Is your production experiencing high rates of losses due to stains on laminated glass in your inventory? Is glass delaminating more frequently than expected? These problems, which directly impact your revenue, may have a common, silent, and invisible cause: ambient humidity.
As a manager in the glass industry, you know that every rejected sheet of glass hits the bottom line. Pinpointing the root cause of these defects is more than a technical task—it's a strategic imperative to protect your product quality, maintain customer trust, and secure the financial stability of your operation. We understand how issues like iridescence and delamination can jeopardize an entire production run and strain your budget.
Long before it impacts your finances, humidity leaves distinct warning signs on the glass surface and within its structure. Recognizing these symptoms early is the first step toward an accurate diagnosis and an effective solution.
Specific to laminated glass (both standard and bulletproof), this is one of the most serious defects. It occurs when polymer layers (PVB/EVA) lose adhesion to the glass, creating air bubbles and layer separation.
Opaque or rainbow-like stains that appear on the glass surface, especially in stacked sheets. This is one of the most common defects and a clear sign of a surface chemical reaction.
The glass loses its shine and transparency, acquiring a whitish or foggy appearance that cannot be removed by cleaning.
Humidity attacks the reflective metallic layer of mirrors, causing dark stains and oxidation, especially along the edges.
Visual defects are just the tip of the iceberg. The real impact of uncontrolled humidity is measured in financial losses that erode your operation’s profit margin.
“It is estimated that losses due to delamination can reach 7% of production, while rejection due to irisation and alkaline corrosion can affect up to 12% of batches in industries without proper humidity control. Additionally, delamination in bulletproof glass can compromise ballistic resistance by up to 20%, an unacceptable risk for safety”, says Sven von Borries, CEO of Thermomatic.
The cost manifests in several ways:
Disposal of sheets and entire batches that do not meet quality standards;
Labor and energy costs to recover or replace defective products;
Costs associated with reverse logistics and, mainly, damage to your brand reputation in the market;
Higher premiums may apply due to the elevated risk of product failure, especially in safety applications such as bulletproof glass.
Precise environmental control over relative humidity, temperature, and airborne particulates has a direct and measurable impact on your operational efficiency. By implementing desiccant dehumidification systems—fully integrated with fan coils, advanced filtration, and automation—you can dramatically lower batch rejection rates and eliminate costly rework caused by delamination, iridescence, and other optical flaws.
Although it appears inert, the glass surface chemically reacts with water molecules (H₂O) present in the air. This reaction, called hydrolysis, forms a microscopic silanol layer (Si–OH) that alters the glass properties. This silanol layer is the starting point for all problems:
In laminated glass, this surface layer is exactly where polymers (PVB, EVA) should bond. The presence of humidity prevents maximum adhesion, causing delamination;
In high humidity and temperature environments, sodium ions (Na⁺) from the glass composition migrate to the surface. This alkaline reaction causes irisation and permanent stains.
“In the glass industry, environmental control is a requirement, not just a precaution. It's essential for preventing defects like stains and bubbles in tempered and coated glass. For lamination specifically, precise control of humidity, temperature, and particulates is the only way to guarantee perfect PVB adhesion and prevent costly failures” says Leandro Nahas, Engineering Manager at Thermomatic.
To effectively neutralize the impact of humidity, your solution must be just as precise as the problem. The only proven method to stop hydrolysis and its damaging consequences is to maintain strict relative humidity (RH) control across all production and storage environments.
Beyond humidity, airborne microparticles are another critical factor in lamination environments. Dust in the air can adhere to PVB or EVA before fusion, causing optical imperfections, delamination, and adhesion failures between glass layers.
In the glass industry, humidity control in the production process must be tailored to the environment and the type of defect identified. Thermomatic offers specific solutions for each situation:
The desiccant dehumidifier, together with the fan coil and filtration unit, also acts as an air purification element it pulls air with suspended particles and dust, traps these impurities in internal filters, and returns clean, dry air to the environment. In glass industry applications, this step is essential to maintain a controlled environment for PVB and EVA, protecting adhesion and transparency.
The desiccant system produces two air streams: cool, treated air that enters the cleanroom, and hot, moist regeneration air that is exhausted externally. To maintain a stable environment, this process must be perfectly synchronized with your primary HVAC system (fan coils or self-contained units). This synergy ensures both the room temperature and the relative humidity in critical areas, like lamination and pre-sealing, are precisely controlled, achieving a consistent thermal and hygrometric balance.
Controlling humidity means:
With integrated solutions, Thermomatic ensures humidity control stability, loss reduction, and technical compliance with the strictest glass industry standards.
Meeting the world's most stringent quality and safety standards in the glass industry requires more than just best practices—it demands effective humidity control. This ensures superior product quality and operational consistency, giving you a significant competitive advantage.
Our systems help you adhere to the globally recognized principles that govern the manufacturing of high-performance glass:
Industry standards demand strict environmental control during assembly to ensure flawless adhesion and optical clarity. This typically involves maintaining low relative humidity (e.g., RH ≤ 30%) and stable temperatures;
Best practices require storing tempered glass in a climate-controlled environment, free from humidity and dust, to preserve its mechanical strength and flawless surface finish;
Quality standards focus on preventing internal condensation and ensuring the unit's longevity. This is achieved by controlling the dew point inside the air chamber, which starts with dry assembly conditions;
To protect delicate metallic or low-E coatings from degradation, global manufacturing protocols specify storage in dry, ventilated areas with strict temperature and RH monitoring;
To prevent oxidation and defects like "black edge," industry guidelines mandate that processing and handling occur in environments free from excessive humidity and corrosive agents;
The performance of multi-layered security glass hinges on perfect interlaminar adhesion. Manufacturing standards require tightly controlled environmental conditions to guarantee ballistic integrity and prevent delamination.
Partnering with Thermomatic equips your facility to surpass critical industry benchmarks, guaranteeing a robust and reliable production process from end to end.
Investing in precise humidity control is a strategic decision that delivers a clear, measurable return on investment (ROI) through:
Don't let an invisible factor like humidity continue to create visible losses on your balance sheet. It's time to address the root cause of the problem and protect your bottom line.
Prefer a personalized analysis? Schedule a no-obligation consultation with one of our engineers and learn how industrial dehumidification solutions can be applied to your operation.
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