Multi-layer paper/PE kraft paper bags are based on customer needs. Under the condition of satisfying packaging performance and loading performance, the raw materials for kraft paper bags of this packaging structure are kraft paper or coated paper, PE, and generally include three-layer paper bags. Four-layer paper bags, For multi-layer paper bags, handbags, square bottom paper bags, seamed bottom paper bags, valve bags, etc., a layer of PP film can be used on the paper to play a waterproof role. Its common structure is:
1. Four layers of kraft paper and one layer of PE trapezoidal pockets.
The four-layer kraft paper plus one layer of PE kraft paper bag is a trapezoid-shaped bag. It is a packaging bag that takes both traditional and advanced ideas into consideration. The bottom of the bag is a trapezoid opening, which makes the overall effect of the bag comparable to that of a square-bottom valve pocket; It is trapezoidal, which is the same as the sealing method of seam-bottomed pockets. It is suitable for the traditional sewing and sealing method. However, the process uses heat sealing and welding. A layer of plastic film can be added between the paper to package products that need moisture resistance. . The production process of this kind of bag type is: printing, cylinder making, PE bottom heat sealing, sealing bottom, trapezoidal mouth gluing, sub-inspection and packaging. The production process of the bag with this structure is relatively complicated, and almost all the knives are used. This kind of kraft paper bag is tough, water-resistant, strong, strong in vertical and horizontal directions, smooth in surface, reliable in quality, and reasonable in price. The bag has a square shape, no wrinkles, no excess glue overflow, no foreign matter, and no peculiar smell at the bottom of the mouth.
2. Four layers of kraft paper and one layer of PE flat bag with square bottom. The kraft paper bag with four layers of kraft paper and one layer of PE also includes a flat-mouthed square-bottomed bag. The flat-mouthed square-bottomed bag is a small bulk packaging container that is convenient, tidy, and has good airtightness. It is currently one of the most popular packaging materials in the world. Especially suitable for export packaging.
3. The valve bag, the bottom of the ordinary open bag is simply stitched, and it is a straight line, and the upper and lower valve bags are manually or machine folded rectangular bottom, after manual or machine brushing glue, the upper and lower sides are formed after hot pressing. A square bottom, filling valve port in the upper right corner. The valve bag has an insertion port with a valve port at the upper corner of the bag, and the filling nozzle is inserted into the valve port for filling during packaging. The filling process is in a sealed state. One packaging machine can basically complete the packaging work without additional stitching. The filling efficiency is high.