The production process of food vacuum bags

Food vacuum bag is a widely used packaging material in the food industry, whose main function is to remove oxygen to prevent food spoilage and extend shelf life. Food vacuum bags are widely used for preservation and packaging of various types of food, such as pickled products (sausages, sausages, pickled vegetables, etc.), fresh meat (beef, lamb, pork, etc.), soy products (tofu jerky, bean paste, etc.), and cooked products (beef jerky, roasted chicken, etc.). In addition, vacuum packaging is also suitable for the preservation of drugs, chemical raw materials, metal products, electronic components, textiles, medical supplies, and cultural relics.
The production process of food vacuum bags mainly includes two types: composite process and co extrusion process. The following are specific introductions to these two processes:
1、 Composite process
Printing: Printing patterns and text onto the substrate increases the aesthetics and practicality of the packaging. During the printing process, gravure printing technology is often used to reproduce the color of the original image through the dots on the printing plate. The printing material is released through a unwinding device, and the ink on the surface of the printing plate is scraped off by a scraper. The ink inside the dot is transferred to a vacuum bag when the printing material is pressed down. Afterwards, the solvent component in the ink evaporates in a heated and blown oven, and the printing film is cooled and shaped by a cooling roller after coming out of the oven.
Coating: Apply a layer of adhesive on the printed substrate to bond different materials together.
Adhesive: A packaging material that uses adhesives to bond different materials together, forming a multi-layered structure. In this step, the adhesive substrate is released through the unwinding device, and the adhesive on the surface of the glue roller is scraped off by a scraper. The adhesive in the dot is transferred to the surface of the vacuum bag substrate when the adhesive substrate is pressed down. Then, it is bonded together with the substrate released by another unwinding device in a heated and pressurized composite roller.
Maturity: Reacting the main agent and curing agent inside the composite film to form the adhesive layer. The maturation process is divided into two types: room temperature maturation and heating maturation.
Cutting: Cutting multi-layer packaging materials according to requirements to form the desired shape and size.
Folding: Folding the edges of packaging materials to improve the sealing and aesthetics of the packaging.
Testing: Conduct testing on the pre made vacuum bags to ensure that their quality and performance meet the requirements.
The characteristic of composite technology is that the production process is relatively simple, suitable for making thick vacuum bags, and its production cost is relatively low, so it has been widely used in fields such as food.
2、 Co extrusion process
Preparation materials: Prepare the necessary raw materials and auxiliary materials.
Melt blending: Melt blending of raw materials and auxiliary materials to form a uniform mixture.
Casting molding: Processing a mixture into a thin film with thickness and width through a casting molding machine.
Longitudinal stretching: Stretching the film longitudinally to increase its longitudinal strength and toughness.
Lateral stretching: Stretching the longitudinally stretched film horizontally to increase its lateral strength and toughness.
Cooling and shaping: Cooling and shaping the stretched film to stabilize its shape and improve its dimensional accuracy.
Cutting and winding: Cutting and winding the finalized film to form the desired shape and size.
Testing: Conduct testing on the pre made vacuum bags to ensure that their quality and performance meet the requirements.
The characteristic of co extrusion technology is that the production process is relatively complex, which is suitable for making thin vacuum bags. Meanwhile, due to the co extrusion process, the composition and structure of the vacuum bag can be controlled, allowing for the production of vacuum bags with special properties such as high barrier and high transparency.
In summary, composite process and co extrusion process are two different food vacuum bag production processes, each with different characteristics and application fields. When selecting the production process, it is necessary to choose based on actual needs and product requirements.