PA modified material

Due to the strong polarity of PA, it has strong hygroscopicity and poor dimensional stability, but it can be improved by modification.

Glass fiber reinforced PA

When 30% glass fiber is added to PA, the mechanical properties, dimensional stability, heat resistance, and aging resistance of PA are significantly improved, and the fatigue strength is 2.5 times that of no reinforcement. The molding process of glass fiber-reinforced PA is almost the same as when it is not reinforced. However, the injection pressure and injection speed must be appropriately increased, and the barrel temperature should be increased by 10-40°C. As the glass fiber is oriented along the flow direction during the injection molding process, the mechanical properties and the shrinkage rate are enhanced in the orientation direction, resulting in warping of the product. Therefore, when the mold is designed, the position and shape of the gate should be reasonable, and the process can be improved. The temperature of the mold was removed and put into hot water to allow it to cool slowly. In addition, the greater the proportion of glass fiber added, the greater the wear of the plasticizing elements of the injection molding machine, and it is preferable to use a bimetallic screw or a barrel.

2. Flame retardant PA

Due to the addition of flame retardant to PA, most of the flame retardants are easily decomposed at high temperatures, releasing acidic substances and corrosive to metals. Therefore, plasticizing elements (screw, rubber head, aprons, adhesives) Washers, flanges, etc.) must be plated with hard chrome. In terms of process, try to control the barrel temperature not too high, the injection speed can not be too fast, to avoid discoloration and mechanical properties of the product caused by decomposition of the rubber material temperature is too high.

3. Transparent PA

Has good tensile strength, impact strength, rigidity, wear resistance, chemical resistance, surface hardness and other properties, high light transmittance, similar to optical glass, processing temperature is 300--315 °C, molding process, need to Strictly controlling the barrel temperature, the melt temperature is too high will cause discoloration of the product due to degradation, the temperature is too low will affect the transparency of the product due to poor plasticization. The mold temperature should be as low as possible, and high mold temperature will reduce the transparency of the product due to crystallization.

4. Weatherproof PA

In the PA, additives such as carbon black, which absorbs ultraviolet light, are added. These self-lubricated PA's and metal's wear are greatly enhanced, and the blanking and wear mechanisms are affected during molding. Therefore, it is necessary to use a combination of screws, barrels, rubber heads, aprons, and rubber gaskets that have strong feedability and high wear resistance.