Passivation of medical devices is an essential step to ensure the longevity and safety of their use as instruments. But is there a way to make this treatment more economical, eco-friendly, and also simpler to undertake?
What is chemical passivation?
Chemical passivation is a process that enables metals to resist corrosive agents. Through this treatment, a thin, dense and uniform film is formed ensuring the metals are not attacked by oxidising agents.
Why is the chemical passivation process important for medical devices?
In an industry where safe and aseptic environments are fundamental requirements, the chemical passivation process for medical instruments is very important. In addition to making the devices safer, it also extends their service life!!
On the left side of the picture above the instruments are without corrosion protection, whilst on the right the devices have been treated with the passivation process.
Our proposal for the passivation of chemical devices.
At Garzanti Specialties we have always focused on providing high-quality chemicals that are safe for personnel, sustainable for the environment, efficient, easy to use, offer a high yield, and are innovative in the market.
We have found all these characteristics in Borer Chemie products. Borer Chemie is a company we have been working with for a long time. Their Deconex MT 19 and Deconex MT 41 product lines are designed precisely for the pickling and passivation processes of medical instruments and implants. With a focus on ease of use, eco-friendliness, and reduced costs, Borer products are perfect for this type of treatment.
How the Borer products are applied.
The ASTM A967 specification describes various possibilities for passivation of medical devices. The most common processes are Nitric 2, Nitric 4 and Citric 4. These differ in terms of duration, temperature, concentration, chemistry, application and the variety of materials.
The Nitric 5 process, for which, Deconex® MT 19 and Deconex® MT 41 from Borer Chemie are classified, is a whole different chapter.
Two steps to guarantee effective passivation processes.
This application allows individual process parameters (time, temperature, chemistry) to be chosen and classified in NITRIC 5.
At the end of each process, a validation to confirm its functionality is required. Before proceeding with passivation, the surfaces to be treated must be totally free of residues such as machining oils, imprints, dust, salts, polishing pastes etc. The cleaning agent Deconex® MT 19 ensures their removal, offering optimal wettability and excellent rinsing capabilities.
The cleaning process creates the basis for optimal passivation with Deconex® MT 41. The perfectly-balanced formula makes the product an ideal solution for the passivation of instruments and implants. Its application delivers a rapid formation of an inert layer to ensure the protection of medical devices against possible corrosion phenomena.
Passivation also subjects the lettering and its contrast to less stress, maintaining its legibility to the naked eye. Fixed-mount products consisting of a combination of metal, silicone, carbon fibre and coloured markings, which are often found on medical instruments, can also be passivated without any issue.
A formulation without critical components.
Let’s now look at how Borer Chemie products are made to see why we call them safe, eco-friendly, and cost-effective.
Deconex® MT 41 consists of phosphoric acid (15-30 %), nitric acid (< 5 %) and non ionic surfactants. The product is biodegradable and does not require treatment of precipitates (heavy metals).
The spent solution can also be easily neutralised and subsequently disposed of in accordance with the law. The formulation does not contain critical substances, such as anti-corrosives, chlorine and silicates, which could compromise the validation or lead to complications in patients.
Optimised corrosion resistance.
Borer Chemie subjected this new process to intensive testing in cooperation with various institutes such as the Naturwissenschaftliches und Medizinisches Institut (NMI) and accredited laboratories such as Niutec AG. In this context, well-known materials used in medical technology, such as 1.4112, 1.4057, 1.4021, 1.4034, 1.4301, 1.4404, were tested for corrosion resistance based on a wide range of process parameters having been passivated by immersion and spraying methods.
The test results are based on Free-Iron and ICP-MS analyses, as well as comparisons with conventional methods (Nitric and Citric) by XPS analysis. The Free-Iron and ICPMS analysis confirmed the resistance by passivation with Deconex® MT 41. The XPS analysis also showed that the Cr to Fe and Cr oxide to Fe oxide ratios are at least two-times better than with conventional passivation methods.
Compared to classical methods, the new passivation process is used in diluted nitric acid concentrations of up to 1,000 times and offers completely new application possibilities for consideration within cleaning and passivation systems.
The passivation solution offers new possibilities, also taking into account zone concepts in the production sector: such as spraying systems, it can now also be used in a closed function.
This significantly reduces process-related efforts, such as compliance with the zone concept, the use of short transport routes and the elimination of additional handling such as moving products into a new transport container or media. The liquid passivation concentrate can also simply be added to deionised water before the start of the process.