Fully interpret the paper characteristics of gray paper
Gray cardboard is produced from a recycled waste paper.The product is divided into single gray cardboard,double gray cardboard,all gray cardboard,the paper surface is smooth and flat,the stiffness is good,no deformation,no separation,bending resistance,the quality of high-grade paper,the price of mid-range paper,gray cardboard is imported high-priced paper Terminator.It belongs to environment-friendly packaging materials.The application scope of gray cardboard is:packaging box,advertising board,luggage,hardcover book,storage box,sample,liner,partition and so on.
It refers to the weight per unit area ofpaper,expressed in g/m2,which is the weight of one square meter of paper.The degree of paper quantification determines the physical properties of the paper,such as tensile strength,tear,tightness,stiffness and thickness.Therefore,according to the characteristics of the equipment,the printing of the corresponding prints corresponding to their performance can be arranged to better reduce the consumption and improve the product quality and equipment efficiency.
It is the thickness of the paper,and the unit of measurement is usually expressed in mm.Thickness is closely related to quantification and tightness.Generally speaking,the paper thickness is large and its quantitative correspondingly high,but the relationship between the two is not absolute.Some papers are thin,but their weight is equal to or greater than the thicker one.This indicates the degree of tightness of the fiber structure of the paper,which determines the basis weight and thickness of the paper.From the perspective of the use effect,it is very important that the paper thickness is uniform.Otherwise,it will affect the automatic paper feeding,sizing,etc.
It refers to the weight of paper per cubic centimeter,with g/cm3.The tightness of the paper is calculated by the formula and the thickness according to the formula:D=G/d*1000,where:G indicates the basis weight of the paper;g is the paper thickness of.Tightness is a measure of the degree of tightness of the structure of the paper.If the tightness is too large,the paper is easily brittle,the opacity and water absorption are significantly reduced,and it is not easy to dry.
It is also easy to calculate the thickness of the cardboard according to the above formula.Its formula is:d=G/D.
Example:Find the thickness of 500g/m2 double gray cardboard(the tightness of the tab stop 0.625g/cm3,which is also our common indicator).500g/m2÷0.625g/cm3=0.0008m=0.8mm
The unit conversion of m2 and cm3 mentioned in the previous step should be remembered,otherwise it is easy to cause misunderstanding.The method is:cm3/m2=(1*0.000001)m,which is converted into mm to be our actual thickness.
It is the performance of the paper against the indentation of another object,and it is also the rough performance of the paper fiber structure.
It refers to the degree of unevenness on the surface of the paper,expressed in seconds,measurable.The detection principle is:the time taken for the air of a certain solvent to pass through the gap between the surface of the glass plate and the surface of the sample under a certain degree of vacuum and pressure.The smoother the paper,the slower the air passes,and vice versa.
It refers to the dimensional variation that occurs when paper is lost after moisture absorption or water dispersion.The softer the fiber structure of the paper,the lower the tightness,the higher the stretch ratio of the paper;on the contrary,the lower the stretch ratio.
The water content in the cardboard.Generally speaking,it is standard.Double gray cardboard has a water content of 8-12%.
8.Vertical and horizontal
It refers to the direction in which the fibrous tissue of the paper is aligned.During the papermaking process,the fibers follow the direction in which the paper machine runs in the longitudinal direction of the paper.It can be identified from the sharp angles presented by the mesh marks.Vertically perpendicular to the longitudinal direction,the longitudinal paper grain uses a small deformation value,and the transverse paper grain has a large amount of expansion and contraction during use.
In general,the thinner the paper,the lower the tightness,the greater the breathability.The unit of air permeability is ml/mim(ml/min)or s/100 ml(sec/100 ml),which means the amount of air passing through the paper in 1 minute or the time required to pass 100 ml of air.
10.Front and back
During papermaking,the pulp adheres to the steel mesh to characterize the manner of filtration and dewatering.In this way,if one side of the net is lost with water due to fine fibers and filler,the web marks are left and the paper surface is thick.The other side is not close to the net.Smooth,so that the paper forms a positive and negative surface difference,although drying and calendering in production,there are still differences between the front and the back.