A Split-Split-Plot Design of Experiments for Foil Lidding of Contact Lens Packages

ABSTRACT

A split-split-plot design of experiments was applied to evaluate foil lidding for contact lens packages through the determination of the effect of the seal parameters to the peel behavior of the package. The experimental design structure was not completely randomized because of the lengthy time involved in temperature equilibration and the practicality of changing pressure. The quality of the package seal was evaluated by measuring continuous peel force and by classifying peel type as a categorical response. The significance and sensitivity level of the seal parameters were evaluated using analysis of variance (ANOVA)-based sensitivity analysis. Graphical and statistical model–based optimization determined that several sets of seal parameters were possible to optimize peel force, produce a robust seal–peel process, and minimize possibility of either leak or delamination.

KEYWORDS:

• global sensitivity analysis
• graphical optimization
• multiple responses
• ordered categorical data
• split-split-plot design

Notes

Note. T is temperature, P is pressure.

Note. **is for not available p-values.

*1σ standard deviation in parentheses.

**DOE order 29 was a control, the existing standard foil lidding.