In the world of packaging, one of the most significant and fundamental advances has been the development of multilayer or complex films. These materials, which are made by joining two or more films with specific technical properties, have revolutionised the way products are packaged and protected. Thanks to their ability to perform different functions in a single material, multilayer films have many applications in different sectors, from food, to pharmaceuticals, to the graphics industry and more.
In this article prepared by Globalfilms, we will talk about what multilayer films are, how they are made and their main benefits, as well as some examples of practical applications in the market.
What is a multilayer film?
A multilayer film is a flexible material made by bonding several layers of different types of plastics, such as PET (polyethylene terephthalate), BOPP (biaxially oriented polypropylene) or PA (polyamide). Each layer of this film fulfils a specific technical function, which contributes to improving the properties of the final packaging, such as strength, barrier against contaminants or protection against environmental factors.
These films can be combined in different ways depending on the needs of the product to be packaged, resulting in what are known as complex films. Complex films are not only multi-layered, but also incorporate different types of materials, each with a different function which, when combined, offer superior solutions in terms of performance and protection.
The composition of multilayer films
Multilayer films are generally composed of two or more layers of different materials, each with specific properties that enhance the overall characteristics of the film. The most common layers include:
- PET (Polyester): It is mainly used for its mechanical strength, transparency and recyclability.
- BOPP (Biaxially Oriented Polypropylene): This material is known for its high tensile strength, excellent moisture barrier and low cost.
- AL (Aluminium): Aluminium is incorporated in most multilayer films to provide an excellent barrier against light, oxygen, and moisture, which is key in products such as food, medicines or cosmetics.
- PA (Polyamide): Used primarily for its high abrasion resistance, flexibility and barrier against gases such as oxygen.
- PE (Polyethylene): Polyethylene is widely used due to its sealing properties and protection against contaminants.
Benefits of multilayer or complex films
Multilayer and complex films offer many benefits, which go beyond the capabilities of traditional single-layer films. Here are some of the main benefits:
1. Increased product protection
One of the most valued characteristics of multilayer films is their ability to provide an exceptional barrier against environmental factors such as moisture, oxygen, carbon dioxide, light and oxidation. These factors can affect the quality of packaged products, especially in the case of food and pharmaceuticals. The different layers of materials work together to provide a much higher level of protection than a single layer.
2. Better preservation of products
Thanks to the barrier properties of multilayer films, products can be preserved for longer without spoilage. This is important in sectors such as food, where freshness and quality are critical. For example, food products such as snacks, biscuits or cereals require packaging that keeps moisture and oxygen out, preventing rancidity or loss of flavour.
3. Versatility in design and function
Multilayer films can be designed and adapted to different products and specific needs. Depending on the combination of layers chosen, properties such as increased impact resistance, flexibility to facilitate automatic packaging, or even aesthetic properties to enhance product presentation can be achieved.
4. Sustainability
Although the production of multilayer films can involve the use of a variety of materials, many of these solutions are moving towards greater sustainability. Some multilayer films can be made from recyclable or biodegradable materials, reducing the environmental impact of packaging. In addition, the increased durability of these films contributes to a reduced need for additional packaging.
5. Improved aesthetics
Complex films are not only functional, but can also improve the appearance of the final product. Transparency or glossy finishes on some layers can make packaging more attractive to consumers, which is a competitive advantage in today’s saturated market.
Common applications of multilayer films
Multilayer films have a wide range of applications in different industrial sectors. Some of the most common include:
1. Food industry
In the food sector, multilayer films are particularly useful for packaging products such as biscuits, chocolates, dried fruits, cereals and snacks. The combination of PET, BOPP and aluminium is one of the most common to provide an effective barrier against elements that could alter the quality of the product. In addition, some multilayer films also allow hermetic sealing, which improves food safety.
2. Pharmaceutical industry
Multilayer films are also essential in the pharmaceutical industry, where protection against moisture and oxygen is crucial to ensure the efficacy of medicines and supplements. Blister packs for tablets, capsules and other pharmaceutical products are often made of complex films combining aluminium, polyamide and polyethylene to ensure product stability.
3. Cosmetics industry
The cosmetics industry also benefits from multilayer films, as they provide excellent protection for light- and air-sensitive products such as creams, lotions and perfumes. The barrier properties offered by these films are perfect for preserving the quality and efficacy of cosmetics.
4. Graphic arts and labelling
Complex films also find their place in the graphic arts world, where they are used to print labels and packaging that require strength, flexibility and aesthetic quality. High quality films can enable vibrant images to be printed, ensuring that the design and branding is visible and durable.
At Globalfilms we have the best plastic film solutions, of excellent quality and with a key factor, their sustainable character. Do you have any questions about our film solutions? Then contact us and we can help you with the best advice.
