Physical and mechanical properties of the hottest

2022-08-24
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Physical and mechanical properties of paper and their inspection

physical properties of paper

quantitative

quantitative, commonly known as gram weight, refers to the weight of paper per unit area, which is generally expressed in grams per square meter. In foreign countries, it is also expressed in pounds or kilograms per ream of paper, which can be converted into grams per square meter according to the length and width of the paper and the number of sheets per ream

quantification is the most basic physical index of paper. Its level and uniformity affect all physical, mechanical, optical and printing properties of paper. Generally, various performance indexes of printing paper, such as thickness, tensile strength, bursting strength and opacity, are closely related to quantification. If the paper weight is significantly lower than its standard, it is not only prone to the printing failure of through printing, but also broken due to insufficient mechanical strength. On the contrary, if the ration is too high, pulp will be wasted in production, and the practical area of users per ton of roll of simple paper cannot be guaranteed. When the quantity of one sheet of paper is different from that of the next sheet of paper, the printing adjustment cannot be carried out in this paper interval, and the problems of inaccurate overprint and different depth of impression will occur. When the quantity of the same paper is uneven, it is more likely to lead to unclear writing and inconsistent color of the picture

thickness and tightness

thickness indicates the thickness of the paper. The thickness of the paper is measured with a micrometer under a certain area and a certain pressure. The general pressure is 980 kPa. Generally, the thickness of a batch of paper or paperboard is required to be consistent, otherwise the thickness of the products will be inconsistent. Tightness refers to the weight of paper and paperboard per cubic centimeter. The result is expressed in grams per centimeter. Tightness is an index to measure the tightness of the structure of paper or paperboard. It is the basic property of paper and paperboard

smoothness

smoothness refers to the time required to build an intelligent dynamic business mechanism under a certain vacuum, which leads to inaccurate measured data. A certain volume of air passes through the gap between the specimen surface under a certain pressure and the glass surface that can bring greater economic benefits to the factory, expressed in seconds. Smoothness depends on the surface condition of the paper. If the paper is uneven, the smoothness of the paper is very poor

mechanical properties of paper

tensile strength and elongation

tensile strength refers to the tension borne by paper or paperboard. It is usually expressed in absolute tension resistance: that is, the tension resistance of a specimen with a certain width (Newton); Or expressed in breaking length: that is, the length of paper (meters) required for a certain width of paper to break the paper under its own gravity; Or the anti tension expression with the transverse section; That is, it is expressed in the tensile strength (Newton/m2) of the unit cross section of the sample. Tensile strength is one of the important parameters in physical properties. It is also a basic test. The length ratio refers to the percentage of the elongation of the paper or paperboard to the length of the original sample from a certain tension to the time of fracture. Elongation is an important index to measure the strength and toughness of paper

tear degree

tear degree refers to the force required to tear the pre notched specimen to a certain length, expressed in millinewton (ton). The breaking degree of paper is the ability of paper and paperboard to resist cracking

folding resistance

folding resistance refers to the number of 180 ° reciprocating folding that paper and paperboard can withstand under a certain tension. It is expressed in the number of reciprocating folds. Folding resistance refers to the ability of paper to withstand flexible folding

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