Magnetic Die Cutting Technology Features and Applications (I)

With the development of science and technology and the continuous improvement of people's living standards, more and more goods and raw materials use different packaging forms and processing techniques, and die-cutting technology has also received more and more attention. Circular press die cutting tools can basically be divided into two categories according to the processing methods: Integral die cutting roller (knife line directly processed on the base roller) and split die cutting roller (magnetic roller + die cutter version). Here We mainly discuss magnetic die cutting technology.

The key points of magnetic die cutting technology

The magnetic roller and magnetic plate (die cutter plate) are mainly made by using the principle of magnetic field. The single permanent magnet pieces are arranged in polarity, and are embedded in the groove of the Stainless Steel roller base body. The magnetic roller produces strong due to the excellent polarity distribution. The magnetic field and permanent magnetic force, the use of magnetic field suction die die plate adsorption on the surface of the roller body.

Usually the base of the magnetic roller protection ring (roller shoulder) and calibration ring is stainless steel. Carburizing hardening can extend its service life. Since the magnetic roller is used as a master roller, its machining accuracy is relatively high, and it is generally required that the concentricity error does not exceed ±2 μm. The distance from the roll shoulder to the roll body surface is a very important parameter, which should be determined according to the product condition (mainly the thickness). The more commonly used in Europe is 0.48 mm.

The die cutter version is manufactured using chemical etching and mechanical engraving. First use chemical etching. The recessed part of the die-cutting knife plate typed by the computer is corroded to a certain depth, and on this basis, the CNC machining center is again used to machine the die-cutting knife plate, and then the post-process processing is performed according to the requirements of the small state, such as nickel plating. Chrome plating, carburizing and laser processing.

There are three basic parameters for die-cutting the J-stencil: die-cutting angle a, knife height h, and floor thickness s. The selection range of die cutting angle a is 30° to 120°, and usually depends on the type of die-cutting material. In general, if the die-cut material is paper, the die-cutting tool plate should be larger. Die-cutting angle; if the processed die-cutting plate is used for die-cutting film materials and composite materials, the smaller die-cutting angle should be selected. A knife height h is selected between 0.30-1.50mm. The specific knife height should be determined according to the thickness of the die-cutting material. In Europe, the knife height of 0.44 mm is used more often. The floor thickness s is determined by the knife height h, in the case of a knife height of 0.44 mm. Floor thickness s is generally between 0.1 2 - 0.14mm.

The die cutter version can be divided into general-purpose, reinforced (hardened) and laser (manufactured) types according to the processing technology. The hardness of the die line of the die cutter produced by laser can reach Rockwell hardness 67-68 (HRC67- 68).

There are many factors that affect the service life of die-cutting tools, such as die-cutting pressure, material type, texture, die-cutting requirements (semi-cut or full-cut), ink, machine commissioning, and operators. So it is difficult to give an exact figure. The service life of general-purpose die cutters is generally 200,000 to 500,000 rpm under semi-cutting conditions. The service life of reinforced die cutters is 40% to 50% longer than that of general-purpose die cutters. The service life of the die cutter is 80% to 100% longer than that of the universal die cutter.

Die cutting tool according to the principle of work can be divided into two types of cutting and cutting methods. With die-cut die-cutting, the cutting edge cuts through the machining material and comes into direct contact with the smooth bottom roller or base plate, while the shear-type die-cutting tool uses two blades to cut the material being machined. Most of the magnetic die-cutting methods use pressure cutting, the process is simple, the production cost is relatively low, and the production cycle is also short. (to be continued)