Making Flat Press Dies: Deformation and Fission (I)

The die-cutting indentation process is a process in which a print sheet is cut and formed using a stencil arranged by a steel knife, a steel wire, or the like under pressure. The processing result is that the print surface has both deformation (indentation) and fission (die cutting).

The production of a die-cut version, commonly known as row knife, refers to the process of putting steel cutters, steel wires, lining empty materials, etc. into the die-cut version according to the specified requirements. The general process of die-cut production is as follows:

Draw the die-cut version of the contour map → cut the original plate → steel knife steel wire cutting and forming → combined imposition → open the connection → paste the sponge strip → try cutting pad plate → make the indentation bottom touch → try die-cutting, signing

First, draw a die-cut version of the outline

Firstly, a die-cut layout should be designed according to requirements. The tasks of layout design include: (1) Determine the size of the layout, match the specifications of the selected equipment and the working capability; (2) Determine the type of die-cutting plate; (3) Select the materials and specifications for the diecut. A well-designed layout should meet the following requirements: the position of the die-cut version should be consistent with the printing position; the working part should reside in the center of the die-cut version; the line and graphics should be transplanted to ensure the required precision of the product; layout knife line To straight, horizontal and vertical lines each other at right angles and parallel to the die-cut side; broken knife, broken lines to be aligned.

The die-cut version outline map is the unfolded drawing of the full-page product and is the first key link in the production of the die-cut version. If the printing is a full-page imposition system, the die-cut layout profile can be directly output in the printing plate-making process, which can effectively ensure the unity of the printing plate and the die-cut plate. If the printing is made using a hand-made film, it is necessary to draw a cut-out version of the outline according to the actual size of the typeset. During the drawing process, in order to ensure that the die-cutting plate does not disperse during the plate-making process, a number of “bridges” should be left in the large-area closed-pattern part, and the width of the bridge can be designed to be 3 to 6 mm for the small plate version. Large version can leave 8 to 9 mm. In order to make the die-cut version of the steel knife and steel wire have good die-cutting adaptability, the following problems should be paid attention to in product design and layout drawing:

1, the slotted hole should be used as far as possible the entire line, the line should be rounded corners to prevent the emergence of vertical steel knife stitching.

2, the joints of the two lines, should prevent sharp corners.

3, to avoid the connection of multiple adjacent narrow waste edges, should increase the connection part, make them into a piece, easy to clean up.

4, to prevent the emergence of a continuous number of sharp corners, for the non-functional requirements of the sharp corners, can be rounded.

5, to prevent the sharp corner line cut to the middle of another straight line, this will make the knife difficult, steel knife easy to loose, and reduce die-cutting fitness, should be changed to the arc or increase its angle.

Second, cutting template (slotting)

The blanking material (bottom plate) commonly used for die-cutting plates is made of metal lined empty material and non-metallic material empty material; among them, multi-layer plywood is used most, and the thickness of plywood is generally 18 to 20 mm. The cutting of the bottom plate (lining material) mainly includes sawing, laser cutting and other methods.

Saw cutting is currently the main method for small and medium-sized enterprises to self-process die-cutting plates. The work of the sawing machine is the use of a special saw blade for up-and-down reciprocating movements. The narrow groove that can hold steel blades and steel wire is machined on the bottom plate. The thickness of the saw blade is equal to the corresponding position steel. Knife and steel wire thickness. The sawing machine is equipped with an electric drill, which can drill holes in the bottom plate. After drilling, the saw blade passes through the bottom plate and is then cut. The current sawing machines are different in terms of the type of use and the type of plate making, and they are rich in specifications and functions. Some sawing machines are equipped with a dust collection system. They can automatically collect sawn sawdust, and the saw blade can be electrically clamped. Some large-format sawing machines work on countertops. There is also an air floatation system. It can make the big plate sawing light and flexible. In recent years, CAD/CAM technology has also been applied to the production of die-cutting plates. The principle is to use CAD/CAM technology and computer control technology to control the sawing machine to complete cutting, and the quality of the grooving has been greatly improved.

Laser cutting is carried out on a computer-controlled laser cutting machine. It uses a laser as an energy source to cut off the substrate material by the high temperature generated by the laser. To perform laser cutting, you first need to enter the full-cut die-cut contour image into a computer. The computer controls the movement of the master plate and uses a laser to cut. However, many parameters are needed in the cutting process, such as material quality parameters, sheet thickness, laser output power, type and pressure of auxiliary gas, diameter of nozzle, aperture, distance between material and nozzle, focal length of lens, position of focal point And cutting speed. Therefore, in actual production, it is extremely important to draw lessons from past experience to determine the processing effect. The main disadvantage of laser cutting is that the laser cutting machine is expensive and the cutting cost is high, so that the production cost of the die cutting plate is relatively high. Therefore, this type of die cutting plate is generally produced by a professional manufacturer, and the user directly fixes it.

(to be continued)