How to Prevent the Rising Oil Temperature of the Injection Molding Machine?

In the injection molding processing industry, the problem of rising hydraulic oil temperature is really annoying us. The increase in hydraulic oil temperature will not only affect the work of the injection molding machine, but also seriously affect the service life of it. Then how do we prevent the temperature of injection molding oil from rising? We should analyze this problem from the following aspects: viscosity index, whether there is a good hydraulic cooling system, viscosity, and other comprehensive performance.

1. Viscosity Index (VI)

This index VI more directly reflects the nature of hydraulic oil viscosity changing with temperature. That is, the viscosity-temperature characteristics of the oil. The higher the viscosity index of the oil, it means that the viscosity of the oil changes to a lesser degree with temperature changes. On the contrary, larger.

The viscosity index of anti-wear hydraulic oils produced by well-known foreign manufacturers is VI≥110. While the viscosity index of domestic (China) high-grade anti-wear hydraulic oils is around 95. The high viscosity index hydraulic oil (HV) and multi-grade engine oil produced abroad have a viscosity index of VI>140. The domestic ones cannot reach this level.

The lowering of the viscosity index will reduce the environmental temperature range that the oil is adapted to. You should consult the oil manufacturer for relevant information. The use range of the oil must be adjusted appropriately. If necessary, the relevant setting value of the equipment should also be changed (Such as extreme temperature, etc.).

2. Good hydraulic oil cooling system

For the improvement of the hydraulic oil heat dissipation system of the injection molding machine (more precisely, the hydraulic oil temperature control system), although the specific methods adopted by the manufacturers are different, the basic idea is the same. Whether the hydraulic oil radiator is clogged with dirt, resulting in a decrease in heat dissipation efficiency. Clean the radiator if necessary. The cycle water for the cooler is needed special attention, we had seen many case that it is just put in one open yard.

3. Hydraulic oil viscosity

(ISO VG, the unit of viscosity is mm2/s) The principle of determining the viscosity of hydraulic oil is to make the viscosity of the hydraulic oil (for components such as pumps and motors) be in the best range (16 – 36×10-6mm2/s), under the premise of considering the working temperature and efficiency of the hydraulic circuit.

The viscosity of the short-term cold start corresponding to the lowest ambient temperature is ≤1000X10-6mm2/s. And the viscosity corresponding to the maximum allowable leakage oil temperature of 90℃ in the short time is ≥10X10-6mm2/s.

4. Other comprehensive performance

Due to the high working pressure of the hydraulic system of modern injection molding machines (≥14MPa or 17.5 Mpa), the maximum allowable working oil temperature of the hydraulic oil is also high (about 50℃). Therefore, to ensure that the hydraulic system can work normally, it is required that the oil selected for the system has good quality in terms of lubricity, oxidation stability, abrasion resistance, rust and corrosion resistance, anti-emulsification, anti-foaming, anti-shear stability and extreme pressure load.

Especially when choosing a new hydraulic oil, you must pay attention to meeting the standard requirements. Otherwise, serious problems such as overheating of the system and damage to components may occur.

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