The original foundation for the Pallmann company, in 1903, was the flour milling industry, in which the company was involved in both milling and the design of wind- and water-powered mills. That essential basic element of size reduction is still the focus of this seventh- generation family-owned firm.
The company now employs around 700 people worldwide and is involved in a variety of industries from food to chemicals, plastics and wood, as well as the agricultural residues used to make panels. However, the panel industry accounts for the majority of the company’s turnover.
Pallmann says it has largely based its success in these very diverse fields on a heavy concentration on research and development (R&D).
The company is headquartered in Zweibrücken in south west Germany, where it has a large R&D facility which includes the largest size reduction test station in the world. The space devoted to R&D alone is 20m x 80m in a separate building. There are three floors, with a training centre on the top floor, smaller demonstration/testing machines on the second floor and three sections for larger machines on the ground floor. These last three areas are for plastic recycling and food processing; the wood processing department; and the main R&D labs.
The size reduction test station employs the company’s smallest machines, but these are not small-scale versions; they are small production machines, emphasizes Harald Fried, area sales manager for North America.
“We have very precise scale-up factors for these machines, enabling us to produce very precise results,” he says. “This means there is very little ‘surprise factor’ when we deliver a machine to the customer’s mill – the specification with regard to throughput and so on will be met.”
The test set-up is a PZU 16-525 OSB production system with a theoretical production capacity of 20 bone dry tonnes per hour (bdtph) of standard OSB flakes.
“People from all over the world send their logs here and we make flakes on a production machine with real production runs,” says Hartmut Pallmann, chief executive of his family’s business. “The flakes then go to an existing board mill for test boards to be produced – it is almost like pre-certification of the panel product.”
The R&D carried out over the years has resulted in a product range which comprises around 800 different machines and models.
“We carry out lots of special designs for customers,” says Mr Pallmann. “Continuous improvement of the machines is one of our main aims and another reason for our large R&D facility – and our test department. After our tests, the machine is run in trials at our customer’s factory before we ‘go public’ with any new development.”
Pallmann began its involvement in the wood panel business principally in particleboard and OSB, then moved into MDF and now claims to be the second largest supplier of refiners in the world for MDF.
The machines produced by the company are identified by a two, three or four letter name, all of which begin with the letter ‘P’ for Pallmann. The other letters describe the function of the machine, in German.
Thus there is the Drum Chipper, PHT and the disc chipper PHS. The former processes sawmill waste, roundwood, peeler cores, veneer waste and wood from forest thinnings and annual plants for particleboard, fibreboard, wood combustion and the paper industry. The latter is a chipper for the paper industry.
The re-chipper PSN is for re-chipping material such as butt ends; gang saw, veneer and particleboard waste; screen rejects; shavings; and splinters.
The Series PZKR covers the family of knifering flakers which have the patented system of counter-rotational flaking and a knife ring exchange system. Pallmann produced its first knifering flaker in the 1950s.
These flakers are designed to produce flat flakes of exact thickness from chips, veneer waste, purchased flakes or any kind of coarse raw material. A fast rotating impeller leads the chips to the knives of the counter-rotating knife ring. It is this counter-rotating feature which Pallmann claims gives trouble- and obstruction-free operation and flake discharge, even with very wet incoming material. The company also says that it promotes good knife utilisation and uniform wear.
The feeding device for the PZKR, named the Cleanomat, offers continuous feeding with simultaneous separation of undesirable material. Metal is removed by drum magnets in the Cleanomat, which is a heavy particle separator, removing grit and stones in a similar way to an air classifier. A vibro-feeder with integrated screen deck at the infeed to the flaker allows the bypassing of fines, thus saving knife wear.
The so-called quick knifering change system developed by Pallmann has reduced the time required for this essential operation to between five and 20 minutes, according to machine size. The door of the flaker is opened, an exchange jig is moved into position and the knifering clamps released. Pushing a button then initiates the hydraulic removal of the ring to be transferred to a transport carriage to go for sharpening. A reconditioned ring is then inserted and clamped.
The removed ring can now be sharpened on the fully automatic PZSE sharpening and setting robot which reduces the man hours needed for the sharpening process from about 21⁄2 hours manually to around 10 minutes and gives far higher sharpening accuracy. The man-hours in a manual system are absorbed in disassembling the knife packages, cleaning and grinding the knives and then setting the packages before final assembly into the ring again. The 10 minutes used in the automatic system are for getting the ring into and out of the robot. Wear shoes can also be re-ground as required in the same machine to ensure constant knife protrusion. The setting and grinding process takes about 40 to 50 minutes, depending on the size of the ring, the degree of wear and the knife length.
The PHMS is the Pallmann high-speed hammer mill series, while the PHPH is the impact hammer mill, particularly suited to processing waste and recyclable wood.
For refining chips for the fine surface layers of particleboard, the double stream screen basket mill PSKM is offered with a grinding path diameter of 600-1500mm and working width of 220-1180mm.
Pressurised refiners for the preparation of fibre for MDF production are identified by the letters PR and the largest of these built to date is a 62in diameter unit, of which there are several in operation. One of the most recent was installed at Yildiz MDF in Turkey and this has a 24in plug screw feeder. Although this is the largest refiner installation to date, Pallmann is prepared to produce refiners up to 72in.
The Yildiz mill also has the largest drum chipper in the world, at 2.4m diameter, and a Pallmann chip-washing system.
The vast majority of these machines are made in-house at Zweibrücken, with only the very largest components being outsourced. To this end the factory is equipped with an array of heavy engineering machinery, including flame cutters which can cut steel up to 300mm thick.
In the past, mills wanted the size reduction equipment supplied as a package, ready to go, but things have changed.
“Customers more and more want to get involved and to build up the equipment on site,” says Mr Pallmann. “It is cheaper in terms of transport costs, taxes and so on. We do all the engineering and quality control and certified welders do the on-site assembly.
“For instance in a chip washing plant, much of the installation can be carried out by the customer, including the steel work for the building. We supply the controls, electronics and key components such as pumps, chip washer, de-watering screw etc, but the rest is built by the customer.”
He continues: “Globalisation is not just a word, it is real. We do the complete engineering here, and some key components, but the rest is done on site under our supervision.”
Brazil offers an example of this approach: Pallmann supplied the Fibraplac project from green end to pressurised refiner as a complete line, using its subsidiary in Brazil to assist in the realization of the project.
China is a major market for Pallmann. Gaofeng, among the largest MDF lines in China, is currently under construction and involves the supply of the complete fibre preparation system, including rotary debarker, chippers, cleaning and refining, all as a turnkey contract. The company already has two Pallmann refiners.
“More and more people worldwide want complete packages,” says Mr Pallmann. “However, there is a trend for customers not only to want a turnkey green end, but to specify the machinery using their own experience.”
Hence the concept of ‘Pallmann Wood Yard Systems – complete systems from one supplier’. The first of these to be built in-line to an MDF line was at Kronopol in Zary, Poland, but several such lines have been supplied for OSB.
“In the last two years, business was good for us in OSB flakers and we got all the orders for the new mills in Europe. That meant 10 flaking lines, including nine debarkers,” Says Mr Fried.
The growing interest in agricultural fibre based boards has also provided opportunities. The company has supplied bamboo chippers to India and Bangladesh, depithers and hammermills for sugar cane bagasse mills, a special version of the PSKM double stream mill to Isobord wheat straw plant in Manitoba, Canada and a specially designed pressurized refiner for cotton stalks to China. Gypsum and cement bonded board mills are supplied as well.
“We have also done a lot of work on oil palm empty fruit bunch preparation and sold a line to Kalimantan,” says Mr Fried.
Recycled wood gets ever more popular as a raw material for panels and Pallmann has machines for processing this sometimes challenging resource.
Refurbishment of wear parts such as plug screws and refiner plates has become increasingly important to the business. “Today, more and more we have to offer a full service,” affirms Mr Fried.
That includes the new service centre in Zweibrücken, which has six distinct groups of engineers specialising in different machine types. Pallmann service centres around the world are computer-linked to the service centre to give a 24-hour service. Engineers are also available to travel anywhere in the world at short notice.
For the future in this currently slow market, Pallmann still expects some growth in China for MDF, the rest of Asia for particleboard and some MDF, with North America providing opportunities in OSB. Some modifications and upgrades to MDF lines in Europe are also anticipated, as well as a few new lines.
“We are a horizontally integrated business, from the original idea to its realisation,” says Mr Pallmann. “Anything from the 10hp lab machine to the 10,000hp refiner we can do; as long as it is a size reduction machine, we can do it. The overall concept must be good but it is the little details that count.
“When you need to produce a board, come and see Pallmann about the raw material preparation to make it.”

Technocell Dekor, a name well known to anyone in the panel industry involved in adding value to panel surfaces, claims to be the world leader in the production of decorative laminating papers.
The company is part of the Felix Schoeller group and possesses eight of that group’s 10 paper machines. Three of these are located at Technocell Dekor’s main factory in Günzach, near Munich in the south of Germany. Other paper mills are located in Osnabrück, Penig and Neustadt in Germany and Drummondville in Canada.
Dr Mathias Rump, vice president of Technology for Technocell Dekor, outlined the structure of the whole decor market and where his company fits in.
“It is a long value-adding chain and very complex, from base paper to finished laminate,” he said. “Our product covers all areas of design – we produce print base papers whose composition can be adjusted to anything you may require. That base paper is then printed, treated, pressed onto panels and those panels are then cut to size and perhaps shaped.
“Therefore it is necessary for us to take responsibility throughout the whole processing chain in order to arrive at good quality products and a stable market. It would be dreadful to foul up the market with poor quality products that don’t perform! Holding the leading position in the market means we must have a sense of responsibility to our business partners.”
To that end, Technocell has relationships with printers, woodworkers, panel producers and furniture makers, he explained.
“We try to ‘de-mystify’ the process and make all the steps that define quality understandable and to make that quality measurable,” said Dr Rump, who went on to explain that the company is also trying to address the problems of terminology in the industry.
“For instance, the word ‘overlay’ means different things to different people. In the US it means any kind of surface – paper, vinyl or whatever; in Europe it mainly means the clear surface layers such as those applied to laminate flooring. Therefore we are trying to establish a uniform terminology in the material we publish and we’re trying to get a two-way exchange in communication,” he said.
To disseminate its considerable knowledge, Technocell holds periodical seminars, or forums, and publishes the papers. It has also published a book called The analysis of decor paper: A compendium of quality parameters and test methods, as part of its contribution to that de-mistifying process.
The latter book, to give just one example, explains the Taber test with a definition, explanation including its relevance, and the method for carrying out the test.
“We see a trend towards integration of the value-adding steps – for example backward integration of panel producers into impregnation,” said Dr Rump. “We also see a trend for printers to forward integrate into lacquering their foils on the printing line – the technology is there and varnishes have developed to become more usable in the printing process.”
Hans-Christoph Gallenkamp, senior vice-president of Technocell Dekor and a member of the Schoeller family, added: “Our task is to make the whole process more transparent and to supply our knowledge on to the value adding chain. It is not only knowing paper making but understanding that whole chain – a partnership approach with the customer and his value chain.”
Capacities of the eight Technocell decor machines range from 11,000 to 40,000 tonnes a year and they produce papers for making high pressure laminate (HPL), low pressure laminate (LPL) and continuous pressure laminate (CPL), paper foils, print base, saturating base and machine glazed papers. The three Günzach machines all have a 2.25m working width.
Drummondville is currently an exception to the other locations in that it produces pre-impregnated papers, but that is because it is a joint venture with the German Kunz Group which owns the panel maker Uniboard, the exclusive customer of Drummondville.
The company has three different kinds of paper machines, including a ‘top wire’ machine to produce symmetrical white papers.
“This is the only machine of its type in the world and it offers the advantage that the paper does not have a ‘top’ and a ‘bottom’ face but can be used either way up, avoiding the need for laminators to have to turn a pallet of paper over during their production cycle,” explained Mr Gallenkamp.
The five hectare Günzach site, situated in a beautiful region of Bavaria at the base of the Alps, employs 232 people on its three paper making lines. One line makes white to brown pastel colour base papers, while the second makes backing papers and edgebanding and the third makes a full range of base colours, from white throughout to intense black.
The site gained ISO 9001 certification in 1994 and EMAS/ISO14001 in 1996. It was one of the first paper mills in the industry to gain the environmental 14001 certificate, driven partly by the fact that it is a very compact site which had nowhere to store waste and therefore every reason to avoid creating it in the first place.
In 1999, the company started producing paper from regenerated paper by recycling waste from its own production into backing paper.
A tour of the factory begins in the colour management laboratory, where the recipes are formulated in a process which simulates real paper production from pulp and the other basic ingredients.
The sample disc of paper so produced can be laminated to a piece of particleboard and colour-checked against a master sample. All data is stored in a computer for repeatability.
At the start of the production line, pulp is stored in bales of sheets, using short fibre from eucalyptus and longer pine fibre. The two types are mixed according to the required final paper properties.
The pulp sheets, together with Titanium oxide, fillers and dyes are mixed with water in the pulper in a swirling action which ensures good mixing. From the pulper, the mix passes to the refiner to equilibrate fibre length and on to a reservoir where other additives such as wet strength agents are added.
The mixture then passes to the machine vat where final online colour checking is carried out just before the paper machine.
A form of hydrocyclone then separates out any dirt or lumps from the mixture and several screens remove any small contaminants before the mixture passes to the machine head box.
The mixture, which is now 99% water, is sprayed onto an endless ‘wire’ and most of the water is removed by a combination of draining and a vacuum under the paper web. This leaves a higher concentration of fillers and fines in the top layer of the web and so this is equilibrated by the Dandy Roll.
A felt now picks up the web and passes it through a nip roller press. The web then enters the dryer at 50-60% moisture content where it passes over a series of heated cylinders, followed by cooling cylinders, the application of steam to adjust the moisture content, and passage through a three-nip Küsters calender press.
The calendering leads to compression of the outer layers for smoothing of the surface, while retaining the springiness of the core of the paper so that it remains permeable to resins.
The final paper product goes to a jumbo reel and is then edge-trimmed and cut to the customer’s required length on a rewinder system.
Another quality management lab checks the final product for all parameters such as ash content, weight, pH as well as colour, and all data is stored on a server to give traceability and repeatability.
Technocell’s quality standards are undoubtedly high in order to satisfy the very demanding decor paper market but Günzach has another, literally high, claim to fame: it is the highest decor paper mill in Europe, standing at 800m above sea level in beautiful Alpine scenery. This at first surprising location is a legacy from its original function of making papers to wrap locally produced butter and cheese. Technocell has come a long way from that speciality to its current specialist décor paper production.

Wood, water and a tradition of iron working all come together in the village of Oberkochen, 100km east of Stuttgart. This is the home of the company known throughout the world as Leitz GmbH & Co KG.
When he founded his company in a small workshop here in 1876, Albert Leitz could surely have had no idea of what was to develop from his hand craft, and water powered machinery, with which he produced tools for the extensive woodworking industry growing up in this richly forested area of Germany.
Early products for Mr Leitz were hand tools such as drills, knives and axes. Tools for water-powered machines soon followed and then, with the advent of electrically powered machines, new demands were placed on tools in terms of wear and stress.
Now the family-owned Leitz business claims to be the world’s largest supplier of tools for the wood and wood-related market, offering a vast range of tungsten carbide and diamond tipped tools, some of which even carry memory chips.
“Our core business was always in wood and wood products,” says Christoph Bollinger, managing director with responsibility for sales and marketing. “We have production facilities in Germany, Austria, Italy, Finland, France, Belgium, the UK, Turkey, Brazil, the US and China and 180 service stations [sharpening and repair centres] worldwide. That is why we say we are ‘globally localised’.” The Brazilian office, opened in 1979, was the group’s first venture outside Europe.
“The company’s turnover amounts to a total of more than €500m, 50% of which is in the woodworking and 50% in the metal working sectors and we employ over 6,000 people,” says Mr Bollinger.
The Leitz Group specialises in machine tools for processing wood and panels, as well as plastics, and has many subsidiaries. It employs around 3,500 people.
The holding company is the Leitz Association and the Leitz Group forms one of two divisions of the Association. The other is Leitz Metalworking Technology (LMT) GmbH & Co KG, also based in Oberkochen. Under LMT there is Böhlerit GesmbH & Co KG, the Austrian tungsten carbide development pioneer, Fette GmbH near Hamburg, Kieninger GmbH in the Black Forest, Bilz GmbH & Co near Stuttgart, Onsrud Cutter LP in Libertyville, US and Belin Yvon SA in France. This group of companies is mainly active in the metal processing tool side of the business
and employs more than 3,000 people.
However, the two sides of the Leitz Association do not act entirely independently, but exploit the synergies of their different operations at regular meetings.
Mr Bollinger describes the CNC market as a fast-developing branch of the industry and Leitz has one factory in Germany dedicated to this sector. It has also diversified into the machining of plastic materials and insulation products such as Rockwool, in response to demand, and as a result of its expertise in wood and metals.
“Laminate flooring gave a turbo-boost to the flooring division and a lot of the tools used today for machining it were developed by us. We are quite possibly number one in that industry today,” said Mr Bollinger. “The processing of every type of panel is becoming more and more important.”
The changing demands of raw materials, mechanisation and ever-increasing cutting speeds mean that research and development has always been a vital area for Leitz and it has three R&D centres – two in Germany and one in Austria, with the largest being at Oberkochen.
Investment in R&D accounts for more than 5% of total sales revenues and the Leitz Association has over 300 patents and registered designs to its name.
One could be forgiven for thinking that it would be difficult to display Leitz’s products in an exciting way – after all they are ‘only’ cutting tools. However, a visit to the company’s technical centre at Oberkochen would soon change your mind.
A four-screen multi-media presentation takes you through the historical and the present day position of Leitz. Meanwhile, tools such as saw blades, router cutters, tongue and grooving cutters, drill bits and myriad other devices are exhibited in static displays with the raw material they are intended to machine. Clever lighting of these displays shows off the tools to best effect. Each display is dominated by a flat screen video of the tools in action, which also shows close-ups of the tool profiles.
The display of tools for machining laminate flooring begins with diamond-tipped circular saw blades to rip-saw the panels into planks. These are followed by up to 10 machining heads – five on each side – depending on the intricacy of the profile. For instance, ‘click-fit’ T&G profiles require more heads to machine their complicated shapes than do simple T&G sections.
“We use poly-crystalline diamond on most of these cutters, with mono-crystalline diamond on the final heads, to get a smooth edge on the hard laminate surface, where finish is very important,” explains Jürgen Graef, head of Leitz R&D.
“We do a lot of basic research on cutting materials – coating knives and blades with different types of tungsten carbide for example and testing on various materials,” he says. “We also do research in other areas such as designing tools for noise reduction and studying chip movements by using perspex hoods over test cutters.” They have also developed a polished foil for covering the faces of circular saw blades to reduce noise and give a smoother finish.
The dust from products such as laminate flooring can be very abrasive and if it is not removed effectively it will shorten the life of the machining heads. Thus Leitz supplies the tools and hoods as a system. For the same reason it is also important to move the dust away from the cutting edge effectively and this is where the Leitz ‘i-System’ comes into play. It is a dust flow control system in which the tools have a special gullet and, literally, cutting edge technology, to guide the chips away from the cutting area to the exhaust system. This exhaust system is not responsible for drawing the chips away from the cutting edge – its role is purely in transporting them from the cutting area of the machine as they are expelled by the gullet.
Computer aided design systems (CAD) are used to produce the tools and Leitz works with universities, institutions, machine makers and its customers in developing new products.
Many of its tools today are held in place in the cutting head by a hydraulic clamping system which the company claims gives high machining accuracy combined with the facility for rapid tool change.
The ‘Tool Information Management Software System’ is another development employing what it calls “intelligent tools” in multi-head CNC routing operations.
The benefits claimed for the system are the rapid relocation of tools, automated procurement of them, on-time scheduling of the required tools, control of tool costs and reduction of tool stocks, tool life checks and increased machine availability.
Each tool carries a memory chip with data concerning its length, diameter, maximum revolution speed and optimum rpm. Obviously some of these factors change after sharpening so it is possible to change the data on the chip at this time.
The CNC machine is equipped to read this chip and know what kind of tool it is and what its precise parameters are. There are several components to this system, including measuring and set-up devices, the intelligent tools with their data chips, tool information management and Leitz’s integrated service concept.
“We sold a Tool Information Management System to a furniture manufacturer in Germany and cut their tooling costs by one third,” recalls Mr Bollinger. “In diamond tooling that meant they quickly recouped the cost of the system!”
Many tools begin life as a cylinder of solid steel. Various diameters of special steels are sourced from all over the world and a blank is cross-cut from the cylinder. It is then milled, ground, shaped and drilled in machines which are CNC controlled from the CAD offices above the factory floor to produce the final machine tool body. Tungsten carbide or diamond tips are soldered to the tools in a special process.
For sharpening diamond tipped tools, spark erosion under a liquid electrolyte is used and wire spark erosion in electrolyte for simultaneous cutting and sharpening of some diamond tipped tools. Finished tools are checked on the profile checker.
Instant communication and remote service are essential in today’s fast-moving business environment and Leitz employs new media in the form of its SOLNET system. This is a package providing online customer access to its consulting services and can be used by Leitz engineers to communicate with customers and find solutions to their problems rapidly. Replacement tools can also be ordered for quick delivery on the system.
Albert Leitz would certainly be confused by such high-tech developments as intelligent tools and online service. He would however, still recognise the wood machining business on which the Leitz Association of today is heavily based. And he would almost certainly approve of his company’s tag line and see his place in its origin: ‘Shaping the future for over 125 years’.

Germany’s oldest industrial company and one of the oldest companies in the world: that is the claim of Schwäbische Hüttenwerke GmbH, or SHW for short, which was established in 1365.
The company used to be just a producer of iron, until the end of the 19th century when it diversified. Then in 1921, it gained two powerful equal shareholders in the form of Baden-Württemberg GmbH, on behalf of the state government of Baden- Württemberg, and MAN AG, perhaps best known for its trucks.
“Thus we have the strength of the state and a huge company behind us, but we are a mid-size company with the flexibility which that brings to enable us to find solutions for our customers,” says Thomas Neuburger, general manager of the Materials Handling and Process Division.
The history of the SHW company is recorded in a museum on its substantial site and shows it still has ties with the heavy engineering and casting industries. It still produces, in a small way, artistic sculptures cast in metal, but its main involvement in heavier castings now has moved from the solid fuel stoves of the past to production of massive engine blocks used in ships or large stationary engines.
Ventilated brake discs for high speed trains, such as the German ICE, as well as for the automotive industry, are also produced by SHW.
Other specialist areas in the metal working field include the production of sinter- formed components such as gear cogs and also oil pumps for automotive engines.
All these products are made at one of the company’s four locations: in Wasseralfingen; Bad-Schussenried Wilhelmshütte; Königsbronn; and Tuttlingen-Ludwigstal.
However, to the panel industry, SHW is best known for its technology in the field of materials handling and processing. The raw materials for the production of particleboard and MDF offer particular challenges due to their tendency to interlock with each other and to stick to each other – especially when wet or glued – forming bridges in silos and transport systems. The systems offered by SHW are designed to overcome these potential problems.
“The wood based panels industry accounts for a minimum of 50%, and has been up to 70%, of our turnover,” explains Günter Staiger, area sales manager for North and South America. “We also work in the pulp and paper and other industries such as cement, power, gypsum, dewatered sludges, chemical, food and pet food and environmental protection,” he says. “But free-flowing material is not our business.” Thus materials such as grain or pelletised products are not likely to require the specialist input of SHW.
The changing nature of the panel business, however, has meant an increasing demand for the company’s expertise, as Mr Staiger explains: “With the rise in continuous press lines in the last 15 years, there has been an increased need for dependable and continuous supply of bulk materials so you need reliable equipment with an even discharge rate and this is our speciality.”
It was in the mid-1960s that SHW was first asked to develop a reliable silo discharge system for wood chips and sawdust and this led to its development as a turnkey supplier of storage and conveying systems for difficult bulk goods.
The main system components offered by SHW are material relief systems, silo discharge systems and the associated handling and processing technology.
At the point of residue arrival in a panel mill, the company offers a live bottom system in the yard at ground level, in a pit, or in a storage silo. This comprises independently sliding plates, hydraulically operated, in a form resembling a ladder. The rate of discharge is controlled by level detectors in the silo. A conveyor belt system is also offered as an alternative.
To sort the raw material into fractions, SHW offers a disc screen. The discs are mounted on parallel horizontal shafts and the spacing between the discs is variable according to the size selection required. Smaller acceptable chips pass down through the screen, while larger rejects and foreign bodies are carried over it to a reject chute. This screen can handle raw material quantities up to 600m3 per hour.
To transport the acceptable chips, chain, belt or closed belt conveyor systems are offered, while bucket elevators and pneumatic conveying systems are also available. Intermediate storage can be in flat-, not conical- bottomed circular or rectangular silos. Rectangular silos up to 25m wide can be fitted with travelling screw augers, whose speed is adjusted to suit the raw material and to avoid either compression of it or a bending strain on the auger. It is possible to have several augers in tandem. Larger rectangular silos would employ a live bottom system with any number of plates required.
Circular silos with a diameter of more than 30m are equipped with a central rotating conical screw auger which revolves as it spins on its own axis and covers the entire cross-section of the silo. A sliding frame system is also offered, while smaller circular silos up to 7m diameter can use the SHW Rotor Discharge System.
For silos with a capacity of up to 300m3, round or rectangular, SHW offers an eccentric oscillating discharge frame which has no hydraulic components. This feeds the material to a discharge screw. A unique feature offered by SHW in circular silos is its drag arm system. The arms are made of layers of spring steel clamped together very much like a cart spring. They are curved and one sweeps above the floor of the silo in the horizontal plane to prevent bridging of the material, while the other sweeps close to the floor, dragging the material to the discharge screw. There is a hook on the outer end of each arm, which passes close the wall of the silo to break up any ‘wall’ of chips that may form.
The silo walls are also equipped with special relief wedges to prevent bridging.
The advantage of the flexibility of the arm, both in the horizontal and the vertical plane, is that it reduces the torque on its drive motor and avoids the risk of the drag arm breaking under the enormous potential strains in the bottom of a large, full silo.
The drive mechanism for all SHW’s silos is located under the floor for ease of maintenance and the drive motor/gearbox is attached by a ‘bayonet-type’ fixing so that it can be removed without emptying the silo.
“Silo rotors are also made of heavy gauge steel (8-12mm thick) because of the high abrasion of wood raw material, and especially bark, and these silos have to work continuously – they may only be emptied once a year for maintenance,” says Mr Staiger. Stainless steel can also be specified for the same reason. The whole silo is normally made of 5-6mm steel plate.
Distribution from the silo can be to several lines independently – you can specify several different augers each operating independently and feeding a separate production line, thus saving costs. You can also operate with one very large silo, since additional metering silos are not required.
For feeding dryer lines, SHW offers a metering bin to feed several drying lines if required and a fire protection bin which can be emptied rapidly in an emergency. A silo full of fibres, such as in an MDF plant, offers special challenges and for this a special vertical conical rotor with drag arms is available, so that the silo can be completely emptied of even glued fibres. Steaming silos are available for MDF lines.
Sander dust for burning is directly metered to the furnace, again obviating the need for a metering bin, says SHW.
All systems are tailored to the specific materials and sliding frame, rotor discharge, rotating floor and pivoting wheel systems for smaller silos are all solutions which are available.
“We don’t just sell discharging systems, we decide what is best suited to the customer’s needs and his raw material – whether it is a rectangular or a circular silo, with live bottom, rotor discharge, or discharge screw,” says Mr Staiger. “The customer tells us what his raw material is and the discharge rate he requires and we do the rest. And it is not necessarily just one piece of equipment that we supply. It is often a whole system from receiving station to production line – often for a variety of raw materials, particularly in the case of biomass or the burning of recycled material.”
The company has designed, supplied and commissioned over 3,000 such systems in more than 50 countries and for a wide range of raw materials, says Jürgen Rapp, who is responsible for key accounts and dealing with the OEM’s such as Siempelkamp, Dieffenbacher and Metso who often include SHW equipment as part of their whole plant concept.
“In a particleboard plant, for example, there are separate systems for the green area and the dry area, with a surface layer, core layer and oversize silo after the dryer – some mills have as many as 12 silos,” says Mr Rapp.
While particleboard and MDF form the bulk of SHW’s involvement in the panel industry, OSB also gets a look in.
The company is currently developing, in its own test set-up at Wasseralfingen, a modified bunker for the forming head on OSB lines which will handle the strands more gently. Strands are often broken by the conventional spike system during forming head bunker discharge and this affects the quality of the finished panel. By the time Ligna comes around next May, SHW hopes to have its improved system on show.
Of course, new-build projects are increasingly rare these days and fortunately SHW is not entirely dependent on these. It also offers upgrades to existing silos, such as converting a conical-base silo into a flat bottomed one if necessary, and changing the discharge system.
“Stable bridge building? Never!” is the slogan of SHW, referring to its silos and discharge systems. However, stability within SHW seem to be a fact – after all, the company has been in business for nearly 640 years.

When the street address of a company is the same as its name, you can guess maybe that company has a long story to tell.
So it is with G Siempelkamp & Co KG of Siempelkampstrasse, Krefeld. This town, close to Düsseldorf in Germany’s industrial heartland, was founded on the textile industry and Gerhard Siempelkamp started his company here in 1883.
He revolutionised the textile press by drilling the hot platens so that they could, for the first time, be heated without being removed from the press. The rest, as they say, is history – and a more recent history that has seen the name ContiRoll® become extremely well known in the world of continuous panel presses.
Today’s Siempelkamp group has two main roots: Siempelkamp Maschinen-und Anlagenbau and Siempelkamp Guss und Anlagentechnik. The former made its name in machinery for panel production, while the latter specialised in the foundry sector and in engineering connected with the dismantling of nuclear facilities.
On January 1, 2002, the two companies were united in G Siempelkamp GmbH & Co KG. The motive behind this structural change was to exploit the synergies existing within the company’s different areas of operation with regard to the knowledge base, design, support, assembly and startup service sectors and also to ‘spread the business risk over a variety of markets with different economic cycles’. Today’s panel industry will appreciate the relevance of that last statement.
There are now five operating divisions within the one holding company. These are machinery and plants, industrial automation, foundry technology, nuclear technology and metal forming.
Siempelkamp Maschinen-und Anlagenbau heads up the machinery and plants division. This includes Dr E Schnitzler and Sicoplan, both specializing in plant and project engineering; Büttner for dryers; CMC-Texpan for forming machines and associated equipment; Imal for on-the-line and laboratory quality control, fire prevention and gluing systems; Pal for raw material processing; and the Siempelkamp service company.
Short cycle lamination lines also come under the machinery and plants division. However, this division is not solely concerned with the wood based panel industry, but also supplies complete lines to the rubber, mineral board and plastics sectors.
Within the Industrial Automation division are two principal groups of companies – electrical and mechanical. Electronic control and automation and software company ATR, and Ferrocontrol with its control systems for window manufacture, occupy the first category, while Siempelkamp Handling Systeme, or SHS, Schermesser, and Strothmann handle the mechanical side of the automation technology, including robot technology.
Heinz Classen, vice-president of the machinery and plants division, is anxious to point out that this organisational restructuring of the Siempelkamp group is just that and does not affect the company’s established relationships with its customers.
“The wood based panel industry is the biggest industry sector for Siempelkamp, accounting for 60 to 70% of the business and for them, nothing has changed with this new organisation,” he says.
It is of course no secret that the panel manufacturing business has been tough for quite a while and Mr Classen acknowledges that fact: “The market has dropped for everybody in recent years but things are not so bad for us,” he says. “We sold eight ContiRoll lines last year and seven so far this year. We have sold 16 in a year in the past but they were very good years. We have had to lay off some people like everybody else. The furniture industry in Germany has been very quiet this year.
“But China has been a major market for us this year and Thailand has picked up a lot, with orders for two particleboard lines, at Vanachai and Metro, and there is more to come in that country.” Siempelkamp supplied one MDF line to China at the end of 2001 and has sold two there this year – to Dare Wood and Dan Yang. The latter will be the largest line in China and is due for start-up in the third quarter of 2003.
“We recently signed an order for an MDF line with Luyuan in Hanzhou,” continues the vice-president. “The company already has 10 multi-daylight lines and is now investing in a 23.8m ContiRoll continuous press for thin board.” This line is also due to start up towards the end of 2003.
“We see a new kind of company coming up in China, investing in high-tech lines from Europe. China now has several thin board lines from different press manufacturers and they will see whose is best,” says Mr Classen, acknowledging that there is stiff competition among the world’s three continuous press line manufacturers.
“Siempelkamp has a lot of experience in thin board production – we have supplied four lines in the last 12 months – to Sunchang in Korea, Fibranor in Spain, Isoroy in France and Plum Creek in the US – and a total of 11 lines in recent years.”
He is also optimistic about the future for the US and points out that Siempelkamp recently sold its longest-ever press line to Huber for OSB production. The press is 60.3m long, incorporating a pre-heater for the strands.
All the major machinery producers are anxious to differentiate themselves and one way is to concentrate on marketing a particular product, while still emphasizing the company’s general capabilities.
Thus thin and ultra-thin MDF and HDF lines are a major area for Siempelkamp at present and it has developed several new technologies specifically for this market.
These include a new mat forming system which removes the need for scalping, a fibre mat pre-heating system, a flexible-infeed ContiRoll to run at speeds up to 295ft per minute and finishing equipment adapted to match this high production speed.
The new scalper-less former for MDF is called the StarFormer. In the past, scalping could remove as much as 50% of the fibre and return it to the former, with three main disadvantages.
Firstly, the recirculated fibre cooled and a high temperature is needed for thin board production. Secondly, the physical process of scalping could lead to density variations in the boards. Thirdly, pre-cure of the resin on the fibre is a risk inherent in the recirculating process. The StarFormer has a levelling head which mechanically organises the fibres to get an even density mat without scalping.
The particleboard sector has also not been forgotten and for this Siempelkamp has developed the CrownFormer. This machine is more compact and is claimed to result in low building costs for halls and steel structures and low maintenance costs for the machinery. It employs mechanical disc rollers to distribute the raw material of the mat.
The CrownFormer has been on the market for just over a year, with the first units being installed in Berneck in Brazil and Finsa in Spain. Its primary purpose is to produce produce improved surfaces for particleboard and Berneck claims it now has one of the best-surface boards in South America.
“The big advantage is that you can decide how thick your surface layer should be and it will be homogenous throughout,” explains Otto R Voss, project development chief for Siempelkamp.
“This means that sanding does not expose coarser particles below the surface.”
That leaves one main area of the composite panel market which we have not mentioned – OSB. Here again, Siempelkamp’s development engineers have not been idle. Because of the bulk of an OSB strand mat, increasing the speed at which a continuous press line can run is more of a challenge than it is for either MDF or particleboard. To address this, Siempelkamp has developed the ContiTherm mat pre-heater.
The purpose of this device is two-fold: to increase the speed of the mat through the press and to add moisture to it in order that the board exits the press at a moisture content closer to that of the ambient air, thus reducing the risk of thickness swell.
The addition of moisture and elevated temperature also leads to increased plastification of the strands which again improves the thickness swell characteristics of the finished board, claims the company. Also, because the strands are more pliable, it is not necessary to have such a high pressure in the press and this leads to a reduction in costs.
For a given press length, the increase in capacity claimed is in the order of 20 to 30% and this may obviate the need to extend an existing press.
When considering a new press, the mill can thus choose between a shorter press than would have been required without the core heater, or a higher output from a longer press.
A further advantage claimed for the ContiTherm is that heat is passed through the entire mat in order to enable a reduction in the mat height, which in turn increases the range of thicknesses the press can produce. However, adding heat and moisture could have a downside if it caused pre-cure in the resin, so the heat/steam mix in relation to the resin used is very important and carefully controlled in the Siempelkamp system.
Every panel manufacturer is looking for ways to cut costs, especially in the current market, and one way to do that is to optimize the production equipment you have.
Electronic control and software company ATR, a wholly-owned subsidiary of Siempelkamp, together with the Krefeld R&D department, has developed a system to achieve such optimisation.
A frequent cause of uneconomic production is when a panel production line changes from one panel specification to another – possibly several times a day.
The new control system changes the settings of the former, pre-press, press, etc in sequence to avoid the necessity of opening the trash gate, re-setting the parameters and then re-starting the flow of the mat. This saves time and reduces the amount of mat recycled during panel thickness or specification change. Also, it avoids having an empty hot press.
Mat width can also be changed gradually and progressively rather than creating a gap in production, says Siempelkamp. Increased uptime and a reduction in capital cost are the main objectives of this optimisation. These costs can be reduced by possibly reducing the length of the press required, or avoiding the need to extend a press where there is perhaps not space in the factory to do so.
A production management system developed by ATR and known as PROMACS can also be retro-fitted to the ContiRoll line. This optimises company-specific information processes by acquiring, displaying, analysing and archiving process data to increase plant uptime, guarantee board quality, save resources and maintain promised delivery dates, claims ATR.
Another system offered by ATR is SPOC – statistical process optimisation and control – a Windows based system for online quality prediction and process optimization for continuous production. This is claimed to save raw material, increase output and achieve online quality prediction of internal bond, density and other physical characteristics of the board.
An alternative way to save capital cost is to improve the equipment you have rather than replacing it. To this end, Siempelkamp offers a modernisation service, notably for the ContiRoll press.
This continuous press has been around since 1984 and has evolved considerably. In fact, the first ContiRoll, which started life as the Siempelkamp R&D press and was then sold to Louisiana-Pacific in Oroville in the US, has just been sold again, dismantled and moved to Korea.
Early versions employed a wedge system to change panel thickness and this can be replaced with a much more efficient modern hydraulic system, controlled remotely. Other modifications available include the installation of a flexible infeed section, a chain cleaning system, improvements to the belt tracking, replacement of the old flexible hydraulic pipes, which could be a hazard in the event of a fire, with rigid pre-fabricated hydraulic pipes, and increasing the heating capacity by increasing the flow of the heating medium.
The most major modification to raise capacity is to increase the press length. This can be done by inserting additional heated sections into the middle of the press, but this is limited by the fact that the length of the pressing zone itself is fixed and with an extension it becomes a smaller percentage of the total press length.
Mixing plastic and wood to produce panels with specific properties is another area of activity for the company.
A new-concept line due to start up any day is a wood-plastic composite siding panel line for Boise Cascade in Sasop, Washington State, in the US. This will utilise waste polyethylene and wood particles to produce a weatherproof siding panel for house construction, suitable for colour application.
Agricultural fibre based boards are not forgotten in the Siempelkamp portfolio and lines to utilise bagasse, straw and other agricultural residues are offered.
Raw board manufacture is, of course, not the only area of expertise. Short-cycle press lines for laminating panels with resin impregnated papers have been supplied for many years.
The basic version is the single board press, offering charging times of eight seconds and cycle times of up to 180 per hour. Standard board sizes are 1220mm x 2440mm to 2440mm x 5600mm. The double board press is similar but laminates two boards simultaneously in lengths up to 5600mm each. Maximum capacity is 360 panels at 180 cycles per hour.
Topping the range is the Multi Power Press, whose development was driven largely by the laminate flooring industry. Short press times of around 12 seconds minimise the absorption of heat by the HDF base board to give a stable product.
Rather than the conventional two rows of pressure cylinders, the Multi Power Press has four pistons across the width and 10 along the length, giving a total of 40 pistons. This is claimed to give more even pressure distribution and the press also offers several pressure circuits with the facility to provide optimum pressure adjustment in both axes for different board sizes. Available with single or double board capacity, the press is capable of up to 180 pressings, or 360 panels, per hour.
Such speeds have to be matched with handling equipment which can feed panels and papers to the press and remove the finished panels in a timely manner.
The recent development of in-register decor papers for designs such as tile effects has increased the demands for accuracy placed on handling systems.
Siempelkamp has always promoted itself as a supplier of complete panel plants, using its own extensive manufacturing facilities and a number of wholly or partially owned subsidiaries with special areas of expertise to complement them.
Many of these plants have been supplied as turnkey projects although there seems to be an increasing trend for panel manufacturers to take more control of specification and supply of various plant components, perhaps mixing and matching machinery from different suppliers.
The other major trend in recent years has been a reluctance by mills to invest in complete new plants if what they already have can be upgraded and optimised.
Siempelkamp has responded to these trends by becoming an increasingly flexible supplier and investing heavily in research and development, which may be two reasons why the company will be able to celebrate its 120th anniversary in 2003.

Leverkusen, on the northern outskirts of Cologne in western Germany, has been home to Schenkmann & Piel (SPV) since October 1, 1977 when two partners founded the business with a one-product portfolio.
That product was an air grader, or air sifter, targeted on the particleboard industry. Today, in addition to those graders, the company offers a variety of dryers for particleboard, OSB and MDF factories, supplying complete systems with all necessary controls and ductwork.
The company is not, and never was, a large manufacturing operation but concentrates on the design and development of products which are largely made by approved sub-contractors with a long experience of working with SPV.
Exceptions to this are the key components of the graders and dryers which are manufactured in SPV’s own workshops; there is no point in transporting ducting half way round the world when it can be fabricated locally at lower cost.
A major change for the company came in 1999 when press and complete line supplier Dieffenbacher of Eppingen, Germany, took a 20% share in SPV. The two companies had worked closely together for some years and so the ‘marriage’ was in a sense a natural one.
One of the founding partners of the Schenkmann & Piel business, Fred Schenkmann, retired in October 2001 and was succeeded by Peter Wolff as general manager. Mr Wolff has considerable experience of the panel industry, having formerly been in charge of sales for press maker Küsters, now part of the Metso Panelboard group.
But back to products and that original air sifter which proved a good foundation for SPV as the company can now boast sales of more than 2,500 units.
Originally, the purpose of the sifter was to remove oversize particles from a pretty clean raw material, but times change and so has particleboard furnish – in some cases dramatically. Thus SPV’s sifters are now more likely to be required to deal with a wide range of contaminants in recycled wood.
Italy has been a particularly strong market in this respect as virtually all Italian particleboard mills use exclusively ‘urban’ wood supplies.
Recent sifter installations by SPV include the Glunz (Sonae group) mill at Nettgau in Germany and Egger’s mill at Rion des Landes in France.
The air grader splits the incoming material into two fractions: accepts and heavyweight rejects. In the process, 85% of the air used is recirculated to reduce dust emissions, while the balance is cleaned before venting to the atmosphere.
Inside the air grader, the material enters via a rotary valve and central tube. Rotary arms then distribute it uniformly over a perforated plate through which air is drawn.
Separation is effected by differing air velocities, with the heavier fraction moved to the edge, exiting via an air lock. The lighter fraction is separated from the air stream by high-efficiency cyclones known as Hurriclones.
This grader system can be used to separate core and surface material (the SR Grader), or to separate out pollutants where recycled wood material is being used (the SR-R Grader).
The company also offers its Heavy Goods Air Grader SGH for contaminated wood supplies. In this version, the incoming material is split into two fractions: accepts and heavy weight rejects. The rejected material drops into the reject hopper and is discharged from the system, while the acceptable material is carried in the air stream to a high-efficiency Hurriclone. In this system, up to two thirds of the air can be recirculated.
For fibres in MDF and hardboard plants, SPV offers the SGF air grader which again separates the incoming material into two fractions, with reject material such as glue balls, wood shives and sand dropping into a reject hopper. Acceptable material is transported in air suspension to a high efficiency cyclone and the exhaust air is cleaned in bag filters. Up to 60% of the cleaned air is recirculated.
Sand is a major problem in particleboard mills using recycled wood as it is highly abrasive and can also cause severe problems in the dryer. A combination of mechanical screening and pneumatic grading is employed by SPV for sand extraction.
Sand particles of less than 300 micrometres are taken out by screening over a 1.2mm and a 0.3mm mesh. Material retained on the 0.3mm mesh is air graded to remove sand particles between 300 micro-metres and 1200 micro-metres, which are separated from the accepts stream. Material retained on the 1.2mm mesh screen is usually free of contaminants, says SPV, and can be used in production. The company claims that 80% of sand can be removed in this system.
Following on to its success in the grading arena, some years ago SPV moved into dryers for composite panel factories and offers single-pass drum dryers for particleboard and OSB, and flash-tube dryers for MDF.
The drum dryers employ indirect heating with heat exchanger tubes, or coils. The drums are virtually air-tight and have thick walls for insulation. They are driven by electric motors through a pinion system to a ring gear. Dryers with capacities of up to 65,000kg per hour mechanical throughput are available.
Drum dryers have been supplied to many mills around the world and recent installations include some large diameter drums to Saviola in Italy and drum dryers are currently under construction for Kronospan in Russia and Falco in Hungary.
This year, flash-tube dryers have been supplied to Homanit’s MDF plant in Mount Gilead, North Carolina and the Kunz plant in Baruth in eastern Germany.
China has also been an important market for SPV, with three plants currently on order for flash tube dryers and sifters for Gao Feng, Oak and Zenghe – all obtained through Dieffenbacher as the main contractor; the source of about 50% of SPV’s business in the last two years.
The flash-tube dryer employs a singlestage system which reduces the moisture content to around 10%.
For pneumatic transport and extraction installations, SPV offers its Rotaclean Filter. This is an automatic filter which requires no compressed air or mechanical vibrating mechanism for cleaning the filter bags.
However, the latest product to be brought to the market by SPV is the superheated steam fibre dryer for MDF. If you think this sounds familiar, it is because the development of this innovative system has been going on for some time.
The brainchild of Wolfgang Allerödder, who began development of the dryer as a project for his university degree and is now a senior engineer with SPV, the super-heated steam fibre dryer was developed with some funding towards the total €600,000 (US$606,000) cost coming from the German Fund for the Environment, Deutsche Bundessiftung Umwelt (DBU).
A pilot plant was built at SPV’s Leverkusen works and started trials in the summer of 2001.
The plant consists of a refiner, blowline, gluing equipment and the pilot dryer itself. Resination tests were carried out in cooperation with Dynea.
The dryer operates in a closed-loop system. Wet material is injected via the blow-line and dried in a continuous closed super-heated steam loop, with fibres being discharged via a rotary valve. The recirculated steam is passed through a heat exchanger for super-heating before being re-used for drying.
The advantage claimed for the use of super-heated steam in place of hot air is that the specific heat and heat transfer are higher, while drying takes place in an inert atmosphere because of the closed circuit.
The process steam and the steam evaporated from the fibres can be utilised, for example, for pre-heating the chips, heating air for air grading and conditioning of grader air to control the wet bulb temperature, explains Klaus Radzimanowski of SPV.
The idea for developing the system came from the known fact that drying efficiency increases with a higher percentage of steam in the drying air. Superheated steam is in a condition where it is above the saturation line and is thus ‘dry’, explains Mr Radzimanowski. The more the steam is super-heated, the more its properties approach those of an ideal gas. Theoretically it can evaporate water and absorb steam up to the saturation line.
“The saturation point is constant for a defined pressure which means the saturation point moves up with increasing pressure,” says Mr Radzimanowski. “Therefore it is necessary to keep the pressure as low as possible in order to avoid high temperature at the end of the drying process.”
The super-heated steam dryer has an operating pressure of approximately 1.5bar (absolute) and a temperature difference between inlet and outlet of 700C. Outlet temperature will be 10 to 200C above the saturation line.
“The super-heated steam dryer is a flash-tube dryer which means that the drying material [the fibre] is conveyed together with the drying medium while heat transfer takes place simultaneously,” explains Mr Radzimanowski.
The steam is transported by a steam fan of special design with a frequency controlled motor. The cyclone is a pressure vessel and thus has to be approved to the appropriate codes.
The fibres are separated from the stream by a specially-designed rotary valve to minimise steam leakage. The steam goes from the dryer cyclone to a collector which defines the pressure in the system. This collector is equipped with a number of steam outlets depending on the number of steam consumers.
The first part is recirculated by the steam fan, the second injected into the pre-steaming bin for the fibre preparation and the third is used to pre-heat air for the graders.
The advantages claimed by SPV for the super-heated steam fibre dryer are firstly that the heat transfer is better. Secondly, the closed loop is completely inert with no, or very low, oxygen content, thus eliminating the risk of fire or explosion. Thirdly, there are no gaseous emissions to the atmosphere. However, because the steam is condensed into water, there is a need for a water treatment plant behind the dryer.
Higher fibre temperature means that the fibre mat has better heat transfer properties although care must be taken to avoid resin pre-cure – hence the involvement of Dynea, which developed a special high-temperature resin.
It is still early days and there have not been any industrial installations of the dryer to date. As it is a pressurised system, and it has to be constructed of stainless steel, there are cost implications compared with conventional blow-line dryers. However, SPV believes the advantages outweigh any disadvantages and several panel manufacturers are reported to be showing serious interest.
Meanwhile the company continues to supply its grading and more conventional drying systems to panel mills around the world.

An unusual feature of north Wales - dry weather - greeted the 120 delegates as they arrived in the coastal resort of Llandudno for the sixth annual European Panel Products Symposium (EPPS6). The weather stayed fine until the last of the three days of the symposium when rain brought a touch of reality. However, this was of little concern to the delegates who had come to hear presentations in four sessions covering fundamental properties; new products; environmental and process control; and resins. In what was probably the most international assembly of delegates in the history of this symposium, representatives came from Canada, the US, Finland, Sweden, Germany, Belgium, Portugal, Spain, Holland, Norway, Austria, Switzerland, New Zealand, Australia, Singapore, Chile and Ecuador. Of these, 19 represented panel manufacturing companies and although this seems a small percentage, it is higher than the average achieved by most of conferences of this type.