Emma Scowen looks at the development of the latest generation of anti microbial films, explains how they work and how they can be applied in cleanrooms.

Achieving and maintaining the highest standards of cleanliness in all cleanrooms is critical. Pharmaceutical cleanrooms require in addition that environments are also sterile or free from bacterial contamination that could threaten production and laboratory processes. Negligible levels of microorganism contamination could adversely affect processes, leading to shutdown and expensive decontamination processes - prevention is therefore the byword for excellence in good working practices in these complex environments.

* Fighting the threat of bacteria - the latest cleanrooms use a combination of sophisticated cleaning, extraction and purging systems, together with rigorous cleaning regimes to ensure that environmental standards are adhered to.

The focus, however, often tends to be on the use of specialised equipment and aggressive cleaning agents, neglecting the role of microorganism-inhibiting materials in the fabric of the cleanroom and on the equipment used.

* Latest Innovations - for example, recent work carried out jointly by MacDermid Autotype, the leading developer and manufacturer of high performance films and chemicals, and Microban International, the world leading company in antimicrobial technology dedicated to enhancing high quality consumer, industrial and medical products with built-in protection against microbes, has led to the introduction of an innovative antimicrobial film substrate.

Called Autotex AM, this unique, hard coated polyester film substrate incorporates built-in Microban antimicrobial protection, making it the first material of its type to inhibit the growth of potentially harmful bacteria, mould and mildew.

The film substrate has been developed and designed specifically for the overlay film on any surface application, for instance membrane keypads, fascia panels, wall coverings, shelf and bench tops, where durability and anti-microbial protection are essential.

The film is primed so that it can be printed on the reverse surface using a variety of printing methods, from short-run digital, to high volume screen-printing methods.

Due to its clarity Autotex AM can be used to reproduce attractive patterns and even photorealistic images, all encapsulated behind its antimicrobial surface.

Signage, door panels, attractive switches and an almost infinite range of new applications can now be devised for these sterile environments.

The Microban antimicrobial technology is incorporated into the textured coating during the manufacturing process of Autotex AM.

This ensures both an even distribution of the antimicrobial agent throughout the texture and film surface together with the permanence of the active agent, for as long as the robust film's surface is not significantly damaged.

The Microban antimicrobial technology works by interfering with the cell wall of microorganisms that come into contact with the surface of the film, disrupting key cell functions and preventing microbes from functioning, growing or reproducing.

By continuously fighting the growth of harmful bacteria this antimicrobial technology provides constant protection against bacterial cross contamination.

Essentially, the dependable and constant antimicrobial protection provided by the film contributes to improved hygiene levels in the cleanroom and ensures that the film surface remains free of damaging microbes in the intervals between normal cleaning procedures.

This new generation of film substrates has been developed to offer major benefits to both manufacturers and end users alike.

The antimicrobial substrates boast an extremely long flex life, making them ideal for tactile membrane keys or curved surfaces; they can easily be embossed without creating stress fractures or weak points; and offer a consistent low gloss, textured surface with high levels of light transmission.

Additionally, they are scratch and chemical resistant, and can withstand the rigors of everyday use.

* Testing in extreme conditions - in order to prove the efficiency, as well as to ensure that customers and end users are confident in its long-term antimicrobial performance, these innovative products were tested independently.

Autotex AM underwent extensive testing by one of the UK's leading independent and accredited analytical testing bodies.

Using standard test protocols that simulated real life cleaning regimes Autotex AM was subjected to a period presenting 15 years of usage.

In addition tests were carried out on a variety of different samples, including unprocessed samples taken straight from the production line, samples that had undergone 24h soak tests in phenol based disinfectant, bleach, quaternary ammonium based disinfectant and aggressive chemicals including MEK, ethanol and IPA.

Further samples underwent testing to simulate extreme surface wear; this included the texture peaks being removed using sand paper and the surface being polished using wire wool until it was smooth.

The test results highlighted the mechanical and physical properties of the new film substrate and, most importantly, showed that the material achieved a durable biocidal kill result, in most cases at a rate of more than 99%, for a wide range of bacteria, fungi and moulds including Methicillin Resistant Staphylococcus aureus (MRSA), Salmonella Enteritidis, Escherichia Coli (E.

Coli) and Listeria Monocytogenes.

Although the use of this new generation of films will not eliminate the need for general cleanliness and hygiene, they nevertheless represent a significant step forward in cleanrooms and provide a proven and continual protection against the risk of bacterial contamination.

For the first time ever, there is an antimicrobial protected, hardcoated film substrate of exceptional clarity and toughness, ideal for the production of long lasting photo realistic images in hygiene critical environments.

* Summary - contamination control within the cleanroom environment is vital for the production of safe and effective products.

Despite the varying degrees of classification, even those cleanrooms with higher classifications, such as Class 10,000 or Class 100,000, should seek to attain the highest possible levels of cleanliness and hygiene.

The introduction of innovative products, such as these antimicrobial films, is making this more financially feasible and simpler to achieve.

Implementing such products can substantially reduce cross contamination risks, in turn, reducing the likelihood of the serious consequences that could otherwise occur.

* About MacDermid Autotype - MacDermid Autotype is the leading global innovator, designer, developer and manufacturer of specialised coating technology for films used in a wide range of applications.

These include touch and vision systems, membrane switches, Film insert moulding (FIM) products for the automotive, telecommunications and domestic appliances sector and screen printing.

With specialist expertise in precision coating technology, MacDermid Autotype, transforms and enhances the performance of films for many high technology and demanding applications.

In recent years MacDermid Autotype has brought screen printing to new levels of control and repeatability, reinforcing the benefits of the process for new applications such as flexible circuit printing, DVD and industrial glass printing.

MacDermid Autotype's most recent launches have been of antimicrobial hard coated films for hygiene critical surface applications and of diffuser and anti-reflection films for use in flat panel displays.

The company is part of MacDermid of Denver, Colorado, USA.

MacDermid is a leading supplier of offset blanket, flexo plates and Colorspan ink jet printers and supplies, and of chemicals for industrial finishing, including plating and coating of metals and plastics.

* About Microban - Microban International is a global technology and marketing company dedicated to enhancing high quality consumer, industrial and medical products with branded built-in protection from microbes.

Microban International licenses the Microban global brand name, sells custom-engineered compounds, and provides a range of services, including regulatory and marketing support.

The Microban brand promises continuous and durable anti-microbial product protection, built-in during manufacture to not wear out for the useful life of the product.

Microban International is headquartered in New York City with operations in the United States, Europe and Asia, and sales offices worldwide.