What are the differences in thermal expansion between WPC and composite plastic outdoor trash cans?

When selecting outdoor trash cans, understanding thermal expansion differences between Wood Plastic Composite (WPC) and composite plastic materials is crucial for long-term durability. WPC materials, composed of wood fibers and thermoplastics, typically exhibit lower thermal expansion coefficients ranging from 4-8 × 10^-5/°C. This results in approximately 2-4mm expansion per meter of material for every 50°C temperature change. Composite plastics, primarily made from polyethylene or polypropylene, show higher expansion rates of 15-30 × 10^-5/°C, causing 7-15mm expansion under similar conditions. The key difference lies in material composition: WPC's wood fiber content provides dimensional stability, while pure plastics expand more significantly. This expansion variance affects structural integrity, with composite plastics requiring more expansion joints in larger designs. Temperature fluctuations cause composite plastic cans to warp or crack at mounting points, whereas WPC maintains better shape retention. For extreme climates, WPC's superior thermal stability makes it preferable, though proper installation techniques can mitigate expansion issues in both materials. Manufacturers often incorporate design elements like expansion gaps to accommodate these material characteristics.