The material used for packaging can be classified into three categories: pure kraft paper bag, paper aluminum composite kraft paper bag, and woven bag composite kraft paper bag which are normally larger in size. The pure kraft paper bag is made solely out of kraft paper, while the paper aluminum composite kraft paper bag is composed of kraft paper and an aluminum foil layer. On the other hand, the woven bag composite kraft paper bag is made by combining kraft paper with woven material and is commonly used for larger bags.
The varieties of kraft paper bags can be classified based on their bag types. The bags can be categorized as follows: a. Three-side sealing kraft paper bag, b. Side organ kraft paper bag, c. Self-supporting kraft paper bag, d. Zipper kraft paper bag, and e. Self-supporting zipper kraft paper bag.
Bag appearance can be categorized into five types, including valve bag, square bottom bag, seam bottom bag, heat sealing bag, and heat sealing square bottom bag. Each bag type has its unique features and uses. Valve bags feature a valve in the bag's top, making them ideal for packaging granular materials. Square bottom bags have a square bottom that allows for easy stacking and are often used to package food and pet food. Seam bottom bags have a folded seam at the bottom and are commonly used for industrial products like cement and chemicals. Heat sealing bags are sealed using heat and pressure, making them ideal for packaging small items such as nuts, bolts, and screws. Finally, heat sealing square bottom bags have the same features as heat sealing bags, with the added benefit of having a square bottom.