done shows that it also lends itself to other applications that require high speed rotary performance. We’re already generating interest from designers of electromechanical actuators and from a wide range of other market segments.

“For many years there has been a standard version of the Turcon® Varilip® PDR – but this new seal operates effectively with less power and is therefore more efficient. We’ve optimised the design so it can run on a range of surface finishes and coatings, including ceramics.”

Using Trelleborg’s bespoke testing equipment, the Turcon® Varilip® PDR RT rotary shaft seal has undergone more than 20,000 hours of endurance testing with latest designs operating at 3,500 hours leak free.

To see our range of aerospace seals go to here