Advanex – The Experts in Reducing Particulate in Medical Device Production
As the Medical Device Market evolves to become highly sophisticated and advanced, manufacturers face constant pressures in being able to reduce particulate in the production and assembly of components. For Advanex Europe, a specialist in medical device component manufacture, developing new methods to reduce particulate is becoming increasingly important.
Over the years the design and engineering teams at Advanex Europe have been working in collaboration with some of the world’s leading medical device manufacturers to develop techniques for reducing particulate.
With management systems approved to ISO 9001 and 140001, Advanex Europe produce metal and plastic components for various medical devices. Components currently include but are not limited to:
Anti-Tangling Coil Springs
These components are used in a variety of medical devices including metered dose inhalers, auto injection systems and nasal sprays. Since Advanex Europe are actively growing their customer base in the Medical Device Market they are firmly committed to ensuring they remain at the forefront of reducing particulate.
What Are Particulates?
Particulates are minute, separate particles of organic or non-organic matter that contaminate components. Particulate can be generated during the coiling and forming process by friction between the raw material and the tooling, and from foreign bodies such as lubricants that are picked up by contact during manufacturing.
What Produces Particulates?
Components can also be contaminated by airborne particulate present in the atmosphere surrounding the process and contact with operators, equipment, packaging materials etc., during manufacturing. Some coiling processes require the raw material to be coated with coiling soap to reduce the effects of friction during the coiling and forming process. Usually these contaminants are removed by secondary processes.
Processes to Remove Particulate
Prevention by Design
In some circumstances particulate can be reduced by prevention. For some applications, Advanex Europe have designed bespoke processes that do not require soap coated wire and design tooling to reduce frictional effects as far as possible.
Designing and building bespoke manufacturing equipment can provide an advantage for customers as the process can be optimised for the product.
Most spring manufacturers use “bought-off-the shelf” machinery which is very versatile and can make a huge variety of products. Traditional spring coilers form springs by continuously pushing wire against an inclined tool which forces the wire to bend and form a coil. This generates high levels of friction, requires lubrication (usually in the form of soap coated wire) and greatly restricts the rate at which the coil can be formed.
In many cases Advanex can form coil springs by wrapping the wire around a rotating mandrel which generates much lower levels of friction, does not require soap coated wire and can produce springs at much higher production rates. Mandrel coiling is not as versatile as traditional coiling methods and bespoke sized tooling will be required for each product. If the required quantities are high enough this method can be very economical.
The versatility associated with traditional coilers requires a relatively large amount of equipment and tooling, some of which is redundant for manufacture of any individual product. All the machine components provide opportunities for generation of particulate. Advanex design manufacturing equipment to fit the product so that all components used in the machine construction are critical to the manufacturing process, and there is no redundant equipment.
The design of each machine component and its potential for generating particulate is carefully considered. Sharp edges and situations where high levels of friction can occur are generally avoided. Using materials which reduce friction and have high wear resistance such as carbide, polished stainless steel, hard eloxated/hard anodized aluminium and other FDA approved materials, can be employed. Opportunities for particulate to collect such as blind holes and internal corners are avoided wherever possible.
This is the process of removing burrs from components in order to smooth surfaces and edges. During the manufacturing process operations such as cutting can leave raised edges or small pieces of material known as burrs that can become detached from the parent component. These can be removed by deburring using centrifugal, vibratory bowls and high density ceramic or synthetic media.
Cutting round section wire can often leave burrs where the wire has been cut. For some components, Advanex Europe have offered laser deburring which provides a “dome” shaped end to the wire by firing a high powered laser beam directly onto the end of the wire.
Advanex Europe can also offer online and offline sieving. Sieving is a vibratory process that removes particulate by gentle abrasion while supported on a mesh or gauze. The particulate is separated from the components by dropping through the mesh. The size of the mesh is critical to the success of the sieving operation.
Solvent and Aqueous Cleaning
Solvent and aqueous cleaning are dedicated washing processes and are suitable for most metallic materials. These both require the component to be immersed in a heated liquid media, either solvent or water based, for a period of time. The components are usually tumbled within the media or the media agitated during the process. Particulate is washed from the components and removed by filtration of the media. Aqueous cleaning is generally more environmentally friendly than solvent based cleaning processes.
Ultrasonic cleaning is carried out in conjunction with either solvent or aqueous based cleaning processes. This involves using an ultrasound generating transducer immersed within the media that creates bubbles using high frequency (20-400 kHz) sound waves to agitate the media. This “cavitation” process removes contaminants that are adhered to, or embedded into the surfaces of materials such as metals, plastics and ceramics etc.
Pickling is usually performed in citric or hydrochloric acid solution, and removes a thin, surface layer of the material taking the embedded particulate and other contaminants with it. It is often performed as a pre-treatment prior to passivation of stainless steels.
Clean Manufacturing Areas
Some spring making processes such as traditional coiling methods that require soap coated wire, generate large amounts of particulate. Other methods such as mandrel coiling with bright wire are inherently cleaner, but still generate particulate to a lesser degree.
The amount of residual particulate that is acceptable to the customer will largely depend upon the application of the product. Advanex Europe have several, clean manufacturing areas, dedicated to the customer’s product and isolated from other processes. These are designed to match the process and the product specification, with the aim of reducing foreign matter introduced by operators and the surrounding environment contaminating the product.
Depending on the process and customer requirements, some clean areas will only require the operators to wear protective clothing, others have interlocking doors and maintain a positive air pressure etc. Manufacturing within these areas can maintain particulate to levels where the cleaning burden on the component can be dramatically reduced without the high costs and limitations imposed by “clean room” manufacture.
Cleanrooms are graded by the number and size of allowed particles per unit of volume. A Class 100,000 cleanroom, for example, can have up to 100,000 per cubic foot of air.
Where springs are ultimately to be assembled into devices within cleanrooms, customers will need the component parts to be free from biological contamination, as well as particulate. Advanex Europe has installed two Class 10,000 (ISO 7) cleanrooms so that parts can be cleaned in-house. The latest facility allows product to be passed into the cleanroom via an airlock ‘pass-through’, directly from the clean manufacturing area. Once inside the cleanroom, the parts are ultrasonically cleaned to remove any contamination, double-bagged within the cleanroom, and passed out through a further airlock to await despatch. The parts can then go into the customer’s cleanroom, with the outer bag removed, so that no contamination is taken in via the outer packaging.
Control of the efficacy of the cleanroom can be achieved by performing regular Bioburden tests on cleaned parts. This will give assurance that the parts meet the prescribed microbial limit for the number of bacteria present.
As designers and engineers continue to evolve methods to reduce particulate and improve clean room manufacturing, Advanex Europe remain firmly committed to delivering first class solutions to medical device manufacturers. Advanex Europe actively welcome the opportunity to discuss design and particulate challenges with all level of suppliers to the Medical Device Market.