Courier bags and express bags can be roughly divided into: courier plastic bags (plastic courier bags), courier document bags (paper courier document bags), courier bubble bags (composite bubble bags), courier bone bags, etc. according to the materials used.
1. Courier plastic bags (plastic courier bags) materials: Polyethylene (PE) can be divided into low-density polyethylene (LDPE) and high-density polyethylene (HDPE), which have the advantages of low cost and light weight. The difference between LDPE and HDPE courier plastic bags: LDPE has better transparency and softness, and the printed color is brighter; HDPE has relatively good mechanical properties; in China, courier bags use LDPE as the main material, while abroad, LDPE and HDPE composite are usually used as the main material of courier bags.
2. Courier document bags (paper courier document bags) materials: usually gray-bottomed white board paper, white cardboard, and cow cardboard. The courier industry usually uses paper with a weight of 200 g/m2 to 450 g/m2, and courier document bags have the characteristics of flatness and uprightness.
3. Express bubble bag (composite bubble bag) material: a transparent soft packaging bag filled with air in the middle layer of air cushion film, mainly used for the packaging of small, fragile and easily damaged goods in the express industry. The express bubble bag is equipped with a shock-absorbing bubble film, and there are many small bubbles in the bubble film, so it is light and elastic, with excellent shock absorption and impact resistance, as well as non-toxic, odorless, moisture-proof and corrosion-resistant advantages.
4. Express bone bag material: bone bag (also known as dense bag, free bag, sealed bag, clip chain bag, self-sealing bag), a plastic bag that can be repeatedly sealed by blowing polyethylene (LDPE) and high-pressure linear polyethylene (LLDPE) through film forming and hot cutting machine bag making. Bone bags can be used for internal and external packaging of various small items. Self-sealing bags produced with food-grade raw materials can store various small foods, tea, seafood, etc., and are moisture-proof, waterproof, insect-proof, and prevent things from scattering.