What is the standard width for the adhesive side of book and magazine packaging? Reference values and judgment methods for different formats

Direct answer: The width of the side glue for regular 16 open books and magazines is 4-6mm, for 32 open books it is 3-5mm, and for large 16 open or thick books (book spine exceeding 20mm) it can be relaxed to 6-8mm. The width of the side glue should be “able to effectively grasp the cover fold without affecting the page flipping and spreading”.

What is the function of the side glue

The main force of wireless adhesive packaging comes from the back adhesive, and the responsibility of the side adhesive is to connect the cover and the two sides of the inner book sticker, preventing the cover from separating from the book block and the spine from opening when flipping through. It bears tearing and peeling forces. If the width is insufficient, it will open, and if the width is too large, the book will be flipped over unevenly and words near the spine will be “eaten” in.

Reference values for different formats

Three methods to determine whether the width is appropriate

• Visual inspection methodOpen the finished product cover and check if the edges of the adhesive marks are straight and continuous. Intermittent and fluctuating width and width indicate that the pressure or height of the side rubber wheel needs to be adjusted.
• Flat methodFlip the book to the middle and press the fold. If the text within 5mm of the spine cannot be opened clearly, it indicates that the side glue is too wide.
• Tear sealing methodTear off the cover from the corner of the book, the qualified standard is that the paper fiber is torn off; If the cover is completely clean and peeled off, it indicates that the side adhesive is too narrow or the initial adhesion is insufficient.

Hidden variables affecting the width of the side adhesive

Many people only adjust the side rubber wheel, but in fact, there are three equally crucial variables: first, the position of the cover crease, and the offset of the indentation line will narrow the actual effective side rubber area; The second is the viscosity of the adhesive used for the side glue. If the viscosity is too low, it will be squeezed open during compression, resulting in the actual width exceeding the standard; The third is the clamping position of the book block. If the clamping is too deep, it will reduce the contact area of the side rubber wheel.

Can the side adhesive and back adhesive use the same adhesive

Most production lines are the same, which is also the most convenient approach. But for high-frequency reading of textbooks, teaching aids, or picture books with cover film, it is recommended to choose models with higher initial adhesion for the side adhesive – the film surface has poor absorption, and ordinary back adhesive is prone to false adhesion on the side, such as “looking stuck and tearing off”. Sunlife hot melt adhesive provides specialized high initial adhesion grades for laminated covers, which can be used in conjunction with conventional backing adhesives.

Frequently Asked Questions

Q: Is the wider the side glue, the stronger the book?
Answer: No. After exceeding 8mm, the strength improvement is extremely limited, but it will significantly sacrifice the page flipping experience, and picture books will also block cross page images.

Question: Is the curling of the spine at both ends due to insufficient side glue?
Answer: Possible, but the more common reasons are insufficient opening time or too short compression time of the adhesive backing. It is recommended to investigate these two issues first.

Q: How to determine the width of the side adhesive for small-scale on-demand printing?
Answer: The paper and thickness of the graphic and text fast printing scene vary greatly. It is recommended to set it uniformly to 5mm for the best compatibility, and adjust it separately for special thick editions.

Guangzhou Sunlife Trading provides side/back glue matching solutions and machine parameter suggestions for book binding and graphic fast printing customers. If you need samples, please feel free to contact us at any time.