10 points on hot runner selection
Typically, before selecting the hot runner system for paint bucket mould, we must have a full understanding for the following 10 factors to select a proper hotrunner system:
- product design. Product design is usually the first stage to be completed, and its ultimate stage is finished by the hot runner system. In order to ensure that the material in the molding process achieve better mobility, and at the end of the molding,the molded product has more smooth appearance, easy ejection, the structural design of products must include these factors;
- plastic material. Different plastic materials have different processing characters, it generally relates to the viscosity, as well as the processing temperature sensitivity. These process variables will influence the choice of hot runner systems;
- Product weight. Generally, for the different weight of products, their requirements for hot runner are completely different. But whether it is a small cap, or big truck bumper, it can be easily designed for their hot runner systems;
- Cycle. Rapid production means that the high demand for the development of nozzles required, for example, the nozzle must be precisely heat transfer, and must be durable. When the temperature of the paint bucket mould hot runner system balance is not good, it will take a big impact on the product’s shape. Generally, as to early hot runner systems, their temperature layout is often not good, but the current development of hot runner systems can provide a stable production performance, its reliability can also meet the requirements of normal production;
- 10L paint bucket mould. Generally, with optional hot runner system ,mold-related factors include: the number of cavities, material processing method, nozzle layout…;
- runner. Often, people often call hot runner mold as “non-runner” plastic mold, this statement is somewhat not correct, since the so-called “non-runner” molding does not really replace the runner. In fact, the use of hot runner system aim to avoid the waste of material, thus saving raw materials, while hot runner system eliminate the runner material,previously manual and mechanical process;
- the gate (pin point style or shut-off style). For point-gate, in order to maintain a good balance of heating in each molding cycle, the heat nozzle must have 2 funtions to melt material and cool to seal material . The shut-off gate adopts mechanical methods(moveable shut-off pins) to seal the gate;
- the temperature control. Usually, each nozzle must be controlled by a relatively complicated temperature control unit. The PID control unit is commonly used to ensure the heating is controlled preciselu . Currently, this control method has been widely used;
- Characteristic of injection molding machine. Usually, the specific requirements of the injection molding machine includes: a given sized molds installment, sufficient clamping force, the manipulated cycle time ,plasticize the enough material ,meet the requirements of strict temperature control and precise injection;
- nozzle. A variety of kinds of nozzles, according to the general size, temperature distribution, physical characteristics, the materials (copper, steel, etc.), maintenance and price.