The small plastic pumps manufactured by MeadWestvaco in Hemer, Germany, are comprised of up to 12 different parts. The small size of the pumps makes their functionality extremely complex. A key criterion is the output: how much liquid is ejected with each puff? Manufacturers can only achieve the right dose when the parts are perfectly matched: the tolerances are generally a few hundredths of a millimeter. The requirements in the medical industry are particularly strict.
Until now, MeadWestvaco used traditional optical and contact measuring machines for quality inspection. However, this process was very time consuming and susceptible to errors, particularly because some of the features were hidden. Employees had to destroy the part to reach them. As a result, mistakes were easily made because the material was deformed during this process.