1) The compatibility between fiberglass and nylon is poor, and during the modification process, nylon has low flowability and does not completely infiltrate the fiberglass.

2) In the process of injection molding, due to the frictional shear force at the screw, nozzle, runner, and gate during the flow of plastic melt, it can cause local viscosity differences and also damage the contact surface of the glass fiber. The lower the viscosity of the contact surface, the more severe the damage to the contact surface, and the smaller the bonding force between the glass fiber and resin. When the bonding force at the contact surface is reduced to a certain extent, the glass fiber will break free from the constraints of the resin matrix, Gradually converging towards the surface area and exposing.

3) Related to the difference in specific gravity between glass fiber and base material, during the melt molding process, due to the different flowability and mass density between glass fiber and resin, they tend to separate, with glass fiber floating towards the surface and resin sinking towards the interior, resulting in exposed glass fiber.

4) Fountain effect: When nylon melt is injected into the mold, it will produce a "fountain effect", where glass fiber will flow from the inside out and come into contact with the surface of the mold. Due to the lower temperature of the injection mold surface, the glass fiber is instantly and lightly condensed and quickly condensed. If it cannot be completely wrapped by the melt in time, it will be exposed and form a "floating fiber".

Therefore, the phenomenon of "floating fibers" in the injection molding of fiberglass reinforced materials not only involves the composition and properties of plastic materials, but also involves the injection molding process, which has great complexity and uncertainty.