What Is A Good Cobb Value?

Cobb values for liner grades are typically specified as being Target 100g/m² up to a Maximum of 150g/m², which means they are moderately chemically sized, and this applies across a broad range of paper weights possibly from 100g/m²–440g/m².

What should be Cobb value paper?

The COBB value has to be maintained as per the need of paper or board. This test procedure includes a quantity of water absorbed in a specified time by no bibulous paper and paperboard with a minimum 0.1 mm thickness.

What is Cobb value?

The Cobb value provides information about the water absorption capacity of cartonboard samples. The Cobb test determines the amount of water that is taken up by a defined area of cartonboard through one-sided contact with water, within a certain amount of time.

For what materials that Cobb value offers resistance against moisture absorption?

Cobb value or water absorptiveness of paper board or other materials explains various features of paper like sizing, porosity, etc. This test can be done to measure the resistance power or absorption of water, oil, or other liquids.

What does Cobb mean in paper?

Cobb test (sized papers and paperboards)
The Cobb test determines the amount of water absorbed into the surface by a sized (non-bibulous) paper, paperboard, and corrugated fibreboard paper or paperboard sample in a set period of time, usually 60 or 180 seconds (Cobb60 or Cobb180). Water absorbency is quoted in g/m2.

Why Cobb test is important for packaging?

The Cobb test is essential as it tests the ability of the paper to resist the penetration of water and quantity of water absorbed by the surface of fiberboard. If fiberboard absorbs too much water, the box may have difficulty maintaining strength and integrity.

Is standard for Cobb test?

The Cobb Test is carried out according to the following standards: ISO 535, EN 20535 and TAPPI T 441.

What Cobb means?

cobb (plural cobbs) A sea-cob or gull. A pier made from cobblestones. A hand-basket, especially made from wicker. A building material consisting of clay, sand, straw, water, and earth, similar to adobe.

How does Cobb sizing value play an important role in printing?

Cobb sizing tester measures and calculates the water or any fluid consumed by the paper, fibreboard, and paperboard in at any given point of time during varied climatic conditions. The high Cobb measure of the papers and other related materials determines the capacity of the materials to contain dampness.

What is the use of Cobb?

Cobb sizing tester determines the amount of water or any liquid absorbed by the paper, corrugated fibreboard, and paperboard in a given period of time under some conditions. Water absorptiveness is a function of various characteristics of paper or board such as porosity, sizing, etc.

How do you reduce Cobb in paper?

Surface sizing with mixture of oxidized starch and AKD, at the ratio of 10 to 1, is the best method for reducing Cobb value of the papers along with preserving paper strength, which is used now in the industry for producing fluting and test-liner papers.

How do you test water absorption?

For the water absorption test, the specimens are dried in an oven for a specified time and temperature and then placed in a desiccator to cool. Immediately upon cooling the specimens are weighed. The material is then emerged in water at agreed upon conditions, often 23°C for 24 hours or until equilibrium.

Why is it called the Cobb?

Various stories recount how the salad was invented. One says that it came about in 1938 at the Hollywood Brown Derby restaurant, where it became a signature dish. It is named after the restaurant’s owner, Robert Howard Cobb.

What is burst strength of paper?

Bursting strength or burst resistance is a property of a plastic, paper or corrugated board -used in packaging- and is general a guide to the strenght of that plastic, paper or corrugated board. With a burst tester you define the pressure needed to burst a plastic, paper or paperboard.

What is burst strength?

Burst strength is the strength of material in pounds per square inch. Burst strength can be used to monitor the quality of cold chain packaging. Often called the Mullen Burst Test, burst strength is an industry standard that measures the amount of force required to burst corrugated boxes and flexible packaging.

Why is thickness of packaging material important?

A suitable thickness of packaging film not only increases the barrier performance of packaging materials, but also effects the seal quality of packaging, for the improvement objects, when you performance oxygen transmission, water vapor transmission or heat seal measurement, we suggested you measure the thickness,

Which are important test for glass containers?

• Powdered glass test: Done to estimate the amount of alkali leached from the powdered glass, which usually happens at elevated temperatures.
• Hydrolytic resistance of glass containers:
• Arsenic test:
• Leakage test:
• Collapsibility test:
• Clarity of aqueous extract:
• Residue on evaporation:
• Sterilisation test:

Which test is used as test for packaging?

Bursting strength test (BST)
The burst strength test, also known as the Mullen test, is commonly compared to the edge crush test, as they both evaluate the strength of corrugated or cardboard materials. Together these two tests are the most commonly recommended packaging lab tests for importers.

What are the testing standards?

Miscellaneous

What are test specifications?

Test specifications are iterative, generative blueprints of test design. They are written at the item level, and allow test developers or item writers to produce new versions of a test for different test-taking populations. The specs serve as guidelines so that new versions can be compared to previous versions.

Who invented Cobb test?

In the 1950s, the Strong-Cobb tester was introduced. It was patented by Robert Albrecht on July 21, 1953. and used an air pump.