Dosing For Effect — Getting It Right The First Time

By Robert G. McGregor

Dosing is that critical step in producing a consumer product where manufacturing wants things to go as smoothly as possible. Two issues that affect acceptance are volume of material in the dose and proper proportions for constituent ingredients. This application note addresses the situation for both liquid and powder-based products.

R&D has the responsibility to get it right for Manufacturing. Scale up from bench tests in the lab need to be based on realistic simulation of process conditions.

Liquid products can be assessed using a texture analyzer with an extrusion cell which simulates the effect of squirting material out an opening of known diameter. (See Figure 1) The test objective is to measure the amount of force required to expel the product and the amount of material that extrudes during that time interval. The test apparatus utilizes a selection of discs with different diameter openings placed in the bottom of the cell to mimic the effect of fill lines with nozzles of varying diameter. This is one test technique that provides data on extrusion rates for the product in question.