Difference between plastic and wood
A new technique for densifying wood without softening it or returning it to its original state has been developed by the team of Liangbing Hu, a materials scientist at the University of Maryland, and published in the journal Nature. It could not only revolutionize industries such as construction, but also lead to the creation of bullet-resistant boards.
The resulting wood is then pressed, and the compression is maintained while it is heated. This applies a combination of pressure and heat that collapses its cell walls and promotes the formation of chemical bonds that strengthen the material at the nanometer scale.
Through this process, the researchers have succeeded in creating compressed wood that is three times denser than untreated wood. What’s more, the resulting wood is 10 times harder to break, 20 times stiffer and 50 times more resistant to compression. The result is a superwood so versatile, malleable and strong that it could compete with steel alloys.
Plastic wood factory
Synthetic wood is a material manufactured from wood waste and selected recycled plastics, resulting in a material of greater durability and less maintenance. It is also known by this name to fully synthetic composites whose finish imitates the appearance of natural wood. The final products can be used in the same way as natural wood, mainly for outdoor use, accepting also and saline environments..
The composition of the different synthetic woods is very variable: the most frequent ones combine plastics such as PVC with wood in proportions close to 50%, while others are 100% plastic.
As outdoor flooring, it is usually presented in the form of slats, to be installed on a decking (wooden beams or battens) on the ground or in tiles, also called tiles, to be installed directly on the outside floor.
Outdoor composite decking stands out from other types of outdoor decking because it has a firm, durable and slip-resistant surface. It requires very little maintenance and in general, it is very resistant to inclement weather and the attack of xylophagous insect pests.
Plastic wood prices
“All plant materials contain a minimum of 25% cellulose,” said Prof. Winter, “Wood from trees has a little more, between 40% and 50%.” Using cellulose nanocrystals to strengthen plastics has advantages over the glass that is normally used. Glass is harder, more complicated to process and therefore more expensive to work with.
Winter and his team work with a reactor that can process about 500 grams (about one pound) of material at a time. This is a significant increase over the 5-gram quantities normally used in laboratories.
The main problem with these composites is the processing temperature which, in general, should not exceed 190°C. Another problem is wood moisture, which is not compatible with most polymers and in some cases can lead to degradation and loss of physical properties by depolymerization.
Wood fibers are randomly distributed within the matrix of plastic materials. The percentage of wood fibers varies depending on the product, from 70% and even higher, to recycled plastic products containing no wood fibers.
Wood: The percentage of wood, both in the form of powder and short fibers (less than 5 mm), normally varies from 50 to 80 %. Wood flour is used to give body to the product, but its purpose is different from that of the fillers used in adhesives, since in this case its purpose is reinforcement. The use of wood dust or other materials is not recommended because of the risk of explosion.