Why are the above requirements for gray paper on moisture specifications so high?
According to the characteristics of gray board paper,product brand and packaging requirements,the quality inspection requirements are relatively high.
The size is only the index of the board quality standard.The flat paper is the length and width,the web is only the width,and the cardboard size is expressed in mm.The allowable dimensional deviation of the cardboard does not exceed±3mm.It is very important,because the paper coming out of the paper machine has lines,and the direction of the grain is parallel to the latter size of the specification.For example,the grain direction of 787*1092 is parallel with 1092,and the grain direction of 889*1194 is 1194.In parallel.
Quantitative refers to the weight of paper in a square meter area.It is generally expressed in g/m2.
The quantitative up-and-down deviation of single gray paper,double gray paper and composite gray board is+3%-5%.Taking 600g as an example,its quantitative standard should be between 570g and 618g.Exceeding this range is unqualified product.
Thickness is the thickness directly measured by a certain pressure between the measuring surfaces on both sides(measured by a pressure of±0.1kg).It is expressed in millimeters or micrometers.
The thickness of single gray paper,double gray paper and composite gray board is 0.155mm~0.16mm per 100g.Taking 600g as an example,its thickness standard is between 0.93mm~0.96mm.
Moisture refers to the water content of the fiber in the cardboard.It is expressed in%.According to the standard GB,single-gray paper and double-gray paper,the water is 6%~12%,and the composite double-grey board is 9%~16%.9%~16%,composite ash board 9%~16%.