Hot runner basic summary
Many conditions are considered when choosing a hot mouth, such as: different plastic characteristics, product shape, size, thickness, weight, cavity arrangement and gate location. We have several different shapes and sizes of hot mouths and runners. Board to suit a variety of products.
The hot runner is heated to ensure that the runners and gate plastic stay molten. Since the heating rod and the heating coil are arranged near the flow path or in the center, the entire flow path from the nozzle outlet of the injection molding machine to the gate is in a high temperature state, so that the plastic in the flow path is kept molten, and it is generally not necessary to open the flow path to remove the coagulation after shutdown. Material, only need to heat the flow path to the required temperature when you turn on the power. Therefore, the hot runner process is sometimes referred to as a heat manifold system, or as a runnerless molding.
Hot runner technology advantages and disadvantages
1. Save raw materials and reduce costs.
2, shorten the molding cycle, improve machine efficiency
3, to improve the surface quality and mechanical properties of products.
4, do not have to use three-plate mold that can use the point gate.
5. It is economical to form single products with side gates.
6, increase the degree of automation.
7, available needle valve gate control gate frozen.
8, multi-cavity mold injection molded parts of the same quality.
9, improve the appearance of injection molded products.
10. Less injection pressure can be used, which can effectively reduce the post-varying of thin-walled products.
However, each technology has its own shortcomings, and hot runner technology is no exception:
1, mold structure is complex, high cost, high maintenance costs.
2. It takes a period of time for the process to stabilize after starting up, causing more waste to start.
3. Melt leakage and failure of heating elements have a great impact on product quality and production schedule.
The third disadvantage of the above is that the occurrence of these disadvantages can be reduced by purchasing quality heating elements, hot runner plates, and nozzles and careful maintenance during use.