Gray cardboard is produced from a type of recycled waste paper. Products are divided into single gray, double gray, full gray, which belongs to environmentally friendly packaging materials. Main uses of products: packaging boxes, advertising boards, folders, photo frame backboards, bags, hardcover books, storage boxes, samples, liners, partitions, etc.
It refers to the weight per unit area of paper, expressed in g/m2, that is, the weight of a square meter of paper. The weight of the paper determines the physical properties of the paper, such as tensile strength, tear strength, tightness, stiffness and thickness. Therefore, according to the characteristics of the equipment, arranging the production of printed materials corresponding to their performance in order to reduce consumption and improve product quality and equipment efficiency.
It is the thickness of the paper, and the unit of measurement is usually expressed by ㎜. Thickness has a close relationship with basis weight and tightness. Generally speaking, if the thickness of the paper is large, the basis weight is correspondingly high, but the relationship between the two is not absolute. Although some papers are thin, their basis weight is equal to or exceeds that of thicker paper. This shows that the degree of tightness of the fiber structure of the paper determines the basis weight and thickness of the paper. From the perspective of use effect, it is very important that the thickness of the paper is uniform. Otherwise, it will affect the automatic paper feed, glue evenness, etc.
It refers to the weight of paper per cubic centimeter, using g/cm3. The tightness of the paper is calculated from the basis weight and thickness according to the following formula: D=G/d*1000, where G is the basis weight of the paper; g is the paper thickness of.
Tightness is a measure of the degree of density of the paper structure. If the tightness is too large, the paper is easily brittle, the opacity and water absorption will be significantly reduced, and it is not easy to dry.