Ahead of the Global CemBoards Conference in Munich, Germany, Global Cement spoke to Bert van Elten, Managing Director of the Dutch wood wool cement board (WWCB) equipment manufacturer Eltomation, about his company’s history, products and how he sees the global cement board sector in 2020.
Global Cement (GC): Can you introduce Eltomation to our readers?
Bert van Elten (BvE): The story of Eltomation began when my father, Gerry van Elten, was a mechanical engineering student in the late 1950s. He was asked to solve a problem at a wood wool cement board (WWCB) plant, which was a fully manual process at that time.
He went away and thought, ‘How do I automate this process?’ From there, he designed the first elements of a plant that could automate the process of manufacturing WWCB products. He founded the Elten Engineering Company, now called Eltomation, in 1956 to produce fully automated WWCB lines. These remain our main product line today. The company was able to grow well on the back of this development as European WWCB producers consolidated and moved towards larger, more modern plants in the 1960s and 1970s. Growth continued in the following decades and, more recently we have launched production lines for two further types of wood wool cement products: Eltoboard, which is a form of compressed WWCB and large wood wool cement elements for pre-fabricated insulated walls.
I became Managing Director of Eltomation in 1992 and I run the firm with my brother Paul, who is the Technical Director. More than 60 years after our father founded Eltomation, the company remains the leading, indeed only, producer of fully automated production lines for WWCB at the start of the 2020s.
GC: What exactly is WWCB?
BvE: WWCB is a medium-density board comprising long soft wood fibres that are bonded together with Portland cement. They are typically 0.6m x 2.4m with a density of 350 - 500kg/m3. They are B1 class fire-resistant and have excellent thermal and acoustic insulation properties. This combination makes WWCB very applicable for use as a ceiling panel, particularly in municipal and commercial buildings and schools, but increasingly in residential ones too.
GC: How does an Eltomation WWCB line work?
BvE: The first part of the production line is the automatic wood wool machine, which cuts pre-cut 50cm long blocks of small-diameter soft wood, typically pine, spruce or poplar, down to 25cm in length. These blocks are then shredded into 1.0 - 3.0mm-wide and approximately 0.25mm-thick fibres, depending on the client and application. Such a machine can typically produce 3t/hr of wood wool, around 60,000 fibres every second! Each fibre is up to 25cm in length and will be slightly curled.
Once the fibres are made, they flow into a submersion unit, where they absorb water at a mass ratio of around 1:1. The water contains a small percentage of sodium silicate to act as a set accelerator. Additives can be added for enhanced fire-resistance, which can take the WWCB from B1 class to A2 class.
Cement is then accurately dosed into the wet wool fibres at a ratio of around 1.5:1 in favour of cement compared to the dry wood wool. The semi-dry mixture is mixed in a continuous double shaft mixer. The combination of 3t/hr of wood wool, 3t/hr of water and 4 - 5t/hr of cement gives us a total mass of 10-11t/hr that enters a double forming line. The fresh mixture is formed as a 625mm wide mat on continuously-moving marine-plywood moulds. A rim line determines the thickness of the board, which is typically 15-50mm in the current market. If requested, adjustments can be made to produce boards up to 150mm thick. Some clients also introduce mineral wool, polyurethane or polystyrene insulation at this point, sandwiching the insulation between two layers of WWCB.
The forming line operates at 20-21m/min. As each panel is 2.4m long, there is a new panel every 7s, around 12,000m2/day. A separating saw cuts between the forms, which head to a low-pressure stacking press to achieve a density of 350 - 500kg/m3. The stack is cured for 24 hours before de-moulding. The form is cleaned and oiled before heading back to the start of the forming line.
Most clients send the panel through a pre-cutting step to clean up the edges of the panel. These are stacked and sent to a second setting area, typically for 10 days. Panels will then be cut to size and may be painted or otherwise further processed at the plant, depending on the product.
GC: With a new panel every 7s, that’s a lot of forms!
BvE: Yes - A plant produces around 2800 boards per eight hour shift, so that’s 8400 over a 24 hour period. However, a plant never runs the same product day-in day-out, so that figure is split across a number of different form types.
GC: How does Eltomation make and install a WWCB plant?
BvE: First of all, the ordering process takes, in most cases, at least 1 - 3 years. The client has to get to know us, conduct market studies, obtain financing and permits, etc...before we can confirm an order. Once the contract is signed we can manufacture and supply the equipment within 10-12 months. We presently install about one WWCB plant every year.
There are clear responsibilities for each party. Eltomation designs the plant and software and is responsible for project engineering. We subcontract the construction of the main equipment to one of our trusted machine shop partners in Europe, which are supervised by our experts. We keep all the technical and IT know-how in house, to keep it as safe as possible. Eltomation also sources off-the-shelf components like motors, hydraulics, conveying systems, etc. The client constructs the building and cement silos, typically at the same time as Eltomation is sourcing and producing the plant equipment.
Once the equipment is assembled, the client is invited to the workshop to inspect the equipment in dry-run mode prior to shipping. Then Eltomation ships the equipment in a set order. To give an idea of scale, a recent plant we sent to Russia consisted of 50 truckloads!
In a typical project, the plant is constructed during months 12 and 15 after signing the contract, with start-up in month 16. At the start of the installation, Eltomation will typically have two technical supervisors on site. They are followed up by the electrical controls guys to supervise the electrical installation works, plant commissioning and start up. Furthermore, we train the operators.
GC: Where are most of Eltomation’s projects coming from at present?
BvE: We are mainly active in Europe, where we predominantly take care of our existing clients’ needs, be it in terms of consumables, modernisations or expansions. We estimate that these clients currently produce around 20Mm2/yr of WWCB. Regarding new plants, there is still an increasing demand in Europe, as well as in newer markets, Russia, North America and China in particular. We have installed six plants in China in recent years, followed by an ultra-modern line in Russia in 2018.
GC: What is driving demand for WWCB now?
BvE: Healthy (emission-free) indoor environments are becoming important to the public and thus are increasingly specified. It is, for example, increasingly common to find WWCBs as ceiling panels in residential buildings. These modern apartments have hard floors and no curtains so the acoustics are terrible! WWCBs can help massively in this regard. Our Scandinavian contacts tell us that there will be EU-wide standards for acoustic performance in the built environment, so this trend looks set to continue strongly.
GC: You just mentioned upgrades at existing clients’ plants. How does Eltomation meet new ones?
BvE: We usually approach the industry from the wood side, promoting our plants for WWCB at wood industry conferences and trade shows. Until now, with our attendance at the Global CemBoards Conference, we had not actively approached prospects from the cement side. This opens up new opportunities for us, including potential clients that we are due to meet from South East Asia. I’m sure the event will provide us with new information and leads for future business development.
GC: How are your clients’ requirements changing with time?
BvE: Unlike many concrete elements, gypsum wallboard or insulation, WWCBs are directly visible in use. This means that recent changes in the demands placed on WWCB products have centred on their physical appearance, as well as their other beneficial properties. The uniformity, structure and colour of the panel is ever more important and so the production tolerances are becoming smaller.
Part of this is a trend to thinner and thinner fibres, from 3mm wide 20 - 30 years ago to 1.0mm wide in the 2010s. There is also a trend from grey to white cement, the ‘natural look’ of which is favoured by architects and owners.
GC: What about automation and service needs?
BvE: As in every sector, our clients constantly request ever greater levels of automation. In the past 10 years this has extended into all elements of the plant, with features like frequency controlled motors for start-up / shut-down and improved control of hydraulics.
Automation is particularly strongly favoured in Western Europe, and Scandinavia especially, where staff costs are very high indeed. A recent plant we installed in Denmark operates its main line with just four shift workers. If we quoted the same project in Russia or China, we might specify 13 - 15 shift workers. Looking further back, a plant in 1980 might have needed two to three times the number of workers per shift as is the case with a modern plant, but it would be running at around 70% of the production rate.
Another trend that took hold in the 2010s, is a VPN connection from the plant to our HQ. This means that we can observe the plant in real time, advise plant operators and solve problems without the need to visit the plant. The data gained also helps us to improve our designs. Maintenance contracts are also important nowadays. We will send a mechanical and control engineer to each plant every six months to tune it up and maintain operating efficiency above 90% - usually we achieve considerably higher levels.
We are always going back to clients’ lines to see what we can do to expand their production. They always want higher speed, less waste, more automation and higher process stability. It’s a lot of work to keep up with this ever-growing list - but we’re not complaining!
GC: You mentioned some other products that can be produced with Eltomation’s equipment. Could you introduce them briefly?
BvE: In the past we made equipment to produce cement-bonded particle board (CBPB), which is much denser than WWCB. It was used as a replacement for asbestos cement board but it has gone somewhat out of fashion in recent years. When we were selling both CBPB and WWCB lines, we asked ourselves, ‘What about medium-density cement boards?’ This question led to the development of Eltoboard, essentially a WWCB product that is compressed after it goes into the mould. It is compressed to around a third of the volume of a WWCB. The advantage of Eltoboard is that it can be used as a structural element. You do however, lose the acoustic and thermal-resistance properties of WWCB, so it’s ‘swings and roundabouts.’
We have also helped a Swedish client to further develop large wall element production from the same material as they make WWCB at the same density. Essentially this is a full-size wall, 6m x 2.8m x 40cm. Such elements can incorporate recesses for windows, wiring and so forth.
The Swedish client has now made over 300 structures, homes, schools, sports halls and many other buildings with these large wall elements. The insulation properties of wood wool cement products come to the fore in the Swedish market. There is no need for any other insulation material, so construction is very simple. The elements are easy to transport and have a six hour fire rating. They are rot-proof, termite-resistant and don’t expand or contract with temperature changes. They’re a great product, for which we have developed a modern automated production line.
GC: What’s the next region with big potential for WWCB and, by extension, Eltomation?
BvE: The Russian market is becoming increasingly important to us, both for WWCB and large wall elements. Elsewhere, we see great potential in sustainable, low-cost housing using our large wall element technology in developing regions, particularly in Africa.
However, selling a turn-key plant to a new client in, let’s say Ivory Coast, is quite an undertaking. Will the market accept a new building material like this? Also, where will the wood come from? Will the source be sustainable? It’s hard to know the answers to many of these questions at this stage. We have a lot of interested parties however, so I hope we’ll enter this market soon.
GC: What threats are there to WWCB / Eltomation over the next decade?
BvE: We are the only producer with this technology. If a client decides that it wants to make WWCB, we’re in a good position. While that’s a nice captive market, it does mean that we have to do a lot of the marketing for this type of material all by ourselves. Of course our clients do this, but only in their local areas. This is a disadvantage compared with other building materials, for example cement or gypsum wallboard.
On that topic, there are, of course, other building materials that can do some or all of the same jobs as WWCB. Wood fibre cement boards are one big sector we’re not involved with, for example. This only partly overlaps with our insulating wood cement products, so it’s only a limited threat.
GC: Does Eltomation have any new products or services in the offing?
BvE: We constantly update our range, mostly due to individual client requests. However, we remain focused on WWCB as our core strength. We are frequently approached by clients who know we are engineers and want us to make different machines.We have to turn them down.
However, within wood wool we are keen to develop new technologies, for example as we have done with the large wall element products. We may also re-enter the CBPB market, should the right opportunity arise.
GC: Bert van Elten, Thank you for your time today.
BvE: You are very welcome!