2.Properties of HPL
“Antistatic” is a general term, it entails no requirements. Antistatic does not mean “not electrostatic” or “counteracting electrostatic charge”. The reactions of the materials regarding the dissipation of electrostatic charges can be described with a scale where the empirical steps are indicated with the surface resistance in ohm (Ω).
Table 2: Surface resistance Ro in Ω
| Charge dissipation possible | Charge dissipa- tion possible to a limited extent | Charge dissipation not possible | |||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Substances cannot be charged | Transition area | Substances can be charge | |||||||||||
| Conductive | Dissipative | Insulating | |||||||||||
| 104 | 105 | 106 | 107 | 108 | 109 | 1010 | 1011 | 1012 | 1013 | 1014 | |||
The lower limit of 105 was chosen for safety reasons. According to VDE 0100, at least 5× 104 Ω are stipulated when working with voltages up to 100 V and at least 1× 105 Ω for voltages up to 1000 V.
Materials which fall into the range between 105 and 109 Ω are referred to as dissipative materials, as long as they are grounded. In the high-Ohm range of 109 Ω – 1011 Ω, electrostatic charges can accumulate.
HPL minimises the generation of electrostatic charge by contact change or friction with other materials and does not need to be grounded. The surface resistance of HPL is 109 – 1012 Ω and the charge capacity according to EN 61340- 4-1 is < 2 kV. HPL is thereforeantistatic. Modificationscan be madetomake HPL dissipative with 105 – 109 Ω. The magnitude of this value depends essentially on the relative humidity.
