PET/PET/LLDPE: This kind of stand up pouch material structure consists of three layers of PET (polyethylene terephthalate) and LLDPE (linear low-density polyethylene). PET provides strength and rigidity, while LLDPE offers flexibility and heat sealability.

PET/Metalized-PET/LLDPE: This structure includes a layer of metalized PET, which provides a barrier against light and oxygen. It is often used for products that require protection from UV rays or need extended shelf life.

PET/Nylon/LLDPE: This structure combines the strength and puncture resistance of nylon with the barrier properties of PET and the flexibility of LLDPE. It is commonly used for products that require high durability, such as snacks or pet food.

PET/AL/LLDPE: This kind of stand up pouch material structure incorporates a layer of aluminum foil (AL) between PET and LLDPE. Aluminum foil provides excellent moisture and oxygen barrier properties, making it suitable for products that need enhanced protection against moisture or oxygen.

PET/Nylon/RCPP: This structure includes a layer of nylon, known for its high barrier properties, combined with PET and RCPP (retortable co-extruded polypropylene). It is commonly used for retort pouches that undergo high-temperature sterilization processes.

PET/AL/Nylon/RCPP: This kind of stand up pouch material structure is similar to PET/Nylon/RCPP but includes an additional layer of aluminum foil. It provides increased barrier properties against moisture, oxygen, and light.

Please note that stand-up pouches with a zipper are generally not suitable for packaging liquids or semi-liquids due to potential leakage issues. Therefore, the material structures for doypack with zipper may differ from those stand up pouch without zipper.