Carefully analyze the light line of the gate area of u200bu200bthe injection molded product
In the design of the point pour button in the direction of the vertical control, the radiant system composed of different color depth and gloss at the center of the pour taste appeared on the surface of the control during injection molding as a ray line. In the point gate design of the vertical part direction, a radiation system composed of different color depths and glosses centered on the gate appears on the surface of the part during injection molding, which is called ray line. Most of these defects appear in the injection of polystyrene and modified polystyrene mixtures. His appearance is related to the following things: the two materials are different in rheology, coloring, etc., and the stratosphere of the casting system is different. The turbulent layer has a difference in flow velocity and heating conditions; plastics produce charred filaments due to thermal decomposition; the interference of gaseous substances when plastics enter the mold. Solution: (1) When using mixed plastics, the plastics should be mixed well, and the particle size of the plastics should be the same and uniform. (2) Reduce injection pressure and speed, shorten injection and pressure holding time, increase mold temperature, increase nozzle temperature, and reduce forehearth temperature. (3) Improve gate design, such as enlarge gate diameter and change gate position. (4) The plastic and the coloring agent should be mixed uniformly, and appropriate dispersing agent should be added when necessary, and the mixing should be done mechanically. (5) Prevent the melting and coking substances that increase viscosity due to the degradation of plastics: if you pay attention to whether the screw and barrel are worn out and there are dead corners, or the heating system is out of control, improper processing operations cause the plastic to decompose due to long-term heating. The inner surface of the front end of the screw and barrel can be polished. (6) Plasticization must be complete, and the plasticization performance of the machine must be good.