Key points of mould design and manufacture
In the process of making the bottle cap mold, the plastic parts will be coated on the punch due to the shrinkage effect, so from the point of view of the plastic parts demoulding, it should be conducive to the plastic parts stay in the side of the moving mold, in order to demoulding. And does not affect the amount of plastic parts and shape appearance, as well as dimensional accuracy. The gating system is generally composed of four parts: main channel, shunt channel, gate and cold feed hole. Because plastic cap has plasticity strong, density is small, specific strength is high, bond sex, chemical stability is high, exterior diversity characteristic, get more and more manufacturers and people to like consequently. The demand of plastic bottle cap molding parts is increasing, the quality requirement is also higher and higher, which requires the development of the mold of plastic parts, the level of design and manufacturing must be higher and higher.
The design of gating system should ensure the smooth flow of plastic melt, the flow should be as short as possible, prevent core deformation, repair should be convenient, prevent product deformation and warping, should be suitable with plastic material varieties, cold material hole design reasonable, reduce the consumption of plastic as far as possible. The section thickness of plastic parts is small, it is not suitable to use push rod to push out, but using push plate to push out is more appropriate. Therefore, it is not suitable to open cold feed hole, so pull feed rod adopts the form of ball buckle. It does not affect the appearance quality of plastic parts in the bottle cap mold design. According to the parting surface mentioned above, circular cross section should be used in the diverter path, and gate cover should be used on the fixed mold plate.
A mold with four cavities is preliminarily determined to be arranged symmetrically for the small-sized bottle cap molds produced in large quantities, considering various factors such as productivity and production cost, as well as the model selection of the injection machine. The side gate is determined by the dimensions of the plastic parts and the factors of machining. It is also known as the edge gate, under normal circumstances, the side gate opened in the mold parting surface, from the product side edge feed, it can easily adjust the form of the gate, the cross section shape is usually rectangular.