Advantages and disadvantages of hot runner mold

advantage

Shorten cycle

The forming cycle of the parts is shortened. Since there is no limitation of the cooling time of the runner system, the parts can be ejected in time after being formed and solidified. Many thin-walled parts produced with hot runner molds can be molded in less than 5 seconds.

Save plastic

There is no cold runner in the pure hot runner mold, so there is no production cost. This is particularly significant for applications where plastics are expensive. In fact, the major hot runner manufacturers in the world have developed rapidly in the era when oil and plastic raw materials are expensive in the world. Because hot runner technology is an effective way to reduce cost and material cost.

Reduce scrap

Reduce waste products and improve product quality. In the hot runner mold forming process, the plastic melt temperature is accurately controlled in the runner system. Plastic can flow into the mold cavities in a more uniform state, and the result is parts of consistent quality. The gate of the hot runner molded parts is of good quality, the residual stress after demolding is low, and the deformation of the parts is small. Therefore, many high-quality products on the market are produced by hot runner molds. For example, many plastic parts in MOTOROLA mobile phones, HP printers, and DELL laptops are made with hot runner molds.

Production automation

Eliminating subsequent processes is conducive to production automation. The product is finished after being formed by hot runner mold, without trimming gate and recycling cold runner. Conducive to production automation. Many foreign product manufacturers have combined hot runners with automation to greatly improve production efficiency.　Many advanced plastic molding processes are developed on the basis of hot runner technology. Such as PET preform production, multi-color co-injection in the mold, co-injection process of multiple materials, STACK MOLD, etc.

Disadvantages

Rising costs

Hot runner components are relatively expensive, and the cost of hot runner molds may increase significantly. If the output of parts is small, the cost of mold tools is high, which is not cost-effective. For mold users in many developing countries, the expensive hot runner system is one of the main problems affecting the widespread use of hot runner molds.

High equipment requirements

The production process equipment has high requirements, and the hot runner mold needs precision machining machinery to ensure. The requirements for the integration and cooperation of the hot runner system and the mold are extremely strict, otherwise many serious problems will occur in the mold during the production process. For example, poor plastic sealing causes the plastic to overflow and damage the hot runner element, interrupting production, and the relative position of the nozzle insert and the gate causes a serious decline in product quality.

Complex operation and maintenance

Compared with cold runner mold, hot runner mold operation and maintenance are complicated. If used improperly, the hot runner parts are easily damaged, making production impossible and causing huge economic losses. For new users of hot runner molds, it takes a long time to accumulate experience.