Exhaust Is Designed To:

Of purpose is: ① block needed oxygen bacteria and mold of development growth; II prevent or reduce for heating sterilization Shi air expansion and makes container deformation or damaged, especially caused volume side by pressure had big, to effect its sealed sex; ③ control or reduce canned food storage in the appeared of tank within wall corrosion; II avoid or reduce food color, and incense, and taste of changes; ⑤ avoid vitamin and other nutrients suffered damage; ⑥ helps avoid will fake expansion tank errors think corruption metamorphic sex expansion tank.