When storing, transferring, or shipping glass products, manufacturers face a simple but crucial challenge: preventing damage from scratching, staining, sticking, or fogging between sheets. That’s where interleaving powders come in. These specialized powders form a protective barrier between stacked sheets of glass, helping maintain clarity, quality, and structural integrity.
Two common additives used in interleaving powders are adipic acid and boric acid. While both can be effective, understanding the differences between them can help buyers and business owners make informed decisions for their operations.
In this blog, we’ll cover:
- Chemical properties
- Performance in interleaving applications
- Safety and environmental concerns
- Which acid may be better suited for specific glass types.
Understanding the Chemical Properties
Adipic Acid (C₆H₁₀O₄) is an organic dicarboxylic acid best known for its role in producing nylon, but it also finds applications as a food additive and lubricant. In interleaving powders, adipic acid serves as both a mild abrasive and a lubricant. It creates a fine, dry layer between glass sheets, reducing friction while helping prevent scratches.
Boric Acid (H₃BO₃) is a weak inorganic acid used in various industrial and household products. It provides flame-retardant and antiseptic properties. In interleaving powders, boric acid forms a smooth, slippery layer between glass sheets, which reduces friction and static build-up. It also provides anti-fungal and anti-static benefits, making it particularly useful in environments where humidity is a concern.
Performance in Glass Interleaving Applications
The choice between adipic acid and boric acid often depends on the type of glass and storage conditions.
Adipic Acid-Based Powders are widely used in applications where clarity is critical. For example, float glass and low-iron glass, commonly used in architectural and automotive settings, benefit from adipic acid’s clean finish.
Boric Acid-Based Powders perform especially well in humid conditions or in environments where static electricity might cause glass sheets to stick together. For tempered glass, which is often used in shower doors, appliance glass, and safety panels, boric acid can provide that extra layer of anti-static and anti-fungal protection. Its lubricating properties also ease the separation of sheets during handling.
Safety and Environmental Considerations
For many buyers, safety and sustainability are key factors.
Adipic acid is generally considered safer for both human handling and the environment. Being biodegradable* and food-safe in certain contexts, it doesn’t require extensive protective measures when used in glass manufacturing environments. It aligns well with companies looking to meet green manufacturing standards or reduce workplace exposure risks.
Boric acid, while effective, carries more handling precautions. In larger quantities, it can pose health risks if inhaled or ingested. Regulatory agencies in some regions classify boron compounds under restricted use categories. This means that companies may need to provide extra training or protective equipment for employees handling boric acid-based powders.
*Disclaimer – While adipic acid itself is biodegradable and considered food-safe in certain contexts, interleaving powders typically contain additional ingredients such as PMMA beads or polyethylene beads. These components are not biodegradable and may have different environmental and handling considerations. Always review the full composition and safety data of any interleaving powder product before use.
Choosing the Right Interleaving Powder for Your Glass Type
There is no one-size-fits-all answer. Selecting the appropriate interleaving powder depends on several factors, including glass type, storage duration, environmental conditions, and processing requirements. Interleaving powders are not a one-size-fits-all solution; each formulation is carefully engineered to match specific needs.
For float glass, low-iron glass, and tempered glass, where surface clarity and minimal residue are essential, adipic acid-based powders can be a good option. Their organic composition and mild abrasive properties help maintain a clean, clear finish while protecting against scratches during stacking, shipping, and storage. We offer a few different powders with adipic acid, such as TEK-A50, TEK-A55, and TEK-A75, that demonstrate these qualities, offering different mixtures of adipic acid and acrylic beads ideal for glass stored in moderate humidity for short to medium durations.
When it comes to tempered glass, float glass, or situations involving high-humidity storage, boric acid-based powders often provide an advantage. Boric acid helps prevent surface corrosion, static build-up, and fungal growth, all of which are critical concerns in these conditions. For example, TEK-B50 and TEK-B35 are specifically designed blends incorporating boric acid alongside PMMA beads, making them suitable for long-term storage in more challenging environments.
Additionally, for specialty applications or where interleaving powders must integrate with automated handling systems, considering particle size and blend ratios is key. Powders like TEK-SC-110+ and TEK-C-UHPE are formulated for specific coated glass types, ensuring both mechanical separation and coating protection.
Ultimately, choosing between adipic acid and boric acid interleaving powders comes down to evaluating your specific production and storage requirements. If environmental impact and ease of use are top priorities, adipic acid-based powders may align better. If controlling static, moisture, and corrosion over longer storage periods is critical, boric acid-based blends may offer the best performance.
Partnering with Powder Technology Inc.
At Powder Technology Inc., we understand the nuances of glass manufacturing and protection. We offer a wide range of interleaving powders formulated with adipic acid, boric acid, PMMA/EA copolymer beads, as well as Ultra High Molecular Weight Polyethylene (UHMWPE) with micro-traces of flow enhancer added to suit different applications and preferences.
If you’re unsure which solution is the best fit for your business, our team is here to help. We welcome the opportunity to learn more about your needs and can recommend the right product for your operation. Contact us today at 952-894-8737 or email sales1@powdertechnologyinc.com to learn more about our capabilities and how we can best help you.
