会社のニュース The Causes of Floating Fiber Phenomenon in Glass Fiber Reinforced PC

  The "floating fiber" phenomenon remains a significant surface quality challenge in the injection molding of glass fiber reinforced Polycarbonate (PC). This issue arises from the inherent differences between the polymer and the reinforcing fibers. During injection, the differing densities and flow behaviors of the PC melt and the glass fibers cause a segregation tendency. Strong separation forces overcome the interfacial adhesion, causing the lower-density glass fibers to migrate toward the part's surface, resulting in a visible, whitish, speckled appearance. Compounding this, the high shear stresses experienced during processing through the screw, nozzle, and gates can degrade the interface between the fiber and the matrix. A lower melt viscosity worsens this interfacial damage, further reducing adhesion and allowing more fibers to break free and accumulate on the surface, creating the characteristic "floating fiber" defect that plagues the aesthetics of these high-performance composites.