Clean machines

Unless we find ourselves baking chocolate cupcakes with a toddler, knee-deep in mud or fixing a bike chain, most of us would say that we are relatively clean. But even at this moment, there are thousands of dust particles swirling past us that we hardly notice. Right now there are probably about 35 million particles in every cubic metre around you - and that's just counting the large ones, of course.

From hay fever to asbestos poisoning, these particulates have no place around sensitive human tissues, but it's only within the past few decades that the medical devices industry has managed to create a controlled manufacturing environment - the cleanroom. After a lull in the past decade as medical device developers contracted much of their work to low-priced overseas cleanrooms, the UK, US and Europe are beginning to compete on price again.

David Bacon and Steve Sansom work at Europlaz Technologies as quality manager and technical director, respectively. Europlaz was one of the first device manufacturers in the UK to build a cleanroom, and is now one of the country's six major cleanroom operators.

Sansom joined the company in the 1980s and, up until the end of the decade, he explains, 'clean' manufacture took place in a hygienic version of a factory floor. "At the time, the whole medical industry was looking at producing devices under particular set conditions," Sansom explains, "so the idea of a cleanroom is all about controlling the environment." All the big pharmaceutical companies wanted to get involved, and cleanrooms quickly became the norm.

Cleaning up

Cleanrooms are given one of a number of ISO classes from four to ten. Each number relates to the amount of particles per cubic metre - the lower the number, the fewer particles are present. As mentioned earlier, the ambient air in a town or city typically carries around 35 million particles in the size range 0.5µm and larger per cubic metre. By contrast, a class-seven cleanroom will house just 352,000 particles of the same size.

A big part of the quality manager's role is ensuring that the cleanrooms comply with ISO 14644, and that the procedures, processes, systems and manufactured devices meet the requirements of ISO 13485, CMDCAS, FDA 21 CFR820 quality system regulations and the appropriate Medical Device Directives. One of the biggest challenges in running a cleanroom moulding facility is financial, not just in the huge outlay to set up your room, but in the ongoing maintenance and monitoring that keeps your operation in line.

When a cleanroom is first installed, the operator must validate standards before the company starts to use them. It must prove compliance with ISO regulation on particulate and microbial monitoring - ISO 14644 and 14698 respectively. Managers must also set up a benchmark through passive and active air sampling. After initial set-up, cleanrooms undergo quarterly checks by an external auditor and daily air pressure readings.

The volume of work for cleanroom manufacturers has gone up over the past decade, thanks in some part to the health profession's preference for disposable and single-use devices over reusable ones. The cost of re-sterilisation is the main reason for the shift, but fears over poor quality re-sterilisation procedures have also fuelled it, as hospitals have taken greater and greater steps to prevent iatrogenic infections. As the trend took off, cost competition was ramped up, and now high-volume, low-cost devices make up a significant proportion of the work undertaken by British cleanrooms.

Cleanrooms do not produce 'sterile' devices - for this, products must be sent on to another business to undergo gamma irradiation, or sterilisation by ethylene oxide or steam. However, for medical device developers that produce 'clean' rather than costly 'sterilised' devices, a low-particulate manufacturing environment is essential to their line.

Debut disposable devices

One of the medical device developers turning out cleanroom-made, single-use devices is Firstkind. The company contracted Europlaz to make the Geko, a deep vein thrombosis (DVT) prevention device for patients in hospital, after undertaking a pan-industry study based on key competencies. The device is made from four main sub-assembly components, including two adhesive surfaces, and the main challenge was ensuring that it was made in a low-particulate environment.

CCO Jerry Walker says: "The Firstkind team undertook a study of UK medical device contract manufacturing companies using a series of pass/fail criteria. "Most importantly, in this instance, was the ability of potential partners to manufacture under ISO13485, their having a record of audited performance and their ability to undertake the injection moulding of critical product components."

Working with an experienced cleanroom manufacturer was vital, Walker adds. The team was also looking for a hands-on approach from cleanroom management and staff, and a good grasp of the critical design and production issues intrinsic to the Geko.

Cleanroom manufacture also suited the device's packaging stage as Firstkind could be sure that no other materials would be present before the devices were sealed in a moisture-proof barrier. The Geko has a shelf-life of up to 18 months, and needs to be kept in immaculate condition for at least that period of time.

"The devices are low-cost disposable items, which means that production volumes are naturally high and manufacturing speeds must keep up," Walker continues. "The cleanroom design and environment match this requirement perfectly, ensuring efficient working practices throughout assembly. This in turn eliminates waste and cuts costs."

Walker adds that, as sales of the Geko increase over time, the need for high-volume manufacturing will lead his company and its manufacturing partner towards greater automation of the device assembly: "In this case, the cleanroom will need to accommodate automation, and the automation systems used will need to be compatible with the cleanroom requirements for any other products assembled alongside. Understanding these parameters is an important design consideration when budgeting for, and commissioning, this automation."

Another of the challenges to cleanroom plastic injection moulding is the question of stability. Manufacturers need to introduce raw materials into a controlled environment without bringing particle, microbe and pressure change with them. Bacon says that Europlaz minimised this risk by installing the materials hopper driers outside the room, feeding material down through the ceiling directly into the hopper in a fully closed system. In the future, the demand for automated processes might make cleanrooms easier to regulate as fewer people are needed inside and the 'bioburden' of particulates people bring in declines.

The green side of clean

Green technology is another moot point in the cleanroom injection moulding sector; unlike other manufacturers, companies cannot simply lightweight products or introduce more recycled materials to the supply chain. Increasing energy-efficiency through a slow and steady programme of equipment upgrades is a popular route for many companies, particularly as overseas companies may already have a head start on the energy-intensive work thanks to low energy prices. If the industry comes to rely on automation, it will be vital for operators to use as little energy as possible when manufacturing, especially if the disparity between Western and BRIC fuel prices grows any larger.

Some cleanroom operators in the UK have even gone so far as to outsource their work to other companies if it is deemed to be better value than working in-house. Medical device developers with relatively low volumes of work may find that it is cheaper to contract out the cleanroom stages of device manufacture than have to fund a short, costly period of 'uptime' in their own rooms. Despite its obvious logic, such a decision is often kept hush-hush, even within the industry.

At least Western manufacturers have one advantage when it comes to energy consumption. Governments in the UK, Europe and the US have all shown a commitment towards sustainable energy, and many grants and subsidies are available for the manufacturing industry.

Last year, for example, Europlaz won a grant from the Carbon Trust to procure a new 300t machine to replace old inefficient equipment. Around the same time, the company also installed all-electric moulding equipment. This new type of machine is popular among plastic moulding manufacturers at the moment because of its increased 'uptime', lower energy and water consumption, lower need for maintenance and reduced rate of scrap. Where the company has failed to compete on price, investment of expertise and finance into lean production will help them make the most of their resources as oil prices climb.

Despite the range of cutting-edge cleanroom technology, sustainability remains a tricky business. For instance, energy-efficient air-handling systems are available that adjust to suit the level of activity in the cleanroom, which would save energy in periods of downtime. Arguably, however, the cost of replacing the old system would be huge, and the energy demands of such a sensitive new one could be much higher as it reads and reacts to minute in-room changes.

Sustainability in the cleanroom relies on clever procurement, which itself hinges on razor-sharp audits and projections. The cleanroom plastic injection moulding industry faces serious pressure from rising oil prices, overseas competitors and the conflicting demands of international regulators. While the West might have pioneered the technology, it must act smart to maximise opportunities in a difficult enterprise.

Did you know?

The first 'cleanrooms' were said to have been invented by Swiss watchmakers who, when grafting away in their busy workshops, stowed their devices under bell jars to keep out dust and other particulates.

How many particles have I generated while reading this article?

The average ambient air in cities contains around 35 million particles per cubic metre. While sitting down to read this article, you have released 100,000 particles alone. If you moved your arms, you released five times this number. When you get up and sit down again, you release 2.5 million particles into your environment. Running and walking can generate ten million particles.

When scientists use a cleanroom they take every opportunity to protect the atmosphere from hair, spit, skin cells and other types of 'bioburden'. However, it is impossible for a person to enter a cleanroom without changing the number of particulates present, hence why so many cleanroom manufacturers prefer automated lines over personnel.