Lithographic die-cut indentation process

At present, in general, when customers do die cutting of cardboard (white paper), the first choice must be flat and flat die-cutting indentation process. It can be said that flat die cutting in the cardboard packaging industry has been more and more widely recognized. But relatively speaking, the use of flat die-cutting in the corrugated box industry has only been a few short years. In recent years, with the continuous improvement of people's needs, the requirements for product quality have become higher and higher, which has led many carton makers to change the heavy and lagging die-cutting process in the past, and to use high-quality flat-press die-cutting and die-cutting creasing machines in large quantities. However, because many manufacturers do not really grasp the points of use of the die-cutting process, and in particular do not understand the characteristics of the carton in the die-cutting process and the difference between the carton die-cutting and the white cardboard die-cutting, they have not been able to actually play flat in practical use. The characteristics of flattening and die-cutting are also difficult to solve when encountering many problems. Therefore, we believe that to make a perfect carton product, it is very important to really grasp the use of die-cutting technology. At the same time, the selection of die-cutting and indentation accessories is also very important. These very many manufacturers do not necessarily understand.
Below, we focus on the following points in the die-cutting process:
1. The choice of indentation line (brew line); 2. The choice of bottom line (bar); 3. Die cutter version of the use of sponge rubber; 4. Indentation knife (beer knife) RBI.
First, the choice of carton die-cutting indentation line (beer line):
The choice of indentation line (brew line) in carton die cutting is very important, but many people do not pay much attention to the selection of their specifications. Unsuitable indentation lines often lead to inconspicuous creases or crease bursts. The correct choice method:
a. The thickness of the indentation line (beer line) ≥ the thickness after the flattening of the corrugated board: d≥e.
b. At present, the indentation line (beer line) is still used in foreign countries and is usually referred to as “point”. Each point (P)=0.014in (≈0.36mm).
The height of the indentation line (beer line) = indentation knife (beer knife) height - the thickness of the corrugated board after flat pressing.
Second, carton die cutting in the bottom mold bar (line) choice;
The correct selection method for the bottom mold strip (line) in the carton die cutting: Formula B=(e×2)+d.
Calculation method: First, after measuring the corrugated paper thickness e after flattening, the thickness A of the bottom mold strip (line) can be calculated. For example: a. After the flattened corrugated board thickness is 1mm; b. According to the formula B=(e×2)+d, the width B of the bottom die bar (line) is found, ie (1×2)+1=3 mm. According to the calculation, it is advisable to choose an appropriate size of 1×3.
In general, the selection of the bottom mold bar (line) can use the same or similar specifications according to the existing bottom mold supplier's specification table. There are different widths for the same thickness in each supplier, and there are also specifications for the same width and thickness. Therefore, manufacturers should pay attention when choosing. First understand the supplier's specification sheet, and then find the required specifications. In addition, in actual use, in order to achieve the best indentation effect, it is placed on the ruled bottom mold strip (line), and the width B is reduced by 0.1mm-0.2mm. For example, if a suitable specification is calculated to be 0.4×1.3 mm, for a ruled corrugated cardboard, 0.4×1.2 mm should be used.
Third, the carton die-cutting in the use of die-cutting knife sponge rubber.
1. The correct use of sponge glue:
When the sponge glue is placed too close to the indentation knife (brew knife), the compressed sponge rubber has no space to expand and contract, and eventually causes the cardboard to tear outwards, resulting in non-smoothing of the printing plate and the paper edge.
a. Place the standard distance of sponge rubber.
b. Die-cut corrugated paper.
Sponge glue is about 150mm long and is placed on both sides of the beer knife continuously, each 5mm apart.
Fourth, the carton die-cutting, die-cutting knife version of the indentation knife (beer knife) hits (NICK) points:
Drilling is very important for the operator. Drilling must be able to pull the cardboard during the drag transfer and meet the appearance requirements. Therefore, pay attention to the setting of the connection point and try to avoid the glueing position. In general, the corrugated cardboard dotting: b = c (corrugated board thickness) + 0.2mm, a = 1-3mm.
The above points are just some of the basic points in die-cutting corrugated boxes. Of course, in actual use, the operator also needs to be flexible in the light of the actual situation and use it better in practice.