What are the precautions for making high temperature cooking bags?

(1) According to the sterilization time and temperature, select the two-component polyurethane adhesive that meets the cooking requirements. The intrinsic quality of the adhesive, first of all, is the percentage content of the curing agent, the percentage content of the curing agent shall not be less than 2% of the original regulation, otherwise the viscosity of the glue will be greatly reduced, followed by the proportion of the curing agent can not be too large, if too large, it is easy to cause the embrittle tear of the composite film. If the activity of the ink or glue is not enough, or if the expired residue is added, the number of groups that can be used to connect the substrate is small, and the adhesion is not strong. The water activity of expired ink and glue is not good, which will cause the adhesion of the boiled bag to meet the requirements. Pay attention to not using expired ink or glue.

(2) Corona treatment strength to reach (PA-- 52dny, PET-- 48dny, PE, RCPP -- 40dny), the amount of glue to reach 4.5~5g/m2 (refers to the amount of dry glue) reference GB/T10004-- 2008 standard. Heat seal film placed too long is not available, otherwise it may appear the phenomenon of separation.

(3) Too many additives (auxiliaries) of printing and heat sealing materials float up to make the composite layer degrade and easy to peel off. The inner film of the cooking bag should have a stable thermal shrinkage rate and good temperature resistance and oil resistance to prevent the contents of grease from penetrating into the rubber layer, resulting in the separation of the composite film. The slippery dose of the heat seal film is too high (above 500PPm), which will also cause low peel degree.

(4) The crosslinking of different adhesives is not the same, in order to ensure the complete crosslinking of glue, different curing processes should be used according to different grades of glue and different uses. Suitable curing time and temperature to ensure composite quality. The curing conditions do not meet the requirements, or the curing time is too short, will result in reduced stripping fastness after sterilization delamination. The curing time can not meet the requirements, the short time is insufficient crosslinking, and the temperature resistance and hydrolysis resistance of the ink layer are reduced. The basic curing time of the cooking bag is 60 hours, but sometimes adjustments are made according to the size of the cooking bag and the size of the ink surface. If the curing time is not enough, it will lead to the ink layer of high temperature resistance and hydrolysis resistance is reduced, so the general high temperature cooking bag curing time is 72 hours.

(5) The compatibility between ink, glue and film is very important, according to the adhesion theory, when the adhesive and the adhesive surface tension is equal and very the same, the interfacial tension is small, the adhesion strength is high. Therefore, the surface of the ink, glue curing into a film and the condition of the film surface may vary with the product situation of different manufacturers, because the groups on various surfaces can not be well attracted to form intermolecular forces or chemical reactions to form chemical bonds, even at low temperatures have a certain effect to form adhesion, but at high temperatures, The weak connections of surface groups may be damaged and delamination may occur. There's a problem with the curing agent ratio of the cooking glue. The ratio of curing agent is not the higher the cooking bag, the more in line with the standard, more will lead to ink delamination, less will affect the adhesion of the ink layer and hydrolysis resistance. The peeling strength of the composite film was measured by sampling. In particular, the sampling inspection at the beginning and near the end of each volume can be greater, and it is easy to have various quality accidents at this stage.

(6) Use 80~90 lines/inch coated cable roller. This ensures a high amount of glue at the right viscosity. If a reverse roller is used to ensure uniform coating. And before the composite, it is necessary to check the cleanliness of the coating roller and whether the mesh roller is blocked to ensure that there is a good coating state. The oven should be well ventilated and the environment clean.

(7) Environmental factors are very important, do a good job of workshop production records, the general air humidity of more than 80%, for printing, composite is very unfavorable, it is recommended not to use production.

(8) When using cooking bags, food enterprises should strictly control the temperature within the scope guaranteed by the cooking bag manufacturer. That is, the actual sterilization temperature is 125℃ when it is fixed at 121 ℃. Because even if it is more than a few degrees, but because the various materials that make the cooking bag at this time often have reached the limit that they can withstand, the excess of several degrees is very critical to whether the performance of the cooking bag can be guaranteed.

For more information about high temperature cooking bags, please pay attention to us!