Laminated glass is composed of "glass+organic intermediate film (such as PVB, EVA)" composite. Its core advantage is that fragments do not splash after breakage, and it also has sound insulation and UV protection functions. It is widely used in multiple fields and requires precise control in multiple stages of production.
1、 Production and use site
1. Construction field (core applications)
Facade and curtain wall: High rise/super high-rise curtain walls (especially the bottom floor and opening fans) must be used to avoid glass breakage and falling; Landmark buildings can use colored glazed laminated glass to balance safety and decoration.
Indoor areas: commonly used for mall partitions, stair railings, bathroom glass doors, and anti debris scratches in densely populated areas; Sunroom/patio glass can resist hail, and PVB film can block over 90% of ultraviolet rays, protecting furniture from fading.
Special scenario: Museum cultural relics display cabinets are made of ultra white laminated glass, which is both anti smashing and anti UV, protecting the exhibits; The hospital operating room partitions are easy to clean and shatter resistant, meeting medical safety standards.
2. Transportation sector (essential for safety)
Automobile: The front windshield is mandatory for use by the country, and after a collision, the PVB film adheres to fragments and does not obstruct the view; High end car models can reduce 3-5 decibels of noise by using laminated glass for side windows and sunroofs.
Rail transit and ships: high-speed rail side windows and ship side windows need to be resistant to wind pressure and impact, laminated glass has strong fatigue resistance, and is suitable for long-term vibration environments; Double layer PVB laminated glass is used for school buses and police cars to prevent stone impact.
3. Security and special fields
Security scenario: Bank bulletproof glass is made of "3-5 layers of tempered glass+multiple layers of PVB film", which can resist gunshots; Jewelry store windows use double-layer tempered laminated glass to prevent damage from hammers.
Special scenario: Explosion proof observation window in chemical workshop to prevent equipment explosion debris splashing; Photovoltaic building integrated glass sandwich photovoltaic modules in the middle, achieving dual functions of "power generation+enclosure"; Low temperature resistant PVB film laminated glass is used in polar buildings to avoid embrittlement at -40 ℃. 
2、 Production process (mainstream dry method, taking PVB as an example)
1. Preprocessing (key: cleanliness+precision)
Select raw materials (tempered/ultra white glass, etc.), CNC cutting (laser/waterjet for irregular shapes), and reserve 1-2mm machining allowance; Grind the edges to remove sharpness (arcs/beveled edges), clean and dry (40-60 ℃ hot air to remove water and prevent bubbles).
Optional process: Tempering treatment (600-700 ℃ heating+air cooling, 3-5 times higher impact resistance); Coating (Low-E film UV protection, completed in a dust-free workshop); Colored glaze printing (low-temperature baking curing pattern).
2. Splicing (core: dust-free and bubble free)
Operation in a Class 1000 dust-free workshop (20-25 ℃, humidity 40% -60%): Cut PVB film (1-2cm larger than glass), stack glass+film+glass, remove air from the center to the surroundings with a scraper, and fix the corners with tape; Trim the film beyond the edge to prevent extrusion in subsequent processes.
3. Defoaming (purpose: preliminary bonding)
Use a pre press machine to remove interlayer air: Roll pre press flat glass (80-100 ℃, 0.3-0.5MPa, speed 1-2m/min); Vacuum preloading (-0.09MPa, 80-90 ℃ insulation for 15-20 minutes) is used for irregular/multi-layer glass, and there are no bubbles detected by strong light testing (rework is required for diameters ≥ 0.5mm).
4. Curing (key: high temperature and high pressure)
Complete in the high-pressure reactor: evacuate to -0.095MPa, heat up at 120-130 ℃ (PVB melting), maintain pressure at 1.0-1.2MPa for 30-60 minutes; Reduce the temperature to below 60 ℃ at a rate of 3-5 ℃/min and gradually lower the pressure to prevent glass breakage.
5. Post processing (ensuring qualification)
Appearance inspection: ≤ 3 bubbles below 0.3mm are allowed per square meter, with no impurities or cracks; Sampling test for adhesion (80% film adhesion to glass after breakage) and impact resistance; Trimming edges, secondary cutting (non tempered glass), packaging and storage (dry and ventilated, away from sunlight).