Using DICAR Equalizer Pads to Improve Carton Die-cut Quality

Environmental protection has become increasingly popular all over the world. The packaging industry requires more use of non-polluting and recyclable materials to ensure sustainable development. This has led to a rapid growth in the corrugated box industry. Corrugated box forming is divided into lithographic die cutting and drum die cutting. The advantage of lithographic die cutting is that the carton size does not change. The advantages of drum die cutting are the speed and large output. In Europe and America where the corrugated box industry is very advanced, thanks to the advanced drum die cutting technology, 90% of cartons are finished with drum die cutting. China's roller carton industry has just started and has great potential for development. However, in order to achieve quality and quantity breakthroughs, we must solve the quality problems in die cutting. Problems in drum die cutting include: incomplete die cutting, incomplete decanting, inconsistent carton sizes, and so on.
The thoroughness of die cutting and the effectiveness of stripping are related to the durability of die cutters and sponges, and also related to the quality of the bottom pad. Due to the time, we will talk about the quality of the die pad at the end. And the impact of accuracy.
First of all, we need to clarify the differences between lithographic die cutting and cylinder die cutting. The lithographic die cutting is a static die cutting. The die and the cardboard are in contact with each other. Therefore, the size of the carton is exactly the same as the size of the die, and no dimensional change occurs. The roller die cutting is die cutting in the movement. The roller die and the cardboard are in point-to-point contact during the advancement. Therefore, it is difficult to ensure that the size of the carton is completely consistent with the die size.
Therefore, the size of the drum corrugated carton is unqualified or inaccurate, and has always been a quality problem in the drum die cutting. The demand for the packaging industry is getting higher and higher, which makes it difficult for a carton with poor accuracy to pass through automated packaging lines. However, people are reluctant to abandon the advantages of large production speed, high speed, and low cost. Therefore, for decades, people have made numerous efforts to overcome the error in the size of the drum carton.
To find a solution, first understand the cause of the carton size change.
The main factors affecting the accuracy of the solution to seek solutions, we must first understand the main factors causing the carton size changes. Under normal operating conditions, there are four influencing factors:
First, it is the height of the drum die cutter, which is determined by the machine manufacturer and then executed by the die cutter.
The second is the theoretical diameter of the die.
The third is the cutting depth of the roller knife on the bottom rubber pad. Most machine manufacturers recommend a standard plunging depth as the ideal setting, but it can change for different orders. The depth of cut depends on the operator and usually requires a sufficient depth of cut to achieve a thorough cut through the cardboard with a slight margin.
Finally, the surface speed of the bottom drum will normally decrease as the bottom pad wears.
Surface Speed ​​Ideally, the surface speed of the die, the surface speed of the bottom drum, and the running speed of the corrugated cardboard should be the same. Unfortunately, under conventional drum die-cutting conditions, this situation exists for only a short period of time when the bottom pad is completely unworn and therefore the upper and lower drums operate at the same 1:1 theoretical rate.
From this point on, the bottom pad wears out, which reduces the diameter of the bottom roller, and thus changes the surface speed of the bottom roller, eventually resulting in a shortened length of the carton.
The surface speed of the die depends on the circumference of the drum to the radius of the blade. The surface speed of the bottom drum depends on the circumference of the radius from the center of the bottom drum to the bottom pad surface. Due to the wearability of the bottom pad, it is obvious that the only variable that cannot be kept constant here is the surface speed of the bottom roller. Therefore, it has been difficult to ensure the accuracy of the cartons from beginning to end under repeated orders.
It is difficult to see how the size of the carton becomes more apparent when two or more carton boxes are successively die-cut from one piece of corrugated paper. In order to control the size of the first carton, the cutting depth of the die cutter or the speed of the bottom drum must be changed. However, this will inevitably change the size of the last carton. In general, the last carton will be cut shorter than the first one.
Experience has shown that if you try to control this phenomenon, you will change the size of the first carton. This is called "difficulty." This effect makes batches of finished products inconsistent due to differences in carton size, machine size, drum speed, and depth of cut of the knife.
Many carton manufacturers have made valuable efforts to solve this problem and found many ways to minimize the dimensional changes caused by die cutting by the rollers. One method is to use a variable-speed bottom roller. The tolerance of the carton is measured by the operator from time to time. The operator then adjusts the speed of the bottom roller through a variable speed motor to compensate for the wear of the bottom pad. Short diameter defects. The system can achieve certain results, but the carton factory must rely on the operator's technology to make the right adjustments. Even in this case, it is difficult to accurately determine the diameter of the undercushion, because in most cases, the wear of the underpad is different everywhere. In many cases, this also gives the operator too much trouble, often causing damage to the die and gear system.
In addition, in the case of multiple editions, some modelers have made the second edition longer to compensate for the size difference between the "end-to-end". Although these methods can solve some problems, they cannot fundamentally meet the needs of customers with high precision requirements, and it is difficult to meet the ISO9000 standard.
Thirty years ago, the United States DICAR invented a long-lived rubber pad to alleviate this conflict. The service life of the DICAR pad is 150% to 300% of that of any similar product, which reduces the difference between the upper and lower drum line speeds and makes the carton size smaller.
However, none of the above is a thorough solution.
The best solution at the moment is the equalizer bottom pad system developed by DICAR. The equalizer controls the surface speed of the bottom drum to reduce operator error. Different from the standard die-cutting device, the bottom pad is not directly covered on the bottom roller, but is first put on the bearing sleeve.
No matter how the diameter of the bottom rubber pad changes, the bearing can slide freely on the bottom roller, so that the surface speed of the bottom rubber pad is completely controlled by the cutter die, so that the shape of the carton and the cutter die are exactly the same.
The greatest advantage of the equalizer in controlling the size of the carton is that it does not require operator involvement, and does not require the operator to adjust the drum speed at regular intervals. Instead, it is automatically adjusted by the equalizer. This is very important in die-cut repeat orders because customers Of course, I hope the size of each shipment is exactly the same. Based on this, when running multiple plates or multiple sets of molds, there will be no end to end phenomenon. The shape of the die-cut carton will be exactly the same as the corresponding mold. In addition to this advantage, the DICAR equalizer has the following advantages:
Make the life of the bottom pad longer. Because the line speeds of the upper and lower rollers are completely the same, the tension of the bottom rubber pad is reduced. In addition, the diameter of the knife mold and the diameter of the bottom rubber pad do not have to be the same, so that the cutting point of each roller knife is uniformly moved on the bottom rubber pad, ie, Each time it does not fall on the same point, the bottom pad wears very evenly and lasts longer. Practice has proved that the life of the bottom pad on the equalizer can be extended by more than 30%.
Replace the bottom pad shorter time. The position of the traditional bottom pad needs to be removed and then installed. The replacement of the bottom pad of the DICAR equalizer is very convenient and takes only 5 minutes. The savings in downtime are considerable. The economic benefits of installing a DICAR equalizer are considerable. According to actual statistics, if a carton machine molds 40,000 cartons a day, it will generate several million yuan in revenue within 10 years of using an equalizer. (as shown in the table)

So, at present, there are more than 1,200 carton drum die cutting machines in the world equipped with DICAR equalizers. In China, only 8 machines have been installed. Obviously, in order to become a roller carton big country, China's carton manufacturers are on the road to technological progress. We must also accelerate the pace.