There are many kinds of food packaging bags, and they have their own unique performance and characteristics. Today we will discuss some common knowledge of food packaging bags for your reference.
First of all, what is a food packaging bag? Food packaging bags generally refer to sheet plastics with a thickness of less than 0.25mm as films, and flexible packaging made of plastic films is widely used in the food industry. There are many types of food packaging bags, they are transparent and flexible. They have good water resistance, moisture resistance and gas barrier properties. They have good mechanical strength, stable chemical properties, grease resistance, and they are easy to print beautifully and can be heat-sealed. Commonly used food flexible packaging is usually composed of two or more layers of different films, which can generally be divided into outer layer, middle layer and inner layer according to the position.
So what are the requirements for the performance of each layer of the commonly used food flexible packaging film? First, the outer film is generally printable, scratch-resistant, and media-resistant. Commonly used materials are OPA, PET, OPP, coating film and so on. The middle layer film generally has the functions of blocking, shading, and physical protection. Commonly used materials are BOPA, PVDC, EVOH, PVA, PEN, MXD6, VMPET, AL, etc. Then there is the inner film, which generally has the functions of barrier, sealing, and anti-medium. Commonly used materials are CPP, PE, etc. In addition, some materials have the common function of the outer layer and the middle layer. For example, BOPA can be used as the outer layer to print, but also as the middle layer to play a certain barrier and physical protection.
Now let's talk about the characteristics of commonly used food flexible packaging films. Generally speaking, the outer layer materials should have the following series of properties. They must be scratch-resistant, puncture-resistant, UV-resistant, light-resistant, oil-resistant, organic-resistant, heat-resistant and cold-resistant, stress-crack-resistant, printable, thermally stable, low-odor, low-odor, non-toxic, glossy, and transparent etc. The material of the intermediate layer generally has the following properties. They must be able to resist impact, pressure, puncture, moisture, and gas. They also need to be able to resist light, oil, organic matter, heat and cold, and preserve fragrance. At the same time, they should be low-odor, low-odor, non-toxic, and transparent etc.
Then it is the inner layer material. In addition to some common properties with the outer and middle layers, it also has its own unique properties, which must have fragrance retention, low adsorption and anti-seepage properties.
Now the development of food packaging bags has the following trends.
Food packaging bags made of environmentally friendly materials.
In order to reduce costs and save resources, food packaging bags are becoming thinner.
Food packaging bags are developing towards special functionalization. High barrier composite materials will continue to increase market capacity. In the future, high-barrier films will be the mainstream of flexible food packaging in supermarkets in the future. It is easy to process and has strong performance in blocking oxygen and water vapor.