With the increasing demand for snack foods, how to produce pure flavors, longer storage time, and easier storage of flavored foods, is currently considered by every R&D department of food factories.
With the increasingly sophisticated production of high-temperature cooking soft packaging, food research and development has also brought a new field, the most obvious is the increasingly extensive use of high-temperature cooking packaging containing aluminum foil. However, in view of the current situation of high-temperature cooking and packaging production, there are many quality problems in aluminum foil-containing packaging. How to improve the production level of aluminum-containing foil packaging bags through various links?
How to choose a composite material reasonably is a key step in packaging. At present, the cooking temperature of the market is above 121°C (inclusive), and the high-temperature cooking packaging with aluminum foil mainly includes the following two material structures, namely BOPET/AL/RCPP and BOPET/AL/BOPA/RCPP.
BOPET is a kind of high-quality plastic film with excellent transparency, non-toxic, odorless, high tensile strength, and good stiffness. , Tear resistance, non-breakage, excellent electrical and optical properties, oxygen barrier moisture resistance, cold (-70 °C), heat (200 °C), and chemical resistance and shrinkage stability of the excellent characteristics. The choice of BOPET should pay attention to the thermal shrinkage at the temperature of 150°C and 30min, the longitudinal direction is ≤ 2%, the transverse direction is ≤ 1.5%, and the surface tension must not be less than 45mN/m.
Aluminum foil is the only type of foil in flexible packaging materials and has a long application time in the packaging field. Aluminum foil is a metal material, and its water-blocking, air-blocking, light-shielding, and taste-protecting properties are difficult for any other packaging materials to achieve. It is a packaging material that cannot be completely replaced until now. Aluminum foil is made of 99.0%~99.97% pure electrolytic aluminum. After many times of calendering, it is rich in resources and has a considerable advantage in performance and price. The aluminum foil used for cooking and packaging should be made of 9-micron-thick grade A soft aluminum foil.
BOPA film has high puncture resistance, impact strength, friction strength and bending strength, and good barrier properties. We must pay attention to the characteristics of BOPA when it is used in BOPA. As the material of the intermediate layer, double-sided corona treatment is required, and the surface tension is not less than 50 mN/m. Some customers use the single-side treated BOPA for compounding. The strength after compounding will be much lower, and increasing the amount of glue on the non-treated surface will compensate.
RCPP film is characterized by transparency, good, good flatness, good temperature resistance, has a certain degree of stiffness, without losing flexibility, good heat sealability, do aluminum packaging foil RCPP should pay attention to the thermal shrinkage rate should not be too large, in The selection should take into account the differences in the content of substances, there is a certain degree of specificity, especially when doing some of the contents containing oils and fats, acids and bases containing substances should pay more attention. It is recommended that the thickness of the CPP be not less than 80 microns in cooking, and that suppliers with better physical control should be selected, and the corresponding products should be selected for the special requirements of the contents.
In the production of retort packaging, the most critical process control is in the compounding process. Each detailed issue of the compounding process will determine whether the packaging performance has reached the desired goal. Therefore, in production, we must strengthen the control of the composite process and master several key control points. Then, it is much simpler to make such packaging.
