How does PMA influence the hydraulic oil’s liquidity?|Chorus| Lube additives

Hydraulic oil is the "blood" of hydraulic system; it can not only be used as a medium to realize energy transfer, exchanging and controlling, but also plays a role in lubricating, antirusting, cooling and shock absorbing. The hydraulic oil quality influences the system's flexibility, accuracy and stability.

 

The common hydraulic oil is easily solidified under low temperatures, causing the failure of hydraulic system. However, the non-solidifying common hydraulic oil under low temperature has a much lower viscosity under common temperature, which will increase the wear of workpieces and low efficiency of hydraulic system.

 

Why does the performance of hydraulic oil deteriorate when the temperature is low?

It is mainly because the base oil (especially the mineral oil) is sensitive to temperature. Once the temperature decreases, the molecular activity will slow, the oil will become thick, and the viscosity will increase quickly.

This will bring the consequences：

• Difficult to start: because the oil is too thick, the pump has difficulty establishing pressure, the system starts slowly.
• Risk of filter element clogging: the viscosity increases, the impurities are easier to attach on the filter, leading to clogging.
• Increase wear: it will increase the inner wear and energy loss, the system efficiency decreases.

 

In the low temperature formulation of hydraulic oil, the lubricant additive plays an important role. Choosing a suitable viscosity index improver (VII) and a pour point depressant is the key to formulating low temperature hydraulic oil.

 

Viscosity index improvers (VIIs): the stabilizer of maintains oil viscosity

The commonly used viscosity index improvers are the four main types: PIB, OCP, PMA, and HSD. The PMA is the most widely used in low temperature hydraulic oil.

Traditional VIIs, like OCP and ethylene propylene copolymer, have a good performance under most situations, but they will cause the oil viscosity to increase high in low temperature environment. Both of them are usually high molecular copolymers, the molecular chain is in a loose state under high temperature, increasing the inner oil wear and improving oil viscosity. Under low temperature, they can not improve the base oil itself thickening problem effectively, and even deteriorate the oil liquidity, especially in extreme weather and cold regions.

High performance VIIs, for example, ester polymer PMA, can keep a certain molecular chain activity in cold weather, reduce the influence to low temperature viscosity, which is helpful to keep the viscosity stable in a low weather.

 

• Polymethacrylate PMA Viscosity Index Improver (Thickener) T630V

PMA additive T630V is a PMA-derived viscosity index improver designed to enhance the performance of various oil products. It is particularly effective for low-temperature and low-condensation hydraulic oil and has excellent shear stability. By adding T630V, you can improve viscosity index and low-temperature performance of your oil products.

 

PPDs: the "ice-breaking axe" to break the wax crystal's ice

In addition to the viscosity increase, mineral oil at low temperature also faces the problem of wax precipitation. The paraffin component in mineral oil forms crystals and precipitates. These crystals will have further growth and connect with each other to form a mesh structure, which has an effective role in preventing oil flow and increasing the pour point.

The main function of a pour point depressant is to inhibit the growth and aggregation of wax crystals by absorption and eutectic interaction to maintain the liquidity of oil under low temperatures.

 

Working principle of PPDs: pour point depressant molecular absorption on the surface with tiny wax crystals and change the wax crystals' growth direction and shape to prevent them from forming a big and hard mesh structure, so that it can decrease the oil pour point.

 

The commonly used PPD is polymethacrylate PMA

Chorus can provide various types of PMA Polymethacrylate PPD T602  is a PMA type pour point depressant, with excellent pour point depressant effect and shear stability. It's suitable for low viscosity group I, II, III base oil and engine oil, gear oil, hydraulic oil. The narrow spread of molecular can avoid the exist of over long chain molecules so as to improve oil's liquidity in low temperature, like winter, cold regions and extreme cold weather.

 

Polymethacrylate Pour Point Depressant (PPD) T248 For Lubricant Oils

Lubricant oil pour point depressant T248 is a high performance lubricant pour point depressant with a good pour point reducing effect, an excellent shear stability and a good formula adaptability. T248 is a PMA type PPD, suitable for various base stocks, such as API II, API III, III+, and hydrogenated base oils. It is widely used in lubricant oil formulations, including internal combustion engine oils, gear oils, hydraulic oils, and others.

 

How does the double-function PMA influence the liquidity of hydraulic oil ?

PMA has a double function of decreasing pour point and increasing viscosity; it can play a different role according to its molecular structure.

As a PPD, PMA can inhibit the wax crystals' growth, reduce the oil pour point and improve low temperature liquidity.

As a viscosity index improver, specific high molecular weight PMA stretches out under high temperature, improving viscosity and viscosity temperature performance. It's particularly effective in ester oil.

 

But using PMA also has its limits. Its copolymer will bring a negative impact in extremely low temperatures: although it can reduce the pour point, when in extremely low temperature environments that are close to or below the pour point, the movement of PMA molecular chains is hindered. And this will cause an increase in low-temperature dynamic viscosity and has a direct influence on the cold start performance and low temperature pumping capacity.

Researches show that compared with traditional VIIs, PMA has an effective role in the low temperature start viscosity's negative impact.

 

Therefore, it is necessary to estimate the formulation's low temperature performance, weigh the advantages and the risks of increased low temperature viscosity.

When choosing a hydraulic oil, it's not only needed to focus on pour point and viscosity index, but also to pay attention to the low temperature performance. And connected with the practical working conditions, choosing the most suitable additives to ensure the equipment can operate smoothly, reliably, and highly efficiently under extreme cold weather.

Chorus is a professional lubricant additive supplier. We can provide you with PMAs for different temperatures use, high viscosity, stable shear, and reduce the pour point.

 

Contact us to get more useful information. We can provide you with the professional situation.