The vacuum silicone bag is an indispensable tool in glass lamination ovens, especially for producing safety glass with EVA or PVB interlayers. Over the years, its design, materials, and performance have undergone significant evolution to meet the industry’s increasing demands for quality, efficiency, and durability.
1. Early Stages – Simple Heat-Resistant Covers
In the early days of laminated glass production, manufacturers relied on basic heat-resistant fabrics or improvised sealing methods to hold the glass layers together during heating. These methods offered limited flexibility and sealing efficiency, often resulting in air bubbles, uneven lamination, and lower product quality.
2. Introduction of Rubber-Based Bags
As glass lamination technology advanced, rubber-based vacuum bags began to replace fabric covers. Natural rubber provided better elasticity and sealing compared to fabrics, but it suffered from poor heat resistance and degraded quickly at the high temperatures required for lamination, especially with PVB films.
3. Rise of Silicone Vacuum Bags
The breakthrough came with the introduction of silicone rubber. Silicone offered exceptional heat resistance (up to 250°C), excellent elasticity, and chemical stability, making it ideal for repeated use in high-temperature ovens. Early silicone bags were single-layer designs that provided better sealing and more consistent vacuum distribution, greatly improving lamination quality.
4. Modern Reusable Silicone Vacuum Bags
Today’s silicone vacuum bags have evolved into multi-layer, reinforced constructions. Many feature fabric reinforcement within the silicone to enhance tensile strength and extend service life. Modern designs also use precision-molded sealing edges and custom-fit dimensions to suit various glass oven models. These improvements have allowed for hundreds of production cycles before replacement, reducing downtime and cost.
5. Current Trends and Future Outlook
Recent developments focus on improved EVA and PVB resistance, as some interlayer materials tend to stick to silicone after prolonged use. Surface treatments and special coatings are being developed to reduce sticking, improve cleaning, and extend the bag’s lifespan. With the growth of solar panel glass and decorative laminated glass, demand for specialized silicone vacuum bags will continue to rise.
Conclusion
From basic coverings to advanced reusable silicone designs, the evolution of the vacuum silicone bag has been driven by the need for higher quality, greater efficiency, and longer service life in glass lamination ovens. This innovation continues to play a key role in modern laminated glass production.
