In clean rooms, which have extremely high requirements for static electricity and particle control, choosing a suitable ESD anti-static chair is not only related to production efficiency, but also to product quality and personnel safety. So, what key parameters should be paid attention to when purchasing ESD chairs? This article provides a comprehensive analysis for you.
1. Anti-static performance: resistance value is the core indicator.
The core function of ESD chairs is to eliminate static electricity, so the surface resistance value is one of the most critical parameters. According to international standards (such as ANSI/ESD S20.20 or IEC 61340), the resistance value of ESD chairs should generally be between 10^6~10^9Ω to ensure that static electricity can be effectively conducted away without causing current leakage risks due to excessive conductivity.
Conductive type (10^3~10^5Ω): Suitable for high static risk areas, such as electronic assembly lines.
Dissipative type (10^6~10^9Ω): Suitable for ordinary clean rooms, balancing static discharge and safety.
Insulation type (>10^12Ω): Not suitable for ESD protection, avoid choosing.
2: Grounding chain or conductive wheel design.
Most of the dust-free rooms have anti-static floors, and the static discharge of ESD chairs depends on a reliable grounding system. This is usually achieved in the following two ways:
Conductive casters: Casters containing carbon fiber or conductive rubber can directly conduct static electricity to the ground.
Grounding chain: A metal chain connects the bottom of the chair to the ground to ensure closed-loop conductivity.
It should be noted that not all anti-static chairs are equipped with grounding chains, especially in low-cost products, which may be omitted. It is recommended to ask for configuration details.
3. Meet the clean room grade requirements.
Different clean room cleanliness levels (such as ISO Class 5~8) have different requirements for ESD chairs:
ISO Class 5 (100): All stainless steel or special coated chairs are required to ensure extremely low dust generation rate.
ISO Class 7 (10,000): Ordinary anti-static PU chairs can meet the needs.
Recommendation: Choose the appropriate ESD chair according to the cleanroom level to avoid over-configuration or under-protection.
4. Certification and standards: Ensure compliance.
A reliable ESD chair should pass relevant certifications, such as:
ANSI/ESD S20.20 (American Antistatic Association Standard)
IEC 61340 (International Electrotechnical Commission Standard)
ISO 14644 (Cleanroom Standard)
Be sure to check the test report when purchasing to ensure that the product meets industry specifications.