92 Energy-Saving Measures for Injection Molding Machines (Recommended to Save)

Injection molding industry is a major energy consumer. Injection molding machine power, electric heating, raw material drying, and mold temperature controllers are all high-power users. Add to that hot runners, robotic arms, air compressors, chillers, pulverizers… electricity is used everywhere as long as production is running.
Statistics show that electricity costs account for 20% of the total cost in injection molding industry (industry average), yet average gross profit margian is only 18%. This demonstrates just how alarming energy consumption of injection molding is. Therefore, cost reduction and efficiency improvement cannot avoid topic of energy saving in injection molding, because every kilowatt-hour of electricity saved is profit.
Today we'll discuss energy conservation in injection molding. Below, we'll introduce 92 common mistakes to avoid in injection molding energy saving.

I. Barrel Section

Phenomenon Description	Underlying Logic	Improvement Techniques
Using factory default temperature control parameters, after changing materials or replacing heating coil, heating coil experiences temperature overshoot due to thermal inertia, repeatedly starting and stopping heating.	A mismatch between PID parameters and current operating conditions causes temperature control overshoot fluctuations, resulting in heating coil being repeatedly powered on ineffectively, increasing energy loss.	After changing materials or heating coil, immediately run barrel temperature PID self-tuning to calibrate power-off advance and eliminate thermal overshoot.
Ordinary heating coils are directly exposed, and a large amount of heat is dissipated into air through radiation. In summer, this also increases the ambient temperature in workshop, increasing cooling load.	Exposed heating coils suffer from significant heat radiation loss; approximately half of heat is not used to heat plastic but is dissipated into environment, constituting ineffective heat loss.	Replacing with a high-density ceramic fiber insulation cover, tightly wrapping outer wall of barrel, reduces radiative heat loss and allows heat to be concentrated and conducted to plastic.
Simply insulating barrel leaves nozzle in direct contact with cold mold sprue, with heat continuously carried away by mold cooling water.	Nozzle is in direct contact with low-temperature mold, forming a continuous heat conduction path. A large amount of heat is drawn away by mold cooling water, requiring continuous reheating of heating coil.	A custom-designed high-temperature resistant insulating sleeve for nozzle blocks heat transfer chain from nozzle to mold sprue.
Traditional resistance wire heating coils use conduction heating, leading to slow heating rates, high heat loss, and long preheating times.	Traditional resistance wire heating relies on contact conduction, resulting in low electrothermal conversion efficiency, high thermal inertia, and significant wasted power during preheating.	Replacing nozzle with a microchannel far-infrared nano heating coil improves electrothermal conversion efficiency, shortens heating time, and reduces preheating costs.
Improper adjustment of drying drum's exhaust fan damper can cause hot air to be directly exhausted if damper is too large, or insufficient drying if the damper is too small.	An excessively large damper results in a large amount of hot air being exhausted before sufficient heat exchange, leading to wasted heat; an excessively small damper results in insufficient hot air circulation, causing heating element to operate continuously.	Precisely adjust the exhaust fan damper based on actual hourly material consumption to create a slightly positive pressure cyclone circulation within drum.
Waste hot air discharged from drying process reaches temperatures of 60℃~80℃; direct discharge into workshop results in complete heat waste.	Exhaust air carries a significant amount of waste heat; direct discharge results in heat loss, and heating elements need to heat fresh air across its entire temperature range, leading to high energy consumption.	Adding a filter recovery pipe to exhaust vent recovers waste hot air to fan inlet, requiring heating elements only to replenish heat due to temperature difference.
After drying, hot material cools naturally upon landing, resulting in a low initial temperature when it re-enters barrel, causing screw to consume more mechanical energy during plasticizing.	The lower initial enthalpy of material, the more heat needs to be absorbed during plasticizing, leading to higher energy consumption for screw shearing and electric heating.	Feeding dried hot material directly into barrel retains its initial heat, reducing energy consumption during plasticizing stage.
During discharge, retract injection station and continuously spray air through nozzle, allowing significant heat to dissipate through air convection.	Direct convection heat exchange between high-temperature nozzle and cold air rapidly removes heat from front of barrel, causing frequent reheating of heating coils.	During discharge, keep nozzle as close to protective cover as possible and use short, inching discharge to minimize heat loss via convection.
Severe scaling in cooling water jacket at feed inlet reduces heat transfer efficiency, causing heat to backflow from one section of barrel to feed inlet, requiring continuous reheating by heating coil.	Scale has extremely low thermal conductivity, which can block heat exchange in cooling water jacket, leading to abnormal heat loss in low-temperature section of barrel. Heating coil requires increased power compensation.	Regularly clean cooling water jacket channels at feed inlet with a weak acid to remove scale and restore normal heat exchange capacity.
When producing flame-retardant, fiberglass, and other engineering materials, downstream process delays can cause machine to wait at high temperatures for more than 15 minutes, leading to material degradation within barrel.	Continuously energizing heating coil during high-temperature waiting periods prevents material from being produced as a finished product and may even cause degradation and carbonization. This necessitates additional discharge and cleaning, resulting in a double waste of energy and material.	When producing flame-retardant and heat-sensitive materials, barrel temperature must be lowered if machine is stopped for more than 15 minutes while waiting for materials.
Older machines using cast iron or cast aluminum heating coils suffer from high weight and thermal inertia, resulting in delayed temperature control response and repeated heating.	Heavy metal heating coils have a large thermal mass, causing significant delays in both heating and cooling, poor temperature control accuracy, and prolonged periods of ineffective heating.	Replacing them with lightweight stainless steel or mica heating coils reduces thermal mass and improves heat transfer sensitivity and response speed.
When starting machine cold, all heating sections are energized simultaneously, easily leading to overheating and drooling in the front sections while rear sections remain unmelted, resulting in prolonged periods of ineffective heating.	Different sections of barrel have different melting requirements; simultaneous heating leads to overheating in the front sections and insufficient heating in the rear sections, resulting in low overall heating efficiency.	When starting machine cold, first activate rear sections and nozzle heating, then activate front sections after 10 minutes to match material melting sequence.
Loose thermocouple probes or those with accumulated carbonized oil can produce low temperature signals, causing system to misjudge insufficient temperature and continue heating.	Temperature measurement deviations can cause temperature control system to output incorrect heating signals, causing barrel to overheat and heating coils to become ineffectively energized.	Monthly tightening of thermocouple screws and cleaning of oil stains at temperature measuring points ensures accurate temperature readings.
Direct connection between feed seat cooling water and mold's chilled water, with valve fully open, results in an excessively low temperature at feed cylinder inlet, drawing away a significant amount of heat from cylinder.	An excessively cold feed inlet creates a strong heat conduction path, continuously carrying away heat from first and second stages of material, forcing heating coil to increase its power to compensate for heat loss.	An independent valve should be installed for feed seat cooling water, with a slight opening to maintain feed inlet temperature between 45℃ and 50℃.
Exposed metal outer wall of drying hopper continuously dissipates heat into workshop environment, acting like an outdoor radiator.	Metal barrel exhibits strong heat radiation and convection, leading to substantial heat loss from within barrel, requiring frequent start-ups of heating elements to maintain temperature.	Wrapping outer wall of drying hopper with aluminum silicate ceramic fiber insulation reduces environmental heat loss and decreases frequency of heating element start-ups and shutdowns.
When drying barrel encounters cold material blockage, forcibly increasing upper limit of heating coil temperature forcing it to operate beyond its rated capacity will cause heating coil to operate under overload.	Overheating not only results in low heating efficiency but also accelerates aging and burnout of heating coil, making it a high-energy-consuming and inefficient operation.	When cleaning drying barrel, use a special cleaning agent or manually rotate screw to avoid overheating.
After prolonged use, internal oxidation of heating coil increases its resistance, reducing its heating efficiency and leading to a situation where it consumes power but does not generate heat.	Oxidation of heating coil increases its resistance, reducing its effective heating power, and significantly extending energizing time to reach set temperature.	Regularly use a multimeter to check resistance of each heating coil group; replace any heating coil with a heating efficiency below 85% of rated value immediately.
Continuing to run heating in drying barrel until shutdown before end of workday or mold change results in overheating of remaining material inside, wasting heat.	If there is little remaining material before shutdown, continuous operation of heating element will cause excess heat, which is not effectively utilized.	Turn off drying drum heating element 20 minutes before leaving get off work or changing mold, leaving only fan on to use residual heat to dry remaining material.

II. Hydraulic System Section

Phenomenon Description	Underlying Logic	Improvement Techniques
When hydraulic oil temperature deviates from reasonable range, too low a temperature results in viscous oil with high flow resistance, while too high a temperature results in thinner oil with internal leakage in pump.	40℃~48℃ is golden range for hydraulic oil kinematic viscosity; too low an oil temperature results in high flow resistance, while too high an oil temperature leads to high internal leakage, both increasing power consumption compensation of servo motor.	Stabilize hydraulic oil temperature within 40℃~48℃ range to balance flow resistance and internal leakage losses.
For thin-walled, short-stroke products with multiple injection speeds, screw completes injection before proportional valve spool is fully open.	Frequent switching of injection speed during short strokes causes high-frequency oscillation of proportional valve spool, generating a large amount of hydraulic pressure heat, resulting in ineffective energy loss.	Short-stroke injections should combine injection speed segments as much as possible; if two segments can complete injection, avoid using more.
If mold opening and closing speed is set too abruptly, a sudden stop after a high-speed sprint will cause braking resistor in electrical box to overheat continuously.	Reverse regenerative electrical energy generated during motor emergency braking is converted into heat dissipation through braking resistor, constituting ineffective energy loss.	Adjust deceleration slope of smooth servo drive to allow motor to coast using inertia, reducing energy loss from braking resistor.
If material storage back pressure is set too high, return oil resistance of hydraulic cylinder is high, and torque power consumption of plasticizing motor increases non-linearly.	For every 1MPa increase in back pressure, return oil resistance of hydraulic cylinder increases accordingly. Plasticizing servo motor needs to output more torque to overcome this resistance, significantly increasing power consumption.	While ensuring that product's venting and color mixing are up to standard, reduce back pressure to minimum critical value.
Continue to apply high pressure at dead point when machine hinge is fully extended during mold closing, and oil pump will continuously output high-pressure flow.	Continuing high-pressure output after machine hinge has passed dead point is an ineffective hard-press, causing high-pressure oil overflow and overheating, wasting oil pump's output power.	Precisely control high-pressure switching position of mold closing mechanism to 1mm~3mm before dead point. Immediately engage mold locking mechanism after high-pressure mold closes past dead point.
Hydraulic oil containing micro-carbon particles causes back pressure valve core to stick, narrowing return oil channel and abnormally increasing material storage resistance.	Incomplete valve core sticking and return reduces cross-sectional area of return oil channel. During material storage, screw must overcome additional oil resistance to retract, increasing servo motor power consumption by approximately 15%.	Regularly clean proportional back pressure valve in return oil circuit to remove impurities from valve core and ensure unobstructed return oil flow.
If there is no release action after material storage, high-pressure internal stress remains at the front end of barrel and in oil circuit, causing oil pump to continuously bear pressure.	Residual high pressure cannot be released, will continue to accumulate in injection valve and oil circuit, requiring oil pump to maintain static pressure output, increasing ineffective power consumption.	After material storage, set a slight release of 2mm~5mm to physically relieve residual stress through negative pressure.
Injection unit misalignment causes nozzle to contact sprue bushing on only one side, necessitating an increase in injection pressure to prevent leakage.	Misalignment of injection unit leads to uneven loading of nozzle, requiring a significant increase in injection pressure to ensure a seal, resulting in continuous high-pressure output from injection unit cylinder.	Fine-tune guide rail support screws and use a dial indicator to control coaxiality of injection table within 0.05mm to reduce seating pressure.
Clogged hydraulic oil filters reduce flow area in oil passage, requiring main pump to increase pressure to overcome filter resistance.	Clogged filter elements create hidden flow resistance, requiring system to increase pump pressure to maintain rated flow, thus increasing motor output power.	Replacing high-rigidity hydraulic oil filters periodically eliminates flow resistance losses caused by filter clogging.
Using a large-tonnage injection molding machine to produce small products results in a situation of "using a large horse to pull a small cart."	Rotational inertia, cylinder dead zone, and weight of moving mold plate of large injection molding machines generate significant amounts of reactive power, resulting in energy consumption far exceeding that of suitable machines.	Matching degree between machine tonnage and product requirements should be controlled within range of 40% to 75% to avoid tonnage mismatch.
When producing ordinary products on high-speed machines with accumulators, maintain maximum charging pressure.	Excessive accumulator pressure forces the oil pump to fill at full load each time, resulting in high peak motor loads. Such high accumulator pressure is unnecessary for normal production.	While maintaining production cycles, lower accumulator's maximum charging pressure by 2-3 MPa to reduce peak motor load.
After core-pulling neutron is in position, solenoid valve remains energized, and oil pump continuously supplies high-pressure oil to neutron cylinder.	After neutron is in position, continuous high-pressure oil supply is unnecessary. Continuous high pressure will cause oil overflow and heat generation, wasting oil pump power.	Set a pressure-free holding period after neutron is in position to shorten high-pressure oil supply time and reduce ineffective pressure buildup.
Insufficient automatic lubrication pump oil supply intervals lead to a large accumulation of sludge at machine hinge, increasing resistance of mold opening and closing.	Excessive lubrication creates sludge resistance, increasing frictional power consumption during mold opening and closing, and wasting lubricating oil.	According to equipment manual, appropriately lengthen lubrication interval based on number of mold openings to ensure adequate lubrication.
Weared or dry-running wear-resistant blocks on moving mold plate support slider significantly increases frictional resistance during mold opening and closing.	Dry or worn guide rails generate significant sliding friction, consuming nearly a quarter of the servo motor's torque to overcome this friction.	Regularly inspect wear-resistant blocks to maintain guide rail lubrication and a smooth surface, reducing frictional power consumption during mold opening and closing.
When producing ordinary molds, auxiliary hydraulic circuits such as threaded rods and oil pans remain in standby mode.	Idle auxiliary hydraulic circuits will generate ineffective micro-turbulence and leakage within valve body, resulting in hydraulic energy loss.	When producing molds without special functional requirements, completely disable auxiliary hydraulic circuits and disconnect corresponding solenoid valve plugs.
After oil changes or maintenance, air bubbles accumulate in hydraulic circuit, causing cavitation under high pressure, resulting in insufficient pump output and motor idle.	Air bubbles in hydraulic circuit can be compressed, disrupting rigid transmission of hydraulic oil, leading to decreased pump volumetric efficiency and wasted motor work.	After changing oil and cleaning valve plate, opening main pump's vent valve allows air to be purged, restoring rigidity of hydraulic oil transmission.
Inappropriate speed settings in low-pressure section of mold closing cause pump to frequently adjust its output during final bonding stage, increasing energy consumption.	Moving platen has inertia; proper utilization can reduce pump's power output during bonding stage.	Smoothly reducing speed in low-pressure section of mold closing allows moving platen's forward impulse to enable natural mold bonding.
Multi-way valve core spring fatigue prevents it from returning to center position after power failure, leaving hydraulic circuit in a state of slight depressurization.	Partially open or closed valve cores cause continuous micro-leakage; frictional heat at gaps forces servo motor to operate at low frequency to maintain system pressure.	Regularly check reset status of solenoid directional valve spool, replace fatigued springs, and ensure that spool returns to its physical center position.

III. Process Parameters Section

Phenomenon Description	Underlying Logic	Improvement Techniques
Blindly using high temperature and high injection pressure to fill cavity, with unreasonable injection speed settings, results in poor melt flowability.	Polymer melts are non-linear fluids. Within a certain range, the faster injection speed, the stronger shearing effect, the lower apparent viscosity, and the less effort required for filling.	Find critical injection speed at which material shear thins through process debugging, and replace high-temperature, high-pressure filling with a reasonable injection speed.
Switching to holding pressure only after the screw has reached the bottom results in continuous high-pressure injection after cavity is full, producing flash and wasting energy.	Continuing high-pressure injection after cavity is full prevents effective pressure transmission, only causing overflow and high-pressure stagnation, unnecessarily increasing injection power consumption.	Accurately switch to holding pressure at the moment cavity is 95%~98% full using pressure-stroke curve.
Setting holding pressure time too long results in screw continuing to apply pressure after gate freezes, preventing pressure from being transmitted to cavity.	After gate solidifies and hardens, holding pressure cannot be replenished into cavity, making subsequent holding pressure ineffective and continuously consuming oil pump power.	Critical time for gate freezing was determined through weighing tests, and holding time was shortened to this critical point.
When clamping force is at its maximum, mold plate undergoes micro-bending, venting channels are blocked, and injection resistance increases.	Excessive clamping force causes mold plate deformation, closing venting channels and preventing gas from escaping from cavity, creating air resistance and forcing an increase in injection pressure.	Clamping force is reduced to a critical value that does not produce flash, ensuring unobstructed mold venting and reducing injection resistance.
If screw speed is set too high, solid bed is pushed before it is fully melted, and motor forcibly crushes material using mechanical torque.	At excessively high speeds, heat conduction in compression section is insufficient, and melting relies on motor's mechanical shearing work, resulting in a significant increase in power consumption.	Feeding speed is optimized based on screw's length-to-diameter ratio, and maximum speed is avoided for ordinary PP and ABS materials.
Initial high pressure is maintained throughout holding pressure process, and high pressure continues to be output even after product has cooled and hardened.	After mold cavity is filled, product gradually cools and shrinks, creating internal reverse pressure. Continuous high-pressure output is ineffective.	A multi-stage holding pressure mode with progressively decreasing pressure (high, medium, low) is employed to match pressure requirements of product during cooling.
If cooling time is set too long, exceeding product's curing requirements, production cycle will be extended, and molten adhesive in barrel will require repeated reheating.	Excessive cooling time will lengthen production cycle. Molten adhesive inside barrel cools down via thermal convection, requiring repeated reheating of heating coil.	Cooling time should be shortened as much as possible while ensuring product does not whiten or deform.
If residual material amount is set too high, screw needs to overcome compression resistance of a large amount of dead material during injection; if residual material is too low, holding pressure will fail.	Excessive residual material will create additional compression resistance, consuming injection power; insufficient residual material will fail to guarantee holding pressure effect.	Residual material amount should be controlled between 3mm and 6mm (approximately 10% of screw diameter) to balance buffering effect and compression resistance.
Clogged venting channels with tar prevents gas from escaping, creating reverse air resistance.	Poor venting can create an "air spring" in mold cavity, requiring additional pressure to compress gas during injection, thus forcing an increase in injection pressure.	Regularly clean mold venting channels with a copper brush to ensure unobstructed venting and reduce injection resistance.
Retracting injection unit after each mold cycle, frequently pulling heavy unit back and forth, consumes a large amount of electrical energy.	Injection unit is heavy, and its reciprocating motion requires a significant amount of mechanical work from servo motor, representing an inefficient and optimizable movement.	When cleaning nozzle and cold slurry after each mold cycle is unnecessary, set injection unit to remain in a forward position without retraction.
In a long-stroke, multiple-ejection cycle, ejector pin and cylinder perform a large amount of unproductive motion.	Long-stroke, multiple ejection cycles increase reciprocating work of hydraulic cylinder, while demolding only requires vibration during critical stroke.	High-frequency, micro-amplitude vibration ejection, with half-stroke inching, allows product to return to its original position as soon as it falls.
Full retraction during mold opening results in violent hydraulic impact and significant pressure loss.	Exceeding required ejection stroke not only increases work done, but also generates hydraulic shock during cylinder ejection, dissipating energy as heat.	Controlling mold opening stop position precisely at critical point for ejection ensures smooth braking and avoids cylinder ejection.
Uneven recycled material particle size leads to secondary moisture absorption, resulting in significantly higher frictional energy consumption during plasticizing compared to virgin material.	Unevenly sized recycled material exhibits inconsistent shear friction during plasticizing, requiring higher motor torque for melting and increasing power consumption.	Ensuring uniform recycled material particle size is achieved by using a closed-pipe hot-feeding method to reduce frictional energy consumption during plasticizing.
However, for thick-walled products with long cooling times, material loading speed remains high, leading to prolonged motor standby after loading.	High-speed material loading causes motor to operate at high load for short periods, but sufficient cooling time allows for smoother, low-speed loading, reducing peak motor power consumption.	For thick-walled products, material loading speed can be reduced to 30%–40% during cooling time window, resulting in smoother power output.
In multi-color injection machines, gaps exist in connection between two injection systems, causing oil pump to consume power while maintaining static pressure during waiting period.	During these gaps, system needs to maintain pressure; the longer waiting time, the more power is wasted due to ineffective static pressure.	Optimizing programmable controller's timing sequence allows for seamless engagement of multiple injection systems, eliminating waiting gaps.
Using low MFI materials requires higher injection pressure and greater filling resistance.	A higher melt flow index (MFI) results in lower apparent viscosity and lower injection pressure, reducing energy consumption at source.	High MFI plastic grades should be prioritized while meeting product performance requirements.
Carbonized coking accumulates on both sides of screw check ring, increasing resistance to melt flow and raising plasticization power consumption.	Coking reduces cross-sectional area of melt channel, increasing flow resistance during plasticization, requiring screw to exert greater thrust to store material.	Regularly remove screw and clean carbonized coke at check ring to keep melt channel clear.
Directly cutting off power during shutdown causes material carbonization in barrel, requiring high-temperature drying and cleaning upon restarting, resulting in high energy consumption.	Chemicalized material is difficult to clean, requiring prolonged high-temperature decoking upon restarting, consuming significant amounts of electricity.	Before shutdown, empty barrel with high-flow-rate PP or washing material, and rapidly cool it to 140℃ to prevent material carbonization.
Prolonged mold changeover operations involve continuous full-power barrel heating and chiller idling, leading to significant wasted energy.	During mold changeover standby, equipment has no output, yet heating and cooling systems continue to run at full load, resulting in wasted energy.	Implement SMED standard mold change operations, switching barrel to 150℃ heat preservation mode during mold change to reduce dry-cooking time.

IV. Cooling Section

Phenomenon Description	Underlying Logic	Improvement Techniques
When product shrinkage occurs, blindly lowering chiller temperature significantly increases the compressor load.	For every 1℃ decrease in chiller temperature, compressor's COP (Coefficient of Performance) drops significantly; most shrinkage issues stem from blocked water circuits, not insufficient water temperature.	When molding problems occur, prioritize checking water flow rate and blockages; avoid blindly lowering chiller's set temperature.
Old molds use series water circuits, resulting in long flow paths, large temperature differences between front and rear sections, and poor cooling in latter half.	Series water circuits have long flow paths, with water temperature gradually increasing along path. The latter half has extremely low heat exchange efficiency, resulting in poor overall cooling and forcing chiller to operate at continuous high load.	Converting series water circuits to parallel water circuits with multiple inlets and outlets shortens single-path flow and improves overall heat exchange efficiency.
Small-diameter cooling water pipes with numerous bends result in high water resistance, causing the water pump to operate at full load and leading to poor heat exchange in a laminar flow environment.	Small pipe diameters and right-angle bends significantly increase water resistance, and laminar flow has low heat exchange efficiency; turbulent flow has approximately 30% higher heat exchange efficiency than laminar flow.	Replacing with larger-diameter, more curved cooling water pipes promotes turbulent flow and improves heat exchange efficiency.
Scale buildup in mold's water system reduces thermal conductivity, worsening cooling and forcing a reduction in chiller temperature compensation.	Scale has extremely low thermal conductivity, hindering heat transfer between steel and cooling water. At the same water temperature, cooling efficiency drops significantly, forcing chiller to operate at high load.	Regularly cleaning mold's water system with an acid pickling pump to restore steel's natural thermal conductivity.
When producing high-temperature engineering materials, mold temperature controller's electric heating and cooling water frequently conflict.	Plastic injection into mold cavity introduces a significant amount of physical heat, which can be used to maintain mold temperature; however, conflict between heating and cooling results in a waste of energy.	Fully utilize physical heat introduced during injection molding; once mold temperature reaches set value, switch to intermittent micro-cooling to maintain temperature.
Sharing a single water circuit with moving and fixed molds at the same temperature cannot accommodate their different cooling needs.	Fixed mold's outer surface requires a higher water temperature to ensure quality, while moving mold's rib surfaces require a lower water temperature for rapid curing. Using same water temperature for both molds leads to cross-heating.	Separate temperature control for moving and fixed molds, matching their respective temperature requirements, avoids unnecessary heat loss.
In summer, condensation on chilled water pipes and water distribution blocks results in significant cold loss into workshop environment.	Condensation on pipe surfaces indicates heat exchange between cold and environment; ineffective cold loss increases chiller's cooling load.	Wrapping water distribution blocks and cooling water pipes with rubber and plastic insulation locks in cold energy and reduces environmental loss.
Small opening of cooling water valve leads to a large temperature difference between inlet and outlet water, causing localized overheating of mold and poor cooling effect.	At low flow rates, water circuit tends to be laminar, resulting in low heat exchange efficiency and a large temperature difference between inlet and outlet water. High flow rates and turbulent flow provide higher heat exchange efficiency and more uniform cooling.	Fully opening cooling water valves and controlling inlet and outlet water temperature difference to 2℃~3℃ enables high flow rate operation with a small temperature difference.
Algae and scale buildup in the cooling tower packing, along with dirty fan blades, reduces heat dissipation efficiency, forcing fan to operate at full load.	Clogged packing reduces contact area between water and air, decreasing heat exchange efficiency and requiring fan to operate at higher speeds to achieve effective cooling.	Regular cleaning of cooling tower packing, algae, and fan blades is necessary to ensure basic heat dissipation efficiency.
Hot runner plate directly contacts mold plate, continuously transferring heat to mold's cooling water system.	Direct metal-to-metal contact creates a strong heat conduction path, resulting in significant heat loss from hot runner system, requiring continuous heating for compensation and increasing chiller load.	Installing high-rigidity ceramic insulation sheets at hot runner support blocks blocks heat conduction to mold.
Cooling tower fans run at full speed year-round, even at night or during winter when temperatures are low.	When ambient temperature is low, natural heat dissipation is strong, and fan does not need to run at full speed; running at full speed is an ineffective energy waste.	Adding frequency converters and temperature probes to cooling tower fans allows for automatic adjustment of fan speed based on water temperature.
Open-air, uninsulated underground cold water tanks are greatly affected by ambient temperature, with water temperature rising rapidly in summer.	Open-air water tanks exchange heat directly with environment, resulting in significant heat loss, requiring chiller to run continuously to maintain water temperature.	Replacing with sealed, insulated plastic or stainless steel water tanks reduces heat exchange with environment.
Direct discharge of high-temperature return water from mold temperature controller completely wastes 90℃-120℃ of waste heat.	High-temperature return water carries a large amount of heat energy; direct discharge results in energy loss. It can be recovered for other low-temperature heating applications.	Installing plate heat exchangers recovers waste heat from mold temperature controller's return water for preheating tap water or auxiliary heating of drying drum.
Refrigerant leakage in chiller will cause compressor to operate under overload, leading to decreased cooling efficiency and increased current.	Insufficient refrigerant will cause a decrease in compressor cooling capacity. To reach set temperature, compressor will operate under continuous high load, resulting in a sharp drop in energy efficiency.	Regularly check high and low pressure of chiller's refrigerant annually, and replenish it promptly when insufficient to restore compressor's rated energy efficiency.
When the mold is directly attached to cast iron platen of injection molding machine, a large amount of cold or heat is conducted to machine body.	Direct metal contact will create continuous heat conduction, causing cold/heat loss from mold to machine base, increasing load on cooling/heating system.	Installing a 5mm thick high-rigidity insulation plate between mold base plate and machine base platen will block interfacial heat conduction.
Keeping manifold far from mold results in long connecting pipes, leading to greater friction loss and heat loss.	The longer piping, the greater friction loss and heat exchange with environment, resulting in higher pump power consumption and greater cooling loss.	Fix manifold directly to side of moving and stationary mold plates, and connect mold with shortest rigid pipe to reduce piping losses.
Internal leakage in valves of chilled water system and cooling tower water circuits causes low-temperature chilled water to flow directly into cooling tower and be lost.	Internal leakage in valves leads to direct discharge of low-temperature chilled water, resulting in complete waste of cooling capacity, and chiller continuously produces ice but cannot maintain water temperature.	Regularly check tightness of cross valves to prevent cross-leakage between chilled water system and cooling tower.
Cooling water pumps are old-style asynchronous motors that operate at full load year-round and cannot adjust flow rate as needed.	Asynchronous motor water pumps cannot adjust their output according to number of pumps in operation, resulting in extremely low energy efficiency at low loads and significant energy waste.	Replace with permanent magnet synchronous variable frequency water pumps to dynamically adjust flow rate and pressure according to actual number of pumps in operation.

V. Electrical and Auxiliary Equipment Section

Phenomenon Description	Underlying Logic	Improvement Techniques
Older models electrical cabinet cooling fan runs 24 hours a day, even at full speed when cabinet temperature is low.	When temperature is low, forced cooling is unnecessary; fan continuously running idle is a waste of power.	Adding a temperature control switch, fan automatically starts when cabinet temperature exceeds 45℃ and automatically stops when temperature drops.
High levels of oil mist in workshop, driver motherboards and heat sinks are covered in oil sludge, causing rapid component temperature rise and increased internal resistance.	Oil sludge hinders heat dissipation, causing component temperatures to rise. For every 10℃ increase in temperature, internal resistance of electronic components increases, leading to increased power consumption.	Regularly clean dust and oil stains from drivers with a special insulating detergent to maintain good heat dissipation.
Material suction machine or centralized feeding pump runs at full speed from start and continues to run idle when not suctioning material.	When there is no suction demand, fan runs at full speed, motor does useless work, consuming a lot of power.	Set to pulse intermittent operation mode, stopping when full or automatically switching to low-frequency idle speed.
Sprue crusher continues to run idle when no material is fed in, causing motor to operate without power.	During idle operation, blades overcome air resistance and bearing friction, still consuming considerable electrical energy.	Implement centralized timed crushing or install intelligent delayed shutdown modules, automatically suspending operation after 3 minutes without material.
Aging air pipe joints and solenoid valves leak, resulting in continuous, small leaks that are difficult to detect.	Compressed air is generated by air compressor; even small leaks accumulate to cause significant air loss, forcing air compressor to operate continuously.	Use soapy water to check for air leaks throughout workshop, promptly replacing aging seals to eliminate leaks.
Robotic arm's lifting and forward strokes are set too large, resulting in large arcs when picking up and placing products, leading to excessive wasted travel.	Excessive travel increases working distance of servo motor, consuming more electrical energy and lengthening production cycle.	Optimize robotic arm's movement trajectory, using low-altitude, smooth arcs to reduce wasted lifting and idle travel.
Low power factor in workshop leads to grid penalties and significant heat loss in lines.	Inductive loads generate reactive power. A lower power factor results in higher line current, greater heat loss, and additional grid penalties.	Regularly inspect capacitor compensation cabinets, replace faulty capacitors, and raise power factor to above 0.95.
Fully illuminating workshop ceiling lights and fully lighting unused machine areas results in significant energy waste.	Full-area lighting does not require full brightness in all areas; low brightness is sufficient for unused areas. High-level lighting has low luminous efficiency.	Replace lighting with low-level independent LED lights close to machines. These lights should illuminate when machines are in use, providing dim illumination in unused areas.
Hot air exhausted from servo motors and electrical cabinets diffuses throughout workshop, raising ambient temperature and increasing load on cooling system.	Hot air exhausted from equipment lingers in the workshop, causing an increase in ambient temperature and requiring additional energy from ventilation and cooling system.	Install heat collectors and ducted fans to directly exhaust hot air outdoors, avoiding convection within workshop.
Old-style fixed-frequency air compressors operate at full load year-round, leading to high no-load energy consumption during air consumption fluctuations.	Fixed-frequency air compressors cannot adjust their output, resulting in extremely low energy efficiency due to no-load operation during low air consumption. Two-stage variable-frequency air compressors, on the other hand, can adjust their output as needed, offering higher energy efficiency.	Replacing with a two-stage variable-frequency air compressor allows for automatic adjustment of motor speed based on actual air consumption in workshop.
Employees use high-pressure air guns to blow clothes and remove particles from ground, resulting in significant waste of compressed air.	Compressed air has high energy costs; open purging consumes a large amount of air in a short time, resulting in high electricity bills.	Equip machine with vacuum cleaners and cleaning tools; strictly prohibit use of compressed air to clean people, floors, and materials.
Mechanical vibration causes loose terminals, increasing contact resistance, causing terminals to overheat, and increasing energy loss.	Poor contact significantly increases contact resistance, generating a large amount of heat when current flows, causing ineffective heat dissipation of electrical energy.	Tighten all AC contactor and terminal wiring screws quarterly to ensure good contact.
Old-style relay mixing machines have high starting current, no timing function, and frequently run idle.	Old-style mixing machines have crude control, high starting inrush current, no automatic shutdown function, long idling time, and high wasted power.	Replace with a lightweight drum mixing machine with microcomputer control, allowing precise setting of mixing time and automatic power-off at designated time.
Using right-angle bends in central feeding pipeline obstructs particle impact and increases vacuum pump load.	Right-angle bends create significant local resistance, causing particle impact and deceleration during conveying, requiring vacuum pump to have higher power to maintain delivery.	Replace all with smooth, large-radius bends to reduce conveying resistance and lighten load on vacuum pump.
Plastic dust clogs vacuum pump filter, hindering air intake, causing high-load operation and increased current.	Filter clogging dramatically increases vacuum pump resistance, resulting in a "stuck" high-load state and significantly increased motor power consumption.	Adding a high-efficiency cyclone dust collector to the front end of vacuum pump pre-separates dust and keeps filter clear.
Continuous air supply from vacuum generator, coupled with suction cup continuously expelling air after gripping product, leads to significant compressed air waste.	Once gripping stabilizes, continuous air supply to maintain vacuum is unnecessary, as it results in continuous compressed air consumption.	Replacing suction cup module with an automatic pressure-maintaining module automatically shuts off air supply after establishing negative pressure during gripping.
Blackening of heating coil terminals and copper busbars due to oxidation increases contact resistance, causing localized heating and power consumption.	High resistivity of metal oxide layer creates contact resistance, generating heat when current flows, consuming electrical energy.	Regularly polishing copper busbars and terminals removes oxide layer, ensuring good conductivity.
Simply counting output without monitoring unit energy consumption makes it impossible to identify high-energy-consuming processes and machines.	Without energy consumption data for performance evaluation, process adjustments lack an energy-saving orientation, and hidden energy waste cannot be detected and corrected.	Installing smart meters to monitor unit energy consumption and establishing an evaluation mechanism will force process optimization and energy saving.
Equipment operating with defects, such as guide column misalignment, screw wear, and valve core jamming, significantly increases internal friction.	Mechanical wear and seal failure lead to significant internal leakage and frictional losses, which even process optimization cannot compensate for.	Establishing a regular preventive maintenance (PM) system will promptly repair equipment faults and maintain equipment in optimal operating condition.

Conclusion:
92 energy-saving measures listed above are technically mature and have successful industry application cases. Some are zero-cost, some require low-cost retrofitting, and some are more expensive, suitable for large and medium-sized injection molding plants and leading companies in industry. When selecting a specific solution, it's essential to consider your company's own circumstances; after all, the most suitable solution is the best.

Gud Mould Industry Co., Ltd