Injection molding products in the vertical parts the underlying purpose of point gate in the plan, when we do the injection parts appearance presented with gate as the core composed of difference color depth and light radiation parts, called light line. Roughly three, namely the dark bottom of the dark line, the bottom of the dark dark lines and dark lines around the gate close and pale. Most of this kind of defect in the injection system of polystyrene and the present, when modified polystyrene inclusions has nothing to do with the following elements: two kinds of material has difference in rheology, coloring, layer velocity of turbulent flow in the stratosphere and casting parts and heat conditions have difference; Plastics are naturally charred by thermal synthesis; The interference of gaseous materials during plastic injection.
The processing steps of the bright line for injection molding products:
(1) when adopting the inclusion of plastic, it should be mixed with plastic, and the particle size of plastic should be opposite and average.
(2) the plastic and colorant should be mixed with the average, and the appropriate dispersing agent should be removed when necessary, and the machine should be mixed.
(3) the plasticization should be complete, and the plastic function of the machine platform should be excellent.
(4) increase the pressure and speed of the injection, prolong the injection time and maintain the pressure time, meanwhile improve the mold temperature, improve the nozzle temperature, and reduce the furnace temperature at the same time.
(5) to avoid the degradation of plastic forming increase viscosity of melt and coking materials: such as attention can screw with a nitrogen-treated barrel wear and corner, or heating parts out of control, processing control wrong form temporary heating and synthetic plastic. Can be polished in front of the screw and cylinder appearance.
(6) modified gate plan, such as reducing the gate diameter, turning the gate position, changing the gate to the round corner, and adding the cooling well at the end of the runner.