Handling of flatness issues in the film

Phenomenon: Curling and wrinkling of the product
Reason:
(1) The design of the upper and lower membranes is unreasonable.
(2) The tension between the upper and lower membranes does not match.
(3) The sterilization method is not good.
(4) The shape and depth of the molding mold are not compatible.
(5) The blank space is not heat sealed.
Resolvent:
(1) Design the upper and lower membranes as symmetrical structures to reduce stress between different structures.
(2) The tension control of the upper and lower films should be well matched. While ensuring the flatness of the film, try to control the tension as low as possible to avoid uneven tension, which can cause the tension of a single film to be high. After sterilization, the film will curl towards the direction of the high tension film.
(3) During the sterilization process, the products should be placed neatly and there should be no mutual squeezing between them, otherwise there may be phenomena such as folding, curling, and wrinkling.
(4) The stretching mold should be as similar to the shape of the product as possible, with a depth slightly deeper than the thickness of the product, in order to reduce problems such as curling and wrinkling caused by stress after stretching the film.
(5) Require the blank space to also be heat sealed to increase the strength between the upper and lower films and resist the effect of film stress.