Cardboard is one of the main materials for making hardcover bookcases and thread-bound books. Paper with a basis weight of 225 g/m2 is called paperboard.
Cardboard generally refers to the number and thickness of its number, for each increase in number 1, the cardboard quantitative increase of 55g/m2, the greater the number, the smaller the number of cardboard in each piece. Books and magazines used in cardboard binding cover cardboard, envelope cardboard, grass cardboard, white cardboard and so on.
1. Cover board
The cover board is made of cardboard for cover books, picture books, etc. It is a high-grade cardboard made from wood pulp, semi-chemical wood pulp, waste paper pulp, etc. Cardboard color is fiber color, after calendering, smooth surface, no sizing, tightness, not easy to warp, is an ideal material for high-grade hardcover bookcase.
The cover board is a plane board. The board size is 1350mm x 920mm. The cover board has three kinds of thickness: 1.0mm, 1.5mm and 2.0mm. The main technical indexes are as follows: QB355-73: tightness is not more than 0.9g/cm3; tension resistance ( The vertical and horizontal average is not less than 140kgf/cm2; the water content is about 10%. Each piece of cardboard weight is not more than 250kg.
2. Envelope cardboard
Wrapped cardboard is a cardboard used to make hardcover books and book covers. The original color of the paperboard is not sizing. The cardboard is calendered, flat and warped, and has a high degree of folding resistance. The envelope cardboard is a plane cardboard. Cardboard size,
Thin type is 1150mm x 880mm, and thick type is 1350mm x 920mm. Cardboard has 0.7mm, 1.0mm, l.5mm, 2.0mm and 2.5mm five kinds of thickness, according to the provisions of QB1316-91, the main technical indicators are: tightness, A type is not less than 0.75g/cm3; B type is not Less than 0.70g/cm3. The folding endurance (vertical and transverse average) is not less than 20 times, and the water content is about 10%. Tensile strength (vertical and horizontal average) according to its thickness 0.7mm, 1.0mm, 1.5mm, 2.0mm, 2.5mm should not be less than, A type is 14, 20, 29, 39, 49kN/m2; B type is 11 16, 24, 31, 34kN/m2. Each piece of cardboard weight is not more than 250kg.
3. Grass cardboard
Grass board is also called horse dung paper board. It is a kind of binding board used earlier in China. Its surface is rough and yellow. It is made from straw fiber as the main raw material. Grassboard size is generally 787mm × 660mm, 787mm × 1092mm, 787mm × 546mm and several other types of flat packaging, divided into symbols, one and two three. Grass board thickness is generally 0.7mm.
The use of grass cardboard for making book covers is inexpensive. However, the cardboard has a low degree of tightness, short fibers, strong water absorption, poor cardboard toughness, and easy paper breakage and warpage. When the book shell is made of cross-hatch paper cardboard paste, or before use, heating, pressure, so that the surface is flat, tightness, humidity is appropriate, can prevent warping, the package can be used to prevent damage. Choosing the right cover material can increase its toughness.
4. Single white cardboard
The surface of the single-sided white paperboard is white, smooth and flat, and the ground is white and rough. Strong water absorption, soft texture, thin and crisp, and resistant to folding, suitable for single-sided color printing and packaging. Book binding is mostly used to make book covers, soft book covers, flexible cover hard liners, hardcover round back cover, etc.
Single-sided white cardboard is flat paper, divided into No.1, No.2 and No.3. The board size is 787mm×1092mm.
