. 1.The processability of PPO. PPO is bibulous rate is very low, but the water will make the product appear on the surface of silver, bubbles and other defects, therefore, materials can be placed in the 80-100 degrees oven drying after use, 1-2h; PPO molecular chain rigidity, glass transition temperature is high, not easy to approach, but forced orientation is very difficult to relaxation. So the products within the residual stress is higher, generally after treatment; PPO for the amorphous material, the rheology in the molten state of the approximate Newton fluid, but with the rise of temperature deviates from the Newton fluid is greater; the viscosity of PPO melt, therefore the processing time should raise the temperature, and increasing the injection pressure, in order to improve the filling ability; PPO feed back can be repeatedly used, generally 3 times of repeated use, its performance is not significantly reduced; PPO should be used to melt molding screw injection machine, nozzle with straight through type is preferred, aperture is 3-6mm; in the PPO injection molding, easy to take the high pressure, high speed injection, holding pressure and cooling time can not be too long; the sprue mould should adopt the Jiaotong University ah taper or the material pulling hook, the runner to stub as well; the gate should adopt the direct type, sector or flat, the needle gate diameter should be appropriately increased, for the long runner can use hot runner structure; molding shrinkage rate of PPO a small, usually 0.2%-0.7%, so the product dimension stability is good.
  2.The main injection molding conditions PPO. Barrel temperature. PPO has high heat resistance, thermal decomposition temperature of 350 degrees, no obvious thermal degradation phenomena in the 300 degrees. Usually, the barrel temperature control in 260-290 degrees, nozzle temperature below the barrel temperature 10 degrees; the mold temperature. Because the PPO melt viscosity, because in injection molding should adopt the high mold temperature. Usually, mold temperature control in 100-150 degrees. Mold temperature is below 100 degrees, thin walled plastic parts easy to appear is full of shortcomings and stratification; and higher than 150 degrees, prone to bubbles, silver, such as warpage defect; injection pressure. Increase the injection pressure, filling to melt, general injection pressure control in 100-140MPa.