Process flow of dry laminated glass machining equipment
(1) Preparation of glass The glass substrate of laminated glass can be float glass, tempered glass, colored glass, heat-absorbing glass, heat-reflecting glass, flat glass, polished glass, etc. First, select the glass according to the national standard for laminated glass, which requires no ripples, gravel, stones or very few ripples. Cut out the glass blank. Then, make a glued template according to the size and shape of the ordering unit's drawing and the size of the edge to be ground off during edging. Cover the template on the blank glass during cutting. Each pair of glass is required to overlap closely, and the size difference should not exceed L 5M/edge.
(2) Washing of glass In order to remove dust, dirt, grease and clothing on the glass surface, the glass should be washed carefully. Glass washing is divided into machine washing and manual washing. Using a glass washing machine to wash glass can save labor, reduce labor intensity, improve washing quality, make the production process continuous, and is suitable for large-scale production. Manual washing is particularly suitable for factories with small-scale production.
After cleaning away any contaminants, a final rinse with clean water is essential to prevent any detergent residue from remaining on the glass surface. The quality of the rinse water significantly impacts the bond strength of the laminated glass, particularly the salinity of the rinse water, which affects the final quality of the bond between the glass and the PvB. Highly hard water can weaken the bond between the glass and the PvB. Therefore, if the water source is high in hardness, it is best to use a water softener to convert the hard water into softened or deionized water. After washing and drying the glass, it is necessary to carefully inspect the cleaning process for defects.
When producing bent laminated glass, the glass must be washed before hot bending. After hot bending, the amount of release powder used determines whether it needs to be removed, but further cleaning is not always necessary. Generally, a small amount of release powder does not significantly affect the quality of the laminated glass. However, if excessive release powder adheres to the glass surface after hot bending, it must be removed. Using a brush or wiping with a rag will not be thorough and may even erode the glass surface. Therefore, using a vacuum cleaner is recommended for removal of release powder.
(3) Preparation of PVB film The film must be cut appropriately according to the specifications of the glass, the size of the margins and the shrinkage of the film after processing to compensate for the shrinkage of the film size during the hot pressing process. When using film stored at low temperatures, the shrinkage depends on the shrinkage rate of the film itself and the stress generated when the film is laid.
If there is alkali powder on the surface of the roll film, the cut film needs to be placed in 10-25℃ water to rinse off the alkali powder on the surface. There are two ways to wash PVB film: machine and manual. When washing manually, use a brown brush to evenly brush both sides of the film in clean running warm water at 25-45℃. After brushing, clamp the clean film with wooden strips, hang it vertically, and then wipe it dry with a clean and dry silk cloth. No water droplets are allowed on the surface of the film. Then, send the film to the drying room for drying. Machine washing and drying are continuous. The washed and dried film is cut according to the template. The cut film is required to be larger than the finished laminated glass. The required margin is determined based on the film type and production experience. Generally, it is required to be 5mm larger on all four sides.
