When a human body generates static electricity, sitting on an ESD chair dissipates static potential until both the operator and the chair share the same charge. Electricity only flows through conductive objects, and normal concrete floors are not conductive. Therefore, any buildup of static potential will discharge when contact is made with an electronic device unless a grounded connection is maintained with an ESD wrist strap. An ESD chair ensures the effectiveness of ESD flooring and ESD mats.
Non-conductive ESD chairs create opportunities for user error, such as when a user rests their feet on something besides the floor such as a separate footrest or stool rail. If both of a user’s feet do not touch an ESD floor or ESD mat, and the user is not grounded with an ESD strap, then the likeliness of an ESD event is greatly increased. Likewise, if the user is not wearing ESD footwear or grounding straps, the insulative character of standard shoe soles threaten the integrity of a conductive ESD chain.
When Do You Need an ESD Chair?
Non-conductive chairs create opportunities for user error, even when using ESD Flooring such as when a user rests their feet on something besides the floor such as a separate footrest or stool rail. If both of a user’s feet do not touch an ESD floor or ESD mat, and the user is not grounded with an ESD strap, static will discharge.
Likewise, if the user is not wearing ESD footwear or grounding straps, the insulative character of standard shoe soles will impede the effectiveness of an ESD chain.
An ESD chair dissipates static potential when sitting down, standing up, or in the chance that feet separate from the floor until both the operator and the chair share the same charge. Dissipative materials and static free fabrics allow charges to dissipate through ESD through ESD casters or drag chains.
When Do You Need ESD Flooring?
ESD flooring is often deployed when ESD wrist straps impede work. Problematically, if an operator were to remove their feet from the floor, or place their feet on a footrest, there is potential for discharge. Because wrist straps can often reduce mobility and workflow, a combination of ESD chairs and static control flooring improves both operator freedom and procedural compliance.
Conductive flooring systems provide the lowest charge generation and quickest charge dissipation for an ESD production environment. The flooring is grounded through a copper strip which connects to the flooring to a grounded connection such as a wall outlet.
Does a Chair Need ESD Casters if You Have a Drag Chain?
Grounding chains provide a dedicated connection that prevents charge buildup when a cart or chair moves across the floor.
As demonstrated in this video, a static control drag chain may only be 20-50% effective. In controlled environments, an ESD grounding chain is much more difficult to clean and accumulates dirt and particles more rapidly.
The dirtier an object the less likely it is to provide conduction. Specially designed ESD chains make contamination more feasible. Problematically, static control chains are always subject to snags and if the chain is not heavy it enough conduction may be lost.
The advantage of ESD casters is that the connection to ground is much more stable and reliable. Chairs with conductive ESD casters maintain almost perfect connection with the floor and provide four points of continuous connection. Casters are also a much better solution for clean-forward environments.
Conductive chair mats provide a continuous path to ground prevents chair casters from damaging or wearing out ESD flooring. The conductive circuit remains continuous while also preventing scratch and scuff marks.