The congressional layer is used in a corrugated cardboard, in the form of a ripple layer between the two layers of paper, the base weight of the intermediate layer of the congress is between 80 and 200 grams per square meter,
The congressional layer gives the required strength to the carton. The most important properties of this type of paper are rigidity and resistance to crushing and fracture. Properties related to mechanical strength such as tensile strength, cracking and tear are not considered important. In many cases, the appearance of the paper can also be passed, a special feature of the conical paper is the ability to pass it into a machine, the ability to cross here means the power of the sheet to withstand tensions and stretches in the congressional operations. Without leaving and breaking, there are two increasing factors in the ability to pass the sheet, high elasticity, and the absence of pebbles of wood and fibers together. These specifications are due to the fine refining of the dough and less elasticity in the process of drying the sheet to optimize the pullability of the conical paper, the fluting paper should have a higher water absorption than the paper liner test because the absorption of very low water prevents penetration The glue is in the paper, given that the fluting paper acts as a buffer in the carton sheet and its congressional structure must be capable of distributing the forces applied to the package, this type of paper should be able to withstand after the congress Static and reversible after environmental forces.