Laminated safety glass (LSG) is produced at both German production sites. The system is capable of processing glass panes up to a maximum size of 3.30m x 7.00m. Our annual LSG production totals over three million square metres. Staff work in two- or three-shift operation.
Various work steps are required to produce the finished laminated safety glass:
1. Glass loading
Straddle carriers position glass panes on the system. Loading each pane takes between 24 and 30 seconds. It takes 60 minutes to empty an entire rack. Loading can take place from four rack stations.
The loading speed on the production line is around 15m/min.
Panes are thoroughly cleaned in the cleaning unit. Brushes rotating on both sides remove the "Lucite" releasing agent prior to throughput of the panes. Extracting "Lucite" prior to the actual cleaning process reduces water treatment costs and protects the environment. The incoming glass pane's thickness is automatically recorded to guarantee ideal cleaning unit parameters. The cleaning unit only uses desalinated and decalcified water. An integrated water treatment system purifies the mains water accordingly. The water's purity levels are comparable to those of distilled water. Basic glass panes must be absolutely clean for processing.
3. Lamination facility
Glass panes and PVB interlayer are fused in the lamination facility. Several PVB interlayers are always available for this process. Having positioned the glass pane, the respective film is applied before the second glass pane is positioned. The edge of the film is then cut to size. All processing steps are fully automated. The cycle time to apply film is 45 seconds.
The PVB interlayers used are very sensitive in terms of temperature and humidity. Each dust particle on the film would impair visual qualities. The lamination facility is therefore an air-conditioned clean room. It is mandatory to wear special protective equipment in this context. The film is also stored in air-conditioned rooms at between 5 and 7°C.
The so-called pre-lamination is created in the pre-lamination furnace from glass panels and an intermediate film. The glass panels are heated to a defined temperature and pressed together by rollers. The first compression roller extracts the air from the "glass/film/glass" composition. The main heating section brings the laminate to the required bonding temperature. The glass is thereby heated to a maximum of 60°C. The throughput rate is automatically adapted to the glass thickness. The second pressure roller removes or binds the remaining air within the composition thus creating the actual pre-lamination.
The glass panes and film form a permanent bond under pressure and at temperature. This process is used to turn pre-lamination panels into finished laminated glass panes. The laminate is 'baked' for around 3 to 5 hours. The heat causes the film to liquefy into a viscous compound, similar to honey. This liquid distributes itself within the crystalline structure of the glass. The remaining air is compressed.
A 100% visual quality inspection is conducted after the autoclave process. Defective panes are discarded and cutting options as well as end racks are specified. Straddle carriers then stack the finished laminated safety glass panes.