1 What is Laminated Glass Delamination?
- Definition: Delamination occurs when the layers of laminated glass separate, causing the interlayer (e.g., PVB or EVA) to lose adhesion to the glass.
- Causes:
- Poor manufacturing quality.
- Exposure to extreme temperatures or UV radiation.
- Moisture ingress at the edges of the glass.
- Physical damage or improper installation.
- Appearance: Delamination often appears as cloudiness, bubbles, or a milky discoloration between the glass layers.
2. Risks of Delamination
- Aesthetic Issues: Delamination makes the glass look unattractive and reduces clarity.
- Structural Integrity: While delaminated glass may still hold together, its strength and safety performance are compromised.
- Safety Risks: In severe cases, delamination can lead to glass failure, increasing the risk of injury.
- Replacement Costs: Delaminated glass often needs to be replaced, which can be expensive.
3. Importance of the Interlayer
The interlayer is the heart of laminated glass, providing its key properties:
- Safety: Holds the glass together if shattered, preventing sharp shards from causing injury.
- Security: Makes the glass harder to break through.
- Sound Insulation: Reduces noise transmission.
- UV Protection: Blocks harmful UV rays, protecting interiors from fading.
- Structural Strength: Adds durability and impact resistance.
4. What is SentryGlass?
- Definition: SentryGlass is a high-performance interlayer material developed by DuPont. It is a type of ionoplast interlayer.
- Properties:
- Strength: Up to 5 times stronger than traditional PVB interlayers.
- Stiffness: Provides superior structural performance, making it ideal for large or load-bearing glass panels.
- Clarity: Maintains excellent optical clarity over time.
- Durability: Resistant to delamination, moisture, and UV degradation.
- Applications:
- Structural glass (e.g., floors, stairs, canopies).
- Hurricane-resistant and blast-resistant glazing.
- High-performance balustrades and facades.
5. EVA vs. PVB Interlayers
Both EVA (Ethylene Vinyl Acetate) and PVB (Polyvinyl Butyral) are interlayer materials used in laminated glass, but they have distinct properties and applications.
a. PVB Interlayer
- Pros:
- Excellent adhesion to glass.
- Good sound insulation properties.
- UV-resistant, protecting interiors from fading.
- Widely used and cost-effective.
- Cons:
- Can delaminate if exposed to moisture or extreme conditions.
- Less stiff than SentryGlass, making it less suitable for structural applications.
- Applications:
- Automotive windshields.
- Architectural glass (e.g., windows, balustrades, skylights).
- Safety glass for residential and commercial use.
b. EVA Interlayer
- Pros:
- Excellent optical clarity and UV resistance.
- Can be processed at lower temperatures, making it suitable for specialized applications.
- Good adhesion to glass and other materials (e.g., fabrics, metals).
- Cons:
- Less commonly used than PVB, so it may be harder to source.
- Generally less stiff than PVB or SentryGlass.
- Applications:
- Decorative laminated glass (e.g., with embedded fabrics or designs).
- Solar panels.
- Specialty glass for interiors.
6. Comparison of Interlayers
| Property | PVB | EVA | SentryGlass |
|---|---|---|---|
| Strength | Moderate | Moderate | Very High |
| Stiffness | Moderate | Low to Moderate | Very High |
| Clarity | Excellent | Excellent | Excellent |
| UV Resistance | Excellent | Excellent | Excellent |
| Delamination Risk | Moderate (if exposed to moisture) | Low to Moderate | Very Low |
| Cost | Low to Moderate | Moderate | High |
| Applications | Automotive, architectural | Decorative, specialty glass | Structural, high-performance |
7 . Pros and Cons of Laminated Glass
Pros:
- Safety: Holds together when broken, reducing injury risk.
- Security: Harder to break through than monolithic glass.
- Sound Insulation: Reduces noise transmission.
- UV Protection: Blocks up to 99% of UV rays.
- Design Flexibility: Can be combined with decorative elements.
Cons:
- Cost: More expensive than monolithic glass.
- Weight: Heavier due to the interlayer.
- Delamination Risk: Poor-quality laminates may delaminate over time.