1.Shorten cycle time
The molding cycle is shortened. Because there is no restriction on the cooling time of the sprue system, the parts can be ejected in time after curing. Many thin-walled parts produced with hot runner molds have a molding cycle of less than 5 seconds.
2.Save plastic material
For full hot runner mold, there is no cold runner, so there isn’t waste. This is especially significant for applications where plastics are expensive. In fact, the major hot runner manufacturers in the world have experienced rapid development in the world when oil and plastic materials are expensive. Because hot runner technology is an effective way to reduce the waste of material and reduce material costs.
3.Reduce the defective product
Reduce the defective product and improve product quality. During the hot runner mold forming process, the plastic melt temperature is accurately controlled in the runner system. Plastics can flow into the cavities in a more uniform state, resulting in consistent quality parts. The hot runner molding parts have good gate quality, low residual stress after demolding, and small deformation of parts.
Eliminating subsequent processes contributes to production automation. After the part formed by the hot runner mold, it is the finished product and there is no need to trim the gate and recycle the processed cold runner, which is conducive to production automation. Many international manufacturers have combined hot runners with automation to significantly increase production efficiency. Many advanced plastic molding processes have been developed based on hot runner technology. Such as PET preforming, multi-color co-injection in the mold, a variety of materials co-injection process, STACK MOLD.
Although hot runner molds have many significant advantages over cold runner molds, mold users also need to understand the shortcomings of hot runner molds. To sum up, there are the following points.
Hot runner components are more expensive, and hot runner mold costs can increase significantly. If the production of parts is small, the cost of mold tools is high and uneconomical. For mold users in many developing countries, the high cost of hot runner systems is one of the main problems affecting the widespread use of hot runner molds.
2.High equipment requirements
Requirement for the production process equipment is high, the hot runner mold requires precision processing machinery as a guarantee. The integration and cooperation requirements of the hot runner system and the mold are extremely strict, otherwise the mold will have many serious problems in the production process. If the plastic seal is not good, the plastic melt overflows and damages the hot runner components, and the relative position of the nozzle insert and the gate is not good, resulting in serious deterioration of the product quality.
3.Operation and maintenance complexity
Hot runner mold operation and maintenance is complicated compared to cold runner molds. If the operation is improper, it will easily damage the hot runner parts, impossible to produce, resulting in big economic losses. For new users of hot runner molds, it takes a long time to accumulate experience.