Of course it's going to be a commercial question. But from a design standpoint, there are four major components to the umbrella. The cover, the stem, the hand

Of course it's going to be a commercial question. But from a design standpoint, there are four major components to the umbrella. The cover, the stem, the handle, and the lever-branches (if collapsible) or straight branches (otherwise). The cover is typically a synthetic polymer based material. In collapsible models, due to levers and fiddly connections it's hugely PITA to replace. If it rips or develops a hole you could theoretically push to use a more readily patchable material, however, the high tension at which this is often maintained will rapidly break down many approaches to patching. Realistically, this sort of thing is best done at a factory given the input costs. The stem and handle virtually never break down and can be any form of metal or wood, depending upon whether you want a telescopic collapsible design or rigid full length. Aluminium is supposed to be the best recyclable metal in terms of recovery rate and is also light, however is prone to deformation in thin configurations. It may be possible to consider carbon fiber, which is very cheap now. The lever-branches of a collapsible model are the biggest problem. They are fiddly, prone to breakage in most designs, and in most designs relatively tedious and difficult to securely re-attach to the cover should the cover require replacement. Original suggestion: Design instead a standard interface between the umbrella stem and the cover-and-lever assembly. This would allow easily replacement of the cover-and-lever assembly as the most frequently broken portion. Alternatively, seek out a full length umbrella with strong branches instead of the tiny collapsible ones. Probably these days you could make them with carbon fiber quite cheaply.