New method for the quantitative determination of the mixing ratio when processing two-component adhesives

Precisely at the beginning of the dispensing, the nonlinear flow behaviour of adhesive components leads to an asynchronous flow of both components with deviations from the stipulated mixing ratio. In order to clarify the questions of how great the deviations can be and how long the unsteady state of the asynchronous flow lasts, a new measuring method was developed and was applied on a commercially available dispensing installation. In this respect, it was shown that deviations from the stipulated mixing ratio which are considerably greater than the tolerances specified by the adhesive manufacturers arise in the short term. The unsteady state is in the order of magnitude of 1 s. The behavior of the overall system (dispensing installation and adhesive)can be optimised in a targeted way by taking suitable countermeasures in the installation controller.