Composite packaging bag production process, see how exquisite packaging bags are made

With the development of the market economy, the demand for exquisite composite packaging bags in various industries has been increasing year by year. The development and processing technology of composite packaging bags are also constantly improving, playing an increasingly important role in many fields.

Below, Shunxingyuan Packaging, a professional flexible packaging manufacturer, will share the production process of composite packaging bags for customers with ordering needs.

I. Composite Packaging Bags Process flow and process introduction

1. Composite Packaging bag

Composite packaging is a combination of two or more materials through one or more composite processes to form a composite packaging with certain functions. It is generally divided into a base layer, a functional layer, and a heat-sealing layer.

2. Process introduction

The plate making process is the process of transferring ink to the printing material in printing. The halftone dots made on the printing plate reproduce the color of the artwork.

The printing process is the process of reproducing images and texts using printing materials, printing plates, inks, and printing machinery. That is, transferring the images and texts on the printing plate to the printing material.

Classified by printing plate type: gravure, flexographic, screen, letterpress, and offset printing methods.

Most color packaging bags are produced using gravure printing. During production, the printing material is unwound from the unwinding device and enters the printing device. The ink on the surface of the printing plate is scraped off by the doctor blade, and the ink in the dots is transferred to the printing material when the printing material is pressed down. Then, it enters the drying oven, and the solvent components in the ink evaporate in the heating and blowing oven. After the printed film comes out of the oven, it passes through the cooling roller to cool and shape. In multicolor printing, the computer automatic register device controls the register between colors. After printing, the winding device winds the printed product into a roll of film.

The quality inspection process is the process of using a quality inspection machine to inspect the printed semi-finished products and remove the unqualified products. This reduces the increase in production losses in subsequent processes and the difficulty of quality inspection.

The laminating process is to laminate two or more materials together to form an integrated material. The composite material can not only maintain the excellent properties of the single-layer material but also overcome their respective shortcomings. After compositing, it has new properties to meet the different requirements of composite materials for goods such as clothing, apparel, cosmetics, hardware, electronics, and food.

Lamination classification: dry lamination, wet lamination, extrusion lamination, solvent-free lamination, hot-melt lamination, co-extrusion lamination.

Most composite packaging bags are produced using dry lamination. During production, the adhesive substrate is unwound from the unwinding device and enters the coating device. The adhesive on the surface of the coating roller is scraped off by the doctor blade, and the adhesive in the dots is transferred to the surface of the adhesive substrate when the adhesive substrate is pressed down. Then, it enters the drying oven, and the solvent components in the adhesive evaporate in the heating and blowing oven. After coming out of the oven, it is bonded with another substrate unwound from the unwinding device in the heating and pressing laminating nip roller. After cooling and shaping, it is wound into a roll of composite film by the winding device.

Shunxingyuan Packaging also has mastered solvent-free lamination technology and can produce various types of composite packaging bags according to customer requirements.

The curing process is the process in which the main agent and curing agent in the composite film complete the reaction. Because the adhesive layer of the newly laminated composite product is not cured and shaped, it cannot enter the processing of the next process. Therefore, it must undergo a curing process to allow the main agent and curing agent to complete the reaction and the adhesive layer to be shaped. Curing is divided into room temperature curing and heat curing. Room temperature curing means that the composite film completes the reaction of the main agent and curing agent at room temperature; heat curing means that the composite film completes the reaction of the main agent and curing agent at a specific temperature. Heat curing can accelerate the reaction speed of the main agent and curing agent and shorten the production cycle.

Slitting is the process of slitting the laminated composite film or unlaminated printed film to the required width. During production, the slitting material is unwound from the unwinding device, and the longitudinal travel position of the slitting material is controlled by the photoelectric control system to keep the cutting knife position of the slitting product constant. The winding device winds the slitting product into a roll of film. Some of the slitting product rolls are used as finished products for the customer's automatic packaging machine, and some are used as semi-finished products for the next bag-making process.

The bag-making process is the process of heat-sealing the composite film into a bag shape according to customer requirements. The inner layer of the composite film must be a heat-sealable film. The flexible packaging bag-making process is divided into two types: back-sealing bag-making and side-sealing bag-making. Among them, the back-sealing bag-making method is a split type, which first forms a shape and then cuts the bag to complete the bag-making.

Common bag shapes include: Center-sealed bag, center-sealed gusset bag, trapezoidal center-sealed gusset bag, side-sealed gusset bag, four-side sealed bag, three-side sealed bag, stand-up pouch, three-side sealed zipper bag, stand-up zipper bag, penguin bag, tear-notch bag, bag-in-box.

II. Composite Packaging Bags Comparison of commonly used heat-sealing materials

Currently, the commonly used heat-sealing materials for packaging bags are CPP and LDPE. Under the same thickness and film-making method:

Transparency: CPP is better than LDPE.

Stiffness: CPP is better than LDPE.

Heat sealability: CPP is worse than LDPE.

III. Shunxingyuan Packaging Quality requirements

1. The length, width, gusset height, stand-up bottom height, penguin bag insert, zipper position, pattern deviation, and compliance with process size requirements of the bag.

2. The pattern position of the bag matches the process sheet or bag sample.

3. The shape, size, and position of the bag's handle, hanging hole, and tear notch match the process sheet or bag sample.

4. No bubbles at the heat-sealing area, good sealing performance, no obvious wrinkles, and the heat-sealing strength meets product requirements.

5. The inside and outside of the bag are clean and hygienic, and there is no odor caused by solvent residue.

6、袋外观无明显划伤和折皱现象。

7、袋的开口性好，无粉。

8、无印刷、复合、分切质量（套印、缺印、拖尾、刀线、墨脏、泡（斑、粒）点、折皱、缺胶线、图案偏差、异味、脏污类）问题。