Because paper packaging has the advantages of being recyclable and reusable and not polluting the environment, under the impact of the current wave of green packaging, people's pursuit of paper packaging is inevitable. In the transport packaging, cartons made of corrugated paper have a tendency to replace wooden boxes; paper-made multilayer paper bags can be used as packaging for loose-bag products (cement, chemical raw materials); composite cans made of cardboard, Metal cans can be used as a substitute for certain commodities; in sales packaging, paper cartons made of paper and paperboard are widely used, and the emergence of paper composites expands the scope of application of paper materials in sales packaging. . As for the typical sales packaging container-folding carton, it is not only widely used in the packaging of medicines, foods, daily necessities, handicrafts, but also used in the packaging of beverages, detergents, cultural and educational supplies, and hardware products.
Facts have proved that the demand of the packaging market in China is gradually following the standards of Europe and the United States. As a result, the variety and style of paper packaging are increasing, and the medium and high-grade fine-colored packaging products are actively developed to increase the added value of goods.
In recent years, people have come to realize that only the prepress, printing, and postpress are truly integrated, and the entire printing industry can respond to the requirements of the development of the times and develop healthily.
Die-cutting, indentation concept and important position
Many prints, such as trademarks, bottle stickers, labels, etc., often use arcs or rounded corners on their edges. Container type prints cannot be cut using general paper cutters due to their complex shapes and the need for pleating and tangling to facilitate molding. Out, must die-cutting and indentation processing.
Die-cutting is the use of steel blades arranged in a mold frame (or carved into a mold frame with a steel plate), in the die-cutting machine, the entire printed matter printed and cut into a single graphic product processing.
Indentation is the use of steel wire in the printed material on the traces or leave the groove marks for bending.
Indentation and die-cutting are the most commonly used post-press processing processes for container-type prints, especially paper boxes. The carton forming process is generally carried out by embedding a steel blade for die cutting and a steel wire for indentation on the same plate surface so that the die cutting and creasing work can be completed at one time.
Die cutting as an important technology for packaging and post-press molding is the key to determining the success or failure of a printed product.
The high quality of the molding process results in a packaged product with a beautiful appearance and a long service life. If the processing quality is poor, the appearance of the packaged printing product will be rough and the service life will be shortened (for example, the carton and other products may crack due to the indentation line); Printed materials are discarded (such as beautifully printed boxes and boxes, which cannot be boxed or boxed due to die cutting errors).
Development trend of die-cutting production technology
1, die-cutting plate material
In addition to the multi-layer wood plywood that is commonly used in the country, fiber plastic plates and sandwich plates have been widely used abroad. The material of the fiber plastic plate is glass fiber reinforced plastic, and no obvious dimensional change will occur even if the temperature and relative humidity significantly change. In the production process, the use of computer-controlled high-pressure water jet cutting process not only ensures the processing accuracy but also avoids the environmental problems caused by gas and smoke generated during laser cutting. The bottom plate (backing) plate used with the synthetic steel filler material structure in the middle of the sandwich plate is also made of steel plate material, which has the advantages of long service life and high precision.
The life of a die-cut version depends primarily on the quality of the die cutter and the number of tool changes. The number of tool change times for die-cut plates made of fiber plastic and sandwich plates were 3 and 6 times that of multilayer wood plywood.
2, floor slot
In only 10 years, China's die-cut manufacturing industry has grown from the original lead block typesetting to today's widely accepted laser-cutting platemaking. At present, a large part of the multi-layer wood plywood floor grooving in China is a manual sawing process and a machine tool seaming process.
In foreign countries, in addition to the use of high-pressure water jet slotting for fiber plastic plates, multilayer wood plywood and sandwich panels are generally laser-cut. The die-cut version of the laser cutting system consists of a laser processing head, computer aided design (CAD) software, a computer numerical control device (CNC), a work bench, and the like.
Laser cutting uses laser as a heat source for cutting as shown in FIG. 4 . Under certain environmental conditions, the surface of the workpiece is continuously absorbed by the radiant energy of the beam and the temperature rises to an overheated state. Melting and Evaporation Due to the heat conduction, the surface heat energy is quickly transmitted to the interior of the material, causing the internal temperature to rise to the melting point. In this case, the material The easily vaporized components generate a certain gas pressure and cause the melt to explode and break. The material that is removed by laser cutting of wood is mainly based on gasification and generates dust. Therefore, a gas with a certain pressure must be sprayed to assist processing. When the laser cuts metal materials, oxygen is blown in the same direction with oxygen in the same direction. Oxygen helps the combustion energy to generate higher energy and melts the metal. At the same time, the blowing effect blows away the molten steel slag, forming a neat, smooth and uniform The kerf. Laser cutting of wood or metal is fast, accurate and accurate.
From the point of view of the relative movement of the laser beam and the plywood, there are a workpiece moving type (fixed laser beam), a laser beam moving type (fixed workpiece), and a composite form of these two methods.
3, die cutting and indentation line processing
The installation of die cutter and indentation line should first cut and bend the die cutter or indentation line to the corresponding length and shape according to the length of each box type cutter line. It can be used to process the die cutter and indentation line. The special equipment mainly includes blade cutting machine, blade forming machine (bending knife machine), blade punching machine (blade cutter), blade angle cutting machine and so on.
In China's packaging industry, manual operation of knife-line processing equipment is widely used. In foreign countries, CAD cutter tooling system software is generally used for processing. In order to ensure the accuracy of the die-cut version, CAD software can automatically calculate the length of the die-cutting tool and indentation line and the size of the bridge missing 13 (to ensure that the die-cut version does not disperse, leave two places in the large-area closed graphics part. The above shall not be cut off, the width of the bridge shall be in the range of 3 to 9mm, and shall be transmitted to a computer-controlled tool forming machine for grooving, cutting, bending, and cutting. Due to the adoption of hydraulic machete, liquid crystal display, hydraulic transmission and vernier positioning, the accuracy of tool forming can be effectively guaranteed.
4, bottom mold (backing) technology
In order to make the folding line of the packing carton (box) clearer and more beautiful, no wrinkles and cracks after folding, the shape of the box (box) is more accurate, and people use a bottom mold matched with the knife mold.
The traditional craftsmanship in the production of domestic bottom molds is the hand boundary "bottom mold (namely carved on thick paper) because the kraft paper system is soft and easy to manually slot, but not pressure, indentation pressure is not transparent. Insulating synthetic fiber board bottom molds are mostly used, because fiberboards are very hard and special slotting machines are needed.The fiber bottom molds are only suitable for die-cutting indentations for extremely long board jobs. The development of the era of China's traditional hand boundary "will be replaced by the advanced German CITO (Xitu) indentation system. This type of bottom mold line is adhesive type, quick outlet, full indentation line, high resistance to printing force. The basic structure is shown in Figure 5. The pressure line die consists of a metal bottom plate, a hard plastic cavity, and a glue bottom die.
The application of CAD/CAM (Computer Aided Manufacturing) technology can not only shorten the cycle of packaging design and production, but also increase market competitiveness. Moreover, due to the same design procedure and parameters, the dimensional accuracy of the back-carved engraving and laser-cutting plates is guaranteed. The consistency, thereby improving the design and manufacturing precision of the carton.
In the domestic box making market, in addition to the use of high-quality die-cutting plates provided by foreign famous die-cutting manufacturers such as MARBACH, in recent years, some companies such as Hexing, Jialuo, Hua Ying, and Rui Lida have also Advanced carton box type CAD software and die-cut version have been introduced from abroad. The bottom die CAM special system makes most of the domestic packaging and printing plants eliminate the traditional manual design, plate making and processing technology, and adopts CAD/CAM advanced technology to produce high-precision exquisite packaging carton.
5, die cutter, indentation line, tape
The quality of the die cutter directly determines the timing and die cutting quality, speed and number of times. The quality of the indented steel wire determines the fineness of the indentation and has a significant effect on the speed of the automatic folder-gluer. High-quality die cutters are processed through the following processes:
Steel treatment: The steel molecules are arranged neatly and solidly, have extremely strong bending force and supporting force, and are particularly wear-resistant. If the steel is loose, the die cutter cannot withstand the long die cutting pressure.
Carbon removal treatment: After the decarburization treatment, the surface of the blade body is flexible and easy to bend, and cracks should not occur. Without removing carbon, the blade can easily break when bent.
Heat Treatment: Can accurately adjust a variety of hardness to meet different needs. Improper heat treatment can affect the die life.
Accuracy processing: High precision is required to meet the high standards of die cutting needs. If the accuracy is not high, the operation of the die cutting machine is affected, and the inferior die cutter will increase the trouble of the bottom filling, and will cause a lot of troubles such as shutdown.
High-quality indentation steel wire should be moderate in hardness, strong in stability, smooth in thread head, symmetrical in axis, low in height deviation, and complete in specifications.
As a leader in the market for die cutters, Austrian Bonaparte continues to focus on the development of die cutter technology and develop die cutters with different hardness and different blade shapes for different die cut objects. Recently, the company has launched a super supreme knife for many long-lasting, dust-free, high-quality cuts for cigarette packs, food boxes, and medicine boxes. It is characterized by a knife-edge convergence and excellent durability The cut-through performance, to minimize the phenomenon of raising hair, silk, etc., has become the new "king of the cutting knife."
After the die-cutting knife line is inserted, both sides are to be pasted with sponge strips. The function is to rebound the die-cut cardboard from the die-cut plate. If the recovery speed of the sponge rubber is insufficient, it may result in unsmooth cleaning, and sometimes it is necessary to stop the machine. If the hardness, height and shape of the sponge are not proper, it may cause dusting, dust formation, breakage of connection points, etc., resulting in waste products. The rate is too high. If the structure of the sponge rubber is loose, the elasticity will be quickly lost, and the number of times of the long version of the cutting can not be guaranteed.
The carefully formulated German Epson rebound rubber series has undergone rigorous die-cutting tests on the material, hardness, and shape of the colloids, and has been widely recognized in the market.
Die-cutting equipment type and development trend
Die cutting equipment type
Die-cutting machine according to die-cutting form can be roughly divided into three types: round press round, round press flat, flat press flat.
Circular press die cutting machine features line contact, low die-cutting pressure, and high production efficiency, so it has a wide range of applications and can be used in online die-cutting with printing equipment such as flexographic printing presses and gravure printing presses. Heavy die-cut corrugated paperboard uses a wooden drum cutter die to cut some mid- to high-grade long-line products, using a die-cut or shear-type metal drum die, and some for die-cut stickers and trademarks The roller knife mold of the sticker is a round die-cutting cylinder made by chemical etching or electric carving.
At the beginning of the introduction of the gravure production line in the country, foreign round-press die-cutting equipment and cutting tools also entered the domestic EP and N markets and occupied an absolute monopoly position. At present, the localization of wire-pressing, round-press processing equipment has begun to take shape, with Shanghai Bernell Yahua Company in the south and Beijing Seiko Diecutting Company in the north.
Circular die-cutting die-cutting machines are mainly transformed from old printing presses. Only a small part of them are special-purpose ones and are mainly used for die-cutting of large-size products.
Flat die-cutting die-cutting machine is currently the most commonly used die-cutting machine, which can be used for die-cutting of various requirements. It is capable of high-speed linkage die-cutting and semi-automated die-cutting of paper. It can not only cut corrugated cardboard ( Thickness below 5mm), cardboard, stickers, but also die cutting sponge, rubber products, metal sheet.
2, the development trend of die-cutting equipment
1 flat die-cutting die-cutting machine to high-speed, high-precision, fully automatic, multi-purpose development
Foreign advanced flat pressing automatic die cutting
