Epoxy resin generates heat during curing—a natural part of the chemical reaction that transforms liquid components into a solid crosslinked structure. However, excessive heat, known as exotherm, can lead to serious defects, including cracks, discoloration, smoke, warping, and even thermal failure.

At CNMI Industrial Corporation, we engineer epoxy systems with advanced exotherm-control chemistry to ensure safe and predictable curing in art, furniture, flooring, and industrial OEM applications.

1. What Is Exotherm in Epoxy Resin?

Epoxy cures through an exothermic reaction, meaning it releases heat as the molecules crosslink.

When the reaction is balanced:

• Controlled warming

• Smooth curing

• Predictable hardness

• Clear results

When the reaction overheats:

• Resin may smoke

• Surface may warp

• Bubbles may form

• Cracks may appear

• Yellowing accelerates

This overheating is one of the most damaging epoxy failures.

2. Why Epoxy Overheats: The Scientific Causes

Several factors trigger excessive exotherm:

① Pouring Resin Too Thick

The deeper the pour, the more heat concentrates internally.

This is why deep-pour systems are designed differently.

② Fast-Curing Formulations Used Incorrectly

Fast-curing epoxy should never be used for deep castings.

Risk when misused:

• rapid viscosity spike

• smoke & foaming

• severe cracking

Flooring resins and adhesives are especially reactive.

③ Large Batch Sizes

Mixing one large cup creates internal heat that cannot escape.

Example:
500g → warm
2 kg → hot
5 kg → dangerous

This is a common issue for furniture makers and factories.

④ High Ambient Temperature

Hot environments reduce working time and accelerate reactions.

Above 28°C (82°F) → exotherm risk rises dramatically.

3. Effects of Overheating on Epoxy Performance

Overheating permanently weakens the polymer structure.

4. How CNMI Controls Exotherm Through Formulation

CNMI epoxy systems are engineered with:

✔ Slow-curing hardeners for deep pours

Prevents thermal runaway.

✔ Exotherm-reduction additives

Modifies peak heat output.

✔ Controlled molecular weight resins

Reduce uncontrolled reaction rates.

✔ Viscosity engineering

Improves bubble escape and heat distribution.

✔ OEM custom ratios

Different industries = different temperature profiles.

Our HL210 deep-pour line is specifically designed for thick resin applications.

5. Engineering Exotherm Control for OEM Partners

CNMI supports OEM customers by:

• Matching resin to product type

• Adjusting cure speed for climate

• Designing custom temperature curves

• Providing safety data & processing sheets

• Simulating production-scale heat release

Factory conditions demand predictability and safety — our systems deliver both.

6. How Users Can Prevent Overheating

To reduce exotherm risk:

• Pour in thinner layers

• Mix smaller batches

• Work at 22–26°C

• Use slow-curing deep-pour resins

• Avoid sunlight exposure

• Monitor container heat

If epoxy begins to overheat:

• Spread it out in a tray

• Do NOT add more resin on top

• Improve ventilation

• Do not cover with a lid

Cooling reduces reaction speed safely.

Conclusion: Exotherm Control is Essential for High-Quality Epoxy Results

Overheating is one of the most damaging epoxy issues—but also one of the most preventable. Through controlled chemistry, slow-curing deep-pour systems, and OEM-optimized formulations, CNMI ensures stable curing across all applications.

Whether for large river tables, industrial flooring, mass-production consumer products, or specialized composites, CNMI epoxy systems deliver safe, consistent, and high-performance curing.