Cobb Sizing Tester

Presto Cobb sizing tester is one of the most accurate testing instruments that is used for fast determination of the quantity of water absorbed by a paper or board in a given time. The Water absorptiveness (Cobb value) of a substance is defined as the mass of water absorbed in a specific time by a 1 sq. meter sample of paper, board, or corrugated board, under standardized conditions. Testing the water absorptiveness of paper products is an essential step in determining how safe it is to use. The main purpose of using a Cobb sizing tester is to determine the various properties of water that includes sizing, porosity, etc. Paper is the most popular material in packaging, for its versatility and cost. Nowadays, paper is still used in many industries to package goods because of its low cost and recyclability. It can be recycled up to 7 times before becoming too weak to use in anything. One thing that makes paper an excellent choice for packaging materials is that it can be processed into different grades and pass several tests to ensure quality. Thus with the help of Presto Cobb sizing tester, you can easily determine the water absorptivity of the cardboard and corrugated box and paper.

Water absorptiveness is a function of various characteristics of paper or board. A high COBB value indicates the ability of the substrate to easily absorb and retain moisture. A low COBB value indicates the ability of the substrate to resist penetration and retention of moisture. Depending upon the application of the paper/board, the COBB value has to be maintained. This test method covers the determination of the quantity of water absorbed in a specified time by no bibulous paper and paperboard with a minimum thickness of 0.1 mm.

To test the Cobb value of the paper, you should first take a piece Sample of a cardboard or paper board, which you need to test. Now, cut the sample in a circular shape more than the diameter of the Rubber pad or fixture. Once you cut the sample, then you need to measure the weight of the circular sample using a digital weighing balance. To place the sample on this testing machine, you should invert the Cylinder by using the screw which is provided on the side of the device to unscrew the rubber pad. After that, place the sample between the cylinder and the Rubber pad and provide smooth support to the sample. After placement of sample, pour 100 ml or 250ml of water up to the marking in the cylinder (as per the requirement of test and size of sample). While performing the test, you must ensure that crushes on the sample must not come while clamping the sample. Now take the sample out and drain an excessive amount of water from the sample using the hand roller by moving the roller over the sample one time forward and one time backward. After the completion of test time, remove the water from the cylinder and measure the weight of the sample using the digital weighing balance. In this way, you can easily test the sample and check its quality.

Water absorptiveness is a function of various characteristics of paper or board such as sizing, porosity. A high COBB value indicates the ability of the substrate to easily absorb and retain moisture. A low COBB value indicates the ability of the substrate to resist penetration and retention of moisture. Depending upon the application of the paper/board, the COBB value has to be maintained. This test method covers the determination of the quantity of water absorbed in a specified time by no bibulous paper and paperboard with a minimum thickness of 0.1 mm.

• To know how this testing instrument works, you can follow the steps mentioned below:
• To operate this testing instrument, you need to prepare the sample first. For this, you can take a small piece of sample like cardboard or paper board that you need to test. Now, you need to cut the sample in a circular shape. You should make sure that the sample you cut should be more than the diameter of the rubber pad or fixture.
• Now, you can easily measure the weight of a circular-shaped sample using Digital Weighing balance. Once the sample will be prepared, you need to place the sample.
• For accurate placement of the sample in this testing equipment, you should invert the cylinder by using a screw that is provided on the side of the device to unscrew the rubber pad.
• When you unscrew the rubber pad, you should place the sample between the cylinder and the rubber pad to provide smooth support to the sample.
• Now, you need to operate this testing instrument by pouring 100ml of water up to the marking of the cylinder. You can tighten the sample manually with the help of the screw provided on the bottom of the cylinder. Ensure that crushes on the sample must not come while clamping the sample.
• Immediately start the stop water for 1 – 10 minutes (as per test requirement) for single-layered to multilayered board respectively. After the completion of test time, remove the water from the cylinder and take the sample out. Drain excessive amount of water from the sample using the hand roller by moving the roller over the sample one time forward and one time backward.
• Now-Again measures the weight of the sample using the digital weighing balance.

In this way, you can easily conduct the Cobb sizing test and determine the Cobb value. Whenever you test the sample, then you should make sure that you should properly put the test specimen on the test fixture.

Features of Cobb Sizing Tester

The Presto Cobb Sizing Tester has been equipped with different set of features that makes it easy for the user to conduct the test. With the help of this consistent testing equipment you can easily check the water absorptiveness (Cobb value) of a given test sample. PRESTO Cobb Sizing Tester is designed as per standards IS 1060, TAPPI –T441. When you check the water absorptiveness value of paper and its related products then you will be able to improve your product’s quality. Thus, you should make the use of Presto Cobb Sizing Tester to ensure that the corrugated box or cardboard can easily retain the water. Here we have listed some of the best features of using this testing instrument. You can have a look at them below.

• High Quality rugged structure with corrosion resistant main body
• Light weight and resilient
• Fast Locking Mechanism
• Single handed hassle free operation
• Highly accurate test results
• High Grade stainless steel test area
• Made with compliance of industry standards

Technical specifications

• Sample Diameter: 130 mm (approx)
• Depth of cylinder: 60 mm
• Diameter of Cylinder: 112mm
• Diameter of rubber pad: 145 mm
• Water level indicator in cylinder: 10 mm and 25 mm
• Weight of roller: 10Kg (approx.)
• Placement of machine: Bench Model
• Two Water Level Indicators in Cylinder: 10mm and 25mm
• Made with standards: TAPPI – T441, IS 1060