💡 In This Article Why a single viscosity value is not enough to describe an adhesive How shear rate connects rheometer data to real processing conditions How 3ITT can quantify thixotropic recovery What changes in rheological behavior matter when coating line speed increases An Adhesive Is Not a Solid Yet If you've been following this … Continue reading Reading Rheometer Graphs ① — Why Measure Viscosity Before and During Cure?
Author: Epoxy Formulation Researcher
Reading a DMA Curve ③ — How Should We Interpret the Tan δ Peak?
💡 In This Article What Tan δ represents and what the relationship between Loss Modulus (E″) and Storage Modulus (E′) tells us about molecular motion What the height and width of the Tan δ peak can reveal How Tan δ relates to vibration and impact damping in epoxy adhesive layers In the previous article, Reading … Continue reading Reading a DMA Curve ③ — How Should We Interpret the Tan δ Peak?
Reading a DMA Curve ② — What Does Storage Modulus Really Tell Us?
💡 In This Article What Storage Modulus really represents Why the onset of the rapid Storage Modulus drop can be more important than the Tan δ peak Why absolute Storage Modulus retention at the actual operating temperature can matter more than a single Tg value How formulation changes can alter the Storage Modulus curve In … Continue reading Reading a DMA Curve ② — What Does Storage Modulus Really Tell Us?
Reading a DMA Curve ① — Why Do Researchers Rely So Heavily on DMA?
💡 In This Article How the measurement purpose of DMA differs from DSC and TMA Why Tg values differ between techniques and how this relates to segmental motion How the position, height, width, and shape of the Tan δ peak can provide clues about polymer structure and relaxation behavior How DMA can be used to … Continue reading Reading a DMA Curve ① — Why Do Researchers Rely So Heavily on DMA?
Reading a TMA Curve — Why Do We Measure TMA?
💡 In This Article What physical-property data TMA provides for epoxy development The physical relationship between CTE mismatch, warpage, and delamination in bonded dissimilar materials How the crosslinked structure of epoxy differs from thermoplastics and affects TMA behavior, including α₁ and α₂ How TMA can be used to simulate production-like thermal conditions In the previous … Continue reading Reading a TMA Curve — Why Do We Measure TMA?
How Do You Read a DSC Curve? — Why Is DSC Used to Determine Tg?
💡 In This Article DSC analysis: How Tg can be identified from changes in heat capacity How to read Tg from a DSC curve: Why Tg is usually identified from a baseline shift rather than simply looking for a peak Why comparing DSC curves can be more informative than comparing Tg values alone Using DSC … Continue reading How Do You Read a DSC Curve? — Why Is DSC Used to Determine Tg?
Why Are There Different Analytical Techniques for Measuring Tg?
💡 In This Article Tg is not simply a single number — it reflects a complex set of property changes associated with polymer segmental motion Why Tg values differ between analytical techniques — how DSC, DMA, TMA, and other methods observe different physical manifestations of the same glass transition When developing an adhesive, two properties … Continue reading Why Are There Different Analytical Techniques for Measuring Tg?
Why Does Epoxy Look Fine When Dry but Fail After Absorbing Moisture? ② — Why Did 85/85 Still Fail Even Though Tg Increased?
💡 In This Article The relationship between 85/85 testing and an epoxy Tg above 85°C Dry Tg vs. Wet Tg and practical considerations for measuring them Moisture saturation and the possibility of irreversible degradation Why moisture reliability must be designed around the entire adhesive system rather than a single property In the previous article, "Why … Continue reading Why Does Epoxy Look Fine When Dry but Fail After Absorbing Moisture? ② — Why Did 85/85 Still Fail Even Though Tg Increased?
Why Does Epoxy Look Fine When Dry but Fail After Absorbing Moisture? ① — Why 85/85, PCT, and HAST Testing Exist
💡 In This Article Why initially strong adhesion can deteriorate rapidly under high-temperature, high-humidity conditions How moisture penetrates an adhesive layer even when no visible damage is present Why accelerated reliability tests are used, and how 85/85, PCT, and HAST differ The basic concept of acceleration factors and humidity-accelerated lifetime models In the previous article, … Continue reading Why Does Epoxy Look Fine When Dry but Fail After Absorbing Moisture? ① — Why 85/85, PCT, and HAST Testing Exist
Why Does Adhesion Fail Later Even When It Was Good Initially? — How Thermal Shock Causes Adhesive Failure
💡 In This Article Why an epoxy adhesive with excellent initial adhesion can lose adhesion after reliability testing How differences in coefficient of thermal expansion (CTE) affect the adhesive interface How cracks initiate and propagate under repeated thermal shock conditions In the previous article (Does More Toughener Always Mean Better Adhesion?), I covered the optimum … Continue reading Why Does Adhesion Fail Later Even When It Was Good Initially? — How Thermal Shock Causes Adhesive Failure