Mechanical engineering: The role of filtration in the machinery manufacturing industry

The areas of industry included in the mechanical engineering sector vary hugely in size, from the small backyard jobbing workshop to large multinational companies, from small vehicle fleet operators to international airlines and shipping companies. Because a significant proportion of what the manufacturers make is transport equipment, for people or goods, the operators of transport systems using this equipment are also included in this coverage.

The machinery manufacturing industry covers the production of:

• stationary engines, pumps and compressors, etc;

• furnaces and other general purpose industrial machinery;

• agricultural and forestry machinery, including tractors;

• machine tools;

• special machinery for various industries, including mining and earth moving, and the paper, food and chemical industries (and thus includes the manufacture of filtration and other separation equipment);

• domestic appliances such as suction cleaners and central heating systems; and

• the original manufacture of all vehicles and their engines, for road, rail, marine and air transport, including private automobiles.

Coverage also includes the operation (and hence maintenance and repair of equipment by the owners or operators) of passenger vehicle fleets, road transport, railway networks, and maritime shipping fleets and airlines of all sizes.

It does not include:

• the manufacture and operation of power generation equipment of any size, including standby systems;

• the replacement filters for all vehicles owned by private individuals and replaced by the owner of the vehicle; nor

• the operation of vehicle repair and maintenance businesses (which are regarded as commercial activities).

It also does not include the manufacture of electrical machinery (although there are many large mechanical equipment makers who also make electrical goods).

For most of the products of these industries, the purpose of any included filter or separator is to keep the machinery running smoothly. Similarly, for most of the manufacturing operations, filters play little part in the production process, but have a vital role in keeping that process operating. As a result, the proportion of the finished product's value, or of the total investment in an engineering workshop, is relatively small - it is the great number of these small installations that creates the filter market in the machinery production and operation industries.

The applications that create this high numeric demand are:

• hydraulic and pneumatic systems in the manufacturing or repair works;

• machine tool coolant recycle systems; and

• fluid filters fitted to vehicles and engines of all types, including cabin air filters.

Economic context

The machinery market was hit quite badly by the recent downturn, and, whilst starting to grow again, is doing so only slowly. As will be seen from some of the comments in the review of the corporate situation that follows, the effects have been widely felt, and have only been kept at bay by enormous injections of capital.

There are some good signs, however. The railway sector in particular is booming (possibly taking passenger business from the airlines), with passenger numbers rising, and with significant capital investment, especially for high speed rail services. It is possible that public concern about global warming may be having some effect.

Business is also good for small car makers — partly because of public conception (but also because of the increase in fuel prices). The small car sells well in less developed areas, which is where the market is growing rapidly: China and India. China has already taken the place of the USA as the largest car market, and, although this market is largely being supplied currently by non-Chinese companies (albeit through Chinese partners), the native Chinese industry is growing rapidly to meet the demand.

Relative sizes of some national manufacturing industries are shown in the accompanying table, as proportions of the global total, with the featured top ten countries responsible for nearly 73% of the world figure — and the three largest countries producing over half of the world's total.

The corporate picture

The mechanical engineering industries are dominated by the automobile manufacturers, with Toyota, General Motors, Ford and Volkswagen the four largest (although GM and Ford both slipped back markedly in 2009). In addition to VW, Europe still has some major players, such as Daimler and BMW in Germany, Peugeot Citroen and Renault in France and Fiat in Italy. Chrysler is now a long way third in size in the USA, but Asian companies have grown rapidly, including Honda, Nissan and Hyundai. The leading truck and other commercial vehicle makers include Caterpillar, Volvo, Deere, Komatsu, Paccar, Iveko and Scania, while the top aerospace companies are Airbus/EADS and Boeing, with Lockheed Martin and Northrup Grumman not far behind in size, and Rolls Royce and Pratt & Whitney the largest aero-engine makers. Deutsche Bahn and SNCF are the largest railway system operators.

There are no companies of this size outside the transport-oriented sectors, although GE and Siemens have sizeable non-electric equipment operations. Many large machinery makers are part of engineering conglomerates such as Mitsubishi and General Dynamics.

The effects of the recent recession have made their mark on the sector's corporate structure. The giant that was General Motors survived near-bankruptcy, but only with the help of massive Government bail-out funds. One of its main US divisions (Pontiac) has gone, and Hummer is going, while, overseas, SAAB has been sold to the Dutch Spyker company, and the European operations of Opel and Vauxhall were rescued only by more loans.

Ford has suffered similarly, having to sell all of its ‘luxury’ car divisions: Jaguar and Land Rover to Tata of India, Volvo to Geely of China, and Aston Martin to Middle Eastern purchasers.

Meanwhile Fiat has set itself for growth, managing to keep all of its factories open, and to create a close working alliance with Chrysler.

Considerable restructuring is also occurring in the airline business. Lufthansa has acquired Austrian Airlines and bmi, while Air France has merged with KLM. United Airlines has recently announced a forthcoming merger with Continental, while British Airways and Iberia are also involved in a deal.

Filtration market size and trends

The manufacture of general machinery represented about 2.7% of the market for filtration and separation equipment in 2009, while that for transport equipment manufacture and system operation was about 15.5%, making this whole group one of the largest components of the market. The estimated market sizes in 2009 were below those for 2008, being $1.1 billion for machinery manufacture and $6.4 billion for transport equipment manufacture and system operation.

These estimates cover both original equipment and the sale of spare parts. The sale of filter media, in bulk or as finished elements, to the makers of filters is not counted separately, because such media sales are covered by the sales of the complete filters. Filter media sales are only included in the estimate where they are made directly to their end-user, as part of the supply of spares.

Some very different growth rates are being suggested for the next year or two, so that it is not an easy time in which to be forecasting market trends, even for so essential an industrial component as filtration and related separation equipment. It is probably best to say that 2010 should see market growth over 2009, but probably not back to the levels of 2008. Global market growth in 2011 will probably then approach 5% year-on-year.

Equipment applications

The machinery manufacturing component has a low level of use for filtration equipment in its main operations, but a relatively very large use in its ancillary, or utility, operations. Almost all machine tools use a cooling fluid and lubricant for the tool tip or pressing or bending zone, and these fluids have become quite complex, and therefore expensive, formulations. Single use of such fluids is economically unacceptable, and so the recycling of coolants has become essential to the safe and efficient working of the associated tooling. A filter or centrifuge, or at the very least a settling tank, is involved as an important part of the recycling system. As with other production processes, the demands on machine tools in terms of precision have risen to such an extent as to require the use of swarf filters that are likely to be automatically operated and to use a complex medium such as a spun-bond, or a composite (melt-blown on paper).

There are other major fluid uses in this sector in the provision of working machinery movement (such as robot arms or conveying belts), employing pneumatic, hydraulic and lubrication systems. The same requirement for precision in machining has also increased the demands on these fluid systems. Here again more complex media are needed for the filters that are an essential part of these systems. This is even more true of compressed air systems in general, with much higher levels of purity - from dust and oil - now being demanded.

There are quite a number of furnaces in use in this sector, mainly for heat treatment purposes, and increasingly their exhausts must be controlled to reduce solid particle emissions. Bag filters and similar equipment are becoming more common as a result.

There is also one application for separation equipment in this sector that can be regarded as a process use, and that is in electrochemical machining, where metal removal is done electrolytically. The solutions in which this is done must be maintained free from dirt, and filtration or simpler settlement equipment is used for this purpose.

These have all been applications within the factory operations, but there is a much larger ‘use’ of filters — those being installed in the engines and cabins of the on- and off-road vehicles and other types of transport equipment, produced by the sector's component industries.

The normal modern automobile or commercial vehicle has filters for engine fuel and lubricants, for intake air, and for cooling water. Other systems in the vehicle that use filters include suspension, automatic braking, power steering, crankcase and safety airbags. The air conditioning unit, an increasingly common accessory, will include a filter, and, throughout the sector, filters are being fitted for cabin air, to remove pollen, dust, and the fumes generated by other vehicles, and so increase the comfort of driver and passengers. Exhaust filters are not yet a feature of the private car, but may become necessary, at least for diesel-engined vehicles. This combination of variety of filter type, with the numerical size of the vehicle component, provides a large market for suppliers of parts, especially filters and filter media.

It is estimated that there are approaching 800 million private and commercial vehicles currently on the roads of the world. This figure includes recreation vehicles, mobile homes, and commercial vehicles of all types, from the small van to the juggernaut of large-scale transport companies, and buses and coaches. These all need servicing with replacement filters, some, of course, being serviced more regularly than others, but this gives an idea of the scale of supply in this sector.

In addition to these road vehicles, this sector covers railway locomotives and metropolitan and tramway power units; ships of all kinds, from the small pleasure boat to the ocean-going oil tanker or cruise liner; and all aircraft (to include, eventually, space travel). The total number of railway engines, ships, and aircraft, currently in use, is not far short of the total number of private and commercial vehicles, but the replacement needs for some of these much larger engines may be quite different from those of the private car.

Although most separation needs in this sector are met by filters, some of the engines are very large, especially on ships, and other equipment types are involved, such as the use of centrifuges in marine engine fuel washing. For overall transport system operation there are quite different needs, such as the effluent treatment requirements of airports.

Market prospects and opportunities

One of the key impacts of environmental pressures on this sector is the movement away from the petrol or diesel driven internal combustion engine, towards the use of electricity as a vehicle motive power (however illogical this may be, in that it needs fossil fuels still to generate the extra electricity). Should this occur in large proportions, then it will have a dramatic effect upon this sector's market, since the electric motor would have much less need of filtration than that driven by fossil fuels. Whether or not this is likely to happen is still far from clear.

The key separation equipment developments in this sector are the need for finer filtration in hydraulic and pneumatic systems, and the slow change of the ubiquitous flat-bed filter away from a paper medium towards nonwoven plastic media. As far as engine and cabin filters are concerned, the gradual change from paper to advanced nonwoven media in the generality of filters will continue, as will the expansion of the installation of cabin filters in all kinds of vehicles, especially aircraft. From the environmental point of view, there is a compelling need to be able to filter sub-micron particles from engine exhausts, especially from diesel engines.