Paper bag classification: the material of the bag contains some paper characteristics: environmental protection, durability and beauty. Main materials: paper bag classification, environmental protection concept, paper bag classification There are many kinds of paper bags, various paper materials and many styles. According to the material, it can be divided into: white cardboard paper bag, white cardboard paper bag, copper cardboard paper bag, kraft paper bag and a small amount of special paper. White cardboard: white cardboard is strong and thick, with high stiffness, bursting resistance and smoothness, and the paper surface is flat. The commonly used thickness is 2 10-300g white cardboard, and the most used is 230 white cardboard. The paper bag printed with white cardboard is full of color and the texture of the paper is also very good, which is your first choice for customization. Coated paper: Coated paper is characterized by very smooth paper surface, high whiteness, high smoothness and good gloss, which also makes the printed graphics and pictures have a three-dimensional effect. Common thickness is 128g-300g. The printing effect of coated paper is the same as that of white cardboard, with full and bright colors and less stiffness than that of white cardboard. White kraft paper: White kraft paper has high bursting resistance, good toughness, high strength and stable uniformity and thickness. According to the relevant national laws and regulations, supermarkets restrict the use of plastic bags, and foreign countries and Europe and the United States advocate the trend of using environmentally friendly paper bags to strictly control plastic pollution. Plastic bags will be replaced by environmentally friendly paper bags, and the market prospect of white kraft paper is promising. Made of 100% pure wood pulp, non-toxic, recyclable and environmentally friendly. White kraft paper has good toughness, and is widely used to make environmental protection clothing handbags, high-grade shopping bags and so on. The thickness of the commonly used white kraft paper is 120g-200g, and the paper has no brightness and luster, so the white kraft paper is not suitable for printing the content with too much ink. Kraft paper: Also known as natural kraft paper. It has high tensile strength, high toughness, usually brown, high tear strength, rupture strength and dynamic strength, and is widely used in shopping bags, envelopes and so on. The common thickness is 120g-300g natural kraft paper. Kraft paper is generally suitable for printing monochrome or bicolor manuscripts, and the color is not complicated. Compared with white cardboard and white kraft paper, yellow kraft paper has the lowest price. Whiteboard paper with gray background: Whiteboard paper is a kind of cardboard with white and smooth front and gray background on the back. Common thickness is 250g-350g. Whiteboard paper is white on one side and gray on the other, which is cheaper than white cardboard. Black cardboard: It is a special kind of paper with black edges. Black cardboard is characterized by thin paper, black heart, firmness, good folding resistance, smooth surface, good stiffness, good tension and high bursting resistance. Common thickness is 120g-350g black paperboard. Because black cardboard is black inside and outside, it can't print color patterns, and it is only suitable for bronzing, silver stamping and other processes. The bags made are also very beautiful. Paper bags are divided into four types according to the methods of edge wrapping, bottom wrapping and bottom sealing: slotted bottom bag, open corner bottom bag, valve seam bag and valve flat hexagonal bottom plastic bag. According to the different handles and hole-digging methods: NKK (hole-piercing rope), NAK (hole-free rope, which can be divided into mouth-less folding type and standard mouth-folding type), DCK (cordless bag hole-digging handle) and BBK (no punch tongue). According to different uses: including paper bags, envelopes, handbags, cement bags, feed bags, wax paper bags, fertilizer bags, composite paper bags, four-layer paper bags, medicine bags, clothing bags, food bags, shopping bags, gift bags and wine bags. According to different purposes, the design specifications, including the thickness of paper bags, have many requirements, which should be customized according to the actual situation, so as to achieve the goal of getting twice the result with half the effort and being economical and applicable, and provide more protection for saving materials, protecting the environment and capital investment of enterprises. As we all know, paper is a recyclable resource. The raw materials for papermaking are mainly plant fibers. In addition to cellulose, hemicellulose and lignin, there are other components with less content, such as resin and ash. In addition, there are auxiliary ingredients such as sodium sulfate. Besides plant fiber, different fillers need to be added according to different paper materials. Commonly used plastic bags are made of polyethylene, and the raw material used is oil, which is already our scarce energy. In contrast, the raw materials of paper bags are trees, which are renewable resources. Because of its biodegradable and recyclable characteristics, it is naturally labeled as green.