Adhesive overflow on taping machines is one of those problems that looks simple on the surface but becomes expensive very fast. Excess adhesive contaminates rollers, sticks to guides, attracts dust, causes tape misalignment, and eventually creates downstream defects during extrusion or jacketing.

What makes this issue worse is that many factories treat adhesive overflow as a material problem — changing glue brands, lowering viscosity blindly, or wiping machines more often. In reality, adhesive overflow is almost always a process balance failure, not a glue quality issue.

This article explains where adhesive overflow really comes from, how to diagnose it correctly, and how cable factories eliminate it without changing machines or adhesive suppliers.

1. What “Adhesive Overflow” Actually Means in Taping

Adhesive overflow does not mean “too much glue” in a general sense. It specifically refers to:

• Adhesive squeezing out from tape edges

• Glue transferring to rollers, dancer arms, or guides

• Adhesive smearing onto conductor or insulation surface

• Accumulation of sticky residue downstream of the taping point

In most cases, the total adhesive volume is not excessive — it is being displaced incorrectly during tape application.

2. Why Adhesive Overflow Is More Common Than You Think

Adhesive overflow tends to appear more frequently when:

• Line speed is increased

• Tape overlap is tightened

• Ambient temperature rises

• Switching to thinner or softer tapes

• Taping over uneven substrates (bunched conductors, fillers)

This is why many factories say:

“It was fine before, nothing changed.”

In reality, something always changed — usually speed, temperature, or mechanical pressure.

3. Core Root Causes Inside the Taping Process

3.1 Excessive Tape Tension (Most Common Cause)

The number one cause of adhesive overflow is over-tensioning the tape.

When tape tension is too high:

• Adhesive is forced outward

• Tape edges squeeze glue sideways

• Overflow appears even with correct adhesive coating

This happens because adhesive is incompressible — it must move somewhere when pressure increases.

Typical reasons for over-tension:

• Brake settings increased to stabilize tape

• Operator compensating for tape wandering

• High-speed operation without retuning tension

Key point:

Tape tension should stabilize tape position, not compress adhesive.

3.2 Incorrect Tape Overlap Design

Too much overlap is a silent overflow generator.

When overlap exceeds the adhesive’s design range:

• Adhesive layers stack

• Pressure builds at overlap edges

• Glue squeezes outward

This is especially common when:

• Overlap > 30% for adhesive-coated tapes

• Switching tape width without adjusting overlap

• Using the same overlap setting across different cable diameters

Correct thinking:

Overlap is a geometry parameter, not a safety margin.

3.3 Adhesive Viscosity–Temperature Mismatch

Adhesive viscosity changes with temperature — often more than operators expect.

When temperature rises:

• Adhesive becomes more fluid

• It flows under the same pressure that was previously stable

• Overflow suddenly appears

Common triggers:

• Summer ambient temperature

• Heat from upstream extrusion

• Poor ventilation around taping zone

Many factories blame the glue, but the real issue is process temperature drift.

3.4 Uneven Substrate Surface (Hidden Cause)

Taping over:

• Poorly compacted conductors

• Irregular fillers

• Oval insulation

creates localized pressure peaks.

At these high-pressure points:

• Adhesive is squeezed out

• Overflow appears intermittently

• Defect looks random

Important insight:

Adhesive overflow can originate before the tape even touches the glue.

3.5 Roller Alignment and Contact Angle Errors

Misaligned rollers or incorrect tape entry angles cause:

• Uneven pressure across tape width

• One edge carrying more load

• Adhesive flowing toward the overloaded side

This often results in:

• One-sided overflow

• Sticky buildup only on one guide or roller

4. Why Reducing Adhesive Is the Wrong First Reaction

A common reaction is:

“Let’s use less glue.”

This often causes:

• Poor adhesion

• Tape lifting during extrusion

• Long-term delamination

Adhesive overflow is usually a pressure and flow problem, not a volume problem.

5. Correct Diagnostic Sequence (Do This in Order)

Step 1: Observe Overflow Pattern

Ask:

• Is overflow on one side or both?

• Is it continuous or intermittent?

• Does it increase with speed?

Patterns reveal causes faster than measurements.

Step 2: Reduce Tape Tension by 10–15%

Without changing overlap or adhesive:

• If overflow reduces → tension is confirmed cause

• If not → continue diagnosis

Step 3: Temporarily Reduce Line Speed

• Reduce speed by 15–20%

• Observe adhesive behavior

If overflow disappears:

Speed-pressure interaction is the trigger.

Step 4: Check Substrate Uniformity

Inspect:

• Conductor compaction

• Filler shape

• Insulation ovality

Fix upstream problems before touching the taping unit.

6. Proven Fixes That Actually Work

6.1 Rebalance Tape Tension (Not Just Reduce It)

Goal:

• Stable tape path

• Minimal compressive force

Best practice:

• Use the lowest tension that still maintains alignment

• Avoid “tight for safety” settings

6.2 Optimize Overlap Ratio

Typical safe ranges:

• Adhesive tape: 15–25%

• Non-adhesive tape with binder: up to 30%

Adjust overlap per cable diameter — not one setting for all.

6.3 Control Local Temperature

Actions:

• Improve ventilation near taping zone

• Shield taping station from upstream heat

• Avoid placing adhesive reels near hot surfaces

Even a 5–8°C drop can stabilize adhesive flow.

6.4 Correct Roller Geometry and Alignment

Check:

• Roller parallelism

• Tape entry angle

• Contact symmetry across tape width

Fixing alignment often eliminates one-sided overflow instantly.

6.5 Improve Substrate Quality

If taping over conductors:

• Improve bunching compaction

• Reduce strand voids

If taping over insulation:

• Correct ovality

• Stabilize extrusion diameter

Good taping depends on what comes before it.

7. Real Factory Case

A factory producing LV control cables experienced severe adhesive buildup on taping rollers.

Findings:

• Tape tension increased after speed upgrade

• Ambient temperature +7°C seasonal rise

• Overlap fixed at 35% for all sizes

Fixes:

• Reduced tape tension by 12%

• Reduced overlap to 22%

• Added local air circulation

Result:

• Overflow eliminated

• Roller cleaning frequency reduced by 60%

• No adhesive change required

8. Why Adhesive Overflow Often Appears “Suddenly”

Because:

• Adhesive behavior is non-linear

• Small pressure or temperature changes push it past a flow threshold

• Wear, speed creep, and seasonal heat accumulate quietly

Overflow is not sudden — it’s delayed.

Conclusion

Adhesive overflow in taping machines is not a glue defect and not a mystery. It is the result of excessive pressure, incorrect geometry, thermal drift, or poor substrate quality.

The solution is not:

• Changing adhesive brands

• Reducing glue blindly

• Cleaning more often

The solution is:

• Correct tension

• Proper overlap

• Stable temperature

• Good upstream quality

When adhesive flows where it shouldn’t, it’s reacting — not misbehaving.