Production process of kraft paper self sealing bag

Kraft paper self sealing bag, also known as kraft paper zipper bag or kraft paper bone chain bag, is a widely used environmentally friendly packaging material. The material of kraft paper self sealing bags is generally divided into two types: single-layer and multi-layer. Single layer kraft paper bags are lightweight and suitable for packaging lightweight items; Multi layer kraft paper bags are more durable and can withstand more weight and pressure, making them suitable for packaging heavier items. Common materials include yellow kraft paper, white card kraft paper, and multi-layer composite of matte frosted film for zipper self sealing bags.

The production process of kraft paper self sealing bags mainly includes the following steps:

1、 Material preparation

Kraft paper: Choose kraft paper that meets the requirements, such as yellow kraft paper, white card kraft paper, etc., to ensure that its strength, thickness, and environmental performance meet production standards.

PE film: High pressure linear polyethylene (LLDPE) is selected as the composite material to enhance the moisture and odor resistance of kraft paper self sealing bags.

Matte matte film: used to enhance the aesthetics and feel of kraft paper self sealing bags, while providing shading effect.

2、 Composite process

Composite pretreatment: Pre treat materials such as kraft paper, PE film, matte frosted film, etc., such as removing dust and static electricity, to ensure the composite effect.

Composite process: Materials such as kraft paper, PE film, matte frosted film, etc. are composite using a composite machine. During the composite process, specialized composite adhesive is required to firmly bond the materials of each layer together. At the same time, it is necessary to control the temperature, pressure, and other parameters of the laminating machine to ensure the quality of the lamination.

Composite post-treatment: After the composite is completed, the composite film is matured to allow the adhesive to fully evaporate and cure, thereby enhancing the strength and stability of the composite film.

3、 Bag making process

Slitting: Cut the composite film into the required width to prepare for the subsequent bag making process.

Bag making: The cut composite film is processed into kraft paper self sealing bags through a bag making machine. During the bag making process, it is necessary to control the size, shape, and sealing quality of the bag. At the same time, according to customer needs, patterns, logos, and other information can be printed on the bags.

Sealing treatment: During the bag making process, the sealing part of the bag is pressed together by a sealing machine to form a structure that can be repeatedly sealed. The quality of sealing directly affects the effectiveness of using kraft paper self sealing bags.

4、 Quality Inspection and Packaging

Quality inspection: Conduct quality inspection on the produced kraft paper self sealing bags, including inspection of appearance, size, sealing quality, strength, and other aspects. Ensure that the product meets customer requirements and national standards.

Packaging: Pack the qualified kraft paper self sealing bags for easy transportation and storage. During the packaging process, attention should be paid to protecting the bag from damage and contamination.

In summary, the production process of kraft paper self sealing bags requires strict control of the quality and parameters of each link to ensure that the products produced have excellent performance and quality. Meanwhile, with the continuous advancement of technology and changes in market demand, production processes also need to be continuously optimized and improved.