Analysis of four examples of modified nylon

01 Glass fiber reinforced nylon 

By adding 30% glass fiber to nylon, the mechanical properties, dimensional stability, heat resistance, and aging resistance of nylon are significantly improved, and the fatigue resistance strength is 2.5 times that of unenhanced ones. The molding process of glass fiber reinforced PA is roughly the same as that without reinforcement, but because the flow is worse than before reinforcement, the injection pressure and injection speed should be appropriately increased, and the barrel temperature should be increased by 10 to 40°C. 

Since glass fiber will be oriented along the flow direction during the injection molding process, the mechanical properties and shrinkage rate will increase in the direction of orientation, causing the product to deform and warp. Therefore, when designing the mold, the location and shape of the gate should be reasonable, and the process can be improved. After taking out the product, place it in hot water and let it cool slowly. In addition, the greater the proportion of glass fiber added, the greater the wear on the plasticizing components of the injection molding machine. It is best to use bimetallic screws and barrels. 

02 Flame retardant nylon 

Since flame retardants are added to nylon, most flame retardants are easy to decompose at high temperatures and release acidic substances, which are corrosive to metals. Therefore, plasticizing components (screws, glue heads, rubber rings, glue rings, etc.) Gaskets, flanges, etc.) need to be hard chromium plated. In terms of technology, try to control the temperature of the barrel not to be too high and the injection speed not to be too fast to avoid discoloration of the product and a decrease in mechanical properties caused by decomposition of the rubber material due to excessive temperature. 

03 Transparent nylon 

It has good tensile strength, impact strength, rigidity, wear resistance, chemical resistance, surface hardness and other properties. It has high light transmittance, similar to optical glass. The processing temperature is 300~315℃. During molding and processing, strict requirements are required. Control the barrel temperature. If the melt temperature is too high, it will cause discoloration of the product due to degradation. If the temperature is too low, the transparency of the product will be affected due to poor plasticization. The mold temperature should be as low as possible. High mold temperature will reduce the transparency of the product due to crystallization. 

04 Weather-resistant nylon

Adding UV-absorbing additives such as carbon black to nylon greatly enhances the self-lubricating properties of nylon and the wear on metal, which will affect cutting and wear of machine parts during molding and processing. Therefore, it is necessary to use a screw, barrel, rubber head, rubber ring, and rubber washer combination with strong feeding capacity and high wear resistance.