The square bag generally has 5 sides, front and back, two sides, and the underside. The unique structure of the square bottom bag determines the packing of three-dimensional goods or square products more convenient. This kind of bag not only takes into account the packaging meaning of the plastic bag, but also fully expands the new packaging idea, so it is now widely used in the production of children's life.
There are two kinds of polymer structures in the plastic side bag:
⒈ linear structure With this structure is called linear polymer
⒉ body structure, the polymer combined with this structure is called the body polymer. Some polymers with branched chains, called branched-chain polymers, belong to linear structure. Some polymers, although there is cross-linking between the molecules, but less cross-linking, known as the reticular structure, belong to the body structure. Two different structures, showing two opposite performance.