Food packaging has brought great convenience to both sellers and consumers, not only in use, but also in safety. Food is liable to contact with oxygen and bacteria in the air, thus affecting the taste and quality of food. Therefore, a sealed food packaging is very necessary when storing or selling food.

不同食品的化学成分，理化性质都各不相同，因此不同食品对包装的防护性要求也不同。在设计食品包装时，我们需要根据食品本身的不同性质来选择包装材料，从而达到保护食品，延长保质期的目的。例如，蛋糕是含油脂较多的、松软的，有一定{zj0}含水量的要求，因此最起码应符合下面要求：防油高阻氧性（防止渗油及油脂被氧化）、高阻湿性（防止蛋糕失去水分变干变硬）。

The chemical composition and physical and chemical properties of different foods are different, so different foods have different protective requirements for packaging. In the design of food packaging, we need to choose packaging materials according to the different nature of food itself, so as to protect food and extend its shelf life. For example, cake is rich in oil, soft, and has a certain optimum water content. Therefore, at least it should meet the following requirements: high oil resistance (prevent oil seepage and oil oxidation), high moisture resistance (prevent cake from losing water to become dry and hard).

传统的包装材料有玻璃瓶，金属罐、纸盒、纸箱等。现代食品包装材料主要有塑料类，纸类，复合材料类（塑/塑、塑/纸，塑/铝，箔/纸/塑等各种类型的多层复合材料）。不同的包装材料带来的功能也是不同的，其包装的精美程度更是会直接影响到食品的销售情况。

Traditional packaging materials include glass bottles, metal cans, cartons, cartons and so on. Modern food packaging materials mainly include plastics, paper, composite materials (plastic/plastic, plastic/paper, plastic/aluminum, foil/paper/plastic and other types of multi-layer composite materials). Different packaging materials bring different functions, and their packaging quality will directly affect the sales of food.

为了延长食品保质期，采用不断开发的新的包装技术，例如活性包装，防霉包装，防潮包装、防雾包装，防静电包装，选择性透气包装，防滑包装，缓冲包装等。发达国家广泛应用这些新技术，我国应用不普遍，有些方法还属空白，这些先进技术的应用可明显提高包装的保护功能。

In order to prolong the shelf life of food, new packaging technologies such as active packaging, anti-mildew packaging, moisture-proof packaging, anti-fog packaging, anti-static packaging, selective breathable packaging, anti-skid packaging, cushioning packaging and so on are adopted. These new technologies are widely used in developed countries, but not widely used in China. Some methods are still blank. The application of these advanced technologies can obviously improve the protection function of packaging.

包装是食品的容器，它给食品的流通带来了极大的便利。同时，设计精美的包装更容易吸引消费者，促进销售，扩大宣传，增强市场竞争力。

Packaging is the container of food, which brings great convenience to the circulation of food. At the same time, beautifully designed packaging is easier to attract consumers, promote sales, expand publicity and enhance market competitiveness.