Structural Plastic LumberThe Construction of a Composite
NOTE: This primer is intended to provide information on FRP composites as it applies to ACT Timbers. There is an extensive amount of information on FRP composite technology. Click here for suggested sites on our Related Links page.
Not all plastics are considered composites. When additional strength is required, many types of polymers (plastics) can be reinforced with structural materials to meet the higher performance demands. Only when a polymer is reinforced is it considered a fiber-reinforced polymer (FRP) composite.
Therefore, the definition of an FRP composite is a combination of:
a reinforcing agent (such as glass, carbon or aramid) or other reinforcing material
FRP composites may also contain:
High impact strength/resistance
ACT Composite Timbers - The Constituent Materials
The primary functions of the resin are:
act as a glue to hold the fibers together
protect the fibers from mechanical and environmental damage.
ACT Timbers are manufactured from recycled thermoplastic resins that are produced by utilizing a mixture of post-consumer and post-commercial plastics. Thermoplastic resins are inherently tough and provide excellent impact resistance. Plus, these versatile resins are naturally impervious to harsh chemicals and environmental conditions. One last benefit is that composites manufactured from thermoplastic resins are readily recyclable so future replacement does not mean an addition to a landfill.
The primary function of fibers or reinforcements is to carry load along the length of the fiber to provide strength and stiffness in the direction of the fiber. While there are many different types of reinforcing agents possible, ACT Timbers utilizes fiberglass filaments evenly dispersed in the resin matrix. Glass is the composites industry workhorse because of its high mechanical properties, low susceptibility to moisture and low-cost.
ACT Timber Additives
Additives are a key ingredient to any resin. ACT Timbers use additives that specifically enhance the performance of timber, extend its durability and increase its aesthetic appeal:
Colorants are additives that are mixed into the resin to provide uniform color throughout the timber. ACT is available in 14 standard colors. Special colors may be formulated.
Flame retardant additives, which can be special ordered, increase the fire resistance of the ACT Timber.
Unique to the composites industry is the ability to create a product from many different manufacturing processes. There are a wide variety of processes available to the composites manufacturer to produce cost-efficient products. ACT Timbers use an extrusion process for its products. To learn more about how a composite timber is manufactured, click here.
Hollaway, Leonard, ed. Handbook of Polymer Composites for Engineers. Cambridge, England: Woodhead Publishing, 1994.
Kaw, Autar K. Mechanics of Composites Materials. New York: CRC Press, 1997.
Market Development Alliance. Product Selection Guide: FRP Composite Products for Bridge Applications. New York, 2000.
Miller, Tara, ed. Introduction to Composites, 4th Edition. New York: Composites Institute, Society of the Plastics Industry,1998.
Murphy, John. Reinforced Plastics Handbook. Oxford, England: Elsevier Science,1998.
Richardson, Terry. Composites: A Design Guide. New York: Industrial Press, 1987.
Rosato, Dominick V. Designing with Reinforced Plastics. Cincinnati, OH: Hanser/Gardner, 1997