Willing®PVB film package is used plywood cases or strong carton barrels. When loading and transportation,it should avoid impact each other and keep package as well and no any damages, even PVB film can not be polluted. Better to use proper handling and transportation equipment for loading and unloading. If carton barrels lay down on the floor, must move it slowly not fall down on the hard floor and make sure there is no any sharped things on floor before lay down, if possible take a cushion pad on the floor to avoid package damage, the handling device need to consider comfortable padding for easy to lift without any damage PVB film and its package.
Proper storage is equal important as using, only corrected storage and using are able to ensure the performance and quality of laminated glass processing. We suggest heavy burden shall not be laid on the products. Avoid to piled up more than three-tier of wooden boxes.. PVB film is actually a kind of adhesive, it will be bonded together if stored at room temperature above 10 ℃, so we must have an interleaf between two layers of PVB film; For other kind PVB film is refrigerated that no need interleaf while transportation but refrigerated PVB film should be kept with refrigerated. For PVB interlayer with PE interleaves kept suitable temperature which not higher 32 ℃.
We suggest PVB film in stock not exceed than 18 months, storage time is 18 months and should finish them within period of shelf life one and half year, because PVB film has special characters of water absorption, and easy to change its moisture along with external environment, therefore, long storage time does not change the physical and chemical properties of the film, but the PVB film surface will change slowly and increase adhesion of PVB interlayers, if PVB layers are bonded together, its hard to separate unless with big power, although be opened finally, this will cause uneven thickness of the film. So we suggest customer purchase PVB film according to your quantities of projects, not much more PVB film as stock out of guaranteed period. When opened and used part of PVB film roll, the rest of PVB film should stored in good condition of relative humidity 23% to 28% & temperature 20 ~ 25 ℃, or packed as well with inter package of vacuumed foilbags to warehouse.
The moisture of Willing®PVB interlayer will directly affect many key performances of laminated glass, not only as bond strength, impact resistance, but also have influences on the preheating processing, so PVB interlayer moisture content is a pivotal factor in glass laminating processes.
For the selected glass and PVB interlayer film, the PVB interlayer moisture content affects the adhesion between the glass and the PVB film, in fact, adhesion strength will be effected laminated glass quality. Adhesion and impact resistance that two parameters related to the performances of laminated safety glass , it requires strict control of the moisture content of PVB interlayer, so the adhesive force and impact resistance are controlled in safety standards range. We suggest processor control moisture in arrange of 0.3％～0.5％.
According to the chemical formula of Polyvinyl Butyral shows, PVB film is a hydrocarbon and an absorbent material. PVB film moisture always change follow environmental humidity if PVB film exposed in the air, when absorbent material is exposed to a certain temperature and humidity environment, moisture will be transferred from each other between the absorbent material and the air, until reached moisture equilibrium between the absorbent material and the PVB film, then can be changed PVB film moisture as suitable environment.
According to balance relationship, final moisture can be determined under the relative humidity. In order to ensure the moisture content, new unwound PVB sheet must be stored at cleaning laminating room at humidity of 23% to 28%, temperature 20 ~ 25 ℃ over than 24 hours, so that the moisture content of the PVB to meet the requirements then laminating.