A Guide to Laminated Glass Production Using SentryGlas®

Introduction

In recent years, the demand for hurricane-resistant and high-security glazing has soared, driven by stricter building codes in coastal areas and heightened safety requirements in both commercial and residential settings. At the same time, architects and designers are looking for new ways to incorporate larger or more intricate glass features into their projects. To meet these needs, manufacturers are turning to advanced interlayer materials that combine superior strength, clarity, and versatility. SentryGlas® has emerged as a leading solution for these demanding applications, and with the right equipment, producers can capitalize on today’s market trends.

What Is SentryGlas®

SentryGlas® is an ionoplast interlayer developed in 1998 by DuPont to meet the requirements of the hurricane impact glazing market. Similar to PVB (polyvinyl butyral) and EVA (ethylene-vinyl acetate), it is used in laminated glass products but features a unique chemical composition that makes it more water-resistant, clearer, and stronger. This structure minimizes moisture infiltration and provides excellent adhesion, giving it a performance edge in challenging environments.

SentryGlas® vs. PVB and EVA: Key Differences

• Moisture Resistance: PVB can be sensitive to moisture, which may lead to edge defects if not properly handled. SentryGlas® is far more resistant to moisture, preventing issues like clouding or de-lamination.
• Stiffness & Strength: SentryGlas® can be up to five times stronger and 100 times stiffer than traditional interlayers, leading to more robust final products. EVA offers ease of handling, but it generally cannot match SentryGlas® in terms of sheer rigidity or clarity.
• Application Scope: While PVB and EVA remain excellent choices in many standard applications, SentryGlas® is ideal for projects requiring both high performance and long-term durability, such as hurricane-rated glazing or large-format architectural features.

Design Possibilities

Because SentryGlas® is significantly stronger and stiffer, architects can push the boundaries of glass usage in their designs. For instance, massive overhead skylights, floor-to-ceiling facades, curved balustrades, and even glass staircases all become more feasible thanks to SentryGlas®’s enhanced structural integrity. Traditional laminated glass might require additional supports or thicker glass layers, but SentryGlas® offers the potential for slimmer profiles and reduced framing requirements. The result is often a more streamlined, modern aesthetic, plus the added benefit of potentially lighter overall weight and lower material costs.

Where Is SentryGlas® Used

Initially employed to meet hurricane glazing requirements in coastal regions such as Miami-Dade County, SentryGlas® now sees a broad range of uses that extends far beyond hurricane zones. Common applications include facades, overhead glazing, balustrades, doors, and partitions, all settings where safety, clarity, and strength are paramount. Outside the architectural sphere, SentryGlas® has proven valuable in the transportation sector, including specialized vehicles that need robust, lightweight windows. Whether for security glass installations, heavy-traffic public areas, or custom enclosures (e.g., in yachts), SentryGlas® is quickly becoming an industry standard for high-performance laminated glass.

Low-Volume Production

We find that the typical customer looking to add glass lamination production to their capabilities already offers laminated glass as an option to its end users, but outsources the actual production. By bringing this process in-house, you gain full control of quality and scheduling while reducing lead times and dependence on outside suppliers. In many cases, customers also see a fast return on investment by saving on outsourcing costs.

Another benefit is that adding the ability to laminate glass allows customers to offer a wider variety of products. The Vacuum Bag Batch Lamination Ovens that Casso-Solar Technologies offers can produce standard, clear laminated glass panels as well as more specialized options. The process is nearly identical across different interlayers, such as SentryGlas®, PVB, and EVA, though cycle times and temperatures may vary.

Common Mistakes to Avoid

• Insufficient Glass Cleaning: Even minor dust or debris between layers can compromise clarity and bonding.
• Incorrect Interlayer Alignment: Misaligned layers can produce uneven edges or force you to scrap panels.
• Inaccurate Thickness Matching: Mixing different thicknesses in the same run may lead to uneven curing and inconsistent results.

These vacuum bag systems are more labor-intensive than higher-volume production lines, but the initial investment is much lower. To use these systems, a customer must first clean the glass, then lay up all the pieces into one of the provided vacuum bags. The bags are sealed and placed into the oven; in Casso-Solar’s ovens, these bags rest on pull-out trays that slide into and out of the oven for ease of access. The operator simply closes the oven doors, selects the appropriate recipe, and allows the lamination cycle to complete automatically.

SentryGlas® is particularly user-friendly in these systems. It is more forgiving than some other interlayers, making it easier to achieve consistent results. For a typical system (max glass size 84" × 144" with four trays), a customer can produce between 800–1,000 ft² of laminated glass in an 8-hour shift. Casso-Solar also builds these ovens with two independent chambers so that customers can process different product thicknesses simultaneously, eliminating bottlenecks in production.

Tip: Contact our Sales Team to find out which vacuum bag system would best fit your production volume and interlayer needs.

High-Volume Production

For companies looking to produce high volumes of SentryGlas®-laminated glass, a laminated glass production line is the preferred choice. In these scenarios, there are two main options:

1. Traditional Nip Roller Lamination Line with an Autoclave
   • Widely used across the industry
   • Produces a large variety of laminated products
   • Ideal for businesses that want maximum versatility
2. Non-Autoclave Nip Roller Lamination Line
   • Similar construction to a traditional line but without needing an autoclave
   • Saves on both initial capital expenditure (autoclaves can cost over $1 million) and ongoing operational expenses
   • Only works on low-moisture interlayers (not suitable for standard PVB)

In both cases, an up-front capital investment is necessary. All incoming glass must go through a washer, pass into a cleanroom or assembly area, and then through the nip roller. With a non-autoclave line, the product is finished at that stage. By contrast, a traditional line typically completes the lamination in an autoclave, subjecting the glass and interlayer to high temperature and pressure.

Typical Equipment in a Nip Roller Line

• Pre-Washer: Ensures the glass is free of contaminants
• Cleanroom/Assembly Area: Minimizes dust and humidity exposure
• Nip Rollers: Applies uniform pressure for bonding
• Autoclave (Optional): Finalizes lamination under heat and pressure
• Cooling Conveyor: Allows laminated glass to cool and stabilize

Casso-Solar builds both types of equipment and can assist customers with procuring all other components required for a complete setup.

Tip: Unsure which system would serve you best? Contact our team to discuss equipment configurations and find the perfect match for your capacity requirements.

Edge Cleanup

One of the benefits of SentryGlas® is its significant stiffness and strength compared to other interlayers. However, this strength can pose a challenge when it comes to cleaning up excess interlayer that may remain along the edges post-lamination. While this excess material is aesthetically undesirable, removing it can be arduous if done manually.

Casso-Solar partnered directly with Kuraray’s engineering team to develop the SentryGlas® Trim Table, which reheats the excess interlayer to soften it and make removal far easier. Depending on your workflow, using this trimming solution can cut cleanup time by up to 50% compared to purely manual methods, substantially reducing labor costs and minimizing rework.

Conclusion

Whether you’re a large-scale glass manufacturer or a smaller operation looking to bring laminated glass production in-house, Casso-Solar has the equipment and expertise to help you succeed. From our cost-effective Vacuum Bag Batch Lamination Ovens to high-volume Nip Roller Lines, we offer the full spectrum of SentryGlas® production solutions. Additionally, we’re a full-service provider, ready to support you from the initial layout and customized equipment designs all the way to installation and post-sales service. This “one-stop shop” approach ensures you can optimize your lamination processes, deliver superior products, and stand out in today’s demanding market.

Please reach out to our Sales Team to learn more about how our equipment solutions can help you expand your business, increase ROI, and offer a broader range of laminated glass products to your customers.