Falling Rod Viscometer Ink Viscosity 2-200Pa·s Automatic Timer

Product Features & Attributes
This falling rod viscometer (also known as Laray viscometer) is used for determining rheological properties of paste inks, vehicles and pigments including apparent viscosity, yield value and shortness. It is ideal rheological testing equipment for printing ink production, coating laboratories, packaging material quality inspection and third-party testing institutions.

Working Principle: Fill the fixed metal slit groove with ink sample. Apply graded weights to the standard falling rod, which drops vertically by gravity. Photoelectric sensors precisely record the time over a 100mm drop stroke. Using the Casson/Bingham fluid model linear regression, three core rheological parameters are automatically calculated: apparent viscosity (Laray viscosity), yield value (minimum force for ink to start flowing), and shortness (characterizing ink stringiness, thixotropy and dot transfer performance).

Structural Features:

• Vertical test main unit: Precision metal guide rail, falling rod, constant temperature water jacket, photoelectric sensor assembly

• Separate control box: Independent digital display for clear reading

• Complete standard weight set: 9 gradings (25g, 50g, 100g, 200g, 200g, 500g, 1000g, 1000g, 1000g), total 4075g

• Constant temperature water circulation system: Standard jacket with 25℃±2℃ precise control

• Ink mixing scraper, leveling base, calibration accessories

Technical Features:

• Separate design for clear reading and easy operation

• Precision metal guide rail for high rod verticality, minimal test error

• Multi-weight combination for wide viscosity range coverage

• Standard water jacket eliminates temperature interference

• Fully automatic photoelectric timing (0.01s accuracy) eliminates manual timing errors

• Shear rate reference 2500s⁻¹, matching actual printing shear conditions

Technical Parameters:

• Total weight (main unit + control box + weights): 18kg

• Power supply: AC220V, 50Hz

Operation Procedure:

1. Temperature control: Pre-condition instrument and ink samples to 25℃

2. Sample loading: Fill the slit groove evenly with ink, level the surface

3. Weight loading: Test from heaviest to lightest, valid data requires two drop time differences ≤0.5s for same weight

4. Data acquisition: Control box automatically records drop time, outputs viscosity, yield value and shortness

Calibration Requirements:

• Factory pre-calibrated, recommended recalibration every 6 months

• Compare with standard oil: deviation >20% requires rod/guide replacement

• Deviation ≤20% can be compensated with correction factor

Available in different specifications: different rod sizes (Φ12mm, Φ10mm, Φ15mm, etc.) and different weight configurations (standard, light, heavy) to suit various ink viscosity ranges and testing standards.

Mainly used in printing ink manufacturers, coating laboratories, packaging material quality inspection institutions, pigment R&D units, third-party testing institutions, university material laboratories, and more for rheological testing of paste inks and vehicles.