Durability materials versus products

Figure 5.11 Durability of base materials versus durability of products.

Figure 5.15 Material durability versus product durability for plastic and composite assemblies.

Artwork Generation. Polyester and glass are the snbstrates used for phototools. They differ in optical properties, dimensional stability, and durability. Silver halide on polyester is used to create first-generation phototools on a laser plotter. This image is often contact printed onto diazo on polyester to make the copies used in production. Optical absorbance of the different phototool materials versus wavelength is plotted in Fig. 26.11. 

Membrane failure modes have been discussed above, and the connection to module design has also been discussed. Poor design for cyclic durability will be measured by the customer - the operating costs will be adversely affected by the requirement to replace membranes prematurely. Although the cost of membrane replacement should be offset by a recycle credit, the cost of materials and labor, and potential lost productivity, is stQl likely to be significant. The credit for recy-cUng palladium alloy membranes may be as great as 95% of the market value of the palladium (for foil membranes, perhaps only 85% of the market value if the palladium alloy is deposited onto a porous substrate). Environmentally, recycle also offers benefits versus recovery and purification of palladium from ore. 

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