Happy landings
Envirotainer\'s customised air transport solution is protecting high-tech products from the rigours of modern travel. Hilary Ayshford reports.
The degree of precision required by the high-tech manufacturing sector and the shocks, vibration and temperature and humidity changes inherent in today's high-speed distribution chains would seem to be incompatible. But when a lithographic system is built in, say, Japan, for delivery to a customer in the US, there is no real alternative to air transport.
Having been built and tested in cleanroom conditions, the machine traditionally had to be dismantled into modules and shipped in wooden crates to the customer. A team of highly specialised technicians would then spend several months at the customer's site reassembling the machine and recalibrating it, tying up capital and labour. Furthermore, the competitive nature of the lithographic systems industry and the rate of evolution of the market means that the multi-million dollar machines become outdated almost as quickly as the microchips they manufacture, meaning that delivering a new one to the customer and getting it up and running as fast as possible is crucial. All this led the machine manufacturers to seek a better way of transporting them. To meet the demands of the semicon industry, Swedish cold chain distribution specialist Envirotainer developed a customised shipping container that offers temperature and humidity control, shock-damping and vibration isolation. The RGX is a 20-foot container providing autonomous atmospheric condition control by road, rail and air transport. Each mode of transport has developed its own standards, such as those developed by IATA to enable air cargo containers to be inter-operated between different aircraft types, or the ISO standards for sea containers. The RGX is a fusion of standards from multiple modes of transport and can therefore be used in a standard way across multiple modes of transport to enable customers to achieve door-to-door shipments in an unbroken chain. According to Envirotainer ceo Magnus Welander, it is "the world's most advanced air cargo container by a long way". It was developed specifically to overcome the three main transport problems of the lithographic systems industry: humidity levels, which affect the lens system for the lasers; temperature fluctuations, because the set-up of the machine requires the temperature to be maintained at the same level as in the factory where the machine will be operating; and shock and vibration, because the bumping experienced during the landing upsets the precision of the machine. Envirotainer had already developed highly successful temperature-controlled air cargo containers for the pharmaceutical and food sectors, and was able to apply its specialist knowledge of the air cargo transport sector in general, and temperature control in particular, to come up with a solution. This different approach gave it the edge over a number of much larger logistics companies in securing the business. The first containers were supplied in 2000, and so far more than 60 have been delivered. The benefits to the high-tech industry have been significant. Although Envirotainer does not manufacture the RGX in cleanroom conditions, it is very aware of the needs of its customers: "We don't use silicon-based materials because that could cause particle contamination on the lenses," Welander explains. "We have had to choose materials in the design of the interior that can be chemically cleaned to create something close to a cleanroom environment."
Constant temperature The internal temperature can be controlled at a set point in a range between +10°C and +30°C in ambient conditions ranging from –20°C to +40°C; humidity is kept below 45%RH. The dehumidification of the RGX is a natural by-product of the cooling process. If dehumidification is required and cooling is not, as the RGX is capable of cooling and heating in equal measure. This results in a constant temperature while the RGX load space is dehumidified. Another advantage is that the additional capacity of the RGX – it has an internal volume of 28m3 and can take a payload weighing up to 8,990kg – means that the machines do not have to be dismantled into small modules. By removing covers and hoods, they can be shipped in fewer, more logical modules, which require less assembly work on arrival. And because temperature and humidity are tightly controlled to maintain conditions virtually identical to those in the final testing facility where the machine was set up, less time is required to reset the machines once assembled. Shock is another issue: "The products that are typically transported in the RGX containers are also frequently sensitive to shock and vibration," says Dominic Hyde, director technical sales and special projects. "There has also been a product that requires inclination control, i.e. the product must remain vertically aligned to the earth throughout transportation, irrespective of the aircraft's altitude and roll."
Minimising vibration Envirotainer supports these requirements by supplementing the container with additional systems, such as shock-damping cradles. Extensive modelling and simulation is used in the design of these additional systems. Through a partnership with Validus Engineering, which specialises in this field of engineering design, the company is able to offer customers a total transportation solution from a single source. At the same time, the base of the RGX is designed to be extremely stiff as distortions in the base could be transferred to the product being transported. Transmission of vibration through the base is high – the walls of the container do absorb some energy but this is not a design feature, says Hyde. The containers are manufactured to order to take account of the specific requirements of the machine to be carried – for example, internal anchoring points. The internal power supply comes from a three-phase diesel generator, which is physically isolated from the load space, while the external supply is three-phase 200/400V. A rechargeable 12V system powers the monitor and control processor, which then automatically starts the diesel generator to supply the conditioning system when air conditioning is required but no external power supply is available.
Autonomous operation The length of time the container can operate autonomously (i.e. without connection to an external power source) is tailored to the customer's requirement and depends on the desired condition inside the container, the ambient conditions and the amount of fuel that can be carried; increasing the size of the fuel tank affects both the volume and weight budgets for the container and therefore the weight and volume available for the customer's product. To date, the RGX containers delivered have had at least 24 hours' autonomy at the extremes of the ambient specifications. The reprogrammable control unit has seven process indicators and 13 alarms. The PLC can be specified to include additional logging devices, GPS positioning and a GSM modem for SMS alerts. The performance of the RGX container has been validated in Envirotainer's newly constructed test facility, which is one of the largest in the Nordic countries and can simulate shipments in the range of –30? to +40?C. "The market for these containers is all high-tech equipment manufacturers, not just lithographic systems," Welander points out. "There are some items of medical equipment, such as MRI scanners, as well as equipment used to manufacture LCD screens, that are potential users." The company is in discussions with other bodies, including space agencies and military authorities, with a view to adapting the container to their requirements – temperature control, for example, may be less important than it is for the semiconductor industry, while other parameters may be more critical. "At present, the conditioning system controls the air in the sealed load space of the container. As requirements increase, there is scope for modifying the container to support replacing and maintaining the air in the load space with ultra clean air or even doping the load with gas, such as CO2, to create a controlled, modified environment for transportation," Welander says. Furthermore, the RGX is currently too high to be loaded into an AN-12 aircraft, but Envirotainer is working with a potential customer to produce a lowered version that would be compatible with both the Boeing 747F and AN-12 aircraft platforms. Another possible advance is the refinement of the docking system to improve the handling of the machine as it is transferred directly from the manufacturer to the shipping container to its destination in optimum conditions. "We have a standard loading configuration and we are looking at the design of our doors to enable a smart docking situation," Welander confirms. With time-to-market an increasingly important feature of the high-tech industry sectors, Envirotainer's custom solutions look set to take off.
