A well designed stand up pouch is made from several layers of plastic and other materials. These layers are glued together to create a multiple layer structure that is sufficiently strong to hold accessories - including spouts - in such a way that no leakage happens during use. If you have to use extra layers of plastic, on top of a stand up bag, you are essentially paying for a poor design.
A stand up spout pouch is made from joining a plastic spout with a stand up bag. Manufacturers use different methods to glue spouts on pouches. They can use heat or powerful glues, or a combination of both. Whatever the method is, a quality manufacturer ensures the spouts are an integral part of the pouch and do not leak.
Spouted stand up bags are an inexpensive, customer friendly, and environment friendly alternative to traditional plastic and glass bottles. They are used to carry juices, soft drinks, and liquids of many different kinds. As these pouches carry liquids, spouts become crucial to the whole design. Pouches with leaking spouts are no match against their traditional rival – the plastic bottle. So manufacturers pay particular attention to the design of the spouts by taking into account the situations they will be put through.
Plastic films can be used to prevent leakages in cases where the spouts are either broken, or loosened due to factors the manufacturer did not consider. A stand up pouch can break its spout if it is thrown from the height of a few meters. Pouch manufacturers may not test their pouches for this robustness.
Other than the physical damage to a pouch, the use of a plastic film to keep a stand up pouch from leaking only demonstrates a sloppy manufacturing process. StandUpPouches.net uses high quality FDA (Food and Drug Administration) approved food grade materials in its pouches. These materials are safe to package juices and other liquids. In addition, a quality manufacturing process ensures that they are sufficiently strong and perfectly glued to spouts.