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, and the per capita annual consumption is close to 10 kilograms. With the continuous popularization of frozen food packaging, higher requirements are 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); 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. The common frozen food packaging on the market now mostly adopts the following structure: OPP/LLDPE The product performance of this structure can achieve moisture resistance, cold resistance, low temperature heat sealing strength, etc., and the cost is relatively economical; the packaging performance of NY/LLDPE can resist freezing , Impact resistance, puncture, relatively high cost, good product packaging performance PET/LLDPE and PET/NY/LLDPE and PET/VMPET/LLDPE and other 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; the above-mentioned product structure is the current domestic market low-temperature frozen product packaging used more concentrated structure.

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 extremely easy to break and open the bag, which not only affects the appearance of the packaged product, but also cannot function as the packaging itself. The role it deserves.

(2) The smoothness of the packaging bag itself is not good. During the production process, the opening is poor and the production efficiency is low. At the same time, the utilization rate of the packaging bag will be reduced and the cost will be wasted.

(3) Insufficient heat sealing strength of the packaging bag and excessive heat sealing temperature cause damage to the heat sealing layer, resulting in a reduction in the protection performance of the packaging bag, greatly shortening the shelf life of the contents, and making 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 it cannot effectively protect the contents. effect.

(5) The cold resistance of frozen food does not meet the requirements. In the case of low temperature, the original performance of the material cannot be maintained. The packaging material is brittle, which reduces the mechanical strength of the packaging material, causing the packaging bag to rupture and crack. Satisfy the protective effect of the contents.

(6) The easy-to-tear function of the packaging bag cannot be effectively exerted. Too much tearing strength will cause the packaging bag to be difficult to open, and too small tearing strength will cause the mechanical properties of the packaging bag to decrease. Design, but also complete the protection of the product.

(7) The puncture performance of the packaging bag. Frozen foods are generally hard after freezing, especially fish and meat products, which contain bones and hard objects. The product squeezing during transportation and stacking can easily make the packaging bag pierce and make the packaging bag The tightness causes damage, so frozen food has high requirements for the puncture of the packaging bag.

Ensuring food safety and strict packaging Frozen food packaging as an important means to ensure the safety and hygiene of frozen food has received more extensive attention. In actual production, the following aspects of frozen food packaging should be paid attention to:

1. The characteristics of frozen food itself and the protection conditions required

Research on the main components of frozen food, especially the sensitive factors affecting fat, protein, vitamins and other nutrients, including light, oxygen, temperature, microbes, physics, mechanical mechanics and other factors. Only by mastering the biological, chemical, and physical characteristics of the 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 after understanding the packaging performance of various packaging materials and containers, can you choose according to the protection requirements of packaged frozen foods, which can protect the flavor and quality of frozen foods, and reflect their product value. Packaging materials that make comprehensive packaging costs reasonable.

3. The market positioning and circulation area conditions of the commodity. 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 for domestically sold products and those for export to different countries are different, and the protective requirements for packaging are also different for different modes of transportation. For frozen food packaging, changes in the climatic conditions of the commodity circulation area are very important, because the temperature has a great impact on the chemical changes in the internal components of the frozen food, microorganisms and the barrier properties of the packaging materials themselves.

4. The impact of the overall structure of the packaging and packaging materials on frozen food. Understand the migration of additives and other components in packaging materials into frozen foods, and the penetration and adsorption of certain components in frozen foods into packaging containers, which affect the quality of frozen foods in the circulation process.

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 inside 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 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.