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PVB Film vs EVA Film Complete Comparison
PVB Film vs EVA Film Complete Comparison
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Key Takeaway: PVB requires an autoclave, while EVA uses a vacuum laminating furnace. Equipment is NOT interchangeable. PVB is for high-end applications like exterior curtain walls and automotive glass; EVA is for low-cost interior decoration and small-batch production. |
1. Production Process Comparison
The two films operate on fundamentally different principles—equipment cannot be shared between them.
1.1 PVB Process Route
Core Principle: Roller pre-pressing for degassing + autoclave high-pressure bubble dissolution
1. Glass sheet loading
2. Washing & drying (pure water, 35–45°°C exit temperature)
3. PVB lay-up in a temperature & humidity-controlled clean room
4. Infrared roller pre-press — heating and squeezing out air
5. Autoclave final pressing (135–145°C, 1.0–1.4 MPa)
6. Cooling, edge trimming, quality inspection
1.2 EVA Process Route
Core Principle: Full vacuum extraction via vacuum bag + thermal crosslinking curing
1. Glass sheet loading
2. Washing & drying
3. EVA film lay-up and assembly
4. Packing into a vacuum bag / vacuum frame and sealing under vacuum
5. Vacuum laminating furnace heating & curing (85–120°C, atmospheric pressure + vacuum)
6. Cooling, unpacking, quality inspection
2. Detailed Parameter Comparison
|
Parameter |
PVB (Polyvinyl Butyral) |
EVA (Ethylene Vinyl Acetate) |
|
Required Equipment |
PVB lamination line + Autoclave |
Vacuum laminating furnace (vacuum bag / frame), no autoclave needed |
|
Key Process Conditions |
135–145°C, 1.0–1.4 MPa high pressure |
85–120°C, atmospheric pressure under vacuum |
|
Optical Clarity |
Optical grade, minimal distortion |
Standard EVA tends to yellow; high-clarity EVA approaches PVB level |
|
UV Resistance |
Excellent — automotive grade standard |
Poor for standard EVA; yellows under prolonged outdoor exposure |
|
Impact Resistance / Safety |
Exceptional — mandated material for automotive windshields |
Moderate — not approved for automotive windshields |
|
Sound Insulation |
Excellent — preferred for acoustic laminated glass |
Average — inferior to PVB |
|
Moisture Sensitivity |
Highly hygroscopic; RH must be controlled at 20–40% |
Low water absorption; tolerant to ambient humidity |
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High-Temp Stability |
Service range: -40°C to 60°C |
Softens and creeps above 70°C; risk of delamination |
|
Edge Stability |
Stable edges, minimal delamination risk |
Prone to edge delamination under outdoor heat & moisture |
|
Film Material Cost |
Higher unit price |
Lower price |
|
Equipment Investment |
High (autoclave is capital-intensive) |
Low — suitable for small and medium factories |
|
Production Cycle |
Long autoclave cycle limits throughput |
Flexible batch sizing; faster for small runs |
3. Film Structure & Performance Comparison
3.1 PVB Film Characteristics
• High Impact Resistance: Exceptional toughness; retains glass fragments upon breakage for superior safety
• UV Resistance: Automotive-grade PVB offers excellent UV protection with minimal yellowing over time
• Superior Acoustics: Industry standard for sound-insulating laminated glass in multi-layer IG units
• Autoclave Required: Full integration requires high temperature and high pressure — high equipment barrier
• Hygroscopic: Absorbs moisture easily; humidity causes clouding, bubbles, and delamination
3.2 EVA Film Characteristics
• Easy Processing: No strict clean-room requirements; no autoclave needed—simple workflow
• Moderate Weatherability: Standard EVA yellows and delaminates under prolonged outdoor exposure
• Interior Grade: Performs well for interior decoration, art glass, and shower enclosures
• Vacuum Furnace Process: Cured via vacuum bag degassing + thermal crosslinking
• Moisture Tolerant: Low water absorption; easy storage and less environmental control required