With the development of economy and the improvement of people’s awareness of environmental protection, people have put forward newer and higher requirements for the production and quality of packaging boxes. The buyers of the goods requested that the packaging box be of bright colors, nice design, clear and smooth lines, and tough texture. Commodity manufacturers require that packaging boxes not only meet the visual needs and application requirements of buyers, but also reduce costs as much as possible. In this way, some box-making manufacturers in the market gradually use recycled paper to make color boxes, further reducing costs and increasing economic efficiency.
However, many color box die-cutting factories often give up on the edges of the recycled paper box, dust, bursts, explosions and headaches. If these problems cannot be solved, the promotion and application of recycled paper box will be greatly limited. The common problems encountered in the recycling of recycled paper color boxes are analyzed, and the causes and treatment methods are analyzed on behalf of peers.
Why is recycled paper easier to fluff, dust, burst, and burst than original paper? Because the high-quality raw paper fibers are long and tightly bound, and the recycled paper fibers are short and loose, they are naturally more likely to fluff and dust when cut by a die cutter; the printed paper is loose due to the loose fibers of the recycled paper. When the surface is indented, it is easily broken by the steel wire and it is not pressed. Practice has proved that, under the same cutting conditions, there are more fluffing, dust, explosions, and bursting of recycled paper than native paper. This is understandable and difficult to avoid.
However, since the cost of recycled paper is lower than that of original paper, considerable economic benefits will be achieved if the problem of fuzzing, dusting, color collapse, and bursting in die cutting is solved. In fact, many color box manufacturers use scientifically selected die-cutting materials to reduce the occurrence of various problems to a minimum, and can also use recycled paper to produce high-quality color boxes.
First, the solution to fluffing and dusting - use high quality die cutter and rebound rubber
The general die cutter includes a lot of high-grade die cutters. Its blade surface looks very smooth. In fact, under the magnifying glass, many blow holes, burrs and uneven rough surfaces can be seen. Such a blade is when the die is cut with fibers. Tissue loose recycled paper will undergo severe friction and produce a lot of paper dust. In particular, the ruled blade, although sharp, but with the friction of the paper more severe, resulting in more dust. At this time, it is necessary to select a die cutter with a very smooth blade, as shown in Fig. 2 for the BOHLER "Supreme Extreme" knife. The Supreme knife uses a special metal coating on the blade to fill in the holes, burrs, etc. on the surface of the blade. This greatly reduces the generation of paper dust and is more suitable for die cutting of recycled paper. As the friction is reduced, the incision is neat and the die cutting quality is improved, and the die cutter itself has a longer service life. This kind of knife is most suitable for die-cut boxes, cosmetics boxes, food boxes, cigarette cases, and any kind of recycled cartons that require long-lasting and dust-free products.
The user does not pay attention to the application of high-quality sponge glue, or understands the use of sponge rubber. He believes that sponge rubber only acts as a "bounce". Some users even use the inferior "slipper glue" on the automatic die-cutting machine and completely lose their purchase. The meaning of automatic die cutting machine. In fact, when the height and hardness of the sponge rubber are not proper, or the installation position is not appropriate, it is difficult to effectively suppress the paper during die cutting, which may cause the paper to shift or pull, resulting in more paper and paper dust. The high-quality sponge glue can prevent fluffing and dusting of recycled paper, and it can play an immediate role. For a more standard installation and material selection method, the selection principle of rebound sponge hardness:
(1) If the distance between die cutters is less than 8mm, sponge rubber should be 600 Shore hardness.
(2) If the distance between die cutters is greater than 8mm, sponge rubber shall be 250 (corrugated) or 350 (jam) Shore hardness.
(3) If the distance between the die cutter and the steel wire is less than 10mm, the hardness of the arched sponge rubber shall be 700 Shore hardness; if it is greater than 10mm, the sponge plastic with a hardness of 350 Shore shall be used. The hardness of the arching glue used in the punching position of the die cutter should be 700 Shore, which is used to protect the connection point from being broken.
Commonly used sponge glue has the following kinds:
(1) 350 breathable sponge rubber (Figure 4A): compression rate of 35%, the number of die cutting 1 million times, speed 9000 beats / hour, for jams.
(2) 200-sealed Arch Sponge (Figure 4B): Compression rate is 50%, number of times of cutting is 250,000, and speed is 7599 times per hour. It is used for corrugated paper.
(3) 600 solid rubber strip: used for narrow position, such as distance between die cutters, <8mm position.
(4) 700 Arch Rubber Strips (Fig. 4C): For the die cutter to open the mouth, and the distance between the knife and the steel wire is <10mm.
Rebound rubber sponge installation method: the sponge strip should leave the distance of at least 1mm on both sides of the die-cutting blade body, and cannot be installed close to the blade body. Otherwise, the sponge strip cannot expand in the direction of the blade after being pressed, and can only expand in the other direction. This will cause the paper to be drawn to both sides. The die cutter will also have to cut the paper in the future and it will have been broken by the sponge glue, which will cause fluffing and paper dust. In addition, sponge rubber should be 1.2mm higher than the blade, depending on the hardness of the appropriate adjustments. If the hardness is> 350 Shore, then it should be <1.2 mm, if the hardness is <350 Shore, it should be> 1.2 mm. In principle, the softer sponge rubber has higher height. Sponge is the correct height. Wood samples can be made more quickly.
In the whole wood mold, the amount, hardness, and height of the sponge glue should be distributed in a balanced manner at each position, and sponge glue should also be arranged on both sides of the balance force.
In short, the height and hardness of all the materials, die cutters, die-cutting steel wire, and sponge glue on the wood mold should be well-balanced. This not only has a good die cutting effect, but also can increase the speed of automatic die cutting machine.
Of course, there is fluffing on the recycled paper. The reason for the dust is also related to the precision of the die-cutting machine and the flatness and pressure adjustment of the bottom steel plate. If the pressure is increased, no matter how good the knife is, no matter how good the sponge rubber is, use. When the automatic die-cutting machine begins to adjust the pressure, it should be adjusted to about 80% wear, and then according to different positions, make up with the make-up material, and then lock the pressure and then formally die-cut. This not only has a good die cutting effect, but also has a fast production speed.
two. Explosion-colored, explosion-proof solution - using high-quality steel wire and bottom mold indentation line
The printed layer of recycled paper is very fragile, and it is not noticed, that is, bursting, whitening, etc., so careful care is required during die cutting. The key factors that determine the quality of indentation are the steel wire, the bottom die system, and the combination of both with the thickness and texture of the paper.
What kind of steel wire can protect the indentation from cracking as much as possible? The answer is not difficult. The accuracy, smoothness, and axial symmetry of the steel wire are the key elements that ensure perfect indentation. In addition to the steel wire height tolerance should be between ± 0. 007mm, the thread head should be very smooth and smooth, the profile of the steel wire should meet the geometric requirements of the axial symmetry, see Figure 7. However, some users did not realize the importance of steel wire. In order to reduce the cost, they chose to use rough wires and even burrs. The poorly spliced steel wires with irregular arcs naturally increased the chance of indentation, bursting, and triangular lines. It is difficult to produce a better indentation effect.
The choice of the height and thickness of the steel wire is also determined by the thickness of the paper. Instead of a high degree of steel wire used for all products. The steel wire selected was too narrow and too high, which increased the explosion color and the chance of bursting. The choice was too low and the indentation was not obvious. At present, there are still many users who use a high degree of steel wire regardless of what products are die-cut throughout the year. This has a high probability of problems.
Corrugated cardboard made from recycled paper has extremely fragile surfaces. If you do not use a high-quality bottom mold system to match, the effect of indentation is difficult to achieve. Under the premise of choosing the right sponge rubber and steel wire, it is also necessary to use brains on the structure of the bottom mold. CITO's original IK-type corrugated paper bottom mold indentation line provides effective protection for the appearance and toughness of corrugated paper indentation, see Figure 8.倨 According to test statistics, the quality of indentation was significantly improved after the use of type IK, and the chance of bursting was reduced by 90%. The waste product rate is further reduced and the production efficiency is further improved.
The die-cut materials used in recycled paper not only pay more attention to quality, but also pay attention to cooperation. Purchasing personnel of color box manufacturers should not simply use the price to purchase materials, but should fully consider the material's performance-to-price ratio and cooperation with our die-cutting machinery and paper. In fact, the proportion of high-quality die-cut materials in production is very small, and the biggest cost in production is paper. If the above die-cutting problems occur, the output from the production line will be a lot of waste products, or because the quality of the box is not satisfactory. Turn back orders. Therefore, the real cost-reduction approach is to scientifically select high-quality die-cut materials, so that the overall quality of color boxes will be improved, and product quality will be significantly improved.
