The fibers in Tyvek are randomly aligned. It is not woven. Between, the strength, and the binding, it doesn't tear in any direction.
Don't even think of DuPont Tyvek tape for a hem. That would supply more strength than you need, and much more than you want to pay. Unless you carefully slit it, fold it, and apply that as a hem.
There are other Tyvek tapes on the market, where the properties and Tyvek brand are the selling point. Art supply houses sell 50 yard lengths for about $15. I don't know, though, whether the glue on those has the same 20-50 year expected life that goes into the the DuPont stuff made for completing house wrap. Sure, you don't need 20 years. But, you do want a really tenacious bond to the Tyvek wrap which is not weakened by conditions in the field.