Paper Bag Materials and Processes

Materials and Processes of Paper Bags

The main materials for paper bags include white cardboard, copperplate paper, kraft paper, textured paper, etc. These materials each have their own characteristics and applicable scenarios:
1‌. White cardboard: With good strength and toughness, it is suitable for loading heavier items. Its surface is delicate and the printing effect is elegant, commonly used in clothing, picture books, brochures, etc.
2. Copperplate paper: The weight of the paper is around 200 to 350 grams, with beautiful colors and high saturation, suitable for printing large-area patterns, and commonly used in promotional activities such as business conferences and offline exhibitions. But it is not resistant to moisture and is prone to softening and damage when exposed to moisture, but it can be improved by laminating
3. Kraft paper: divided into natural kraft paper and bleached kraft paper. The natural color of kraft paper is yellow brown or brown, with long fibers and tough texture, suitable for packaging heavy gifts or items that need to withstand external forces. Bleached kraft paper has a lighter color and a smooth appearance, making it suitable for packaging high-end gifts

The process of paper bags includes pulping, gluing, surface coating, etc
1. Pulping process: The commonly used pulping method is the sulfate method, which uses chemicals such as sodium hydroxide and sodium sulfide to improve the strength and toughness of paper
2. Adhesive treatment: By adding adhesive between the paper fibers, the surface properties of the paper are changed to improve its water resistance and prevent external moisture from affecting the contents of the paper bag
3. Surface coating treatment: Matte or glossy coatings can be used. The former can reduce light reflection while maintaining the texture of the paper bag, while the latter enhances the visual grade of the paper bag
The selection of these materials and processes depends on the purpose, design requirements, and environmental protection requirements of the paper bag. For example, kraft paper is commonly used in packaging scenarios that prioritize environmental protection due to its sustainability and environmental friendliness; White cardboard, on the other hand, is suitable for packaging that needs to showcase brand image and high-end items due to its elegant printing effect and high strength