Q: How does BS 3084 test zipper slider locking strength?
BS 3084 sets performance requirements and test methods for zippers, including the ability of a locking slider to stay closed under load. A locking slider is tested by engaging the pin, locking the slider, and applying a separating force across the closed chain; the slider must not open and the elements must not separate beyond the specified amount. The force is applied through the specified grips at the specified rate.
The standard also covers reciprocating life, in which the slider is cycled open and closed a set number of times under defined conditions, and then re-examined for locking function, tooth damage and slider distortion. Cycle count, stroke length, speed and the applied lateral load are fixed by the standard, so refer to the standard text for the values that apply to your product type.
A pass requires the slider to remain locked and the chain to remain engaged through the specified load or cycle count, with no permanent distortion that impairs use. Test across sizes and slider types, because a locking spring that works on a size 5 body may behave differently on a size 3.