Evaluation of antistatic finishes

Perhaps the simplest test method for the evaluation of antistatic finishes is the ash test. A piece of the fabric to be evalnated is mbbed briskly on a piece of plastic or rubber (the vinyl covered arms of a chair, for example). The fabric is then placed over an ashtray containing cigarette ash. The amount of ash transferred to the fabric is an indication of the amount of static charge imparted to the fabric. Owing to the difficulty in quantifying the results, this test is mainly nsed as a qualitative tool to distinguish between antistatic-treated and untreated fabrics. 

The surface resistivity is easy and relatively reproducible to determine with the ring electrode but it is limited for various reasons, for example it is based on a static test with no information about the important charging and discharging behaviour of the textiles. Therefore, combination with a charge dissipation test is favoured. 

Field intensity half-life time (s) Assessment 

---