Vacuum bag, aluminum foil bag packaging freezing method

1、 Aluminum foil packaging, vacuum packaging methods and forms

1. Vacuum bag packaging method

Another form of packaging that replaces filling the contents into small bags is vacuum bag packaging, which is widely used in frozen foods. Its advantage is that for foods that are relatively heavy for individuals (such as pig trotters or meatballs), this tight packaging will give consumers a certain sense of value in their senses. The vacuum automatic packaging equipment is easy to operate, has a good appearance effect, and is easy to adjust. Another approach is to use fully automated new equipment to package the upper and lower films separately. The filled contents are first placed on the machine with the lower film, then sealed on three sides with the upper film for the first time, followed by vacuum pumping, and then a continuous operation of sealing and cutting for the second time. In foreign countries, this type of equipment is a highly efficient system and has been used in the large-scale production of various frozen and prepared foods such as hamburgers and roasted wheat. The main body of the packaging material is made of soft materials, mostly nylon/PE with good formability and no stretchability. The upper film is made of polyester/PE composite material that is sensitive to the photoelectric cell logo and suitable for printing.

2. Paper box packaging

In addition to flexible packaging based on plastic film, the use of paper box packaging is increasing. This packaging form not only maintains an expanded appearance, but also accelerates the filling speed, improves production efficiency, has a good appearance effect, and is characterized by easy handling and convenient conditioning. The cardboard packaging of frozen food is divided into two methods: upper loading and inner loading. The material of the former is made of PE, PP plastic film and cardboard pressed together on the surface, stamped and cut by a small packaging machine, and boxed by a box making machine. After the contents are filled from the top, the machine automatically seals with a lid. The lid and body of the box are connected as a single piece. When the machine separates them up and down, the contents enter from the side and then automatically seal. This method is commonly used.

3. Aluminum foil packaging

Aluminum foil, as a packaging material, has the advantages of heat resistance, cold resistance, and good barrier properties, which can prevent food from absorbing external odors, odors, drying, and weight reduction. This material has good thermal conductivity and is suitable as an aluminum foil cooking bag for thawing and reheating containers.

4. Packaging materials for microwave ovens

With the popularity of microwave ovens, packaging containers for frozen foods suitable for microwave heating include heatable plastic boxes, which can be used in both microwave ovens and ovens. The laminated container developed by the American company Internationalpaper is extruded from long fiber base paper and polyester, with a paper thickness of 0.43 mm to 0.69 mm and a coating thickness of 25 microns to 38 microns. It can generally withstand high temperatures of 200 ℃ to 300 ℃. The packaging materials used for frozen food heated in Japan's specialized microwave ovens include polyester/paper, polypropylene, and heat-resistant polyester.

2、 Inspection and weight management of foreign objects

During the packaging process, if there are packaging defects such as insufficient weight, loose sealing, exposed holes, or foreign objects such as metal sheets mixed in the product, they should be inspected by sensory or specialized settings. The commonly used detectors are metal and weight sorting machines. The foreign object detection equipment is very important in the quality management of large-scale production of frozen processed foods. Detecting all foreign objects with equipment is still a topic that is currently being intensively researched internationally. The weight sorting machine calculates the allowable range before packaging and sets it in the automatic confirmation device. The setting must be correct and appropriate. It sorts out the lightweight ones, sends them through the conveyor belt, and separates them out by the separation device, thus combining them into continuous production.

3、 Freeze

The texture (organization structure and physical properties, i.e. taste) and taste of food sensory quality are the above requirements of consumers. The factors that make up the taste include protein, carbohydrates, fats, and the composition of water. The state in which these substances exist in food determines its physical properties. The denaturation of proteins during the freezing process is the main reason for the decrease in their taste and flavor, and the effective way to reduce their negative effects to low Z is to freeze them quickly and at low temperatures. The frozen processing of rice products and starch based products, as the main component of these foods is starch, will cause a decrease in taste and flavor due to starch aging during low-temperature freezing. The temperature range of 0 ℃ to 4 ℃ is the temperature environment where they are prone to aging. Therefore, when these types of food are frozen by a quick freezing machine, they need to quickly pass through a temperature zone that is prone to starch aging and enter the rapid freezing temperature to complete the quick freezing process. If there is an appropriate amount of liquid present in rice, it will freeze to the desired quality. Using liquid nitrogen as a refrigerant for rice products results in good freezing quality. In recent years, there have been many new types of frozen equipment for processed foods both internationally and domestically, which have evolved from the original box type quick freezing machine to various quick freezing equipment such as spiral, liquid nitrogen, tunnel, and flat plate. For the production of quick freezing convenience food, the conveyor belt quick freezing method currently accounts for a large proportion due to its small size, short freezing time, and easy implementation of rapid freezing, which improves product quality, increases production efficiency, saves energy, and reduces production costs. At present, many enterprises sometimes fail to reach the freezing temperature in pursuit of freezing production efficiency, resulting in the production of non-conforming products. The freezing time of food packaged in food bags must be determined according to their type and shape. Suitable temperature and freezing conditions should be selected from the surface and center of the product.