Analysis of the advantages and disadvantages of PA6 nylon plastic raw materials
The main advantages of PA6 nylon plastic materials:
1. High mechanical strength, good toughness, high tensile and compressive strength. The specific tensile strength is higher than that of metal, and the specific compressive strength is comparable to that of metal, but its rigidity is not as good as that of metal. The tensile strength is close to the yield strength, more than twice as high as ABS. The ability to absorb shock, stress and vibration is strong, and the impact strength is much higher than that of general plastics, and is better than acetal resin.
2. Outstanding fatigue resistance, the parts can maintain the original mechanical strength after repeated inflections. Common escalator handrails, new bicycle plastic rims and other occasions where periodic fatigue is extremely obvious, PA is often used.
3. High softening point and heat resistance (such as nylon 46, etc., high crystalline nylon has a high heat distortion temperature and can be used for a long time at 150 degrees. After PA66 is reinforced with glass fiber, its heat distortion temperature can reach 250 degrees or more).
4. The surface is smooth, the friction coefficient is small, and it is wear-resistant. It is self-lubricating when it is used as a movable mechanical component and has low noise. It can be used without lubricant when the friction is not too high; if lubricant is really needed to reduce friction or help heat dissipation, water, oil, grease, etc. can be selected. As a result, it has a long service life as a transmission component.
5. Corrosion resistant, very resistant to alkalis and most salt solutions, also resistant to weak acids, engine oils, gasoline, aromatic compounds and general solvents, inert to aromatic compounds, but not resistant to strong acids and oxidants. It can resist the erosion of gasoline, oil, fat, alcohol, weak base, etc. and has good anti-aging ability. It can be used as packaging material for lubricating oil and fuel.
6. It is self-extinguishing, non-toxic, odorless, good weather resistance, inert to biological erosion, and has good antibacterial and antifungal capabilities.
7. It has excellent electrical properties. Good electrical insulation. Nylon has a high volume resistance and high breakdown voltage. It can be used as a power frequency insulating material in a dry environment, and it has good electrical insulation even in a high humidity environment.8. The parts are light in weight, easy to dye and easy to shape. Because of its low melt viscosity, it can flow quickly. It is easy to fill the mold, the solidification point is high after the mold is filled, and the shape can be set quickly, so the plastic machining has a short molding cycle and high production efficiency.
The main disadvantages of PA6 nylon plastic raw materials:
1. Easy to absorb water. The water absorption is large, and the saturated water can reach more than 3%. To a certain extent, it affects the dimensional stability and electrical performance, especially the thickening of thin-walled parts has a greater impact; water absorption will also greatly reduce the mechanical strength of the plastic. When selecting materials, consideration should be given to the influence of the use environment and the accuracy of coordination with other components. Fiber reinforcement can reduce the water absorption rate of the resin, so that it can work under high temperature and high humidity. Nylon has a very good affinity with glass fiber. It is commonly used to make machining uhmw combs, toothbrushes, clothes hooks, fan bones, net bag rope, fruit outer packaging bags and so on. Non-toxic, but not long-term contact with acid and alkali. It is worth noting that after adding glass fiber, the tensile strength of nylon can be increased by about 2 times, and the temperature resistance can be improved accordingly.
2. Poor light resistance. In a long-term high temperature environment, it will oxidize with oxygen in the air, and the color will turn brown at the beginning, and then the surface will be broken and cracked.
3. The injection molding technology requirements are strict: the presence of trace moisture will cause great damage to the molding quality; the dimensional stability of the product is difficult to control due to thermal expansion; the existence of sharp corners in the product will cause stress concentration and reduce the strength of CNC mechanical parts; If the wall thickness is not uniform, it will cause distortion and deformation of the parts; the precision requirements of the CNC machining factory equipment are very high during the post-processing of the parts.4. It will swell by absorbing water and alcohol. It is not resistant to strong acids and oxidants, and cannot be used as acid-resistant materials.