As early as 156 years ago, the British discovered the corrugated structure and invented corrugated packaging. The corrugated box industry in today’s world is undergoing rapid changes. The corrugated board production line is an assembly line composed of the reel base paper after corrugating, gluing, bonding and shaping, paper separation and pressing, cross-cutting into specification board, and finally stacking and outputting. From structure, speed, specification to control, corrugated cardboard production line has experienced a century-old development process from simple to modern, from low speed to high speed and from mechanization to computer digital control mechatronics.
In the early 1920s, the production technology of corrugated products began to replace the early manual operation with stand-alone production.
In 1922, the electric single-sided corrugating machine with a width of 1.32 meters was born.
In 1923, a single-sided corrugating machine with a width of 1.6 meters appeared.
In 1925, a single-sided corrugating machine with a width of 1.88 meters came out.
In 1938, a single-sided corrugating machine with a width of 2.2 meters was launched.
In the 1940s, the continuous rotary single-sided corrugating machine came out.
In the 1950s, driven by the rapid development of the world economy and trade, a double-sided corrugated cardboard production line that connected multiple processes appeared. The width of the cardboard production line in the initial period is generally only 1000~1600mm, and the running speed is only 60~100m/min. After the advent of single-sided corrugated cardboard, it has been developed for 64 years.
In 1950, the double-wafer composite corrugated cardboard assembly line was born.
In 1959, a mechanically linked corrugated board production line was manufactured. Main achievements in the development of tile lines: starch paste glue started to be used in the 1960s; automatic stacking machine; single-sided machine without guide jaws; automatic slitting and creasing machine; central control concept; preheater and double-sided heat input Quick adjustment; direct drive cross-cutting machine. In addition to the application of starch paste glue, the tile line in the 1970s has experienced many other developments.
A new generation of carbon-free cold setting corrugator production line
The invention of “corrugated” by the British was the first wave; the invention of “honeycomb” by the Americans was the second wave, and it took more than half a century; now the Chinese invented the “carbon-free cold-setting corrugated production line”, which has become a The third wave. But it must be seen: the output of corrugated boxes is on the rise, and the civilization of the enterprise is still in the primary stage of the global modern corrugated industry compared with the modern international level. Therefore, the Chinese corrugated industry needs to study advanced countries even more. It is the third generation of corrugating machines after corrugating and honeycomb.
The cold-setting stand-alone patent has won the patent gold medal at the Geneva International Patent Achievement Expo.
Microwave cardboard production line, that is to say, the production line does not need boiler, gas, oil furnace heating to avoid pollution, reduce production costs, and improve production environment. Extended service life.
The electromagnetic wave production line is transformed from the microwave production line. The performance of the cold-setting electromagnetic wave cardboard production line is better than the first two, and it can integrate printing, slotting, and creasing, and can be tracked by computer throughout the process.
The new low-temperature adhesive is also called “cold setting” adhesive. It adopts a new generation of self-developed polymer adhesive and does not need to be heated and cured at high temperature. Natural drying in the curing channel increases the toughness and realizes fast bonding at room temperature. It is composed of polymer resin and corn starch, with high initial viscosity, less glue consumption, reliable effect, and the glued corrugated cardboard is not easy to open glue. And it also solves the bonding problem of high-sizing paper and high-density paper. Compared with the traditional starch glue, the adhesive strength is increased by more than 10%, and the product yield is significantly improved, usually reaching or exceeding the national standard. Industrialization has been realized.
Normal temperature setting technology
(1) Corrugated forming – redesign of corrugated roll shape
Common sense tells us that when the fiber has a certain moisture content, it is easier to heat and form. Electric irons, spray irons are good examples. The corrugated paper of traditional corrugated cardboard production equipment uses this thermal processing principle. Under the same moisture content at room temperature, it is also possible to change the shape of the fiber (paper) under the action of external force. There will be two problems first, one is the rebound, such as origami, the external force is not enough, the paper folded in half It will rebound and stretch out; the second is excessive force, and the fibers are damaged. In short, the forming is not ideal. If you want to fold the paper at an angle of 30°C, it will either be overstressed and folded to 5°C, or the paper will bounce to 60°C.
On the basis of several experiments, and through the production of a simulation machine, four single machines and two production lines, we have successfully determined the corrugated shape of the corrugating roller. Under the condition that the A, B and C flute requirements of national standards are maintained, the optimal radius ratio of flute tip and flute bottom is 1:1.08. In order to meet the requirements of different paper specifications and different users, we design the meshing degree of the main corrugated roll and the main auxiliary roll to be adjustable. And the paper thickness is adjustable.
(2) Differential feeding–solve the problem of paper breakage under optimal stress conditions
In the test to determine the optimal tile tip and tile bottom radius, we also encountered the problem that the tile paper often breaks. After eliminating the factor of the quality of corrugated paper, we analyze that the stress state of normal temperature setting and thermoforming corrugated paper is different in the section between the feeding mechanism and the corrugating roller, and it is not easy to break; while the normal temperature forming is at room temperature Under the work, the tile paper has no size change in the longitudinal direction, and the corrugated paper is subjected to a large force at room temperature, so it is easy to break the paper.
After finding the reason, we immediately redesigned the transmission ratio of the single-sided corrugating unit. Ensure that the paper feeding speed of the corrugated paper is slightly faster than the receiving speed of the corrugated roller, and can be adjusted, that is, differential feeding, to ensure that the corrugated paper enters the corrugated roller in a tension-free state from the feeding roller to the corrugating roller. . So far, we have successfully solved the technical problem that the normal temperature forming corrugated paper is easily broken.
(3) Differential compensation
Differential speed compensation method, when the face paper contacts the glued single-sided corrugated cardboard, the face paper begins to expand, and it is easy to cause uneven tension, which is easy to produce the phenomenon of off-line corrugated cardboard, uneven surface, warping and other phenomena. The speed compensation method makes the surface paper fully expand after absorbing the glue, so that the tension remains the same forever, which solves the unevenness and warpage of the cardboard. The compensation method is to use different linear speeds to achieve the purpose of compensation.
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