To make a fused plastic bag tote here are the steps to making the fused plastic part. Above you can see that we have cut the tops and the bottoms off of the plastic bags so that they lay flat.
and move the iron over the bags quickly. Lift up the paper to see if the bags have fused together, if not repeat the process. I have also found that it works really well if you sandwich the two grocery bags in between a clear dry cleaning bag, there is a lot less shrinkage with that method.