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).
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.
How do you detect Cobb in paper?
Approx. 100 ml of water is poured into the cylinder. After 30 Minutes, the water is poured out. The specimen is weighed while wet and the amount of water absorbed by 1 m² of specimen material is calculated.
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 is meant by Cobb control in paper manufacturing processing?
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 determine the strength of a paper?
The strength of paper is determined by the following factors in combination: (1) the strength of the individual fibres of the stock, (2) the average length of the fibre, (3) the interfibre bonding ability of the fibre, which is enhanced by the beating and refining action, and (4) the structure and formation of the
Is standard for Cobb test?
The Cobb Test is carried out according to the following standards: ISO 535, EN 20535 and
How can Cobb value be reduced 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.
What is it called when paper absorbs water?
The water is being absorbed, or soaked up, by the paper towel material through a process called capillary action. Capillary action, also known as capillarity, is the rising or absorption of liquids through small gaps and holes certain materials.
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.
Why do we do Cobb test?
The direct Coombs test is used to detect antibodies that are stuck to the surface of red blood cells. Many diseases and drugs can cause this to happen. These antibodies sometimes destroy red blood cells and cause anemia .
Why is it called Cobb?
Cobb salad received its name from a restaurant owner named Robert Cobb. After a long night of service, Chef Cobb was tired and hungry at the Brown Derby in Hollywood, CA. He threw together a bunch of leftover ingredients into a bowl with lettuce and tossed them together with French dressing.
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 the pH of pulp?
Before processing, the raw pulp pH is in the range of 7-8. This should be controlled and brought down to acidic range i.e. 5 to 6 pH.
What is quality control in paper industry?
A quality control system (QCS) is installed at the final stage of the paper machine to measure the final quality of the manufactured paper. A QCS accurately measures the paper to ensure uniform quality, thus significantly contributing to improved quality and efficiency during the paper production process.
Which paper is the strongest?
Because of its strength and durability, scrim paper is used to wrap heavy materials including lumber and steel. Scrim in the paper reinforces it to avoid rips and tears that would occur with regular paper when sharp edges or corners come into contact with the packaging.
What type of paper is strong?
Kraft. Kraft paper typically produced during what is known as the Kraft Process where wood is turned into word pulp. This process keeps almost all of the wood fibers making it 100% recyclable, durable and strong. This makes it the ideal paper for shipping and packaging.
Which paper would make the strongest paper bag?
Ivory paper is thick and durable so the paper bag is also firm and stronger. This paper has a bright white color, and often used in printing offset to give sharp designs and high quality.
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.
What is kit value in paper?
The highest numbered solution (the most aggressive) that remains on the surface of the paper without causing failure is reported as the ‘kit rating’ (maximum 12).
What are test standards?
Software testing standards are a set of rules or standards that are expected to be met in a particular product or service offered by a company.
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