Does the action of dipping line up molecules?
No. It is the stressing of the latex upon inflation that lines up (orients) the molecules. As an aside, the plastic grocery bags that you get at the supermarket are made from oriented polyethylene (oriented by stretching during the rolling of the polyethylene sheets). They are very strong in the vertical (load bearing) direction because that is the way the molecules run, and they are rather weak in the sideways direction (play with one and see!). For a definite example of orientation effects in latex, try pulling on a 260 as hard as you can as it is inflated. When you pull it really hard it is very difficult to inflate by mouth. With a pump you can inflate the 260 about the diameter of a 130. This is the way Roger Seigel (?I think?) gets a great looking elephant trunk in one of his books. A balloon inflated this way will take an incredible amount of abuse – much more than a standard inflated 260. Additional stretching or pinching of the balloon will further stress, strain and orient th
