Before conducting the experiment, the knowledge of the product/process under investigation is of prime importance for identifying the factors likely to influence the outcome. In order to compile a comprehensive list of factors, the input to the experiment is generally obtained from all the people involved in the project with expert knowledge. In this case the main source of such knowledge was Dr Daniel Nuh of EETS, who designed and built the laminator used for module production.

The typical lamination cycle for a fast cure Solar EVA is illustrated in figure 4. First the Solar laminate is assembled from its individual layers and placed face down on the hot plate. The lid of the laminator is closed and the plate is held at a constant temperature. Under vacuum, the EVA is now subjected to a set time, TEVA. At point A, atmospheric air is allowed into the top of the vacuum divider sheet, which applies a pressure on the laminate pressing it down onto the hot plate. Here the laminate is left for a further set time, TPC. Finally the vacuum is switched off and the laminate removed for cooling.

The different variables or factors associated with the Lamination process are:

* Temperature, 0C — Operating Temperature

* Pressure, Torr — Vacuum pressure

* TEVA — Solar EVA Molten Time, mins.

* TPC — Post Curing Time, mins.

The pressure is a fixed factor throughout the cycle therefore it is excluded from the Design of Experiments. Therefore the Factors to be studied are:

* Temperature, 0C — Operating Temperature

* TEVA — Solar EVA Molten Time, mins.

*

TPC — Post Curing Time, mins.