Injection molding machines are widely used in the plastic industry, often operating for extended periods. Ensuring their stable and normal operation during continuous production is a crucial and challenging issue for both manufacturers and users. From the user's perspective, selecting the correct type of injection molding machine and conducting regular preventive maintenance are effective ways to ensure its proper functioning. Preventive maintenance involves a series of proactive measures and inspections to prevent machine failures, extend the lifespan of various components, and convert sudden breakdowns that could lead to production halts into planned and scheduled repairs or overhauls. Promptly identifying and replacing damaged parts to prevent cascading failures is also a key goal of preventive maintenance.

Hydraulic preventive maintenance and maintenance work

Hydraulic Oil Volume

Insufficient oil levels can lead to increased oil temperature and air contamination, affecting oil quality and the normal operation of the hydraulic system. Oil loss is often due to leaks or loss during repairs. Therefore, it's essential to regularly check for leaky areas, replace worn seals early, tighten loose connections, and after maintenance, inspect the oil level in the reservoir and replenish it promptly.

Hydraulic Oil Temperature

The ideal operating temperature for hydraulic systems should be between 45℃ and 50℃, as these systems are designed based on a selected oil viscosity, which, however, varies with oil temperature, thereby affecting the performance of working components such as cylinders and hydraulic valves, leading to reduced control accuracy and response sensitivity, especially in the case of precision injection machines. Excessive temperature can also accelerate the aging of seals, causing them to harden and crack; conversely, low temperatures result in higher energy consumption for processing, slowing down operation speed. Therefore, closely monitoring the working temperature of hydraulic oil is crucial. The causes of elevated oil temperatures are varied, but often attributed to issues with the oil circuit or failure of the cooling system.

Hydraulic oil quality

One of the important properties of hydraulic oil is its chemical stability, specifically oxidation stability. Oxidation is a primary factor determining the effective service life of hydraulic oil. The oxidation products, such as asphalt, sludge, and carbon residue, are insoluble and can contaminate the hydraulic system, increasing wear on hydraulic components, reducing clearances, plugging small holes, and causing system failures. The rate of oxidation of hydraulic oil depends on various factors, including its own composition and operating conditions, with temperature being a major factor. Therefore, it is essential to use the appropriate hydraulic oil and to regularly check the degree of oxidation (judged by the deepening color of the oil itself). It is necessary to proactively change the oil after a certain number of operating hours.