5 layer 1800mm corrugating paperboard making line
5 layer 1800mm corrugating paperboard making line
Types of pits
According to the size of the pits on the core paper, i.e. its
height and the number of pits in each unit length, the corrugated
board can be further subdivided. Core paper pits
corrugated board
There are four kinds, and the following table shows the paperboard
produced by Mitsubishi and Langston pit machines.
Compared with "B" and "C", cartons made of thicker "A" pits have
better top and bottom compressive strength, but compared with "A"
and "B" pits, thinner "B" pits have better resistance to upward
pressure. The "A" and "C" pits are used in the manufacture of
cartons which are pressed from bottom to bottom and need pads for
packaging. The "B" pit pattern is suitable for the manufacture of
cartons where the capacity and space are more important and the
stacking strength is less important. The "E" pit pattern has the
highest compression resistance, but its shock absorption ability is
slightly poor, which is mainly used in offset (color printing)
corrugated boxes carrying heavy objects.
Core paper material
corrugated board
The bigger the pit diameter of corrugated board is, the stronger
its rigidity is. The toughness of paperboard comes from the core
paper layer, without thick and hard fillers, which can reduce the
weight and cost of paperboard. Core paper can be made of
semi-chemical pulp (this kind of pulp can provide the best paper
strength) and recycled paper. The latter is adopted by many
manufacturers because of its low cost. Although the paper strength
is not as good as the former, it can be improved by adding starch
in paper mills.
Pit pattern occupies a certain space in corrugated paper, and its
role is also very important, through which it can withstand flat
pressure, lateral pressure and other irregular pressures.
Cowhide card
The main function of cowhide card is to form the inner layer and
outer layer of corrugated cardboard, and its function can be
structural or decorative. Each layer of cowhide card provides a
variety of characteristics for cardboard, and these characteristics
can be expanded through processing procedures such as bonding and
waxing.
