When selecting electrical insulation sleeving for motors, transformers, or wiring assemblies, one of the most common questions is:
Should I use acrylic coated or silicone coated fibreglass sleeving?
Both products are manufactured from braided fibreglass yarn and designed to provide electrical insulation and mechanical protection. However, the resin coating dramatically affects temperature performance, flexibility, and application suitability.
This guide breaks down the key differences to help you choose the right solution.
What is Acrylic Coated Fibreglass Sleeving?
Acrylic coated sleeving is braided fibreglass yarn impregnated with a specially formulated acrylic resin. The coating improves mechanical strength, abrasion resistance, and electrical insulation performance while maintaining good flexibility.
Typical Properties:
- Class F insulation
- Operating temperature up to 155°C
- Strong dielectric performance (commonly 2.5kV)
- Good abrasion resistance
- Economical insulation solution
Common Applications:
- Electric motor windings
- Transformers
- Generators
- Wiring harness assemblies
- General industrial equipment
Acrylic sleeving is often chosen when moderate heat resistance and cost efficiency are priorities.
If you are after Acrylic Sleeving we suggest checking out our Vidaflex 942 Sleeving or our highly economic Acrylic Resin Coated Fibreglass Sleeving.
What is Silicone Coated Fibreglass Sleeving?
Silicone coated sleeving uses the same braided fibreglass base but is coated with silicone rubber instead of acrylic resin.
The silicone layer provides superior thermal resistance and enhanced flexibility, especially at elevated temperatures.
Typical Properties:
- Often Class H insulation
- Operating temperature up to 180°C–250°C (Short Term)
- Excellent heat ageing performance
- High flexibility
- Improved resistance to thermal shock
Common Applications:
- High-temperature motors
- Industrial ovens
- Heating elements
- Automotive and heavy-duty electrical systems
Silicone coated sleeving is preferred when higher continuous temperature performance is required.
If Silicone coated sleeving sounds right for your application, we recommend checking out our Vidaflex SD550 or Sleeving, or the thick wall Silicone Coated Fibreglass Sleeving, commonly known as Fyrejacket sleeving.
Key Differences at a Glance
| Feature | Acrylic Coated | Silicone Coated |
|---|---|---|
| Temperature Rating | Up to 155°C (Class F) | Up to 200–250°C (Class H) |
| Flexibility | Good | Excellent |
| Heat Ageing | Moderate | Superior |
| Cost | More economical | Higher cost |
| Best For | General industrial use | High-temperature environments |
Which Sleeving Should You Choose?
Choose Acrylic Coated Sleeving if:
- Your application runs below 155°C
- You need reliable 2.5kV insulation
- Budget is a consideration
- You require strong mechanical protection
Choose Silicone Coated Sleeving if:
- Your application exceeds 155°C
- Equipment experiences continuous high heat
- Flexibility at elevated temperatures is critical
- Long-term thermal ageing resistance is required
Why Temperature Class Matters
Electrical insulation materials are classified by temperature rating (Class F, Class H, etc.). Selecting a sleeve below the operating temperature of your equipment can lead to premature insulation breakdown and failure.
When in doubt, it’s better to choose insulation that exceeds your maximum operating temperature.
Final Thoughts
Both acrylic and silicone coated fibreglass sleeving offer excellent electrical insulation and mechanical durability. The decision ultimately comes down to:
- Operating temperature
- Budget
- Application environment
- Required flexibility
If you’re unsure which sleeving suits your application, contact the team at Associated Gaskets for technical guidance.