How to solve the problem of glue overflow and dirtying the book pages? Thoroughly explain the 12 checklist items at once

Direct answer: Glue overflow dirtying the book pages is essentially due to at least one of the four variables, “glue amount, temperature, pressure, and rhythm,” exceeding the appropriate range. The three most common reasons are excessive glue application, high glue temperature leading to low viscosity, and excessive clamping pressure squeezing glue from the spine to between the pages. Check item by item according to the list, and in most cases, it can be located within half an hour.

Industry Status: Rubber overflow is not considered a major accident, but losses occur every day

Compared to hard faults such as page drops and cracks, glue overflow is often treated as a minor issue. But for on-demand printing and short editions, glue overflow means that each batch has to be manually inspected, wiped, and scrapped, and the cost is not low for each book. The graphic and text fast printing shop is particularly obvious, as customers can easily see the offset printing on the first page and immediately rework it.

12 Checklist for Investigation

• 1. Glue application amountFirst, reduce the trial version by 10% to 15%, which is the step with the highest hit rate.
• 2. Adhesive temperatureWhen the viscosity drops sharply above the recommended upper limit, the glue flows away like water. Gradually lower the temperature by 5 ℃ for observation.
• 3. Thickness setting of adhesive layerThe spine glue layer is generally 0.6-1.0 millimeters, and if it exceeds 1.2 millimeters, it will almost overflow.
• 4. Width of side adhesiveNormally controlled at 3-6 millimeters, if set too wide, the tape will be directly applied to the front of the book page.
• 5. Clamping pressureExcessive pressure is equivalent to squeezing the glue on both sides. Follow the machine instructions to lower it to medium and try again.
• 6. Milling depthThe milling is too shallow, and the paper scraps block the glue, leaving nowhere to go and only overflowing.
• 7. Gap between upper rubber rollersGap wear can cause the amount of adhesive to lose control and requires regular calibration.
• 8. Scratch film statusScratches that are worn or have gaps may result in local adhesive buildup.
• 9. Consistency of book thicknessWhen binding in mixed batches, thin books will inevitably overflow according to the parameters of thick books.
• 10. Does the viscosity of the adhesive particles matchLow viscosity models are suitable for high-speed thin notebooks and are easy to flow when used on thick notebooks.
• 11. Workshop temperature and humidityIn summer, the glue in the high-temperature workshop cools slowly, and the overflow window is stretched.
• 12. First book after shutdownDuring the shutdown period, the glue in the glue pot continued to degrade and become thinner. The first few books that resumed production were picked out separately.

Suggested sequence for quick positioning

Improvements that can be made in the selection of adhesive layers

If the machine parameters have been adjusted to a reasonable range and there is still glue overflow, it is necessary to return to the glue itself. Models with low viscosity and long open time are prone to flow on slow lines; Changing to a slightly higher viscosity and faster curing specification is often more effective than continuing to adjust the machine. Guangzhou Sunlife Trading divides the models of books and periodicals online into three stages: machine speed book thickness viscosity, Sunlifehot melt adhesiveThe advice given to customers has always been to adjust the machine first, and if it cannot be adjusted, then replace the glue to avoid blaming the equipment problem on the material.

Frequently Asked Questions

Can a book that has already overflowed be saved?

After the glue has completely cooled down, you can use a wooden scraper to gently remove it along the edge of the book page. Do not use solvents to wipe, as it will leave marks. Those that infiltrate the inner pages can only be scrapped.

Will reducing the amount of adhesive lead to weak bonding?

Not within a reasonable range. A uniform adhesive layer of 0.6-0.8mm has higher strength than an uneven adhesive layer of 1.5mm, and the key is uniformity rather than thickness.