Thermal insulation of Injection mold construction

　　Heat preservation method of Injection mold construction

　　Mold temperature is the most important variable in injection molding - no matter what type of plastic is injected, it is necessary to ensure that the surface of the mold is basically moist. A hot mold surface keeps the plastic surface in a liquid state for a long time, enough to create pressure in the mold cavity. If the cavity is filled and before the frozen skin hardens, the cavity pressure can press the soft plastic onto the metal, then the replication of the cavity surface is high.

　　On the other hand, if the plastic entering the mold cavity at low pressure pauses, no matter how short the time, slight contact with the metal can cause stains, sometimes referred to as gate stains.

　　For each type of plastic and plastic component, there is a limit for the surface temperature of the mold, beyond which one or more adverse effects may occur (such as components that can overflow burrs). A higher mold temperature means less flow resistance.

　　On many injection molding machines, this naturally means faster flow through the sprue and cavity, as the injection flow control valve used does not correct this change, and faster filling can cause higher effective pressure in the sprue and cavity.

　　May cause overflow and burrs. Due to the fact that the hotter model does not freeze the plastic that enters the overflow edge area before high-pressure formation, the molten material can overflow the burrs around the ejector rod and overflow into the gap of the dividing line. This indicates the need for good injection rate control, and some modern flow control programmers can indeed achieve this.

　　Usually, an increase in mold temperature will reduce the condensation layer of plastic in the mold cavity, making it easier for molten material to flow in the mold cavity, resulting in larger part weight and better surface quality. At the same time, the increase in mold temperature will also increase the tensile strength of the parts.

　　Insulation methods for molds

　　Many molds, especially thermoplastic materials used in engineering, operate at relatively high temperatures, such as 80 degrees Celsius or 176 degrees Fahrenheit. If the mold is not insulated, the heat lost to the air and injection molding machine can easily be as much as the heat lost to the injection cylinder.

　　So it is necessary to insulate the mold with a skeleton board, and if possible, insulate the surface of the mold. If the Hot runner mold is considered, try to reduce the heat exchange between the Hot runner part and the cooled injection part. This method can reduce energy loss and preheating time.