Cobb Sizing Tester

cobb tester

Cobb Sizing Tester

A Cobb tester or Cobb Sizing tester is an equipment which is used for determining the water absorbing capacity of a sheet of paper.

The observance of water is a function of several characteristics of board or paper such as sizing etc. The ability of a material to retain moisture is indicated by the High Cobb value of the paper. The Cobb value should be maintained if it depends on the application of the board. The Cobb test measures the amount of water absorbed by the paper at a specific period. 

There is a metal ring in the Cobb tester that holds the sample of paper. This ring is then placed in water for a specific time.

Excess water is removed after the test and the wet paper is measured by a weighted. 

Hence, Cobb testers evaluate the quality of the paper and its ability to withstand moisture.

Model      ELI-CST

Procedure Cobb Sizing Tester

Effective Lab India manufactures the best Cobb tester according to industrial standards. The standard operating procedure of Effective Lab India according to the ISO standards is mentioned below.

  • Pick up the sample of the corrugated box and weigh it to 0.1 grams.
  • Place the cork sheet on a metal plate and after it place the specimen and clamp it firmly. The clamping is for preventing any kind of leakage between the ring and the sample.
  • If you would like to ensure leak-free clamping then use a soft gasket of the same dimension as the ring.
  • Now, put water into the fixture according to the sample requirement.
  • Hold the sample for some time. (120 seconds for paper and 300 seconds for a corrugated box).
  • If any sample shows the sign of leakage. Reject it.
  • If the sheet to the rubber mat goes through any liquid, then the test will not be acceptable.
  • After completion, the buzzer starts buzzing. If it’s going then pick up the sample from the tester.
  • Drain out the excess water from the sample with the help of a hand roller.
  • After that, weigh the sample again and your test is completed.

Formula of Cobb Test

For calculating the Cobb value use this formula.

Cobb value= Weight of the sample after testing – Weight of the sample before testing.

You can easily test the Cobb value of paper by following the above standards of Effective Lab India’s Cobb tester.

  • High: Grade stainless steel test area
  • Single handed High-Quality hassle free operation
  • Fast Locking Mechanism
  • Highly accurate test results
  • Lightweight and resilient
  • Rugged structure with corrosion resistant main body
      • Sample Diameter: 130 mm (approx)
      • Weight of roller: 10Kg (approx.)
      • Diameter of rubber pad: 145 mm
      • Water level indicator in cylinder: 10 mm and 25 mm
      • Depth of cylinder: 60 mm

    Get in Touch

    6 + 1 =

    Cobb tester manufacturers

    If you are in search of the best manufacturers and suppliers of Cobb testers, then effective Lab India best suits you.

    Our products are purely designed by a team of experts and these are ranked.

    Contact us online or place your order by visiting us in Faridabad India.

    If you would like to know the Cobb tester price or other information about the equipment then contact us online.

    Our team will assist you with your queries.


    1: What is a Cobb tester?

    Ans: It is a testing instrument for determining the water absorptivity of paper or corrugated cardboard.

    2: How do you test Cobb’s value?

    Ans: Cobb value is tested by using the formula.

    Weight of sample before testing – the weight of the sample after testing.

    3: What is the ISO standard for the Cobb test?

    Ans: The ISO standard for the Cobb test is 535.

    4: Why is Cobb’s value important?

    Ans: The Cobb value is important for measuring the absorption of water or any other liquid on paper or corrugated boxes.

    5: What is the Price of the Cobb tester?

    Ans: The Pricing of the Cobb tester is 16000 INR to 22000 INR in India.

    Our Related Products

    Hot Air Oven

    Peel Seal Bond Strength Tester 

    TP 800 Portable spectrophotometer

    Co- Efficient of Friction Tester

    Bursting Strength Tester

     GSM Round Cutter Machine

    Color Matching Cabinet

    Box Compression Tester

    Laboratory Heat Sealer

    GSM Balance- Digital Model

    Edge Crush Tester

    Tensile Testing Machine