The production process of plastic bags can be divided into the following main steps:

1. Blown film (blow molding)

Process: Blowing film is to heat and melt plastic particles, and then extrude the molten plastic through a mold to form a film. Commonly used plastic raw materials include polyethylene (PE),
polypropylene (PP), etc. The molten plastic is blown into bubbles, which gradually expand and stretch to form a film of a certain thickness.

Equipment: Film blowing machine, mainly including heating device, extruder, cooling device, bubble stretching system, etc.

Purpose: To obtain plastic films with required thickness, width and strength.

2. Print

Process: If the plastic bag needs to be printed with patterns or text, flexographic printing or gravure printing technology can be used. This process involves printing ink evenly onto the surface of the film,
usually by transferring the pattern to the film via a roller or printing roller.

Equipment: printing press (flexo printing machine, gravure printing machine, etc.), printing offset plate, ink.

Purpose: To give plastic bags a brand, logo or other design elements.

3. Bag making

Process: The printed plastic film is processed into bags through heat sealing technology. The film is crimped and cut to the appropriate size and then sealed by heat sealing equipment.
Different types of bags can be made according to needs, such as ziplock bags, vest bags, tote bags, etc.

Equipment: bag making machine, usually including cutting device, heat sealing device, forming device, etc.

Purpose: Process the film into a sealed bag for packaging or storage purposes.

This production process covers all aspects from raw material processing to finished product packaging,

ensuring that the plastic bags have good quality and adaptability and can meet market demand.