Every Die-hard Die-cutting--Aware Die-cutting Process (II)

Equipment features and trends

The equipment used for die-cutting and indentation processing is called die-cutting machine. According to the different shapes of the main working parts of die-cutting plate and die-cutting structure, there are three types of die-cutting machines currently on the market: flat-pressing flat die-cutting machine, flat pressing Round die-cutting machine and round press die-cutting machine. However, no matter which type of die-cutting machine, the structure is composed of die-cutting table and press-cutting mechanism. Here's a brief look at how they work and their advantages and disadvantages:

Flat-press die cutting machine

Working principle: The die-cutting platen and the press-cutting mechanism of the flat-pressing die-cutting machine are flat-shaped. The die plate is fixed on a flat plate table, and the processed sheet is placed on a press plate (press plate). During the work, the die-cutting platen is fixed and the pressure plate reciprocates through the crankshaft connecting rod, so that the platen and the pressure plate are continuously separated and pressed, and once each combined pressure, a die-cut is realized. Common flat and flat die-cutting machines include vertical die cutters and horizontal die cutters. At present, the vertical die-cutting machine is mainly converted from a flat-pressing type printing press. The horizontal die-cutting machine is similar to a single-color offset printing press in that it consists of a feeding section, a molding section, and a delivery section, and some have Automatic stripping device and other components.

Advantages and Disadvantages: Due to its advantages of simple structure, easy maintenance, easy operation, easy replacement of die-cutting indentation plate, suitable for different grammage materials, accurate die-cutting, etc. So it has a wide market. However, its inadequacies are also obvious. For example, it needs a great deal of pressure to work, resulting in labor intensity and low productivity. It has a wide range of applications and is suitable for die-cutting and indentation processing of folding cartons, pasting cartons, and corrugated cartons. It is currently a relatively common die-cutting equipment for domestic use. The continuous feed automatic die cutting machines produced in Tangshan Yuyin in China are the most popular.

Round flat die cutting machine

Working principle: The working principle of the round-press flat die-cutting machine is similar to Heidelberg's early round-flattening type printing press. Its die-cutting platen is flat, the die-cut plate is fixed on its upper surface, and the die-cutting platen can be With the help of the pulley on the back, it moves back and forth, and the processing sheet passes through the gripper of the embossing cylinder. During work, the platen moves forward as the embossing cylinder is running, thereby achieving die cutting. Before the gripper continues to pick up the next piece of paper, the platen moves back to the starting position (at this time The table is not in contact with the working surface of the mold roller, which is convenient for the next die cutting work.

Advantages and Disadvantages: Most of these die-cutting machines were transformed from early Heidelberg round-pressing presses. The device uses a cylindrical pressure roller instead of the platen, so the work is not "surface contact" but "line contact" The machine requires less pressure when die-cutting, so the load of the machine is relatively stable. However, due to the component force generated when the die-cut plate and the embossing cylinder roll on each other, it easily leads to deformation and displacement of the knife line, and its application range is relatively narrow, generally only suitable for die-cutting of cardboard with a grammage less than 400 g/m2, particularly suitable for Paper die cutting and electro-aluminum foil bronzing. In the paper cutting process, attention should be paid to the fiber direction of the paper, generally it should be parallel to the axial direction of the molding roller, otherwise it will cause serious paper stretching phenomenon.

Round press die cutting machine

Working principle, the shape of the working part of the die cutting table and the pressure cutting mechanism (pressure roller) of the circular press die cutting machine is cylindrical, and the principle of molding is similar to the offset printing press. A semi-circular die plate (or metal die-cutting roll) with the same or two arcs as the die platen substrate (ie, die-cutting platen cylinder) is fixed on the die-cutting plate cylinder, and the pressure roller surface is coated with a layer Protect the cutting edge of polyester plastic. As the molding process progresses, the surface layer of polyester plastic will be destroyed. Therefore, the polyester plastic on the surface layer is generally removed from time to time to replace the new plastic layer. During molding, the feed roller feeds the processed sheet material between the die-cutting plate cylinder and the pressure roller, both of which sandwich the roller platen and press it. The die-cut platen roller completes a die-cutting task after one rotation.

Advantages and Disadvantages: Because the drum is continuously operated when the die cutter is working, its working efficiency is the highest compared to other die cutters. It is particularly suitable for mass production, but it is precisely because of its fast die cutting speed. As a result, sometimes the required die-cutting accuracy cannot be guaranteed. Like the round flat die cutting machine, it adopts the line contact principle to complete the molding work. Therefore, when the die cutting requires less pressure and the pressure distribution is relatively uniform, the load of the machine is relatively stable. However, its die-cut version is bent into a curved surface, so it is cumbersome in the plate-making and loading process, the technical difficulty is relatively large, and the plate-making cost is also relatively high. The die-cutting plate required for the round-pressing rotary die-cutting apparatus is flatter than flat. The cost of die cuts is 25% to 100% higher. Round press die cutting machine is mainly used for die cutting of corrugated products. The current market share is very low. However, with the advancement of science and technology, the development trend of the die cutting machine is better, because it adapts to the requirements of the future mechanization, linkage and automation of the postpress processing, and people can link the molding mechanism and the printing machine as required. The production line realizes the online operation, which can effectively reduce the demand for labor, shorten the process flow and reduce the loss in the process, thereby increasing production efficiency, reducing labor costs, and obtaining greater profits.

(Author: Liu Chao Shandong Iowa packaging Government Printing Co., Ltd.)
Source: Corrugated Box 2005, 9