What is the shelf life of Guanfudun? How long can it be kept unopened?

A: The recommended shelf life of unopened Guanfudun is one year (counting from the date of production). Store it in a cool and dry place. Reason: ① The glass substrate of the film (Nanshan high alumina glass) has stable chemical properties and will not expire; ② The adhesive layer of the film (optical transparent adhesive OCA) has a service life. Its stickiness may decrease after long-term storage (especially in high-temperature and high-humidity environments). ③ The oleophobic layer is stable when unopened, but it may slightly deteriorate over time. ④ Plastic parts such as dust removal bins will not expire. Storage method: ① Unopened films should be kept in their original packaging in a cool and dry place, away from direct sunlight and high temperatures (such as not placed in a car or near a radiator). ② Avoid heavy pressure (Do not place heavy objects on the packaging box, as it may crush the diaphragm); ③ Stay away from damp environments (such as bathrooms and kitchens). The service life of the applied film: ① 6 to 12 months under normal use (the wear cycle of the oil-repellent layer); ② If the film is not scratched, cracked or curled at the edges, the oil-repellent layer can still be used after wear (only the hand feel will decline), and there is no mandatory replacement period. It is recommended to replace it every 12 months or so to maintain a good feel and protection. Note: ① The production date is indicated on the packaging box. Please check it carefully when purchasing (although the film can still be used after expiration, the adhesiveness of the adhesive layer may decrease). ② If it has been stored for more than two years, check whether the adhesive layer still has stickiness before use (tear off a little release film and touch the adhesive surface). If the stickiness drops significantly, it is recommended to replace it. ③Guanfudun costs 129 yuan for 1 piece and 159 yuan for 2 pieces. The 2 pieces are suitable for backup, but don't stock up too much at one time (to avoid expiration).