LANXESS
Additive Packages for Challenging Hydraulic Applications

By Mary Moon, Presque Isle Innovations, LLC | TLT CMF Plus November 2019

Like the beating heart in a human body, the mechanical pump is the single most critical (and valuable) component of an industrial hydraulic system. 

Mechanical pumps circulate hydraulic fluid, which is essential for precise, continuous and efficient operation of systems for processing plastics, manufacturing steel and making paper, as well as operating assembly lines, machine tools and robots. Pump failure not only disrupts production, it spews debris that can damage valves, actuators and hoses. 

High quality hydraulic fluids (and its proper maintenance) are the most effective insurance to prevent catastrophic pump failure. Many commercial hydraulic fluids meet basic national and international standards. Conventional oil analysis tests can reveal the presence of contaminants and moisture to signal the need for preventive maintenance. Additive packages from LANXESS provide lubricant suppliers with the performance they need to blend hydraulic fluids to meet national and international specification and to qualify as top tier products.

Top tier hydraulic fluids have the highest quality formulations and receive approvals from leading pump OEMs. These premium products pass rigorous testing in pumps under severe operating conditions as well as meet standard technical criteria. Formulation development and pump testing present a double challenge to lubricant manufacturers.

LANXESS Additin® RC 9200 N and 9300
LANXESS (Cologne, Germany) is a leading global supplier of specialty chemicals. The Lubricant Additives Business supplies more than 660 synthetic base fluids, additives and fully-formulated lubricants to over 800 customers. Mannheim, Germany is the principal facility for the development, production, and distribution of additive packages for the lubricant industry. In 2018, LANXESS commissioned a new manufacturing line for producing Additin® brand dimercaptothiadiazole (DMTD) derivatives at Mannheim. The business unit is globally positioned, with its headquarter in Shelton (CT, USA), and additional production facilities as well as sales and customer service organizations in all regions of the world.

According to Dr. Steffen Sandhoefner, Senior Manager Application Technology, Lubricant Additives Business, LANXESS Deutschland GmbH, "LANXESS provides a portfolio of additive packages to target three hydraulic fluid segments. First, we sell Additin® RC 9207 and Additin® RC 9305 for 'basic' hydraulic fluids that meet national and international specifications (e.g., DIN, ISO, ASTM, ….) Second, the LANXESS premium performance segment - Additin® RC 9200 N and Additin® RC 9300 – covers all of the basic requirements plus approvals obtained from pump testing. And third, we customize specialty additive packages to meet unique requirements of individual customers, regional conditions, and so forth.”

Top tier Additin® packages were developed to provide reliable performance in state-of-the-art pumps, which operate at higher pressures and faster speeds than prior generations. Warranties for new hydraulic systems entail warranties for pumps, and pump OEMs write warranties that require the use of top tier hydraulic fluids meeting their proprietary requirements (or specifications).

Dr. Sandhoefner explained, "There has been a progression from the Eaton (Vickers) V-104C vane pump (1440 rpm / 140 bar), which was used since the 1970s in standard wear tests for hydraulic fluids, to testing with the Parker Denison T6H20C (1750 rpm / 280 bar) and the Bosch Rexroth RFT-APU-CL (4000 rpm / 500 bar) pumps. So, LANXESS started to develop new Additin® packages to provide the exceptional fluid performance that these new pumps demand. But there were unanticipated challenges. (Figures 1 and 2)


Figure 1. The Parker Denison T6H20C hybrid (piston + vane) pump


Figure 2. The Bosch Rexroth RFT-APU-CL piston pump and motor

Pump Tests
Parker Denison and Bosch Rexroth had developed separate qualification tests for hydraulic fluids using their respective pumps. Each pump test of a hydraulic fluid involves many steps and typically requires about two months:

• run-in to condition the fluid and the pump
• phase 1 test
• stop the pump, take the pump apart, photograph, measure and document wear on pump components
• reassemble the pump and put the fluid back into the pump
• run-in
• phase 2 test 
• stop the pump, take the pump apart, photograph, measure and document wear on pump components
• prepare an extensive, standardized report 
• expert evaluation of worn parts and report 

According to Dr. Sandhoefner, the pressure and temperature conditions and duration in the first phase of each OEM test challenge the performance of premium hydraulic fluids. (Figure 3)


Figure 3. Comparison of both test procedures

The second phase increases the severity of the operating conditions. In the case of the Parker Denison T6H20C test, it is necessary to add 1% water to the hydraulic fluid. The Bosch Rexroth (RFT-APU-CL) test requires operators to increase the pressure from 450 bars in phase 1 to 500 bars in phase 2. 

To accelerate the development of Additin® packages for top tier hydraulic fluids, LANXESS purchased test rigs from Bosch Rexroth and Parker Denison and installed them in their laboratory in Mannheim.

Additin® RC 9200 N Approvals
LANXESS has two additive packages in their portfolio that perfectly fit the top tier hydraulic fluid requirements of pump OEMs. 

Additin® RC 9200 N is a premium metal containing performance additive package with a low level of zinc. Performance strengths include high thermal and hydrolytic stability, excellent filtration properties and a balance of anti-wear, antioxidant and corrosion protection properties. Recommended treat rate of Additin® RC 9200 N for premium fluids is 0.6%, which provides less than 300 ppm zinc in the finished fluid. 

Already, Additin® RC 9200 N has been approved for stationary hydraulic machinery and mobile hydraulic traction drive systems. (Figure 4)


Figure 4. Premium Additive Package: Additin® RC 9200 N

LANXESS also obtained the Bosch Rexroth RDE 90235 approval to a formulation of 0.6% Additin® RC 9200 N (by weight) in an API Group II (ISO 32) neutral base oil from Chevron. 

Sandhoefner explained, "This approval automatically covers all hydraulic fluids formulated with Additin® RC 9200 N in this specific base oil. LANXESS received a letter of approval from Bosch Rexroth with an approval rating number in the 4th Quarter of 2018. Our customers can use this approval rating number to gain their own reblend approval for their hydraulic fluids formulated with Additin® RC 9200 N in the Chevron Group II oil. Work is underway at LANXESS to obtain Bosch Rexroth approval of Additin® RC 9200 N formulated in a second base oil." (Figure 5)


Figure 5. Approvals for Additin® RC 9200 N

LANXESS has also received a series of HF-0 approvals from Parker Denison for hydraulic fluids formulated with Additin® 9200 N in Group I oil and Group II oils.

Additin® RC 9300
LANXESS has also commercialized Additin® RC 9300 for the formulation of top tier ashless hydraulic fluids. Additin® RC 9300 meets all major hydraulic specifications and is suitable for use in API Group I, II, III, and IV (PAO) base oils. Formulations made with Additin® RC 9300 in several base oils have received HF-0 approval from Parker Denison. (Figure 6)


Figure 6. Premium Additive Package: Additin® RC 9300

LANXESS also recommends Additin® RC 9300 as a multifunctional additive package for various applications including compressors. 

LANXESS seeks to obtain full read across approvals based on hydraulic fluids formulated with Additin® RC 9200 N and Additin® RC 9300 from Bosch Rexroth and Parker Denison. Full read across approvals provide automatic approval of hydraulic fluids formulated with these Additin® products and any type of mineral base oil.

Economical
LANXESS premium hydraulic packages provide a high economic efficiency due to their very low treat level of 0.6% by weight.

Net treat costs as well as necessary stock volume are reduced compared to many other hydraulic additive packages commercially available.

LANXESS supports its customers in testing, qualifying and obtaining OEM approvals. 

All LANXESS products are sold in accordance with LANXESS General Conditions of Sale and Delivery and without warranty unless otherwise expressly stated.

Additin®, LANXESS and the LANXESS logo are trademarks of LANXESS Deutschland GmbH or its affiliates. All trademarks are registered in many countries in the world.