When we talk about multi-layer co-extruded films, we are referring to co-extruded films that have three layers or more and incorporate barrier elements.

There are many benefits associated with this type of film, including a high barrier, a strong function, a low cost, a flexible structural design, high strength, and the absence of pollutants. This material is suited for use in all flexible packaging industries, including but not limited to food, daily chemicals, beverages, medicine, electrical items, protective films, and other uses.

High barrier: The barrier qualities of various plastic materials are distinct from one another. In order to obtain high barrier effects on oxygen, water, carbon dioxide, smells, and other substances, multi-layer co-extruded films are utilized.

Strong features include resistance to oil and moisture, resistance to high temperatures of cooking up to 120 degrees Celsius, resistance to freezing at low temperatures, preservation of quality, preservation of freshness, and preservation of odor.

As a result of the straightforward manufacturing method, the cost of multi-layer film products can be lowered by ten to twenty percent in comparison to the cost of other composite films.

A flexible structural design allows for a variety of structural designs to be utilized in order to fulfill a variety of quality assurance standards.

During the processing phase, multi-layer co-extruded films exhibit the properties of stretching, which contribute to their high strength. It is possible to increase the strength of the plastic after it has been stretched, which will result in the material having a composite strength that is greater than that of standard plastic packaged goods.

There is no pollution, as there is no problem with residual solvent contamination, and it is environmentally benign and green.

A symmetrical structure and an asymmetrical structure are both components of the structure of the multi-layer coextruded film. The barrier layer, the adhesive layer, and the support layer are the three different types of functional layers that make up the symmetrical structural layer.

In order to accommodate a variety of packaging requirements, the barrier layer is responsible for modifying the barrier qualities of the film material. This is accomplished by altering the material and thickness of the barrier layer. A number of barrier materials, such as PA, EVOH, PVDC, and others, are frequently utilized in the industry. The barrier layer serves a variety of tasks, including preventing oil leakage, preventing oxygen from entering, and preventing moisture from entering.

Layer of support: In general, symmetrical structural materials consist of two levels of support. Because it is a heat sealing layer, the inner layer is utilized for the purpose of heat sealing. Additionally, the outer layer can be utilized for printing, so transforming it into a printing layer, or it can be used directly as the outside layer of packaging film. It is essential that the support layer possesses excellent mechanical strength, heat sealing performance, water vapor barrier function, transparency, and printability. This layer is typically constructed out of LDPE or a combination of LDPE and LLDPE, which are both composite materials.

For the purpose of ensuring that there is sufficient peeling force between the layers, the adhesive layer is responsible for bonding the barrier layer and the support layer firmly together. In most cases, the materials of the support layer and barrier layer, as well as the needed bonding strength, are taken into consideration when selecting the material and thickness of the adhesive layer. It is necessary to identify the adhesive material that was utilized for the sticky layer.

The majority of multi-layer co-extruded composite films employ polyolefin combinations as their primary building blocks. At the moment, the structures that are utilized the most frequently are as follows: PE/PE, PE/EVA/PP, LDPE/adhesive layer/EVOH/adhesive layer/LDPE, and LDPE/adhesive Layer/EVOH/EVOH/EVOH/Adhesive layer/LDPE.

When using the extrusion technique, it is possible to make adjustments to the thickness of each layer. Films with a variety of barrier qualities can be designed in a flexible manner by altering the thickness of the barrier layer and employing a wide range of barrier materials. It is also possible to replace the materials that make up the heat sealing layer in a flexible manner in order to accommodate the requirements of various types of packaging. The multi-layering and multi-functionality of this sort of co-extrusion compound will be the mainstream development path of packaging film materials in the future, but this will be determined by the demand.