Five major hazards and solutions to excessive temperature of injection molding machines

Excessive temperature in injection molding machines poses significant risks to their operational integrity, affecting various components and functionalities. Among the myriad issues arising from overheating, thermal deformation of machinery, reduced oil viscosity, and accelerated wear and tear are primary concerns. This article delves into the five major hazards caused by the excessive temperature of injection molding machines and provides insightful solutions to mitigate these challenges.

One of the hazards: causing thermal deformation of the machinery

The moving parts with different thermal expansion coefficients in hydraulic components become stuck due to the smaller fitting clearance, causing movement failure, affecting the transmission accuracy of the hydraulic system, and resulting in poor working quality of the components.

Hazard 2: Reduce the viscosity of the oil

Excessive temperature rise of the injection molding machine will cause the viscosity of the oil to decrease, leakage to increase, and the volumetric efficiency of the pump and the efficiency of the entire system to be significantly reduced. As the viscosity of the oil decreases, the oil film on moving parts such as slide valves becomes thinner and cut, and frictional resistance increases, leading to increased wear.

Hazard No. 3: Deformation of rubber seals

Excessive temperature rise of the injection molding machine will deform the rubber seal, accelerate aging and failure, reduce sealing performance and service life, and cause leakage.

Hazard No. 4: Accelerated oxidation and deterioration of oil

Excessive temperature rise of the injection molding machine will accelerate the oxidation and deterioration of the oil, precipitate asphalt substances, and reduce the service life of the hydraulic oil. The precipitates block the damping holes and slot valve ports, causing the pressure valve to become stuck and unable to operate, the metal pipeline to stretch and bend, or even rupture.

Hazard No. 5: Leading to poor quality of components

If the temperature of the injection molding machine rises too high, the working quality of the components will deteriorate, and the dissolved air in the oil will escape, causing air pockets, which will reduce the working performance of the hydraulic system. The ideal operating temperature of the hydraulic system should be between 45 degrees and 50 degrees. The reason is that the hydraulic system is designed based on a selected pressure oil viscosity, but the viscosity will change with the oil temperature, which will affect the work of the system. Components, such as oil cylinders, hydraulic valves, etc., reduce control accuracy and response sensitivity, especially for precision injection machines.

At the same time, if the temperature is too high, it will also accelerate the aging of the seal and cause it to harden and crack; if the temperature is too low, the processing energy will be consumed and the operating speed will be reduced. Therefore it is necessary to pay close attention to the operating temperature of hydraulic oil. There are many reasons for excessive oil temperature, but they are mostly attributed to oil line failure or cooling system failure.

How to deal with excessive temperature of injection molding machine

(1) According to different load requirements, frequently check and adjust the pressure of the relief valve to make it just right.

(2) Reasonably select the hydraulic oil, especially the oil viscosity. If conditions permit, try to use a lower viscosity to reduce viscosity friction loss.

(3) Improve the lubrication conditions of moving parts to reduce friction losses, which is beneficial to reducing workload and heat generation.

(4) Improve the assembly quality and accuracy of hydraulic components and hydraulic systems, strictly control the fitting clearance of mating parts and improve lubrication conditions. Use sealing materials with small friction coefficients and improved sealing structures to reduce the starting force of the hydraulic cylinder as much as possible to reduce the heat generated by mechanical friction loss.

In conclusion, managing the temperature of injection molding machines is pivotal for sustaining optimal performance and longevity. The hazards associated with overheating are far-reaching, impacting machinery components, oil viscosity, rubber seals, and overall product quality. Employing proactive measures, such as adjusting relief valve pressures, selecting suitable hydraulic oils, and enhancing lubrication conditions, is crucial in preventing these issues. By adhering to stringent quality controls and addressing temperature-related challenges promptly, manufacturers can ensure the reliability and efficiency of injection molding processes.

FAQs

1. Why does excessive temperature cause thermal deformation in injection molding machines?

Excessive temperatures lead to smaller fitting clearances in hydraulic components, causing thermal deformation and resulting in movement failure. This adversely affects the transmission accuracy of the hydraulic system, diminishing the working quality of components.

2. How does overheating impact the viscosity of hydraulic oil in injection molding machines?

High temperatures reduce oil viscosity, increasing leakage, and significantly decreasing the volumetric efficiency of the pump and the efficiency of the entire system.

3. What are the consequences of temperature rise on rubber seals in injection molding machines?

Elevated temperatures cause deformation, aging, and failure of rubber seals, diminishing sealing performance and service life, eventually leading to leakage issues.

4. How does excessive temperature affect the oil's oxidation and deterioration in injection molding machines?

Overheating accelerates the oxidation and deterioration of hydraulic oil, causing the precipitation of asphalt substances, which can block damping holes and valve ports, resulting in stuck pressure valves and potential pipeline damage.

5. Why is maintaining an optimal operating temperature crucial for injection molding machines?

Excessive temperatures degrade the working quality of components, release dissolved air in the oil, create air pockets, and reduce the hydraulic system's overall performance.