1. Dry composite

Among the various processing technologies of composite films, dry composite is the most traditional and widely used composite technology in China, which is widely used in the packaging of food, medicine, cosmetics, daily necessities, light industrial products, chemicals, electronic products and so on.

Dry compounding is to use a coating device (generally using gravure screen roll coating) to coat a layer of solvent-based adhesive on the plastic film, the laminating machine to remove the solvent and dry, in the hot pressing state and other substrate composite. Such as film, aluminum foil and other adhesive composite film.

The process flow is shown in the figure below. Because it is compounded in the "dry" state of the adhesive, it is called dry compounding.

Dry composite is suitable for a variety of composite film substrates and film and aluminum foil, paper between the composite, a wide range of applications, excellent resistance to chemical medium erosion, such as food in alkali, acid, spicy, grease and other ingredients, cosmetics in water, flavor, emulsifier and other ingredients, chemicals in solvents, pesticides and other ingredients, widely used in the contents of the more harsh packaging conditions.

Its composite strength is high, the stability is good, the product transparency is high, not only can produce high, mid-grade composite film, but also can produce frozen, fresh-keeping or high-temperature sterilization composite film; easy to use, simple operation, suitable for many varieties, small batch production.

However, dry composite itself also has the defects of poor safety and health, environmental pollution and high cost, while the development of alcohol-soluble and water-soluble adhesives has slowed down the pressure of solvent-based adhesives in safety and health, environmental pollution and cost to a certain extent.

Dry composite still occupies a large proportion in the processing of composite materials, and at this stage, it is still a composite processing method that cannot be replaced by extrusion composite, wet composite and solvent-free composite.

2. Solvent-free compound:

The adhesive used has attracted much attention because it does not contain organic solvents. In developed countries such as Europe and the United States, solvent-free compounding has become the main method for the production of flexible packaging composites.

It is the use of solvent-free adhesive coating substrate, directly with the second substrate for bonding a composite method, although the same as the dry composite use of adhesive, but the adhesive does not contain organic solvents, without drying device. Because of its superior environmental friendliness, product performance can also be the same as dry composite, which is the future development direction.

From the current development of our country, the application range of dry composite is the widest and the proportion is the largest. In the development stage of solvent-free composite technology, it is the development direction of composite processing mode in the future. At the same time, our company has a dry composite and solvent-free composite production line. According to the customer's needs and the nature of the product, we choose the corresponding composite form to provide customers with high-quality packaging bag products.