Stand up pouches are normally sealed with specially designed heat sealing machines. These machines come in different shapes, sizes, and styles. Heat sealing can be applied to plain or custom printed pouches, and it constitutes the last step in the manufacturing of standup bags.
Stand up pouches can be made from either of the two kinds of plastic – thermoplastic and thermosetting plastic. In theory, barrier bags made from thermoplastic can be resealed, although the results are often far from satisfactory. Bags made from thermosetting plastic take a shape which is permanent at first sealing. Even in theory it is not possible to reseal them using an iron.
Food pouch manufacturers and others have industrial grade machines which are used in the sealing of stand up pouches. Compared to those machines, a home iron can only do a makeshift job at best.