When customers complain about the binding quality of certain folding products, folding is one of the important processes in the binding process, and it is often easy to become the focus of blame. In fact, the various defects and deficiencies reflected in the binding process of the product are not entirely the responsibility of the folding department, and sometimes they are completely irrelevant. The following quality failures all seem to be related to the quality of the folding pages, but in fact, they are all "mistakes and wrongs". Wrinkled paper at the corners Folding of digital prints Living Room Arm Chairs,Purple Accent Chair,Living Room Couch Sets,Livingroom Sets Foshan City Misirui Furniture Co., Limited , https://www.nbmisiruifurniture.com
Polyline position does not coincide with color boundary
When designing folding products, the influence of paper thickness on folding quality must be considered. Generally speaking, in multi-folding, the size of the page folded inside must be slightly smaller than the outside page, that is, the design department must give a certain amount of cutting compensation to increase the actual cutting amount. If the compensation amount is too small. The internal pages will interfere with other pages due to the excessive size, and the pages will squeeze each other to make the external pages arched and lifted, and the overall level of the book stickers is poor. Therefore, for multi-folding, it is best to clearly give the amount of compensation in the design process. Otherwise, once the document with this design defect is sent out, as the binding department of the last line of defense, it will have to compensate for the amount of page cut during the folding process. At this time, if the product's folding line position is just right If the boundaries coincide, it will cause actual misalignment due to crop compensation.
Infolded page size is too small
In general, the standard cutting compensation amount for a single page is 1.5 to 3 mm, but if multiple layers of paper or thick paper are used, the cutting compensation amount for the inwardly folded pages should be appropriately increased. However, if the amount of compensation is too large, the actual size of the inward-folding page will be small due to the large amount of actual cutting. In reality, we often see this approach: the design department does not specify or set the amount of cutting compensation in the design sheet, but is eager to save trouble and directly requires the binding department to be responsible for solving the problem of cutting compensation. Such practices are particularly common in simple folding operations. For example, when designing a direct mail envelope for sending bank statements, the shorter page should be about 2mm shorter than the other two long pages. However, most of the practice is to bypass the design link. Directly cut the size of the third page to be relatively short. In order to fundamentally prevent the problem that the inwardly folded pages are too small due to the actual cutting amount. It is best to directly specify the amount of cutting compensation in the design sheet. In general, it should be stated that it should not exceed 3mm.
The paper cracked at the fold line
When the fibers of the paper are stretched and separated too far. There will be paper cracking. If this phenomenon occurs on the ground, the result is particularly bad. There are many reasons for paper cracking, such as no indentation treatment before folding; the moisture content of the paper is too low; the setting of the folding roller is not correct, etc. Among them, the first reason is the most common. No matter what kind of printed products. Customers want the cost to be as low as possible, and the added value of the product to be as high as possible. In the case where the customer recognizes the importance of the added value of the product and the appearance effect, it is necessary for the relevant department of the printing and processing unit to recommend that the customer perform indentation processing before folding, so that the customer willingly increases the cost input. In general, if the folding direction of the paper is perpendicular to the direction of the thread, the fold line passes through a thick ink layer on the ground, the paper has a large quantitative weight, or the cover of a book, etc., the fold line must be pre-indented before it Obtain clear and accurate polylines.
In multiple vertical folding. The corners of the page (near the intersection of the polylines) are easily wrinkled. To avoid such phenomena. You must take appropriate precautions. Common causes are:
â‘ The folding sequence is unreasonable, so that the folding pressure is too high, so that the paper at the corners is wrinkled.
â‘¡ The folding process is unreasonable. The air is trapped inside the sticker and cannot be discharged smoothly, which affects the folding effect. For example, first fold the page twice in parallel, and then fold it twice in the vertical direction. This scheme can easily cause air trapped inside the sticker. But if you change the previous two parallel folds into fan-shaped folds, you can get rid of the predicament.
â‘¢ The folding speed is too high, which increases the pressure on the paper during the folding process. Generally speaking. Both heavier and lighter weight paper must use a lower folding speed.
â‘£ Sometimes changing the paper type will get better results. For example, recycled paper has short fibers and low strength. There is a greater possibility of wrinkling at the corners, if you change to a better quality paper. You can greatly improve the folding effect.
The margin of the finished product is too small or part of the image is cut
When binding. Sometimes the margins of the finished product are too small and some graphics are cut off. If the folding edge is straight and tidy, the cutting amount and the size of the finished product are correct, then this situation should be a cutting failure, not related to the folding quality. In order to ensure the cutting quality, the graphic should be at least 1cm away from the cutting edge when designing. If it cannot be guaranteed, the phenomenon that the margin of the finished product is too small and some graphics are cut is inevitable.
The thickness of the finished product is too large or too small
When selecting the paper model. Sometimes people just easily look at the samples provided by customers to easily determine. Some even choose directly based on the verbal advice of others. However, the types of paper are distinguished according to basis weight, and the papers of the same basis weight are actually different in thickness. This is not difficult to understand, why sometimes the standard quantitative paper is selected, but the actual thickness of the final product does not meet the standard. In order to prevent the thickness of the finished product from meeting the requirements, the customer should be asked to provide the correct paper pattern at the beginning of the operation.
The folding effect of digital prints is often not comparable to offset prints.
First, the toner solidifies on the paper surface due to heat melting during fixing, thereby forming a graphic. These cured toners only stay on the surface of the paper (the ink is mainly infiltration and drying in offset printing), and it is easy to fall due to friction when folding. It is especially serious in pager.
Secondly, because the paper is subjected to high-temperature baking, the moisture content decreases, the brittleness increases, and the strength decreases, and it is easily damaged when folded.
Third, the static phenomenon of digital prints is relatively serious, which is not conducive to correct folding.
With the improvement of toner formulation in digital printing technology, the first problem has been better solved. For the second problem, there are two measures: â‘ Before folding, first indent the fold line to increase its toughness; â‘¡ Place the printed product after the salty image in the room, and use the natural humidity in the air to adjust the paper Wet processing, then folding. Of course, in the case of on-demand printing, the delivery cycle is often tight. The feasibility of the second scheme will be restricted to a greater extent. In response to the third problem, the problem of static electricity, many folding machines use an ionized airflow system. Come and neutralize the static electricity carried by the paper to ensure smooth folding.
From the above analysis, we can see that the defects and deficiencies reflected in the folding process are not entirely the responsibility of the folding department. To achieve perfect folding and avoid various failures, we must start with the pre-press design process. The three departments of pre-press, printing and post-press work together to strictly implement the operating standards.
Get out of the misunderstanding of folding machine