The Eight Most Common Book Printing Problems Identified in The '3·15' Quality Inspection And Improvement Measures

In recent years, the Beijing Printing Industry Product Quality Supervision and Inspection Station (hereinafter referred to as the "Quality Inspection Station") has effectively performed its duties to supervise the quality of printing products, and completed the sampling, inspection and entrusted testing of publishing units, printing enterprises and book sales markets in Beijing. However, after inspection, it was found that some publications had printing quality problems, and the quality problems, causes and rectification measures were summarized as follows, so as to promote the further improvement of the quality of printing products in Beijing.

Missing strokes that affect reading

Individual products have missing pen scratches that affect reading, among which the rubber blanket is damaged by foreign objects, there are foreign objects on the printing plate, paper diseases (such as folds, creases, etc.) on the paper, and the printing plate body is missing pen scratches that affect reading.

Printing enterprises should carefully check the paper before printing, remove the waste paper, and clean up the blanket foreign matter or repair the printing plate in time during the printing process. Lack of pen and scratch is a very serious problem of graphic printing quality, and publishing units and printing enterprises should strictly control the printing quality to prevent this problem.

Film loss or blistering

Some products have lamination or film loss blistering problems, and the wrong cutting direction during operation, wear of the cutting tool, incomplete cutting, wrong positioning of rules, failure to remove problem proofs in time may lead to film loss; When the cover is loaded, the distance between the two sides of the splint is set to be small, and the clamping force of the two sides of the splint is too large after gluing, and while the post line is extrusion, the pre-coated film and the cover will also be partially peeled off, which will eventually lead to lamination blistering.

The reasons for the formation of lamination quality problems are complex, and should be strictly controlled from the process, cutting, transportation and other links.

Dew gum root

The reason for the formation is more complex, not only caused by a certain process in the binding process, but also caused by multiple processes and factors, the quantitative difference between the cover and the text of the paper is too large, the indentation of the flip line is shallow or the width is unreasonable, the glue application on the back of the book is uneven, the depth of the core milling back is not enough, the temperature of the hot melt glue is too low, etc. may become the cause of the exposed glue root.

Printing enterprises should strengthen the control of key links, detect the problem of exposed rubber roots in time and analyze which link the problem occurs, and solve it in a targeted manner.

There are vacuums at one or both ends of the back of the book

Some binding products have cavitation at one or both ends of the book backing, the air in the book core and the hot melt glue is not completely drained, the gluing height is not properly adjusted, and the cover and book back are not tightly fitted.

Correctly adjusting and using the folding machine cutter to expel the air in the book as much as possible, the folded book book is bundled and pressed, and the height of each rubber wheel can be correctly adjusted to effectively reduce the occurrence of such problems.

Dirty marks

Some products have dirty marks, mainly manifested as dirty cover glue and dirty content. The cover glue is mainly caused by the failure to install the disconnection device or the cover length is shorter than the length of the book core, resulting in the cover glue caused by burrs exposed and dirty book bands. The dirt on the text is mainly due to the ink not being completely dry, and the rush to bind causes the text to rub the text.

The gluing part of the glue binding equipment should be installed with a disconnection device and the disconnection position should be accurately set, and the ink should be completely dried in a special drying way for special paper. If the area of dirt is too large and seriously affects reading, the publishing unit and printing enterprise should promptly supervise and inspect and remove the stained products that affect reading in a timely manner.

The side rubber part cracks

Some products have the problem of cracking of the side glue part, which may lead to the side glue part cracking due to the stoppage of the gluing process, improper selection of adhesive, insufficient temperature and humidity during sizing or improper adjustment of the time interval between the support and tightening. Partial cracking of the side adhesive is easy to cause complete cracking of the side adhesive during long-term placement or flipping.

If the downtime exceeds the opening time of the glue, it is necessary to remove 6~8 volumes, choose the appropriate glue type according to the paper blockage, and adjust the tightening according to the thickness of the book core to effectively avoid such problems.

Linked knife page

When individual products have the problem of connecting pages, it will seriously affect readers' reading. At present, with the improvement of equipment technology, the occurrence rate of this problem has gradually decreased, but it still occurs from time to time.

Printing enterprises should pay attention to regularly calibrating the positioning device, folding and page matching device, when the page matching machine is positioned accurately, there will be no cutter page when cutting.

Inner text crease

The problem of creases is mainly manifested by the presence of folds on the inner pages. When handing over the paper, the angle of opening the mouth is insufficient; When collecting paper, the suction wheel and pressure air are not properly adjusted; When cutting, the folding corners of the book core will lead to creases, resulting in the folds of the inner pages.

Regularly debugging the machine's teeth and tablet, moving the paper take-up suction wheel, and adjusting the suction power and pressure air can effectively reduce the problems of inner page creases and folds.

The quality inspection station will focus on the above-mentioned outstanding problems in printing quality in the 2023 quality inspection activities, effectively improve the pertinence of inspection and sampling work, and provide a strong publishing and printing quality assurance for the study, publicity and implementation of the spirit of the 20th National Congress of the Communist Party of China.

All publishing and printing units should conscientiously carry out self-inspection and self-correction against the above-mentioned printing quality problems, avoid such problems from repeatedly occurring, and deeply study the relevant national and industry standards through quality training, so as to draw inferences from one case to another, form a complete quality management system, effectively resolve quality risks, create more fine products, and better meet the people's new expectations for a better life.