Poly kraft paper bag:  also known as paper-plastic composite bag, is a small bulk container, mainly manpower or forklift to achieve unitized transport, it is easy to ship small bulk powder and granular materials, with high strength and waterproof good, beautiful appearance, easy to load and unload and so on, it is a kind of the most popular and practical general packaging materials.

Paper-plastic composite bag is made of plastic and kraft paper composite, usually the plastic layer is made of polypropylene (PP) or polyethylene (PE) as the base material of flat wire woven fabric, kraft paper is made of refined composite special kraft paper, which has the characteristics of high strength, good waterproof and beautiful appearance.

Paper-plastic packaging is one of the popular packaging materials, which is widely used in plastic raw materials, cement, feed, chemical, fertiliser and other industries. Paper-plastic composite bag in the use of usually it will be very good waterproof, so in the process of using paper-plastic composite bag generally will not be affected by the impact of water on the damage.

Why paper-plastic composite bags can be widely used in the chemical, food, spices industry? This is inseparable from its production process and advantages. Paper-plastic composite bag composite process can be roughly divided into four: coating method, dry composite method, wet composite method, hot melt composite method.

1, coating method: the method refers to the surface of the film coated with a fluid substance, paper-plastic packaging manufacturers so that the surface of the film to form a tightly adhering to the skin film of a method. Can improve the film's thermal adhesion, moisture resistance, gas insulation, ultraviolet absorption and anti-static properties;

2, dry composite method: dry composite method is also called dry lamination composite, the process is: in the base film coated with solvent-based adhesive, after hot drying baking channel so that the solvent in the adhesive on the bonding layer of the material in the adhesive completely evaporated, and then with the second layer of the substrate by the heated and pressurized composite, total amount of composite not only suitable for composite between the plastic film is also composite between the plastic film and aluminum foil, paper;

3, wet composite method: wet composite method is also called wet lamination composite. The process is: the first layer of substrate surface coating water-soluble or water emulsion adhesive, in the wet state, that is, with the second layer of substrate together through the composite device for extrusion composite, and then through the hot drying channel to remove solvents, so that the two layers of substrate composite together;

4, hot melt composite method: this method is the hot melt adhesive heat dissolved into a flowing form after coating, and immediately pressure bonding other films for composite. Compared with the dry composite and wet composite, its advantages are no need for hot oven drying, composite time off, energy saving, low cost, and no solvent pollution. Used in paper, plastic and aluminum foil composite.

But in the use of paper-plastic bags also need to pay attention to the reasonable use of paper-plastic bags, and do not directly place the paper-plastic bags in too wet place, although the paper-plastic bags have waterproof performance, but long time placed in the wet place will lead to paper-plastic bags in the use of the problem, so the paper-plastic bags, despite good waterproof, you should pay attention to the use of paper-plastic bags reasonable waterproof problem. Paper-plastic composite woven bags have many advantages, whether in industrial production of chemicals, cement, feed, and even electronics, aerospace and other packaging materials, or life in the packaging of food and other applications.