Plastic lumber is a product manufactured from a mixture of recovered materials such as plastic. The product resembles wood and can be used in place of wood, concrete or metal to perform various structural functions. These applications include building recreational equipment, landscaping, and decking. The product however has not yet fully substituted wood in all its functions since it is still under research.
The most common uses of plastic lumber or RPL include: gardening where it is used for making flowerpots, compost bins and fences; agriculture where it is used in making ranch fences, vine stakes, animal stalls and gates; building recreational equipment such as playground equipment, picnic tables, park benches, informational kiosks and decking; among other uses.
There are four major types of Plastic wood, namely; Commingled RPL, High Density Polyethylene (HDPE) RPL, Fibre-Reinforced RPL, and Wood-Filled RPL. The types are highly dependent on the composition of materials. The first type is the Commingled RPL which is made from recycled thermoplastic and consisting majorly of polyethylene. This is so far the cheapest type to manufacture and is mostly used for landscaping and decking.
High Density Polyethylene (HDPE) Recycled Plastic Lumber, on other hand, is of higher density than the Commingled variety; hence a bit more costly. It has a distinct advantage in that it is available in a wide range of colours. It is also suitable for landscaping functions and decking.
The third type is manufactured by mixing plastic and glass fibre. The glass fibre is used to reinforce and can be in either continuous or chopped strands. This variety is suited for structural support applications due to the stiffness of the product. A similar product is the Wood-filled Plastic Lumber, which is made by mixing plastic with sawdust. The sawdust fibres reinforce the lumber resulting in great traction and creating a rough texture that is ideal for painting.
Plastic Lumber has several distinct advantages over wood. To begin with, Recycled Plastic Wood is more durable, nontoxic, clean, and nonporous. Other advantages include resistance to moisture and chemicals, maintenance free, splinter free hence no cracking, resistant to graffiti, do not require painting since they are already coloured,, impervious to insects, do not require preservatives or sealants; among others.
Plastic Wood is also very beneficial to the community. Since the lumber is maintenance free, it is a cost effective option for the community and government projects. In addition, it is environmentally friendly since it reduces plastic waste in landfills. Apart from that, Recycled Plastic Timber leads to reduction in treated wood waste.
In comparison to wood, Plastic Lumber is slightly expensive to purchase. However, when the life-cycle costs i. E. Maintenance and replacement that are associated with wood are included, Recycled Plastic Wood is more cost effective. It is also important to note that RPL can be recycled at the end of its useful life; thus making it superior to wood.