Corrugated board flatness is one of the important indicators of carton production technology, it is directly related to product printing, mounting pit, die cutting or bonding quality. Corrugated cardboard flatness difference, will produce corrugated cardboard multi-arch shape, mechanized adsorption printing easy to stuck and cause cardboard scrapped and forced to stop cleaning; two-color printing or multi-color printing prone to ink uneven, The color of the edge of the gap, etc .; in the slot machine slot size displacement, carton up and down the lid overlap or not fit; die cutting feed will also produce stuck and size displacement defects, and may lead to a large number of cardboard scrapped.
In order to improve the corrugated board flatness, to ensure product quality and pass rate of normal production efficiency, we continue to test carton production practice analysis, worked out some improvements. Are summarized as follows.
Corrugated cardboard flatness of the appearance of poor shape
Corrugated board flatness of the appearance of the shape of the general can be divided into three types: horizontal arch, vertical arch and any arched.
Horizontal arched, refers to the corrugated direction along the arches; vertical arch, refers to the cardboard along the speed of the production line vault. Arbitrary arches, which are undulating arches in any direction. The surface of the paper surface is called the arch, the surface of the paper arch called the negative arched, the surface, the paper surface of the ups and downs are known as positive and negative arches.
The main reason for affecting the flatness of cardboard
1. Face paper type, grade different. There are imports, domestic kraft paper, imitation kraft paper, corrugated paper, tea board paper, high-strength corrugated paper, etc., and points A, B, C, D, E, level. According to the paper poor material, the general paper than the paper to be better.
2. The main technical parameters of the paper in the surface. From the performance requirements of the carton or the user from the cost reduction considerations, requiring the carton side of the paper are different, usually:
(1) The amount of paper in the face is different. There is a large amount of paper and paper.
(2) paper paper moisture content is different. Due to the supplier, transport inventory and other environmental humidity is different, there is a paper than the paper moisture content, there are small.
(3) surface paper quantitative, moisture content is different. First, the amount of paper is greater than the paper, moisture content is greater than the paper or less than the paper. Second, the amount of paper is less than the paper, moisture content is greater than the paper or less than the paper.
3. With the same paper moisture content is different. Part of the paper moisture content is greater than the other part of the paper or between the two ends of the paper, the outer edge of the side; core side of the water content is different.
4, the paper by the preheater (package angle) heating surface length selection and improper adjustment or (wrap angle) heat and length can not be arbitrary, affecting the preheating drying effect.
6. After the paper is preheated, the moisture content is insufficient or the humidity is large, the ventilation is poor and the production line is inappropriate.
7. Single-sided corrugated machine, glue the amount of glue on the improper, uneven and the introduction of cardboard shrinkage uneven.
8. Vapor pressure is insufficient, unstable, trap and other accessories damaged or pipeline water discharge at the end of the discharge caused by the preheater can not work properly.