Gate position

There are many kinds of mold gate for daily necessities, but no matter what kind of gate is used, the opening position of the gate has a great influence on the forming performance and forming quality of plastic parts.Therefore, the reasonable selection of mold gate opening position is an important design link of high quality plastic parts.When selecting the position of mold gate, the flow state, filling condition and exhaust condition of molten plastics in the mold should be analyzed according to the geometric characteristics and technical requirements of plastic manufacture.Mold gate should be set in plastic section of the thickest place.When the wall thickness of plastic parts is quite different, if the mold gate is opened in the thin wall, it is the plastic melt entering the cavity, which not only has a large flow resistance, but also is easy to cool, which affects the melt flow distance, and it is difficult to guarantee the filling of the whole cavity.The wall thickness of plastic parts is usually the last place where the melt solidifies. If the gate is arranged in the thin wall, the wall thickness will form a surface hollow or shrinkage hole because the shrinkage of the plastic melt can not be compensated.Die gate size and location should be selected to avoid spray and creep phenomenon.If a small mold gate is facing a large width and thickness cavity, the melt fracture phenomena such as jet and creep will occur when the high speed material flow passes through the gate, because of the high shear stress.Sometimes the spray phenomenon also causes the plastic parts to form ripple flow marks.The choice of mold gate position should make plastic flow shortest and material flow change least.The choice of mold gate position should be favorable to the gas discharge in the mold cavity.The extrusion deformation of the cavity, core and insert should be prevented.