What are the effects of fiber surface modification on the interfacial bonding in WPC trash cans?

Fiber surface modification is a critical process for improving the performance of Wood Plastic Composite (WPC) trash cans. The primary effect is a significant enhancement in the interfacial bonding between the natural fibers (like wood flour) and the polymer matrix (such as PE or PP). Strong interfacial bonding is crucial because it directly transfers stress from the weak polymer matrix to the stronger fibers. This leads to several key improvements in the final product. Firstly, mechanical properties are substantially increased, resulting in greater tensile strength, flexural strength, and impact resistance, making the trash can more durable and less prone to cracking. Secondly, modified fibers have reduced hydrophilicity, which decreases water absorption. This improves dimensional stability, preventing the trash can from warping or swelling in humid conditions and enhancing its weatherability. Common modification techniques include alkali treatment, which cleans the fiber surface and increases roughness for better mechanical interlocking, and the use of coupling agents (like silane or maleic anhydride grafted polyolefins), which create chemical bridges between the fiber and the polymer. These treatments ensure a more uniform dispersion of fibers within the plastic, reducing voids and defects. Ultimately, effective fiber surface modification produces a WPC trash can that is stronger, longer-lasting, and better suited for both indoor and outdoor use.