The hydraulic system is the power core of injection blow molding equipment, undertaking all key actions such as mold clamping, injection feeding, blow molding stretching, core pulling and product demolding. Compared with ordinary plastic processing equipment, injection blow molding machines have higher requirements for hydraulic system stability, response speed and pressure control accuracy, as the molding quality of precision hollow products such as medical bottles, food packaging containers and cosmetic bottles directly depends on the stable operation of the hydraulic system. In long-term continuous production, the hydraulic system will inevitably face problems such as oil pollution, seal wear, valve body aging and pipeline corrosion. Lack of scientific maintenance will not only lead to slow equipment action, unstable pressure and reduced product qualification rate, but also cause sudden major failures, resulting in long-term production shutdown and huge economic losses.
For most injection blow molding production enterprises, the hydraulic system is often the link with the highest failure rate and the most difficult daily maintenance. Many enterprises adopt the passive maintenance mode of repairing after failure, which not only has high maintenance cost, but also seriously disrupts the production plan. In fact, more than 80% of hydraulic system failures can be effectively avoided through standardized daily maintenance and regular preventive maintenance. Establishing a complete hydraulic system maintenance system can not only extend the service life of components, reduce the probability of unplanned shutdown, but also keep the equipment in high-precision operation state for a long time, stabilize product quality and reduce the total cost of ownership of the equipment.
As a professional manufacturer focusing on the R&D and manufacturing of injection blow molding equipment, AiBiM has rich technical accumulation in hydraulic system design and maintenance. Its full series of injection blow molding machines adopt optimized hydraulic circuit design and high-quality brand hydraulic components, which have natural advantages in operation stability and maintenance convenience. Combined with years of project service experience, AiBiM has also formed a complete set of standardized hydraulic system maintenance schemes to help customers achieve long-term stable operation of equipment. This guide will systematically explain the structural composition and core functions of the hydraulic system of injection blow molding machines, sort out daily inspection items and graded preventive maintenance plans, analyze the causes and troubleshooting methods of common hydraulic faults, provide scientific hydraulic oil management and spare parts reserve strategies, conduct detailed cost-benefit analysis of maintenance investment, and clarify safety operation specifications, so as to provide comprehensive practical guidance for injection blow molding production enterprises to do a good job in hydraulic system maintenance.
1. Core Functions and Structural Composition of Hydraulic System
1.1 Position of Hydraulic System in Injection Blow Molding Process
In the whole injection blow molding process, the hydraulic system provides power support for all mechanical actions. In the injection stage, the hydraulic system drives the injection seat to move forward and backward, and pushes the screw to inject the molten plastic into the mold cavity with precise pressure and speed. In the mold clamping and locking stage, the hydraulic system provides stable and sufficient clamping force to ensure that the mold is tightly closed, and there will be no flash or mold expansion under the action of injection pressure and blow pressure. In the blow molding and stretching stage, the hydraulic system drives the stretching rod and the blow molding mechanism to complete the stretching and blowing actions according to the set speed and position. In the demolding stage, the hydraulic system drives the mold opening and the ejector mechanism to complete the product taking out action.
The stability of the hydraulic system directly determines the repeatability of the process parameters of the injection blow molding machine, and then affects the dimensional accuracy, weight consistency and appearance quality of the product. For precision hollow products used in medical and food industries, small pressure fluctuations may lead to product size out of tolerance and scrap. At the same time, the hydraulic system is also the main energy consumption part of the whole equipment, and its operating state directly affects the energy consumption level of the equipment. Good maintenance can keep the hydraulic system in efficient operation state, reduce unnecessary energy loss and reduce production costs.
1.2 Main Components of Hydraulic System
A complete injection blow molding machine hydraulic system consists of four core parts. The first is the power component, mainly the hydraulic pump, which converts the mechanical energy of the motor into the pressure energy of the hydraulic oil, providing power source for the whole system. Common types include gear pumps, vane pumps and plunger pumps. High-precision injection blow molding machines usually use variable plunger pumps with higher pressure stability and better energy-saving effect.
The second is the executive component, including hydraulic cylinders and hydraulic motors, which convert the pressure energy of hydraulic oil into mechanical energy to drive each mechanism to complete linear or rotary motion. The clamping cylinder, injection cylinder and ejector cylinder of the equipment all belong to executive components. The third is the control component, including various pressure valves, flow valves, direction valves and proportional servo valves, which are used to control and adjust the pressure, flow and flow direction of hydraulic oil to meet the action requirements of different process stages. The fourth is auxiliary components, including oil tanks, filters, coolers, accumulators, pipelines, joints and pressure gauges, which undertake the functions of oil storage, filtration, heat dissipation, energy storage and signal display. Although auxiliary components are not the core of power, they are the most common parts of hydraulic system failures. Understanding the composition of each part is the basis for formulating a targeted maintenance plan.
2. Daily Inspection and Standard Operation Specifications
2.1 Pre-Startup Inspection Before Each Shift
Standardized pre-startup inspection is the first line of defense to ensure the safe and stable operation of the hydraulic system during the shift. Operators should check item by item according to the specified process before starting the machine every shift. First, check the oil level of the hydraulic oil tank. The oil level should be between the upper and lower scale lines of the oil level gauge. If the oil level is too low, add hydraulic oil of the same brand and model in time. If the oil level rises abnormally, it is necessary to check whether cooling water penetrates into the oil to avoid emulsification of hydraulic oil. At the same time, preliminarily judge the oil quality by observing the color and transparency of the oil. If the oil is turbid and blackened, the cause shall be found out in time.
Second, check the oil temperature. Under normal room temperature, if the oil temperature is too low at cold start, preheat operation should be carried out first, and the system can run under no load for a period of time to raise the oil temperature to above 20℃ before formal production. If the oil temperature is still too high before starting the machine after the last shift, it is necessary to check whether the cooling system works normally. Third, check the indication of each pressure gauge to confirm that the pointer returns to zero correctly under no pressure. Check whether all pressure regulating valves and control valves are in the initial state to avoid sudden action of the equipment after starting. Fourth, visually inspect all hydraulic pipelines, joints and valve bodies for oil leakage, and check whether the pipeline has loose fixation and abnormal shaking. Fifth, check the cooling water system to ensure smooth water flow and normal cooling effect. AiBiM injection blow molding machines are equipped with intuitive oil level and temperature display devices on the operation interface, which can quickly complete the pre-startup state check and improve inspection efficiency.
2.2 Patrol Inspection Items During Production Operation
During normal production, operators should conduct regular patrol inspection of the hydraulic system, usually every 1 to 2 hours, to find abnormal signs in time. First, monitor the system pressure. The pressure display of each circuit should be stable within the set range, without frequent large fluctuations. If the pressure is unstable or cannot reach the set value, it indicates that there may be internal leakage or pump body wear, which needs further investigation.
Second, observe the oil temperature change. The normal working oil temperature should be controlled between 35℃ and 55℃, and the maximum should not exceed 60℃. If the oil temperature continues to rise, check whether the cooler works normally, whether the cooling water flow is sufficient, and whether the system has abnormal heating caused by internal leakage. Third, listen to the operation sound of the hydraulic pump and valve group. Under normal operation, the sound is uniform and regular. If there is abnormal squeal, knocking sound or obvious noise increase, it may be air suction, pump wear or valve core jamming, which should be checked in time. Fourth, check the action state of each executive mechanism. The action should be stable and smooth, without crawling, jamming or slow response. Fifth, always pay attention to whether there is oil leakage at each sealing part. A small amount of seepage is an early signal of seal failure, which should be handled in time to avoid large-scale leakage after deterioration. Make inspection records truthfully during patrol inspection to facilitate subsequent fault traceability and maintenance arrangement.
2.3 Standard Shutdown and Post-Shift Maintenance
Correct shutdown operation is very important to protect the hydraulic system and extend the service life of components. When shutting down normally, first reduce the system pressure to the minimum, then stop the hydraulic pump motor, and then cut off the power supply. Do not cut off the power supply directly under high pressure, which will cause impact on the hydraulic pump and valve body and accelerate damage.
After shutdown, clean the dust and oil on the surface of the hydraulic station and valve group to keep the equipment clean, which is also convenient for observing leakage and other abnormalities. Check the oil level and oil temperature again, and record the operation status of the shift. If any abnormal phenomena are found during the shift, they shall be recorded clearly and handed over to the next shift. For long-term shutdown, the system pressure should be completely released, the oil tank should be sealed to prevent dust and moisture from entering, and anti-rust treatment should be done for exposed piston rods. Standardized shutdown operation can reduce the impact on hydraulic components and slow down the aging speed of components.
3. Periodic Preventive Maintenance Plan
3.1 Weekly Maintenance: Cleaning and Fastening
Weekly maintenance is the basic maintenance work, mainly focusing on appearance cleaning, pipeline fastening and simple state confirmation. First, thoroughly clean the outer surface of the hydraulic station, oil tank, valve group and pipeline, remove the attached oil stain, dust and debris, keep the equipment clean, and also facilitate the observation of leakage and other abnormalities. Second, re-tighten the pipe joints, flange bolts and valve group fixing bolts that are prone to loosening. Under the long-term alternating action of pressure and vibration, joints and bolts may loosen slightly. Regular fastening can prevent oil leakage and pipe falling off caused by loosening. When tightening, apply force evenly according to the specified torque to avoid excessive force leading to thread damage.
Third, check the liquid level of the oil tank again and check the oil quality preliminarily. If obvious bubbles or emulsification are found in the oil, find out the reason in time. Fourth, check the working state of the cooler, clean the dirt on the surface of the radiator, and ensure the heat dissipation effect. Fifth, check the fastness of each pressure gauge and sensor to avoid signal abnormality caused by loosening. Weekly maintenance takes a short time, but it can eliminate many small hidden dangers in time and avoid the expansion of minor faults into major faults.
3.2 Monthly Maintenance: Filter and Accessory Inspection
Monthly maintenance needs to go deep into the functional level of the system to verify the working state of key auxiliary components. First, check and clean the oil suction filter and return filter of the hydraulic system. If the filter element is blocked, replace it in time. The filter is the core component to control the pollution of hydraulic oil. Timely replacement can keep the oil clean and reduce the wear of pumps and valves. The blockage of the oil suction filter will cause the oil suction of the hydraulic pump to be blocked, resulting in noise, cavitation and even damage to the pump body.
Second, check the sealing condition of each hydraulic cylinder piston rod. Observe whether there is oil seepage on the rod surface, and check whether the dust ring and sealing ring are aged or damaged. If there is slight leakage, replace the seal in time to avoid further deterioration. Third, check the accumulator air pressure. Use a pressure gauge to detect the pre charged nitrogen pressure. If the pressure is insufficient, supplement it in time to ensure the energy storage and pressure stabilization effect of the accumulator. Fourth, calibrate each pressure gauge and pressure sensor to avoid inaccurate pressure indication leading to process deviation. Fifth, comprehensively check the hydraulic pipeline for aging, cracking and wear, and replace the seriously aged pipeline in time. Monthly maintenance can effectively ensure the normal operation of the auxiliary system and reduce the probability of system failure.
3.3 Quarterly Maintenance: Oil Quality Testing and Valve Body Inspection
Quarterly maintenance requires in-depth inspection and evaluation of the core state of the hydraulic system. First, take oil samples from the hydraulic oil tank for oil quality testing, including viscosity, acid value, moisture content and impurity content. Judge the deterioration degree of hydraulic oil through testing, and decide whether to replace the hydraulic oil according to the test results. If the oil quality does not meet the standard but has not reached the replacement cycle, it should also be replaced in time, because deteriorated oil will accelerate the wear of all components and bring greater losses.
Second, inspect and clean the main control valve body. Check whether each valve core acts flexibly without jamming, and clean the dirt attached to the valve body. For proportional valves and servo valves, special cleaning agents can be used for cleaning to ensure the flexibility of valve core action. Third, check the wear of the hydraulic pump. Judge the wear state of the pump body by detecting the pressure rise speed, maximum pressure and noise during no-load and load operation. If the performance of the hydraulic pump decreases obviously, arrange repair or replacement in time. Fourth, comprehensively maintain the cooling system, clean the scale and impurities inside the cooler, and ensure the cooling effect. Fifth, check all sealing elements of the system, evaluate the aging degree, and arrange replacement plan for seals that are about to reach the service life.
3.4 Annual Overhaul: Comprehensive Disassembly and Performance Recovery
Annual overhaul is the most comprehensive and in-depth maintenance work, which needs to conduct comprehensive inspection, maintenance and replacement of vulnerable parts of the whole hydraulic system to restore the system performance to a good state close to the new machine. First, drain all the hydraulic oil in the oil tank, thoroughly clean the inside of the oil tank, remove sediment, sludge and impurities at the bottom, and clean the oil suction filter screen inside the oil tank. After cleaning, wipe it with clean non-woven fabric to avoid secondary pollution.
Second, disassemble and inspect the hydraulic pump and hydraulic motor, check the wear of internal gears, bearings and sealing elements, replace the worn and aged parts, and reassemble and debug after maintenance to restore the working performance. Third, disassemble and inspect all control valves, clean the valve body and valve core, replace the sealing elements, and ensure flexible action and reliable sealing. Fourth, replace all sealing elements of each hydraulic cylinder, and check the wear of the cylinder inner wall and piston rod. If there are strain and wear, repair or replace them. Fifth, replace all hydraulic oil filters in an all-round way, and replace the hydraulic oil with new oil as required. Sixth, conduct overall pressure test and action test on the system after reassembly to verify the working performance of each circuit, and calibrate pressure and flow parameters. Annual overhaul is equivalent to a comprehensive physical examination and performance recovery of the hydraulic system, which can effectively eliminate major hidden dangers and ensure stable operation in the next year.
4. Common Hydraulic System Fault Diagnosis and Troubleshooting
4.1 System Pressure Insufficiency or Pressure Instability
Insufficient or unstable pressure is one of the most common faults of hydraulic systems, which will directly lead to problems such as weak mold clamping, reduced injection speed and unstable product quality. There are many possible reasons. The first common reason is the wear of the hydraulic pump, which reduces the volumetric efficiency and cannot establish normal pressure. At the same time, it is usually accompanied by increased noise and oil temperature rise. The treatment method is to repair or replace the hydraulic pump.
The second reason is the failure of the pressure regulating valve, such as the wear of the relief valve core, the blockage of the damping hole or the fatigue damage of the spring, resulting in the inability to stabilize the pressure. The treatment method is to disassemble and clean the relief valve, replace the damaged spring or the whole valve. The third reason is serious internal leakage of the system, including internal leakage of hydraulic cylinders, valve bodies and pipelines, resulting in pressure can not be maintained. Check each executive component and control valve one by one, find out the leakage point and replace the seal or valve body. The fourth reason is the blockage of the oil suction filter or insufficient oil level, which leads to air suction of the hydraulic pump, and the system is mixed with air, resulting in pressure fluctuation and unstable pressure. It is necessary to clean or replace the filter element, supplement hydraulic oil and exhaust the system. The fifth reason is the deterioration of hydraulic oil and too many impurities, leading to the jamming of the valve core. It is necessary to replace the hydraulic oil and clean the valve body.
4.2 Abnormal Rise of Oil Temperature
Excessive oil temperature will accelerate the aging of hydraulic oil and seals, reduce the service life of components, and also lead to changes in oil viscosity, affecting the stability of action and pressure. The first common reason is the failure of the cooling system, such as the blockage of the cooler pipeline, insufficient cooling water flow or too high water temperature, resulting in the heat can not be taken away in time. The treatment method is to clean the cooler, check the cooling water pipeline, and adjust the water flow and temperature.
The second reason is serious internal leakage of the system. A large amount of hydraulic oil leaks through the gap, and the pressure energy is converted into heat energy, resulting in rapid temperature rise. Find out the leakage point and repair it to reduce unnecessary heat generation. The third reason is the improper setting of system pressure, long-term overload operation or high pressure unloading, resulting in excessive power loss and heating. Adjust the pressure parameters reasonably to avoid the system working under overload for a long time. The fourth reason is the wear of the hydraulic pump, which reduces the efficiency and increases the heat generation. Repair or replace the pump body in time. The fifth reason is that the viscosity of hydraulic oil is too high or too low, which leads to increased friction and heat generation. Replace hydraulic oil with appropriate viscosity according to the equipment requirements and ambient temperature.
4.3 Slow Action or Action Crawling
Slow action and crawling will affect the production beat and product molding quality. The first reason is insufficient flow, such as wear of hydraulic pump, reduced output flow, or failure of flow regulating valve and small set flow. Check the pump body and flow valve to adjust the flow to the normal range.
The second reason is that the system is mixed with air. Air bubbles are compressed and released in the hydraulic oil, resulting in unstable movement speed and crawling. Fully exhaust the system, check whether the oil suction pipeline has air leakage, and eliminate the air suction point. The third reason is the wear and strain of the hydraulic cylinder inner wall or piston rod, or the damage of the guide sleeve, resulting in increased friction resistance and unsmooth movement. Repair or replace the hydraulic cylinder assembly. The fourth reason is the jamming of the valve core or the blockage of the throttle hole, resulting in unstable flow. Clean the valve body and remove the blockage. The fifth reason is the deterioration of hydraulic oil and increased impurities, which leads to the increase of system resistance. Replace the hydraulic oil and clean the system pipeline.
4.4 Hydraulic Oil Leakage Fault
Oil leakage is divided into external leakage and internal leakage. External leakage is intuitive and easy to find, while internal leakage is hidden and needs to be judged by detection. External leakage usually occurs at pipe joints, sealing surfaces and piston rods. The most common reason is the aging or damage of sealing elements, which lose their sealing effect under high pressure. Replace the corresponding sealing ring and gasket. The second reason is loose pipe joints or uneven flange joint surfaces. Re tighten the bolts or replace the connecting parts.
The third reason is strain or corrosion of pipeline and parts, resulting in perforation and oil leakage. Replace the damaged pipeline or parts. Internal leakage mainly occurs inside hydraulic cylinders, valve bodies and hydraulic pumps. Although it will not cause oil pollution on the surface, it will lead to pressure drop, slow action and oil temperature rise, which is more harmful. The internal leakage can be judged by detecting the action speed, pressure maintaining effect and oil return flow. After finding out the leakage point, replace the seal or repair the worn parts. Long term oil leakage will not only cause waste of hydraulic oil and pollution of the working environment, but also may lead to safety accidents such as fire. It should be dealt with in time once found.
5. Hydraulic Oil Management and Spare Parts Reserve Strategy
5.1 Scientific Selection and Replacement of Hydraulic Oil
Hydraulic oil is the working medium of the hydraulic system, and its quality directly determines the service life of the whole system. When selecting hydraulic oil, it must be selected according to the model specified in the equipment manual. Injection blow molding machines usually use anti-wear hydraulic oil with appropriate viscosity. For equipment with proportional valves or servo valves, anti-wear hydraulic oil with higher cleanliness grade should be selected to ensure the flexible action of precision valve bodies.
The replacement cycle of hydraulic oil should be determined according to the actual use conditions and oil test results. Under normal working conditions, it is recommended to replace it completely every 12 to 18 months. If the working environment is bad and the equipment runs for a long time, the replacement cycle should be appropriately shortened. Do not blindly extend the service time of oil products in order to save costs. Deteriorated hydraulic oil will accelerate the wear of pumps, valves and oil cylinders, and the resulting maintenance cost is far higher than the cost of oil replacement. When replacing hydraulic oil, thoroughly clean the oil tank and pipeline to avoid secondary pollution of old oil to new oil. Different brands and different models of hydraulic oil shall not be mixed to avoid chemical reaction and performance degradation of oil products.
5.2 Pollution Control of Hydraulic Oil
More than 70% of hydraulic system failures are caused by oil pollution. Controlling oil pollution is the core of hydraulic system maintenance. First, ensure the cleanliness of the oil filling process. Use a special oil filter truck to fill new oil, and do not pour it directly into the oil tank. The oil injection tool shall be specially assigned and kept clean to avoid bringing impurities into the oil tank.
Second, maintain the integrity of the oil tank sealing system to prevent dust and impurities in the air from entering the oil tank. The air filter on the oil tank shall be replaced regularly to ensure the filtering effect. Third, replace the filter element regularly according to the maintenance cycle to ensure the filtering effect. The filter element with blockage alarm shall be replaced in time after alarm, and shall not be used forcibly. Fourth, control the moisture content of the oil. Regularly check whether the cooler has water leakage to avoid cooling water mixing into the hydraulic oil. If moisture is found in the oil, remove water and replace the oil in time. Fifth, avoid mixing impurities generated by component wear into the system for a long time, and clean the oil tank and pipeline regularly. Keeping the hydraulic oil clean can greatly extend the service life of all hydraulic components and reduce the failure rate.
5.3 Spare Parts Reserve and Management
Establishing a scientific spare parts reserve system can minimize the shutdown waiting time caused by spare parts shortage. According to the service life and failure probability, hydraulic system spare parts can be divided into three categories for classified management. The first category is quick-wear parts with short service life and high replacement frequency, including various sealing rings, filter elements, oil seals, etc. Such parts have low value and high failure frequency, so sufficient inventory shall be reserved. It is generally recommended to reserve 2 to 3 sets of such spare parts for each equipment.
The second category is medium-term wearing parts with service life of 1 to 3 years, including solenoid valve coils, pressure gauges, relays, etc. Such parts have medium value and can be properly reserved. For enterprises with multiple same models of equipment, they can be reserved in a unified manner. The third category is core components with long service life, such as hydraulic pump, hydraulic cylinder, proportional valve, etc. Such parts have high value and low failure probability, so there is generally no need for stock reserve. However, the supply channel and delivery cycle should be confirmed with the supplier in advance, so that they can be purchased quickly when needed. AiBiM provides customers with a complete list of recommended spare parts, marking the recommended service life and inventory quantity of each part, which is convenient for customers to formulate reserve plans according to their own production intensity.
6. Design Advantages and Maintenance Support of AiBiM Injection Blow Molding Machine Hydraulic System
The design of equipment itself has a decisive impact on the difficulty of later maintenance and failure rate. AiBiM injection blow molding machines fully consider maintainability and reliability at the beginning of hydraulic system design, and adopt a series of optimized designs to reduce the maintenance workload and operation cost for customers.
6.1 Optimized Hydraulic Circuit Design
AiBiM adopts the optimized hydraulic loop design, which reasonably arranges the trend of each loop, reduces unnecessary pipeline connections and elbow structures, reduces the system pressure loss and heat generation, and also reduces the leakage points. The valve group adopts integrated modular design, which concentrates most control valves on the integrated valve block, reduces the use of external pipelines, makes the whole hydraulic station more tidy, and greatly reduces the probability of pipeline leakage. At the same time, the integrated valve group is more convenient for disassembly and maintenance, which can reduce the time of fault handling and parts replacement.
The system is equipped with perfect overload protection and pressure relief mechanism, which can automatically protect when the system pressure is too high, avoiding component damage caused by overload. The oil circuit design follows the principle of energy saving, reduces throttling loss and improves energy utilization. The standard configuration of high-efficiency cooler can quickly take away the heat generated by the system, keep the oil temperature within the optimal working range, and slow down the aging speed of hydraulic oil and seals. In terms of price, the standard configuration of AiBiM injection blow molding machine ranges from 65,000 to 95,000 US dollars. The optimized hydraulic system can reduce the annual maintenance cost by about 1,500 to 2,500 US dollars compared with ordinary equipment, and the energy consumption is reduced by 15% to 20%, which has very obvious long-term benefits.
6.2 High Quality Brand Components
AiBiM strictly controls the selection of hydraulic components, and all core hydraulic components adopt well-known brands at home and abroad. The hydraulic pump adopts high-performance plunger pump or vane pump with stable performance, high volumetric efficiency and long service life. The valve group adopts famous brand hydraulic valves with reliable action and low failure rate. Sealing elements adopt high-quality sealing products with temperature resistance, wear resistance and long service life.
Using high-quality brand components not only ensures the stability and reliability of the system, but also because these brands have perfect global after-sales service networks, customers can easily purchase corresponding accessories locally, reducing maintenance cost and downtime loss. At the same time, AiBiM has established long-term strategic cooperation with these component suppliers, which can not only ensure stable supply quality, but also have priority supply guarantee, which will not affect the maintenance progress due to the shortage of components.
6.3 Intelligent Monitoring and Early Warning Function
AiBiM new generation injection blow molding machines are equipped with intelligent hydraulic system monitoring function. The system collects real-time data such as system pressure, oil temperature, oil level and pump operation parameters through multiple sensors, and conducts big data analysis through the built-in algorithm. When the system has abnormal signs such as oil temperature over temperature, pressure abnormality and filter blockage, the system will automatically send out early warning information and prompt maintenance suggestions, so that maintenance personnel can arrange maintenance in advance during production gaps, changing from passive after-the-fact maintenance to active predictive maintenance.
The system also has a complete equipment maintenance file function, which automatically records the operation time, maintenance history and replacement records of vulnerable parts, and automatically reminds the maintenance time according to the preset maintenance plan. This intelligent system greatly reduces the dependence on the experience of maintenance personnel, improves the scientificity and accuracy of maintenance, and further reduces the probability of unexpected failures.
6.4 Professional After-Sales Service and Technical Support
AiBiM provides customers with full life cycle technical support and after-sales service. After the equipment is delivered, professional engineers will be sent to guide the installation and commissioning, and provide systematic operation and maintenance training for customers’ operators and maintenance personnel to ensure that the customer team can master daily operation and basic maintenance skills. The company has sufficient spare parts warehouse, and common hydraulic vulnerable parts and maintenance parts are in stock all year round, which can be shipped quickly after receiving customer demand and shorten the waiting time for spare parts.
For customers who need professional maintenance services, AiBiM also provides contract type annual maintenance services. Professional after-sales engineers regularly go to the site to carry out quarterly maintenance and annual overhaul work, so that customers do not need to equip professional hydraulic maintenance teams, but also can ensure that the hydraulic system is always in good operating condition. In case of emergency failure, the after-sales team can provide remote diagnosis guidance for the first time, and if necessary, arrange on-site service at the fastest speed to minimize the shutdown loss.
7. Cost-Benefit Analysis of Preventive Maintenance
7.1 Direct Loss Caused by Hydraulic System Failure
To measure the value of preventive maintenance, we must first clarify the actual loss caused by unexpected failure shutdown. Take a medium-sized injection blow molding production line as an example. The production line produces about 8,000 precision packaging bottles per day, and the gross profit of each product is about 0.25 US dollars. If a major hydraulic system failure occurs, it usually takes 1 to 3 days from troubleshooting, spare parts procurement to maintenance and commissioning. Calculated by 2 days of shutdown, the direct gross profit loss alone reaches 4,000 US dollars. This does not include the maintenance cost of about 800 to 2,000 US dollars, the customer claim loss caused by delivery delay and the intangible loss of brand reputation.
Even if it is a minor fault, it will take half a day to one day to deal with it, and the loss will reach hundreds of dollars. For high value-added products such as medical devices and high-end cosmetic bottles, the unit output value is higher, and the loss caused by shutdown is even greater. Many enterprises only see the direct cost of maintenance, but ignore the huge potential loss caused by shutdown. In fact, the economic benefits brought by avoiding a shutdown accident are enough to cover the maintenance cost of several years.
7.2 Input Cost of Standardized Preventive Maintenance
The investment in standardized preventive maintenance mainly includes spare parts consumption cost, regular maintenance labor cost and testing consumables cost. Take the above medium-sized injection blow molding production line as an example. The annual preventive maintenance cost includes four times of quarterly maintenance and one time of annual overhaul. The cost of consumables such as filter element and cleaning agent is about 800 to 1,200 US dollars per year. The cost of hydraulic oil replacement is about 600 to 1,000 US dollars per year. The labor cost is about 1,500 to 2,000 US dollars per year. The total annual maintenance investment is about 2,900 to 4,200 US dollars.
If the enterprise is equipped with AiBiM high configuration injection blow molding machine, the system has high stability and intelligent early warning function, the maintenance frequency can be appropriately reduced, and the annual maintenance cost can be controlled at about 2,500 to 3,500 US dollars. Compared with the loss caused by failure shutdown, the investment in preventive maintenance is very low, but the return is very considerable.
7.3 Return on Investment Calculation
By comparing the loss of passive maintenance and the investment of preventive maintenance, it can be clearly seen that the return on investment of standardized maintenance is very high. The annual investment of about 3,500 US dollars can reduce the probability of major hydraulic failures by more than 80%, and basically avoid long-term shutdown caused by hydraulic system failures. Calculated by reducing one major shutdown accident and 2 to 3 minor faults every year, the direct loss of more than 6,000 US dollars can be avoided every year.
In addition to avoiding losses, standardized maintenance can also bring additional benefits. Stable hydraulic system can keep product quality stable, reduce the defective rate by 1% to 2%, and save about 3,000 to 5,000 US dollars in raw material costs every year. The service life of hydraulic components is extended by 30% to 50%, which saves the cost of parts replacement. The reduction of energy consumption of the system can also save a lot of electricity bills every year. Comprehensive calculation shows that the return on investment of preventive maintenance is more than 3 times, which is a very cost-effective investment.
8. Safety Operation Specifications for Hydraulic System Maintenance
Hydraulic system maintenance involves high pressure, heavy load and other risk factors, so safety must be put in the first place. All maintenance work must strictly abide by the safety operation specifications. First, implement the power-off listing system. Before any maintenance work, the main power supply of the equipment must be cut off, and a warning sign of under maintenance, do not switch on must be hung at the power switch, and a specially assigned person shall be responsible for guardianship. It is strictly forbidden to carry out maintenance work with electricity. Before disassembly, the system pressure must be completely released to avoid high-pressure oil injection injury.
Second, do a good job in personal protection. Maintenance personnel must wear protective glasses, safety shoes and other labor protection articles. When disassembling high-pressure pipelines, stand on the side to avoid the nozzle direction to prevent high-pressure oil from spraying out and hurting people. Third, pay attention to fire prevention. Hydraulic oil is flammable. Fireworks are strictly prohibited at the maintenance site, and fire-fighting equipment shall be prepared on site. Waste oil and oil stained rags shall be disposed in a centralized manner and shall not be stacked randomly.
Fourth, use special tools for disassembly and assembly, and do not knock violently to avoid damage to parts. After maintenance, carefully check whether all pipelines and joints are firmly connected, and conduct pressure test after power on to ensure no leakage. In addition, establish complete maintenance records, record maintenance time, maintenance content, replaced parts and other information in detail, establish equipment maintenance files, which is convenient for subsequent fault traceability and maintenance cycle formulation. Regularly conduct safety training for maintenance personnel to improve safety awareness and operation level, so as to ensure that all maintenance work is completed safely and efficiently.
Conclusion
The hydraulic system is the power heart of the injection blow molding machine, and its operation state directly determines the production efficiency, product quality and comprehensive operating cost of the whole equipment. Extensive use and lack of maintenance will not only lead to frequent failures and high shutdown losses, but also greatly shorten the service life of the equipment and increase the total cost of ownership. Establishing a systematic preventive maintenance system, doing a good job in daily inspection, regular graded maintenance, oil pollution control and spare parts reserve, can effectively reduce the failure rate, extend the service life of equipment, and obtain very high return on investment.
As a professional injection blow molding equipment manufacturer, AiBiM not only provides high-quality injection blow molding machines with excellent hydraulic system design and reliable performance, but also provides customers with perfect maintenance technical support and after-sales service to help customers build a scientific hydraulic system management system. Choosing reliable equipment and adhering to standardized maintenance can not only ensure long-term stable and efficient production, but also create more economic benefits for enterprises in the whole equipment life cycle. Whether it is a new equipment project or an existing production line upgrading maintenance management, attaching importance to hydraulic system maintenance is the key to achieving stable and efficient production of injection blow molding.
