What are the effects of resin melt flow rate on the surface finish of WPC outdoor trash cans?

The resin melt flow rate (MFR) is a critical property that significantly influences the surface quality of wood-plastic composite (WPC) outdoor trash cans during the injection molding process. A higher MFR indicates a lower viscosity resin that flows more easily into the complex mold cavities, resulting in a smoother, more uniform surface with better replication of fine details and a higher gloss. This easy flow helps minimize visible defects like flow lines and weld lines. Conversely, a resin with a low MFR has higher viscosity, making it difficult to fill the mold completely. This can lead to a rough, uneven surface finish, visible short shots, and increased internal stresses that may cause warping. However, an excessively high MFR can also be detrimental, potentially causing jetting or flash. Therefore, selecting a resin with an optimal, balanced MFR is essential for achieving a high-quality, durable, and aesthetically pleasing surface finish on WPC trash cans destined for harsh outdoor environments.