Structural analysis of retort pouch products

The thickness of the packaging material is small, and the heat transfer is fast, and the sterilization time can be shortened. Therefore, the color and flavor of the contents are small, and the loss of nutrients is small.

The packaging material is light in weight and small in size, which can save packaging materials, and has low transportation cost and convenience.

Beautiful patterns can be printed.

It has a long shelf life (6-12 months) at room temperature, and the sealing is easy to open.

You can save on cooling costs without refrigeration.

Suitable for a variety of varieties, such as meat and poultry, aquatic products, fruit and vegetable cereals, soups are suitable.

It can be heated together with the package when eating, which can prevent the loss of flavor, especially suitable for field work, tourism, military food.

Complete retort pouch production, including a comprehensive understanding of the type and quality of the contents, structural design of the product, selection of substrates and inks, adhesives, production process, product inspection, packaging and sterilization process control, etc. The product structure design of the bag is the core. Therefore, a general analysis is made to analyze not only the substrate configuration of the product, but also the performance, use, safety and hygiene, and economy of different structural products.

1 Food decay and sterilization

Human beings live in the encirclement of microorganisms. There are countless microorganisms in the biosphere of the whole earth. When the amount of microbial reproduction in food exceeds a certain limit, the food will be corrupted and eaten.

Common bacteria causing food spoilage are Pseudomonas, Vibrio, both are not heat-resistant, intestinal bacteria are killed at 60 ° C for 30 minutes, some varieties of lactic acid bacteria can withstand 65 ° C, 30 minutes of heating. Bacillus Can withstand 95-100 ° C, heating for a few minutes, a few can withstand heating at 120 ° C for 20 minutes. In addition to bacteria, there are a large number of fungi in food, including mucor, yeast, etc. In addition to light, oxygen, temperature, moisture, PH value, etc. can cause food spoilage, but the main factor is microbes. Therefore, using high temperature cooking to kill microorganisms is an important method for long-term preservation of food. Food sterilization can be divided into 72 ° C pasteurization, 100 ° C boiling sterilization, 121 ° C high temperature cooking sterilization, 135 ° C high temperature cooking sterilization and 145 ° C ultra high temperature instant sterilization, and some manufacturers use non-standard Sterilize at a temperature of around 110 °C.

2 retort bag raw material characteristics

(1) PET film

BOPET film tensile strength is the highest of all plastic films, very thin products can meet the needs, rigidity, hardness, cold resistance, heat resistance. BOPET film temperature range from 70 ° C -150 ° C It can maintain excellent physical properties in a wide temperature range, and is suitable for most product packaging. It has good barrier performance. It has excellent comprehensive water-blocking gas barrier performance, unlike nylon, which is affected by humidity, its water blocking rate. Similar to PE, the gas permeability coefficient is extremely small. It has a very high barrier to air and odor and is one of the fragrance materials. Chemical resistance, grease resistance, most solvents and dilute acids, dilute alkalis, etc.

(2) BOPA film

BOPA film has excellent toughness. Tensile strength, tear strength, impact strength and burst strength are among the best in plastic materials. Outstanding flexibility, pinhole resistance, not easy to pierce the contents, is a major feature of BOPA, good flexibility, but also makes the packaging feel good. Good barrier properties, good aroma retention, resistance to chemicals other than strong acid, especially oil resistance. It has a wide temperature range and a melting point of 225 ° C. It can be used for a long time between -60 ° C and 130 ° C. The mechanical properties of BOPA remain at low temperatures and temperatures. The performance of BOPA films is greatly affected by humidity, and dimensional stability and barrier properties are affected by humidity. After being wetted, the BOPA film generally stretches laterally in addition to wrinkles. Longitudinal shortening, elongation up to 1%.