Raw materials – too valuable to waste

The world’s population is growing exponentially. But most available raw materials are limited. Using these efficiently is a matter of survival for nearly nine billion people. Intelligent machine technology helps to make optimum use of the right raw materials, to save material and to recycle used material.

Quelle: istock/xijian

A tricky task

Mert Ilter is doubtful. The 21-year-old bachelor student from Frankfurt am Main is expected to prepare a presentation on the efficient use of raw materials in daily life as part of his dual studies. This does not mean raw materials which are used for the generation of energy, but those which are used materially for the manufacture of goods: valuable raw materials, mainly metals and plastics, but also wood.

Material use means that resources are used as raw materials for industry. Generally, they are first turned into simple geometric shapes (semi-finished products), which are then processed into final products. Abiotic raw materials include fossil fuels, ores, industrial minerals, stones, earths and construction minerals. Wood or natural fibers and all organic substances of non-fossil origin fall under the umbrella term of renewable raw materials.

Energy resources, on the other hand, are burned for electricity and heat generation or as a fuel.

Many natural raw materials such as oil, gas or wood can be used both materially and as a source of energy. Oil is used either as a basis for plastics or as a fuel.

Mert is to find out where and how a clever use of these materials already conserves valuable resources and summarize the results in a multimedia report. “Just go out onto the street and take a good look around,” his professor advised.

But where to start? “You’re doing a dual study course, you’re used to taking a practical approach, so you can come up with something,” Mert says to himself. After all, he has known about these raw materials for a while thanks to his studies. Confidently, he puts his smartphone in his pocket and sets off.

Mert Ilter from Frankfurt is studying for a Bachelor of Arts in Business Administration as part of a dual study course at the Hessian University of Cooperative Education (Berufsakademie) in Frankfurt am Main and at VDMA. Source: Team Uwe Nölke

The new generation – cross-laminated timber

Cross-laminated timber (CLT) is a solid wood panel where several layers are cross-laminated. This is how a flat building product is created from elongated tree trunks — like a concrete ceiling, but much lighter. The timber has several advantages: The mostly large-size elements are suitable as ceiling and roof components. They can be produced in any desired size. They hardly swell, can barely deform and can carry heavy loads. Well insulated component constructions with visible wooden surfaces contribute to a comfortable atmosphere. The high humidity and heat storage capacity improves the climate indoors.

Tailor-made and resource-efficient

CLT components can be manufactured very cost-effectively in modern production facilities to almost any measurement desired. Door and window openings as well as gables are taken into account during the gluing of the individual wood layers. Depending on the shape of the elements, this can save between 10 and 20 percent of wood waste and adhesive. When flat gluing these panels, each glue nozzle is controlled separately so that the openings are not encrusted with glue. Finally, the highest precision is used to shape them to the exact millimeter in joinery facilities.

New possibilities for the world’s oldest construction material

CLT products have become increasingly important since the 1990s. However, they have only become common in the last few years, since cross-laminated timber expands the possibilities of construction in areas that were previously reserved for materials such as concrete or brickwork. Thus, today, CLT products can be used in wind turbine towers and in timber engineering.

Wood – not just for looking good in your house

Mert has an idea. On the way to university, he regularly passes a construction site. A new school is to be built there. The remarkable thing about that is: The structure is made completely from wood, which is more often only the case for roof frameworks. Why, then, is a school board bothering to do this? Mert decides to begin his research with this topic.

As he reaches the school, the facade is being erected. Mert asks for the architect and eventually finds him. “Why did the developers choose wood?” he asks. “Wood is significantly lighter than steel with the same load bearing capability and has almost the same pressure resistance as concrete,” explains the architect. And he lists the further advantages of this renewable plant material for construction: The processing of trees requires far less fossil energy than the production of steel, concrete or even aluminum. Wood also has the highest load bearing capability of all heat-insulating materials and the low weight allows for transportation in large quantities. Mert had never thought of wood in that way before. He listens attentively. He then takes some photos of the nearly completed building. So wood is used as an efficient raw material for construction.

“Where else is wood used as a raw material?” Mert wants to know. “Check out the furniture industry,” suggests the architect, before leaving.

 

The new generation – cross-laminated timber

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Wood is a versatile building material. It can withstand as much pressure as concrete and has the same load bearing capacity as steel. Source: Team Uwe Nölke
Mert interviews the architect of the school built out of wood. Source: Team Uwe Nölke

Less wood in the panel

Mert is curious. Where can he find a manufacturer of furniture? He gets a good tip from the VDMA Woodworking Machinery Association: “Go and find out about particle boards,” says an employee. “You will learn a lot about wood as a material.” He even tells Mert where to get this information.

A while later, Mert sits opposite the branch manager of a company which deals, among other things, with particle boards. “What do particles boards suddenly have to do with efficiency?” Mert wants to know. “They have been around for decades.”

“Correct,” says the expert. “Particle boards enable a much higher yield than solid wood since we use wood of low quality and waste from the sawmill industry to produce them.” Mert wants to understand this in more detail.

“In production today, there is a totally new generation of systems. This makes it possible to produce panels of much higher quality, with less wood and using less glue. We therefore save on valuable resources. It is also possible to add recycling wood or to produce panels of 100 percent recycled material.” In the past, it was not possible to produce panels of quality furniture from waste, since the waste was contaminated with metal residues from fittings or nails. “Today you can even make particle boards from grass plants like rice, sugar cane or bamboo – these are also excellent, sustainable materials,” explains the branch manager.

 

The principle of sustainability has established itself in many industries. Originally, the idea comes from forestry: In 1713, the Royal Saxon Chief Mining official Hans Carl von Carlowitz used the term in view of a major shortage of wood. According to Carlowitz, only so many trees should be cut down as could grow back in the foreseeable future. Sustainability therefore ensures that a natural system is maintained in the long term.

Today’s systems produce much higher-quality particle boards made of less wood and using less glue. Source: Team Uwe Nölke, Mit freundlicher Unterstützung der Becher KG, Maintal
We can even manufacture particle boards from grass plants including rice, sugar cane and bamboo. Source: Team Uwe Nölke, Mit freundlicher Unterstützung der Becher KG, Maintal

Sustainable use of oil palm wood

Oil palm wood is a secondary product which is created in large quantities during palm oil extraction. This renewable raw material could become one of the raw materials of the future and replace precious tropical timber – if the technical challenges to date did not put off potential users. For the first time, technologies are making its use possible and economically interesting.

Available in abundance but difficult to handle

The worldwide cultivation area for oil palm trees already exceeds 20 million hectares and this trend is increasing. Oil palm plantations are exclusively established for palm oil, which is primarily used in the food industry but increasingly in demand by the cosmetics industry, for basic chemical substances and fuels. After 20 to 25 years, the oil yields become uneconomical. The plantations are then replanted – an average of 0.8 million hectares per year. This is the reason there are such large quantities of oil palm wood: Global estimates range from 100 to 120 million m³ of rough timber per year (mainly in Asia). In comparison: In 2016, German logging amounted to around 52 million m³.

Underused raw material

Currently, the fallen oil palms are mostly left to decay. They are also occasionally burned. Use of the trunks could, however, considerably reduce the existing pressure on natural forests and replace the wood taken from them. Since the trunks have an extremely varying density distribution and a high content of water, silicates, sugar and starch, they have not yet been materially exploited. The heavily differing wood properties lead to varying requirements in processing and use.

Production in harmony with nature

As part of a federally-funded project, the five core partner companies of the PalmwoodNet network have succeeded in developing comprehensive solutions for the sustainable use of oil palm wood under technical, economic, ecological and social aspects. This makes the production of marketable products with high value creation from this material possible, such as one and multi-layer solid wood panels, blockboards, laminated timber or cross-laminated timber (CLT). The project has the following objectives: Conservation of resources, rainforest conservation, climate protection, job creation and income generation and maintenance in the resource-rich countries and the development of new markets for oil palm wood products.

Oil and wood supplier in one

Oil palm plantations can be found around the globe at the equator. Oil palm is cultivated in large monocultures which often destroy the natural diversity of plant and animal species. After 20 to 25 years, palm trees are no longer of value for their oil production. Recently, it was discovered that they could be used as a raw material for wood production.

Palm wood as a renewable raw material of the future

Mert is already in the process of turning off the recording device, when the branch manager adds: “In the future, there will be completely new possibilities of using wood efficiently. One word: palm wood. But I can’t give you much more information than that.” Mert remembers that the architect had mentioned something about it too. He decides to visit him again.

Shortly before the end of the shift, Mert is back at the school construction site and finds the architect there. “Palm wood is grown in large quantities on plantations around the equator for the extraction of palm oil,” he explains. “The plantations are a lucrative business for which the companies often cause huge damage to rare animal and plant species. After around 20 years, the yield of an oil palm decreases. New plantations are often established at that point. Or more trees are cut down to make room for new ones. Previously, the wood was left to decay. It cannot be burned and is very difficult to process. Some parts of the trunk are very soft, others are extremely hard.”

“But it is possible now?” asks Mert.

“Yes, there are technologies which can process this wood,” says the architect. “And they are opening up major application possibilities. Palm wood is a waste product and there is a lot of it – and now you can use it almost everywhere.” Then he adds: “This also means that the need for additional space for plantations decreases.”

Mert listens thoughtfully. Palm wood can thus reduce the pressure from consumer society on natural forests – and at the same time, it takes away forest habitats elsewhere.

Sustainable use of oil palm wood

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The wood from oil palms is very difficult to process. Some components are very soft while others are extremely hard. Source: PalmwoodNet

A second life

Secondary raw materials are raw materials obtained through the recycling of disposed material. They are versatile and can be found in many sectors – in the construction industry, in packaging, in the electrical industry and above all in the automotive industry.

When yogurt pots become park benches

Plastics are manufactured from crude oil. Crude oil is a fossil fuel which will run out in the foreseeable future. This is why the recycling of plastics is becoming increasingly important. When one ton of recycled plastic is used, 2.5 tons of carbon dioxide ( are saved compared to the primary plastic.

The sorting accuracy of the waste is essential for high-quality recycling. This is the aim during the collection, which is why collection systems such as the yellow garbage container or yellow liner have been in place for a while. Since it is often impossible to collect sorted waste, the mechanical and plant engineering industry supplies innovative technologies. For example, different types of plastics can be distinguished and sorted by sensor technology. Using valuable aluminum can also be sorted from the waste. Particularly in the car industry, the share of recycled plastic continues to increase. In some Opel models, for example, there are already 170 components made of recycled materials.

Recycled aluminum – more economical than new aluminum

Producing the light metal aluminum from the raw material aluminum ore bauxite requires enormous amounts of energy. With the energy required to produce a single kilogram of aluminum, it would be possible to vacuum for around 15 hours. In the production of aluminum from scraps of aluminum, however, up to 95 percent of the energy required for primary aluminum can be saved.

The aim of the aluminum industry is a complete life cycle management in which all aluminum in circulation can be used over and over again. But this is not possible today, because aluminum is mostly used with alloys. It is still very difficult to filter out the components that are added.

Germany and Austria are the world leaders in the recycling of aluminum since municipal waste, such as beverage cans, has been collected since the 1980s and included in the recycling management.

Black plastics – perfectly separated

“I would never have thought that wood would become such an innovative building material,” thinks Mert to himself. In the bus on the way home, he looks around. The seats are made of plastic, the handles, poles, the interior textile trims, the gray floor and the black dashboard. He stares at the driver’s black sun screen. Was there not some sort of problem with black plastics? Suddenly he remembers: Right! The color of the plastic creates problems in recycling. But why?

The following morning, Mert goes in search of a recycling technology specialist at VDMA and asks him about black plastics. “You will find them in many places,” says the employee, “even in the car. Textile trims, covers, practically every dashboard has been painted black because it absorbs the light and doesn’t cause a glare for the driver. But many technical products are also created from black plastics today. This property, however, is precisely the problem during recycling, because the black not only absorbs light, it also absorbs the optical signal of the traditional sorting machines. Black plastics are basically invisible to these systems.”

“Is there no solution to this?” Mert asks.

“There is now. One of our member companies has developed a technology that works with a very high spectral resolution. This means that the different black parts can be recognized and sorted.” Mert is impressed. “Wow, that means that black plastics can then be re-used as secondary raw materials?”

“Absolutely,” says the expert. “From now on, they can also be better integrated into life cycle management.”

The waste is sorted by using optical detection over the assembly line: A light source illuminates the crushed plastics, while a camera system analyzes the reflected light and recognizes the respective type of plastic. The software sends the position data to the compressed air system at the end of the conveyor belt. It opens the appropriate valve within a split second, so that a targeted blast of compressed air precisely separates the part which is to be sorted out.

Ideally, processed materials are to be re-used at the end of their life cycle or returned as secondary raw materials to the production process in order to conserve natural resources. The five-stage waste hierarchy is central to life cycle management:
1. Prevention of waste
2. Preparation for re-use of waste
3. Recycling of waste
4. Other recovery, e.g. energy recovery
5. Disposal of waste (landfill)

A second life

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Part of our daily life

Every day, we use very different plastics – from microparticles in cosmetics and packaging to plastic parts in cars and other modes of transport. It is therefore particularly important to recycle these raw materials as far as possible and to feed them back into the life cycle management.

Steel – the harder, the more economical

In the evening, Mert sits at his desk and writes up everything that he has learned. Who would have thought that wood would be such an interesting topic – and how difficult it could be to separate black plastic from other plastics. Which other raw materials could he write about? “Just go out onto the street and take a good look around,” his professor had advised. Mert goes to the window and looks out at the busy road. Suddenly, he knows exactly which other raw material he wants to report on. The next day, he goes looking for an expert in steel production at VDMA, and he is immediately given the address of a press plant where he could get information.

“Until 10 to 15 years ago, vehicle bodies were almost completely made from soft deep-drawing steels, which can be stamped when cold. The industry has developed hot-stamped high-strength steels in an effort to reduce weight and therefore fuel,” explains the manager of the press plant.

Mert realizes that steel is a very important raw material. “How does that work?” he asks.

“A particular steel alloy is heated to around 900 degrees before it is fed to the forming presses. The steel is then allowed to cool to below 400 degrees. The cooling down of the molten mass sets the steel. Through this process, it gains in strength. And the harder the steel, the thinner the metal needed for one and the same application. This means a huge weight saving,” says the plant manager.

Until then, Mert had never realized that weight reduction is an important aspect of resource conservation. He offers his thanks for the information and sets off home.

Steel – the raw material from the furnace

Steel is an important and sought-after material. It can be 100 percent recycled and can be processed very efficiently.

Raw materials – the stuff of interesting term papers

Mert is happy with his research. He had not expected that the topic of raw materials would be so diverse – and that it would be such a huge part of his daily life. Mert was particularly fascinated by the creative and innovative solutions in mechanical engineering which pave the way for new production methods and conserve resources. And it is becoming increasingly clear how very important resource efficiency is. After all, the world’s population may be growing but our earth isn’t.

Mert writes his term paper in a way that makes the topic come to life – with quotes, photos and small videos – so that he can raise awareness of the importance of the topic among his fellow students.

Late at night, he closes his laptop proudly. He hasn’t just completed his work, he also learned a lot in the process and he even had the opportunity to talk to people with interesting jobs. Mert looks forward to holding his presentation and to sharing his new knowledge with his fellow students.

Source: Shutterstock/Syda Productions

Useful links

Waste Treatment and Recycling Technology Association

There are approximately 80 manufacturers of reduction, sorting and mineral processing technology, thermal treatment of waste and landfill gas technology as well as complete system builders from the industry represented in the trade association.

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Programme for the sustainable use and conservation of natural resources

With the adoption of the German Resource Efficiency Programme (ProgRess) in February 2012, Germany was one of the first countries to lay down guiding principles and solutions for conserving natural resources.

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International cooperation network PalmwoodNet

The international cooperation network PalmwoodNet is an initiative of engineering and technology companies as well as R+D institutions from Europe, Malaysia and Thailand with the aim of developing marketable products from oil palm wood and suitable manufacturing processes and technologies under consideration of ecological and socio-economic effects.

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Ligna TV

Ligna TV is the internet TV channel for the woodworking industry. Contents are the classic TV information formats: Daily news programmes, magazines, journals that cover the topics at the fair and condense the diversity of the innovations to trends.

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Glued Laminated Timber Research Association inc.

The Studiengemeinschaft Holzleimbau e.V. (Glued Laminated Timber Research Association inc.) is the organisation of manufacturers of laminated, load bearing products active in Germany.

Go

The authors

Ingo Bette

VDMA Woodworking Machinery Trade Association

Ingo Bette has worked in the woodworking branch of VDMA since 2002 and is responsible for the conception and implementation of projects around B2B communication as well as for organizing and participating in trade fair events in Germany and abroad.

Sylvi Claußnitzer

VDMA Technical, Environmental Affairs and Sustainability

Sylvi Claußnitzer has been responsible for the areas of resource efficiency, hazardous substances and substance law at VDMA since 2014.

Sören Grumptmann

VDMA Waste Treatment and Recycling Technology Trade Association; VDMA Technical, Environmental Affairs and Sustainability

Sören Grumptmann has worked for the Waste Treatment and Recycling Technology Trade Association within the Technical, Environmental Affairs and Sustainability department since 2015. His duties include the representation of interests and the exchange between VDMA and policy makers.