Impact of Mold Insulation Board Damage on Molding Energy Consumption
Mold insulation boards are installed between the mold and the injection molding machine's mounting platen; their primary function is to prevent heat from the mold from conducting into the machine frame. If these boards crack, go missing, or suffer damage due to carbonization, heat loss increases, leading to a series of issues such as higher energy consumption and reduced molding stability.
If the thermal insulation plate fails, heat from the mold is conducted directly to the metal mold clamps and tie-bar frame, accelerating the mold's overall heat dissipation. To maintain the set temperature, the mold temperature controller and heating bands must continuously supply heat to compensate for the loss; as heating units operate at full power for extended periods, the equipment's overall power consumption increases.
When processing thick-walled products or materials requiring high molding temperatures, the required mold temperature is higher; consequently, the disparity in heat loss becomes more pronounced, and the load on the temperature control equipment increases significantly.
When mold thermal insulation performance deteriorates, the overall cooling rate of the mold cavity becomes uneven, leading to excessively rapid cooling in localized areas. To prevent issues such as shrinkage, deformation, and dimensional instability, operators typically extend the cooling time; this increases the cycle time per mold, prolongs the total equipment operating time required for a given production volume, and consequently raises the electricity consumption per plastic unit produced.
Continuous fluctuations in mold temperature lead to unstable melt filling, making defects such as short shots and minor flash more likely; this requires operators to repeatedly fine-tune injection and holding parameters and frequently adjust hydraulic pressure output. The frequent ramping of servo motor power to correct pressure and flow results in additional electricity consumption compared to stable molding conditions.
Mold temperature controllers and barrel heater bands operating under high loads for extended periods experience accelerated aging of heating elements, leading to more frequent component replacements.
Increased temperature fluctuations during the mold's heating and cooling cycles intensify the thermal expansion and contraction at parting lines and inserts; this raises the likelihood of defects such as flash and deformation, driving up both material waste and labor costs associated with sorting.
The machine frame continuously absorbs heat from the mold, raising the ambient temperature of the workshop; this increases the operating load on auxiliary equipment-such as ventilation fans and air conditioning systems-thereby further increasing the facility's overall electricity consumption.
Regularly inspect the condition of the insulation boards; promptly replace any boards showing signs of cracking, thinning, ablation, or detachment to ensure complete thermal isolation between the mold and the machine's metal structure.
Select insulation boards with appropriate high-temperature and compressive strength ratings to minimize the risk of rapid failure under high-temperature and high-pressure conditions.
Check the condition of the insulation boards whenever changing molds to prevent the continued use of damaged boards during production.
If a damaged insulation board cannot be replaced immediately, the mold temperature setpoint may be slightly increased to temporarily compensate for heat loss; however, as this method raises energy consumption, it should be used only as a short-term emergency measure.
When the thermal insulation board is intact and the mold's thermal insulation conditions remain stable, the heating load on the temperature control equipment can be reduced, the molding cycle does not need to be extended, and the energy consumption per unit produced can be effectively controlled.
