Advantages and Disadvantages of Glass Fiber Reinforced Nylon 6

PA6 (full name Polyamide 6, also known as Nylon 6) is a thermoplastic engineering plastic polymerized from caprolactam monomers. Its molecular structure contains amide groups and imine groups, which gives it good mechanical properties, thermal properties, chemical stability, as well as excellent processability and low water absorption, making it widely used in the field of engineering plastics.

When glass fiber is added to nylon, the molding process is roughly similar to that of unreinforced nylon, but the performance is significantly improved and the application range is expanded. However, it also introduces some defects caused by glass fiber. The specific advantages and disadvantages are as follows:

Advantages of Glass Fiber Reinforced Nylon:

Firstly, mechanical properties, dimensional stability, heat resistance and aging resistance are significantly improved: the fatigue strength reaches 2.5 times that of the unreinforced version; the high temperature resistance of glass fiber itself greatly increases the heat resistance temperature of the reinforced plastic compared with non-glass fiber reinforced plastic.

Secondly, the addition of glass fiber restricts the movement between plastic polymer chains, which not only significantly reduces the shrinkage rate of the reinforced plastic, greatly improves the product shrinkage phenomenon, but also significantly increases the rigidity.

In addition, after glass fiber reinforcement, the plastic is less prone to stress cracking, and the impact resistance is significantly improved; at the same time, the high strength characteristics of glass fiber also drive the improvement of mechanical strength indicators such as tensile strength, compressive strength and flexural strength.

Disadvantages of Glass Fiber Reinforced Nylon:

Firstly, the material fluidity will decrease, so it is necessary to appropriately increase the injection pressure and injection speed during injection molding, and the material temperature and mold temperature also need to be increased moderately.

Secondly, the toughness decreases and the brittleness increases accordingly.

Thirdly, during the injection molding process, the glass fiber will orient along the flow direction, resulting in enhanced mechanical properties and shrinkage rate of the product in the orientation direction, which easily causes deformation and warpage. Therefore, the gate position and shape need to be optimized in mold design, and the process can be alleviated by increasing the mold temperature.

Fourthly, glass fiber tends to float on the surface of the product during injection molding, resulting in rough surface, fiber floating, material flow marks and other defects; even if a mold temperature machine is used to heat the mold to promote the plastic polymer to cover the surface, it is difficult to achieve the appearance quality of pure plastic.

Fifthly, the higher the proportion of glass fiber, the more serious the wear on the plasticizing components of the injection molding machine, especially the screw.