Outdoor electrical enclosures operate in some of the most demanding environments.
They are continuously exposed to UV radiation, temperature fluctuations, moisture, pollution, and mechanical stress, while still being required to provide long-term electrical insulation and structural integrity.

Among available material options, BMC (Bulk Molding Compound) and SMC (Sheet Molding Compound) have become preferred solutions for outdoor electrical enclosures across power distribution, renewable energy, rail infrastructure, and industrial systems.

1. Excellent Weather and UV Resistance

Outdoor enclosures must withstand long-term exposure to sunlight, rain, and humidity without degradation.

BMC and SMC materials offer:

• Strong resistance to UV aging

• Minimal surface chalking and color degradation

• Stable mechanical properties under outdoor conditions

Compared to many thermoplastics, BMC/SMC do not soften or deform under prolonged heat exposure, ensuring enclosure stability even in harsh climates.

2. Superior Electrical Insulation Performance

Electrical safety is the core requirement for any enclosure used in power and control systems.

BMC/SMC materials provide:

• High dielectric strength

• Stable insulation resistance over time

• Excellent arc and tracking resistance

These properties make them particularly suitable for low-voltage and medium-voltage electrical enclosures, where long-term insulation reliability is critical.

3. High Mechanical Strength and Dimensional Stability

Outdoor enclosures often face:

• Mechanical impact

• Wind load

• Installation stress

• Long-term static loads

Thanks to their fiber-reinforced thermosetting structure, BMC and SMC deliver:

• High flexural and impact strength

• Low creep under continuous load

• Excellent dimensional stability across temperature changes

Once cured, thermoset materials do not re-melt, ensuring consistent geometry throughout the product lifecycle.

4. Fire Safety and Low Smoke Performance

In outdoor public infrastructure and energy systems, fire safety regulations are becoming increasingly strict.

BMC/SMC formulations can be engineered to:

• Meet flame-retardant requirements

• Achieve low smoke density

• Reduce toxic gas release during combustion

These characteristics are especially important for applications in railways, power substations, EV charging stations, and renewable energy systems.

5. Design Freedom and Integrated Molding

BMC/SMC molding processes allow:

• Complex geometries

• Integrated ribs, bosses, and inserts

• Reduced part count compared to metal assemblies

This design flexibility helps manufacturers:

• Optimize enclosure strength-to-weight ratio

• Improve sealing and protection levels

• Reduce assembly and maintenance costs

6. Cost Efficiency in Medium to High Volume Production

For medium to large production volumes, BMC/SMC offer a strong balance between performance and cost.

Key advantages include:

• High production efficiency

• Stable cycle times

• Long mold life

• Low scrap rates in mature processes

This makes BMC/SMC enclosures highly competitive over the full product lifecycle.

Conclusion

With their combination of weather resistance, electrical insulation, mechanical strength, fire safety, and design flexibility, BMC and SMC materials are ideally suited for outdoor electrical enclosure applications.

They provide a long-term, reliable solution for industries where safety, durability, and performance cannot be compromised.

About Jintong

Wenzhou Jintong Complete Appliances Co., Ltd. provides complete thermosetting solutions, covering:

• BMC/SMC material selection

• Tooling design and manufacturing

• Compression, injection, and transfer molding

• Application-specific engineering support

With over 20 years of experience, Jintong supports customers worldwide in developing reliable thermoset components for electrical and industrial applications.

👉 Contact us to discuss your outdoor enclosure project.