what transparent wood

What is Transparent Wood?

Transparent wood! With the image we all have of wood, this term may sound like the strangest thing you’ve ever heard. However, in today’s era, where modern knowledge and advanced technologies have made almost anything possible, the creation and availability of “transparent wood” is no longer so unusual. Transparent wood is the result of separating the lignin content of wood and replacing it with transparent polymer materials. This unique wood has interesting physical, mechanical, and optical properties. Not only is transparent wood recognized as a renewable material, but it has also created fascinating ecological aspects for wood, resulting in greater profitability and more stunning visual effects in the decoration, construction, and other industries.

In fact, lignin is the most important component in the structure of wood, which makes most of them appear in shades of cream and brown. For this reason, in 1992, a German scientist named Siegfried Fink, aware that the opacity of wood is due to the combination of its two main components—cellulose and lignin—managed to separate these materials from the wood structure. Approximately two decades later, two scientists from Sweden and Maryland completed this idea and succeeded in producing transparent wood by using bleaching methods and removing lignin and water from the wood structure.

The Process of Making Transparent Wood

The threat of natural resource depletion and the need for energy conservation have turned the production of transparent wood into an environmental priority to combat the increasing burden of environmental pollution and reduce energy consumption. Therefore, scientists have been working to produce higher-quality transparent woods with enhanced capabilities through the following combined process:

1. Selection of Wood: Scientists and wood specialists recognize that each type of wood or tree has its unique properties. For making transparent wood, they choose wood with suitable visual characteristics and the ability to absorb resin and transparent materials. The trunks of poplar, pine, orange, and cedar trees are among the best options for this purpose. The selected wood must be dry and free from defects.
2. Separation: The natural structure of wood consists of three main components: lignin, hemicellulose, and cellulose. Cellulose includes strong structural fibers that are naturally transparent, while lignin is a type of natural adhesive that holds the cellulose fibers together. Unlike cellulose, which has a crystalline structure, lignin is darkly colored and sticky. During the separation phase, the non-structural, opaque parts are removed using sodium hydroxide alkaline solution, which is then replaced with transparent epoxy. The bleaching and separation of lignin for each large log of wood takes about 24 hours.
3. Cutting: The selected wood for producing transparent wood must be turned and cut into smaller pieces. Thus, the wood pieces are precisely cut into thin dimensions using specialized industrial machines for the next stages.
4. Rolling: In this stage, the cut wood pieces are smoothed and leveled using special rollers. This process removes any irregularities and scratches.
5. Wood Saturation: One of the main stages in the production of transparent wood is saturating the wood with transparent materials. For this purpose, synthetic resins such as epoxy resin can be used. The wood pieces are fully immersed in resin, allowing it to penetrate the wood. This penetration clarifies the color of the wood through the porous cellulose tubes, forming a unified optical structure similar to fiberglass.
6. Finishing: After saturating the wood, the surface needs to be smoothed and polished. This is done using finishing materials like lacquer and oil, which give the wood a clear, glossy appearance.
7. Drying: After finishing, the wood must be thoroughly dried. This process is time-consuming and may take several days. Complete drying of the wood is essential to ensure its strength and stability.

By following the above steps and using appropriate equipment and materials, it is possible to produce transparent wood with high visual properties, lightweight, mechanical resistance, and resistance to decay and insect penetration. Researchers and scientists continue to investigate this field to offer transparent wood with newer methods and higher quality levels, relying on their expertise and advanced technologies.

Currently, North America is the largest stakeholder in the global transparent wood market, and it is expected that in the coming years, with the export of transparent wood production technology and a shift in the use of this wood instead of glass, plastic, and traditional woods, the market for this valuable product will flourish even further, facilitating trade of transparent wood with other countries.