In recent years, with the rapid development of supermarkets and chain stores and the formation of cold storage chains, frozen food has become more and more popular. According to statistics from relevant departments, the current annual output of frozen food in my country has reached about 6.5 million tons, and it is increasing at a rate of 25% per year. The per capita annual consumption is close to 10 kg. With the increasing popularity of frozen food packaging, higher requirements have been put forward on the performance of packaging materials.
The status quo and problems of frozen food packaging The basic requirement of frozen food packaging is to maintain the quality characteristics of its products from production, transportation to sales, prevent bacterial contamination and be convenient to eat. For this purpose, packaging materials need to have the following conditions: have a certain mechanical strength (resistance to high and low temperatures); have barrier properties (a high degree of barrier to gas and liquid); and have resistance to the contents (acid and oil resistance); Hygiene; operation resistance.
At present, there are two types of packaging for frozen food: soft type and hard type. The soft type is based on plastic film. Thick and rigid packaging, such as thicker paper packaging boxes, composite aluminum foil stamping containers, etc., the former account for a larger proportion. Now the common frozen food packaging on the market adopts the following structure: OPP/LLDPE product performance can achieve moisture resistance, cold resistance, low temperature heat sealing strength, etc., and the cost is relatively economical; the packaging performance of NY/LLDPE structure can resist freezing , Impact resistance, puncture, relatively high cost, good product packaging performance PET/LLDPE, PET/NY/LLDPE and PET/VMPET/LLDPE structures are also used in frozen products, but the utilization rate is relatively low; in addition, One is a pure PE bag, such as vegetable packaging, etc.; the above-mentioned product structures are the more concentrated structures used in the packaging of low-temperature frozen products in the domestic market.
In actual production, frozen food packaging is prone to the following problems:
1. The impact resistance of the bag is poor, and it is easily damaged by external forces during transportation, loading and unloading, and shelf placement. It is very easy to break the bag and open the bag, which not only affects the appearance of the packaged product, but also cannot fulfill the packaging itself. Some role.
2. The smoothness of the packaging bag itself is not good, and the production process is characterized by poor opening and low production efficiency. At the same time, it will reduce the utilization rate of the packaging bag and cause a waste of cost.
3. Insufficient heat sealing strength of the packaging bag and too high heat sealing temperature will cause damage to the heat sealing layer, which will reduce the protection performance of the packaging bag, greatly shorten the shelf life of the contents, and make the contents not reach the corresponding shelf life.
4. The peeling strength between the layers of the packaging bag is small, the tensile force is insufficient, and the mechanical properties of the packaging bag are poor, which causes the packaging bag to layer, and the packaging bag cannot achieve its due load-bearing effect, and cannot effectively protect the contents. .
5. The cold resistance of frozen food is not up to the requirements. In the case of low temperature, the original performance of the material cannot be maintained, and the packaging material is brittle, which reduces the mechanical strength of the packaging material, causing the packaging bag to rupture and crack, and it cannot meet the requirements. Protect the contents.
6. The easy-to-tear function of the packaging bag cannot be played effectively. Too much tearing strength will cause the packaging bag to be difficult to open, and too small tearing strength will reduce the mechanical properties of the packaging bag. Therefore, it is necessary to meet the humanized design of the easy-to-tear packaging bag. , But also complete the protection of the product.
7. The puncture performance of the packaging bag. Frozen food is generally hard after freezing, especially fish and meat products, which contain bones and hard objects. Product extrusion during transportation and stacking can easily break the packaging bag and seal the packaging bag. Because of the damage caused by sex, frozen food has high requirements for the puncture of the packaging bag.
Ensure food safety and strict packaging. Frozen food packaging has received wider attention as an important means to ensure the safety and sanitation of frozen food. In actual production, frozen food packaging should pay attention to the following aspects:
1. The characteristics of the frozen food itself and the required protection conditions. Research on the sensitive factors that affect the main components of frozen foods, especially the nutrients such as fat, protein, vitamins, etc., including light, oxygen, temperature, microorganisms, and physical and mechanical factors. Only by mastering the biological, chemical and physical characteristics of packaged frozen food and its sensitive factors, and determining the protection conditions required, can we determine what packaging materials and packaging technology to use for packaging operations to achieve its protective function and appropriateness The purpose of extending its storage period.
2. Packaging performance and scope of application and conditions of packaging materials. There are many types of packaging materials with different performances. Therefore, only by understanding the packaging performance of various packaging materials and containers, can you choose according to the protection requirements of packaged frozen foods that can not only protect the flavor and quality of frozen foods, but also reflect their product value, and Packaging materials that make comprehensive packaging costs reasonable.
3. The market positioning and circulation area conditions of the product. The market positioning of the commodity, the mode of transportation and the climate and geographical conditions of the circulation area are factors that must be considered in the design of frozen food packaging. The packaging and decoration requirements of domestically sold products and those exported to different countries are different, and the protective requirements of packaging for different modes of transportation are also different. For frozen food packaging, changes in the climatic conditions of the commodity circulation area are very important, because the temperature has a great influence on the chemical changes of the internal components of the frozen food, microorganisms and the barrier properties of the packaging materials themselves.
4. The impact of the overall structure and packaging materials on frozen food. Understand the migration of additives and other components in packaging materials to frozen food, as well as the penetration and adsorption of certain components of frozen food into packaging containers and the impact on the quality of frozen food during circulation.
5. Carry out reasonable packaging structure design and decoration design. According to the protective requirements required by frozen food, the packaging cost, packaging volume and other conditions are expected to carry out reasonable packaging design, including the design of container shape, compressive strength, structural form, size, sealing method, etc., should be done as much as possible The packaging structure is reasonable, saves materials, saves transportation space and conforms to the trend of the times, and avoids excessive packaging and deceptive packaging.
6. Carry out packaging inspection. Qualified goods must have qualified packaging. In addition to testing the product itself, the product must also be tested for packaging. Only qualified products can enter the circulation field. There are many packaging testing items, but not every package needs to be fully tested. Which tests are required for specific packaging depends on the characteristics of the frozen food and its sensitive factors, the type of packaging materials and the requirements of national standards and regulations. Frozen food packaging bags can be tested as follows: ① packaging bag strength and strength performance test; ② packaging bag heat sealing strength test; ③ packaging bag opening performance test; ④ packaging bag impact performance test; ⑤ packaging bag sealing test; ⑥ Tear performance test of packaging bag; ⑦ Heat resistance; ⑧ Oil resistance test.
7. Packaging standards and regulations. Packaging operations should strictly comply with national standards and regulations, and export products should also comply with relevant standards and regulations of the importing country. Only in this way can we ensure the smooth progress of the processes including the supply of packaging raw materials, packaging operations, commodity circulation and international trade. With the development of market economy and international trade, the standardization and standardization of packaging are becoming more and more important. Only in this way can our products go further.