Automatic Oil Absorption Tester

Ideal for Evaluating Negative Electrode Materials for Secondary Batteries

The performance of secondary batteries, including lithium-ion batteries, depends heavily on the quality of carbon black and graphite-based materials used for negative electrodes. Oil absorption (DBP absorption) is widely used as an index to quantitatively evaluate the structure (aggregate structure of particles) of carbon black, and is an essential parameter for predicting the formation of conductive networks within electrodes and the impregnability of electrolyte solutions.

The S-500 has been adopted by major domestic and overseas battery and material manufacturers, earning high acclaim in acceptance inspections of negative electrode materials, lot-to-lot quality control, and R&D for new materials. The adoption of a speed control motor suppresses the temperature rise of the device, realizing stable repeatability even for electrode materials sensitive to temperature changes.

It also supports powders that react with minute torque, such as acetylene black and Ketjen black used as conductive additives. Its unique torque detection mechanism enables clear endpoint detection even for low-structure materials.

Measurement Principle

The S-500 measures oil absorption using the torque change method in conformity with JIS K 6217-4. The sample powder is placed in a mixing chamber, and DBP (dibutyl phthalate) is dripped at a constant rate by a high-precision macro metering pump while being kneaded by blades.

As the powder absorbs the liquid, the torque applied to the blades increases, and eventually, when the powder is saturated with the liquid, the torque drops sharply. The point at which it reaches 70% of the maximum torque is defined as the measurement endpoint, and the oil absorption amount (mL/100g) is calculated from the amount of liquid dripped up to that point.

The combination of precise liquid feeding control by the high-precision macro metering pump and a highly responsive torque sensor significantly reduces variations between operators compared to conventional manual spatulation methods.

Supported Samples

The S-500 can measure the oil absorption of a wide range of powder materials, not limited to carbon black. It is used in the following industries and applications:

• Carbon Black — For rubbers/tires, conductive additives for batteries, inks/paints
• Electrode Materials — Graphite negative electrode materials for lithium-ion batteries, silicon-based composite materials
• Silica (White Carbon) — Tire/rubber additives, cosmetic raw materials
• Calcium Carbonate — Fillers for papermaking, paints, and plastics
• Pigments / Ceramic Powders — Dispersions for inkjets, electronic component materials

The measuring liquid is not limited to DBP; it can be switched to linseed oil, silicone oil, water, NMP (N-Methylpyrrolidone), DOP (dioctyl phthalate), etc., depending on the sample or standard.

Main Features

• Adoption of a speed control motor — Suppresses device temperature rise and stabilizes rotational speed
• Proprietary torque detection mechanism
• Simple temperature control function (Adopts heat insulation structure)
• Built-in high-precision macro metering pump (Variable dripping speed, easy calibration)
• Supports DBP, linseed oil, silicone oil, water, NMP, DOP, etc.
• Built-in thermal printer
• LCD touch panel operation
• Standard inclusion of PC communication software (Can be used without a PC)
• Compact and lightweight — Approx. 50kg
• AC100V (200V support for overseas available)

Options

• Buffer tank unit
• Approximation formula correction function
• Stainless steel measuring unit
• High torque type (Maximum 20Nm) — For tire carbon black

Main Specifications