Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Interzum 2015: WPC furniture with low flammability

04.05.2015

Wood is a popular material in interior design, but its water absorbency limits its use in bathrooms, where natural wood easily becomes discolored or moldy. Fraunhofer scientists and partners have developed a wood-polymer composite material for furniture that is resistant to humidity and has low flammability.

Resource-saving wood-polymer composites (WPCs) are the latest trend in materials for garden furniture and other outdoor applications, especially for terrace decking and also for weatherboarding and fencing panels.


WPC board without (above) and with (below) flame-proofing.

© Fraunhofer WKI

As part of the EU-sponsored LIMOWOOD project, researchers at the Fraunhofer Institute for Wood Research, Wilhelm-Klauditz-Institut WKI in Braunschweig are now collaborating with industrial partners in Belgium, Spain, France and Germany on the development of materials suitable for pressing into moisture-resistant WPC boards for indoor furniture manufacturing.

These boards are composed of around 60 percent wood particles and 40 percent thermoplastic material, generally polypropylene or polyethylene. Both wood and plastic components can be sourced from recycling streams.

The wood component in WPC boards can be replaced by other lignocellulose products derived from the fibrous part of plants such as hemp or cotton, or the husks of rice grains and sunflower seeds. All of these materials are 100-percent recyclable. Moreover, the pressed WPC boards produced by the WKI researchers are formaldehyde-free.

“The controversial question of formaldehyde emissions due to the binder used in conventional pressed wood products is therefore not an issue in this case,” says WKI research scientist Dr. Arne Schirp.

Tests prove low flammability of WPC boards

By choosing appropriate additives, the researchers were able to enhance the fire-retardant properties of their WPC boards. They initially developed their formula on a laboratory scale, using commercially available, halogen-free fire retardants which were added to the wood-polymer mixture during the melt phase.

The first step involved determining the limiting oxygen index of the item under test: this parameter defines the behavior of plastics or wood-filled plastic compounds when exposed to flames. It represents the minimum concentration of oxygen at which the material will continue to burn after catching fire. The higher this value, the lower the material’s flammability. Schirp and his colleagues obtained the best results with a combination of fire retardants such as red phosphorus and expanded graphite.

The limiting oxygen index of WPC boards treated in this way extends up to 38 percent, provided the wood particles they contained were also flame-proofed. By comparison, the limiting oxygen index of a standard wood particle board is 27 percent, and that of an untreated WPC board is 19 percent. Even in a single-flame source test, in which a Bunsen burner is held against the test sample, the treated WPC boards demonstrated a high fire resistance. Even after 300 seconds’ exposure, the boards didn’t catch fire. By contrast, the reference samples – of a standard wood particle board and an untreated WPC board – caught fire and continued to burn.

Another particular feature of the new WPC material is that it absorbs very little water and is thus highly suitable for use in bathrooms and kitchens. Even after being immersed in boiling water for five hours, the material emerges intact, whereas conventional wood particle board was completely destroyed by this test. The only limiting factor on applications of WPC is its inability to support high static loads. But even here, it has been possible to increase its bending strength to a level that far exceeds that of conventional particle board by utilizing a judicious mix of component materials.

Wood-polymer composites can be produced in many ways. The most commonly used processes are injection molding and extrusion, in which the various components – wood fibers, thermoplastic materials, and additives – are melted under high pressure at a high temperature and formed in a continuous mold. Arne Schirp’s team has placed its focus on press technology, because it is the best way to produce boards for use in furniture construction.

“The resulting boards have the same visual appeal as all-wood products and can be glued or screwed together to produce attractive furniture. They’re suitable for all decorative, non-loadbearing elements.” But there are many other applications for wood-polymer composites, including exterior weatherboarding of buildings, the construction of trade-show booths, and interior fittings for houses and ships.

Through their development work, the partners in the LIMOWOOD project aim to fill the gap between the high and low ends of the furniture market, which ranges between expensive and not necessarily ecologically sound materials and cheap products made of particle or fiber board, which at present are mainly produced using formaldehyde-based binders. The WKI researchers will be presenting prototypes of their flame-resistant WPC boards at the Interzum trade show in Cologne from May 5 to 8 (Boulevard, B077).

Simone Peist | Fraunhofer Forschung Kompakt
Further information:
http://www.fraunhofer.de/en/press/research-news/2015/may/WPC-furniture-with-low-flammability.html

More articles from Trade Fair News:

nachricht Medica 2018: Mobile motion feedback to help patients reduce relieving postures when walking
07.11.2018 | Technische Universität Kaiserslautern

nachricht Medica 2018: Control with your feet - computer game to help prevent thrombosis
05.11.2018 | Technische Universität Kaiserslautern

All articles from Trade Fair News >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: A Chip with Blood Vessels

Biochips have been developed at TU Wien (Vienna), on which tissue can be produced and examined. This allows supplying the tissue with different substances in a very controlled way.

Cultivating human cells in the Petri dish is not a big challenge today. Producing artificial tissue, however, permeated by fine blood vessels, is a much more...

Im Focus: A Leap Into Quantum Technology

Faster and secure data communication: This is the goal of a new joint project involving physicists from the University of Würzburg. The German Federal Ministry of Education and Research funds the project with 14.8 million euro.

In our digital world data security and secure communication are becoming more and more important. Quantum communication is a promising approach to achieve...

Im Focus: Research icebreaker Polarstern begins the Antarctic season

What does it look like below the ice shelf of the calved massive iceberg A68?

On Saturday, 10 November 2018, the research icebreaker Polarstern will leave its homeport of Bremerhaven, bound for Cape Town, South Africa.

Im Focus: Penn engineers develop ultrathin, ultralight 'nanocardboard'

When choosing materials to make something, trade-offs need to be made between a host of properties, such as thickness, stiffness and weight. Depending on the application in question, finding just the right balance is the difference between success and failure

Now, a team of Penn Engineers has demonstrated a new material they call "nanocardboard," an ultrathin equivalent of corrugated paper cardboard. A square...

Im Focus: Coping with errors in the quantum age

Physicists at ETH Zurich demonstrate how errors that occur during the manipulation of quantum system can be monitored and corrected on the fly

The field of quantum computation has seen tremendous progress in recent years. Bit by bit, quantum devices start to challenge conventional computers, at least...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

“3rd Conference on Laser Polishing – LaP 2018” Attracts International Experts and Users

09.11.2018 | Event News

On the brain’s ability to find the right direction

06.11.2018 | Event News

European Space Talks: Weltraumschrott – eine Gefahr für die Gesellschaft?

23.10.2018 | Event News

 
Latest News

Epoxy compound gets a graphene bump

14.11.2018 | Materials Sciences

Microgel powder fights infection and helps wounds heal

14.11.2018 | Health and Medicine

How algae and carbon fibers could sustainably reduce the athmospheric carbon dioxide concentration

14.11.2018 | Life Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>