These pouches are formed on what is called a Form Fill and Seal Machine and it does just that. It forms the pouch, Fills it and then Seals it. Sometimes zippers are added for the reclose feature. I have attached a link that will give you more info.
As far as material goes, that varies depending on what you are putting in it. Most are made from Poly Prop but if you need barrier properties or thing of that nature the material can change. What type of product are you putting in this pouch? If it is something similar to what you are showing I am not really sure why that needs to be in an SUP. I looks like to me that unless there is display reasons it can be in a simple pegged pouch and work just fine. It would also be cheaper.