The top key when producing the retort pouch bags
Printing process
1. Before printing, the BOPA nylon film can be placed in a room with a temperature of 35 degrees in the curing chamber for 2 hours for preheating. The printing workshop should be controlled for relative humidity. When more than 75% relative humidity is recommended, we do not recommend printing. When printing, we should pay attention to the gradient of drying temperature, otherwise, it will affect the drying and overprinting accuracy of BOPA.
2. According to the characteristics of the printing material and the composite film structure, select the appropriate ink. For example, BOPA nylon is used as the printing layer. The pigments of individual colors may penetrate on the BOPA in the cooking state, as well as only the printing layer and heat sealing. In a two-layer retort pouch, the ink also has the potential to penetrate on the RCPP, posing a risk of contamination of the contents. Therefore, it is recommended to choose the anti-cooking ink, please choose to use the penetration-resistant ink to further reduce the risk.
3, need to use a large area of spot color and white ink to add 3% of the ink curing agent, must be based on the technical information provided by the ink manufacturer to determine the amount of addition, not too much or too little. This place should be called with a precise electronic scale. The remaining ink recovered in the ink tray, no matter how long it is stored, can no longer be used for printing high-temperature cooking products. It is recommended to be used on other products as soon as possible after use. (Only if there are not enough orders for high-temperature cooking products.)
4. Minimize the residual amount of solvent in the printing material, and the adhesion fastness of the ink is good. It is necessary to select standard production process parameters, such as oven temperature, air volume and machine speed. For large-area inks with ink curing agent, the oven The temperature is 10~15 °C higher than other inks.
5. The printed BOPA film must be wrapped with a composite film of AL foil or composite aluminized film to prevent moisture shrinkage and performance changes.
6. The printing material with the ink curing agent added should be re-rolled once, and the storage time should not exceed three days, that is, at least the printing layer should be composited within three days.
Laminating process
1. The use of high-temperature cooking glue must be in accordance with the manufacturer’s instructions, such as the ratio, the temperature and time of curing, etc., the purity of the ethyl acetate solvent used for dilution should reach 99% or more.
