A conclusion became increasingly clear: the same process steps show control level differences of up to 10x between different factories, yet the locations where problems occur are strikingly consistent.
The following six major pitfalls are ranked from highest to lowest by "occurrence rate." See how many your production line has hit.
Pitfall 1: Relying Solely on "Pump Display" for Ratio Control — Never Actually Weighing ItOccurrence
Rate: 93%
Nearly all production lines are equipped with automatic metering and proportioning equipment, but only 7% of factories actually use electronic scales to verify the output weight of A and B components each shift. The majority of factories rely long-term on equipment display readings, unaware that pump wear, pipe blockage, and sensor drift can all cause actual ratio deviations.
Tensan randomly sampled the actual ratio values from 12 production lines and found that 5 of them had B-component deviations exceeding +2.5% — far beyond the allowable tolerance of ±1% — while the control panel still displayed the "set value."
Risk Consequence: Incomplete curing or over-crosslinking leading to brittleness; high risk of entire batch rejection.
Remediation Cost: Extremely low. Just 2 minutes per shift for a weight verification check.
Pitfall 2: Trusting the Curing Oven's "Set Temperature" — Never Measuring Actual TemperaturesOccurrence
Rate: 88%
The temperature displayed on equipment screens doesn't equal the actual temperature experienced by the product. Tensan's measurements have found that in the same fully loaded oven, temperature differences between upper and lower trays can reach 8°C, and between the door and the back can reach 5°C. Yet 88% of factories have never conducted any form of temperature field mapping.
An even more concealed issue is the ramp-up rate. Some ovens take over 40 minutes to reach the set temperature from room temperature, during which the adhesive is already slowly crosslinking — effectively "stealing" one-third of the actual curing time.
Risk Consequence: Inconsistent curing degree within the same batch — some under-cured, some over-cured.
Remediation Cost: Low. A temperature field mapping using 9 thermocouples costs less than a thousand yuan.
Pitfall 3: Temperature Recovery by "Feel" — Never Measuring "Core Temperature"Occurrence
Rate: 82%
The surface temperature of adhesive taken from cold storage can differ from its core temperature by more than 15°C. The number one cause of winter potting defects is mixing adhesive before it's fully returned to room temperature, judged by merely touching the barrel surface to see if it "feels cool." Unfortunately, many factories carry this bad habit into summer as well.
Tensan's recommendation: Use an infrared thermometer to measure the center of the barrel's sidewall, confirming that internal and external temperatures are consistent (within ±2°C) before opening and using. Large drums (20kg+) should be allowed to return to room temperature for no less than 8 hours; small pails (5kg or less) no less than 4 hours.
Risk Consequence: Uneven mixing of cold adhesive; condensation water film forms when cold adhesive contacts hot substrates, causing interfacial delamination.
Remediation Cost: Extremely low. Just one infrared thermometer.
Pitfall 4: Surface Treatment "Depending on Mood" — Never Standardizing ParametersOccurrence
Rate: 76%
The effectiveness of plasma cleaning or corona treatment is highly dependent on the stable combination of four parameters: power, time, distance, and gas flow rate. Yet on-site observations reveal that 76% of factories have not codified these parameters into standard operating procedures. Operators make "experience-based adjustments," and the treatment effectiveness of the same plasma gun can vary by more than 50% between different shifts.
An even more common scenario: the plasma equipment's filter is clogged without replacement, or electrodes are aged without maintenance — the machine "lights up but doesn't deliver," while operators mistakenly believe the equipment is functioning properly.
Risk Consequence: Insufficient surface energy prevents effective adhesion anchoring, leading to high delamination risk.
Remediation Cost: Moderate. Replace consumables, calibrate parameters, and add daily dyne pen spot checks.
lPitfall 5: Static Mixing Tube Used "Until It Breaks" — Never Managed by Service LifeOccurrence
Rate: 61%
Static mixing tubes contain internal helical structures where adhesive gradually cures and forms hard deposits in the flow channels, progressively shortening the effective mixing length day by day. 61% of factories follow a "replace only when adhesive stops flowing" management approach, at which point the effective mixing section may have been reduced to less than 40% of the original length.
Tensan conducted a comparison on one production line: after replacing the static mixing tube with a new one, the post-cure hardness under the same ratio and temperature increased from Shore A 28 to 45 — approaching the theoretical value.
Risk Consequence: Insufficient mixing → localized A/B ratio imbalance → localized incomplete curing.
Remediation Cost: Extremely low. Set a replacement cycle based on usage count or time; each tube costs only a few dozen yuan.
Pitfall 6: Retained Samples as "Formality" — Never Testing Hardness or Bonding StrengthOccurrence
Rate: 54%
More than half of factories claim to "retain samples," but only conduct visual inspections on these samples, never performing quantitative tests with hardness testers or tensile testers. The true value of retained samples is this: when problems occur in batch products, the samples serve as the most direct evidence for tracing back to the curing process status.
Tensan recommends retaining at least 3 standard-sized cured sample blocks per batch, labeled with batch number, date, and operator, and recording hardness (Shore A) and shear strength data to establish a batch-based internal control archive.
Risk Consequence: Inability to trace whether a problem originated from equipment, materials, or operations once it occurs, leaving no direction for corrective action.
Remediation Cost: Low to moderate. Equip with a Shore hardness tester (approximately one thousand yuan) and establish a sample tracking log.