When making shoes, sudden sole separation right before the shipping deadline is every factory and buyer’s worst nightmare. Many people jump to quick conclusions just by looking at a photo. But whether the factory blames the glue or the supplier blames the workers, pointing fingers does not solve the problem of what to do with the bulk order sitting on the floor.
A proper shoe degumming troubleshooting guide requires teamwork between the shoe factory and the glue supplier: the factory must share clear facts, and the supplier must give tested, fact-based answers.
“We used your glue, but the shoes still broke. What do we do now?”
If a shoe factory asks this right before shipping day, they worry about everything: the boxes in the warehouse, the active machines, and the next orders already on the list.
A simple “Our glue passed our quality tests” does not solve the delivery crisis. And saying “Just try a different glue” will not give buyers peace of mind. As a glue maker, we believe a quality report must answer one key question: What is our next move, based on facts?
To find that answer, information must flow two ways:
- The factory shares clear details so we can find the root cause.
- The supplier gives clear advice so production can go on safely.
Part 1: How to Find the Root Cause of Shoe Degumming
1. A photo shows the break, but not the exact reason
When shoe degumming happens, a photo can show where the sole came off, but it cannot tell the full story. According to SATRA TM411, a test method for footwear sole bond strength, bond strength can be measured at different points between the sole and upper.
This is why checking the actual failed shoes matters more than judging the problem from a photo alone.
- What to do: Keep the broken shoes. Take clear photos of the damage. Note the batch numbers for both the glue and the shoe materials.
- Do not fix them too fast: If workers re-glue every broken shoe before checking, the original clues are lost. Save a few original samples and keep them separate from fixed ones.
- Asking “Where exactly did it separate?” helps narrow down the search. Blaming the glue or the workers too early from just one photo is a mistake.
2. Good shoes are just as important as bad shoes
Imagine you make the same shoe model: the old batch was fine, but the new batch has shoe degumming problems. What changed between them?
- Is the glue from the same batch?
- Did you buy shoe parts from a new supplier?
- Did the primer, mixing ratio, or work speed change?
Put good shoes and bad shoes side by side. Good shoes provide a baseline; bad shoes point to the clues.
For shoe factories, keeping records of good batches creates valuable clues for future troubleshooting.
3. What happened after the shoes left the line?
Saying “They broke after a few days of wear” is an honest user report, but it misses the full journey of the shoe.
We need to know: When were they made? How long did they sit in storage? Were there issues during shipping? Where were they worn first? “Worn for a short time” does not mean the shoe itself is brand new off the machine.
SATRA points out that shipping, storage, retail, and wear are all part of a product’s lifespan. While this does not apply to every glue failure, it reminds us to look beyond just how many days a customer wore the shoes, rather than blaming the warehouse or user right away.
4. “Only a few pairs” is not enough to know the full impact
A few cases of shoe degumming in one batch mean something very different from similar problems found across several orders.
For example, on July 16, 2026, the U.S. CPSC recalled about 211,000 pairs of kids’ sandals because decorative beads fell off 23 pairs. No one got hurt, and it was not a glue issue.
This shows that the number of reports, the range of products affected, and the risk level must be checked carefully. A low number of complaints does not mean every box is safe. At the same time, batches with no complaints yet cannot automatically be called proven.
Part 2: Answers from the Supplier Give Clear Next Steps
1. “Our lab test passed” is not the end of the story
Glue makers must check their own factory records first. Batch records, test results, and saved samples should all be reviewed. If there is a product problem, we must admit it and offer real help.
Lab tests show how glue performs under set test conditions. But when shoe degumming happens in real production, buyers need to know why the bond failed on their own shoes and materials.
A useful supplier reply must tell you:
- What we checked.
- What the test results prove.
- What questions are still open.
You should not have to guess what a lab report means.
2. Stop passing messages back and forth
Imagine a buyer gets a “glue is fine” note from us, a “materials are fine” note from the upper supplier, and a “we did it right” note from the workshop floor. If everyone looks at different things, the stories will never match.
Forwarding messages back and forth does not bring you closer to the truth. All parties need to look at the same broken shoe and agree on the facts.
Pick one contact person to track the problem. Make sure the brand, buyer, and factory all get the exact same updates. This person does not need to make technical calls for everyone, but they ensure everyone stays on the same page.
3. Deadlines will not wait for a full check
A factory cannot wait forever for a message that says “we will update you when we know more.” Buyers have to update the brand, production managers have to run lines, and warehouses need to know what stock can ship.
Even if we do not know the final cause of shoe degumming yet, we must give a safe plan for right now.
For example, if one batch has issues, we should stop that batch, plan the next test, and give a clear date for updates. Do not just say “It should be fine.” Give real facts and clear rules.
4. If changing the glue works, know why it worked
If you switch glue, dry it longer, press it harder, and the shoes are fine now—that is great. But do not give all the credit to the new glue alone.
The American Society for Quality (ASQ) explains root cause analysis as a way to find why a problem happened and prevent it from happening again. For shoe factories, this means checking which change really improved the bond, rather than assuming that switching glue solved everything.
If you do not know which change fixed the issue, you might fail the next time you swap the glue without adjusting the process.
Suppliers must confirm the test results with the factory:
- How did we test it?
- Which samples did we test?
- Did it work in real mass production?
- If there are no new complaints, how long did we watch the line?
5. Save your lessons for the next order
If you fix a problem, but the answer only stays in a chat app, you lose that knowledge. When new workers join or you make the shoe again, the buyer might only know “we changed glue models” without knowing what else changed.
What you should write down in your records:
- What you guessed at first.
- What tests proved wrong.
- What you changed in the end.
- Exactly what conditions made it work.
If a test failed, write that down too, so people do not try it again.
Glue makers can make simple guide sheets. Factories can save them with the order files. When staff change, the knowledge stays. When orders change, you know what rules to use.
Fixing a bonding problem is only one part of better production. Factories also need to review how materials and bonding steps affect daily costs. For more practical ideas, read our guide on how shoe factories can cut bonding costs.
At Heley, we know that when a customer brings us a broken shoe, they want to see if we will truly help solve it.
Solving shoe degumming takes more than a quick glue change. When factories share clear facts and suppliers provide reliable test results, both sides can make better decisions and reduce the risk of repeat problems.
We want you to walk away with a clear, tested plan for your next production run. That is what a real glue partner should do.