Types of Paper bagsa. Kraft paper bags: Made from a chemical pulp produced in the Kraft process. Pulp produced by the Kraft process is stronger than that made by other pulping processes; acidic sulfite processes degrade cellulose more, leading to weaker fibers, and mechanical pulping processes leave most of the lignin with the fibers, whereas Kraft pulping removes most of the lignin present originally in the wood. Low lignin is important to the resulting strength of the paper as the hydrophobic nature of lignin interferes with the formation of the hydrogen bonds between cellulose in the fibers. Kraft pulp is darker than other wood pulps, but it can be bleached to make very white pulp. Fully bleached kraft pulp is used to make high quality paper where strength, whiteness and resistance to yellowing are important.
b. Wood free paper bag: is paper created exclusively from chemical pulp rather than mechanical pulp. Chemical pulp is normally made from pulpwood, but is not considered wood as most of the lignin is removed and separated from the cellulose fibers during processing, whereas mechanical pulp retains most of its wood components and can therefore still be described as wood. Wood-free paper is not as prone to yellowing as paper containing mechanical pulp. Even though the name says wood free wood is still used to make these bags.
c. Art paper bag: Thicker, stronger, and more stylish than other types of paper bags, these more expensive bags often have ribbon handles and are used in high end shops.