This case study is an example of how one can combine computer based analytical tools and Taguchi Robust Design techniques for optimizing mechanical systems. The goal was to understand how variations in positional tolerances of rollers affect the amount of film wrap on the transfer roller in a copier. The amount of film wrap and contact pressure affects image quality. Low pressure leads to inadequate transfer and poor image quality whereas high pressure leads to film handling problems elsewhere in the film loop.
Eight design factors(positional tolerances of rollers) were identified that had an influence on the wrap between the film and the roller. A non-linear FE model of the nominal design was simulated and the results matched with the data from the nominal breadboard. A L18 Orthogonal Array was used to develop a design matrix that had 18 different combinations of 8 tolerances. For each of those combinations, non-linear FE model was used to determine the film wrap and resultant forces on the transfer roller needed to produce the wrap.
The analysis of L18 Orthogonal Array showed that the nip width and the contact pressure were sensitive to the position of the movable roller (Roller D).
This case study resulted in reduced cost and cycle time and eliminated the need to build breadboards to simulate 18 design combinations.
