Plastic lumber, short for PL, is a form of plastic lumber made from virgin or recycled plastic Compared to composite wood which is made of wood and plastic, plastic lumber is made of 100% plastic.
Plastic lumber is widely used in outdoor flooring, but also in molding and trimming and especially garden furniture such as park benches, outdoor dining tables, etc. When properly installed, it is highly resistant to cracking and wear. Plastic lumber can be easily molded with or without imitating the details of wood grains. Even though the wood-grain design is adopted, plastic lumber is still visually distinguishable from natural wood because its grains have the same uniform color as the rest of the material.
Many manufacturers claim that composite wood is more environmentally friendly and requires less maintenance. But the fact is that plastic lumber is also eco-friendly and low-maintenance, and it can be 100% recycled after its initial use.
Production of Plastic Lumber
Plastic lumber is made up of virgin or waste plastics including HDPE, PVC, PP, ABS, PS and PLA. The powder or pellets of these plastic are mixed to a dough-like consistency at approximately 204°C and then extruded or molded into the desired shape.Additives such as colorants, coupling agents, stabilizers, blowing agents, reinforcing agents, blowing agents, and lubricants help the finished plastic lumber fit different applications. The plastic lumber can be made into both solid and hollow profiles, as well as injection molded parts and products.
Properties of Plastic Lumber
Plastic lumber can be made into the products that fits in any space, which is a significant advantage over natural wood. It can also be bent and fastened to form a firm arched curve.In addition, plastic lumber works like wood—it can be shaped, drilled, and cut with regular woodworking tools. At the same time, it is not as hard as wood and may deform slightly in extremely hot weather, but it is waterproof and resistant to all types of rot and mildew.
Plastic lumber is not sensitive to staining by various reagents. The main selling point of this material is that it does not require painting and is low-maintenance. It can be made in a variety of colors, and in particular gray and earth tones are widely available.
Engineering Properties of Plastic Lumber
While the compressive properties of plastic lumber are equal to or greater than wood, the modulus of elasticity is very low. Also, plastic lumber creeps more easily than wood.When used in load-bearing structures, different considerations need to be taken into account than wood. If needed, aluminum tubes or other metal parts can be installed inside the plastic lumber to increase its strength and bearing capacity.
When it comes to fire problems, plastic lumber is at a disadvantage. It performed worse than various wood and composites in tests.
What’s more, plastic lumber is also prone to deformation at high temperatures. Therefore, if you use it for outdoor furniture in the areas with extremely hot weather, some protections should be done, such as adding a UV-resistant cover when the furniture is not in use.
