How to do the book binding strength test to meet the standard? Complete tutorial from sampling to interpretation

The core of the book binding strength test is to useSingle page pull-out forceandWhole book folding durabilityWill the two sets of data manuals be missing pages. Conventional practice: Sampling and curing for 24 hours, measuring the pull-out force of a single page inside the book core, and generally requiring wireless adhesive products to be no less than 4; N/cm， And it should be flattened and folded 180 degrees without cracking.

Step 1: Sampling and Maintenance

• Take 5 books per batch, avoiding the first three books and the final book when starting up.
• Sample at 23; If the adhesive layer is not completely stable after being placed in an environment with a temperature of ± 2 ℃ and a humidity of 50% ± 10 for 24 hours, the data will be lower.
• Record the type of paper, weight, milling depth, gluing temperature, and machine speed, and the data should be traceable to the process.

Step 2: Single page pull-out force test

Take one page from the front, middle, and back of the book block, and clamp it along the spine direction; Cm width, using a tensile testing machine to measure approximately 100; Pull out vertically at a constant speed of mm/min, record the maximum force value and convert it to N/cm. Take the average of three points and look at the minimum value at the same time – the weakest page determines the user experience.

Step 3: Folding and Flattening

Spread the book completely flat to 180 degrees, open and close it 50 times repeatedly, and observe whether there are cracks on the spine and whether the inner pages are loose. Copperplate paper and laminated covers are more likely to expose the problem of insufficient penetration at this stage.

Step 4: Supplementary items for temperature resistance and weather resistance

Step 5: How to reverse check if the data does not meet the standard

• The pull-out force is generally low → first check the amount of adhesive and milling depth, and then check whether the viscosity of the adhesive is too high or the penetration is insufficient.
• Only a few pages are low, mostly due to uneven clamping or issues with paper fiber orientation.
• Folding and cracking, but the pull-out force is qualified → The adhesive layer is too hard and requires a more flexible grade.
• During the summer, there were concentrated issues with the batch – either the softening point was selected too low or the workshop environment temperature was out of control.

Frequently Asked Questions (FAQ)

Q: What if there is no tensile testing machine?
Answer: Hand tear comparison tests can be conducted, where different batches of the same process are torn in parallel, and significant degradation can be observed. However, this cannot be used as a basis for external quality commitments.

Question: How often do you do it?
Answer: New adhesive batches, new paper, and new machine debugging must be tested; It is recommended to draw one book per shift for daily production, and it must be tested before changing orders.

Question: How long should the data be retained?
Answer: It is recommended to keep the order file until the end of the warranty period, and in case of customer complaints, it can be directly retrieved for comparison.

Using Sunlifehot melt adhesiveFor book and magazine clients, Guangzhou Sunlife Trading can provide reference pull-out force ranges and recommended process windows for this brand on different papers, allowing for benchmark comparability in experiments instead of trial and error every time.