What Is Interleaving Powder?
Interleaving powder is a fine, dry material applied between glass sheets during stacking. Its main function is to create a buffer that prevents direct glass-to-glass contact. This protective barrier helps eliminate scratching, sticking, and other damage that can occur during handling, shipping, or storage.
The powder’s physical properties, such as particle size and chemical composition, are carefully engineered to meet the specific needs of different types of glass, such as soft-coated, hard-coated, float, or tempered glass.
Why Glass Sheets Need Protection
Glass surfaces, especially specialty coatings like low-emissivity (low-E) or sputter coatings, are sensitive to friction and pressure. When stacked without separation, even minor vibrations or shifts can cause micro-abrasions, scratches, or irreversible surface damage.
Interleaving powder acts as a cushion, maintaining a slight gap between layers. This not only protects the integrity of each sheet but also improves de-stacking, especially in automated handling systems.
Alternatives to Interleaving Powder
While interleaving powders are a common and effective solution for glass separation, some manufacturers also use alternative materials such as paper interleaving sheets or polyethylene films. These materials provide a physical barrier between glass sheets and can be effective in preventing scratching and contamination. However, they come with trade-offs. Sheets and films are more expensive, can be labor-intensive to apply or remove, and may not perform as well in high-humidity environments where moisture can become trapped. Interleaving powders, on the other hand, are more cost-efficient, allow for faster stacking and de-stacking, and are better suited for automation. That said, powders require careful application and appropriate storage conditions to avoid caking or uneven distribution. Ultimately, the choice between powder and alternative materials depends on the specific type of glass, handling process, storage time, and cost considerations.
Interleaving Powder’s Offered
At Powder Technology Inc., interleaving powders are formulated with specific use cases in mind.
TEK-SC-110+
Best for: Soft-coated glass
Designed for soft-coated (sputter-coated) glass, this powder is composed of PMMA/EA copolymer beads. The tight particle size distribution (mean: 112 ± 7 microns) ensures uniform application and consistent separation. A micro amount of flow enhancer is added to aid with even distribution across automated systems. Its resilient copolymer structure is gentle on delicate coatings, reducing the risk of damage during stacking and shipping.
TEK-SC-110
Best for: Soft-coated glass
Designed for soft-coated (sputter-coated) glass, this powder is composed of PMMA/EA copolymer beads. The tight particle size distribution (mean: 112 ± 7 microns) ensures uniform application and consistent separation. Its resilient copolymer structure is gentle on delicate coatings, reducing the risk of damage during stacking and shipping.
TEK-C-UHPE
Best for: Hard Coated glass
Recommended for hard coat glass, TEK-C-UHPE is 100% ultra-high molecular weight polyethylene (UHMWPE) with micro-traces of flow enhancer for consistent application. With a mean particle size of 118 microns (±18 microns), it provides durable separation and protection for coated glass surfaces.
TEK-C-47GS
Best for: Coated glass (wide variety)
Recommended for a wide range of coated glass types, TEK-C-47GS is a PMMA/EA copolymer with micro-traces of flow enhancer for consistent application. With a tightly controlled particle size distribution averaging 128 microns (ranging from 110 to 148 microns), it provides effective separation while minimizing surface damage to delicate coatings.
TEK-B50
Best for: Float and tempered glass
Ideal for float and tempered glass stored in moderate to high humidity, TEK-B50 is a 50/50 blend of boric acid and PMMA acrylic beads. The PMMA beads provide separation while the boric acid helps prevent surface corrosion. With a mean particle size of 135 microns (±15 microns), TEK-B50 flows freely and is easily washed off with water under 40°C, making it a reliable choice for maintaining glass surface quality over extended periods.
TEK-B35
Best for: Float and tempered glass
Formulated for float and tempered glass stored for extended periods in high humidity, TEK-B35 is a blend of 35% boric acid and 65% PMMA acrylic beads. The acrylic beads maintain physical separation while the boric acid combats surface corrosion. With a mean particle size of 146 microns (±15 microns), TEK-B35 flows freely and can be easily removed with water under 40°C, offering durable protection for sensitive glass applications.
TEK-APE50
Best for: Hard coat glass and float glass
Designed for use with hard coat glass and often paired with liquid stain inhibitors on uncoated glass, TEK-APE50 is a 50/50 blend of adipic acid and polyethylene beads. The polyethylene provides effective spacing while the adipic acid helps resist surface corrosion. With a mean particle size of 120 microns (±25 microns), TEK-APE50 is less free-flowing than acrylic-based powders and requires closer attention to dispensing and wash system maintenance. It washes off easily with water around 40°C, though filtering is important due to the buoyant nature of polyethylene beads.
TEK-A75
Best for: Float and tempered glass
Formulated for float and tempered glass stored for several months in humid environments, TEK-A75 is a modified interleaving blend containing 75% adipic acid and 25% acrylic (PMMA) beads. The high acid content offers strong corrosion resistance, while the PMMA beads provide mechanical separation. Due to the low bead ratio, a heavier application—typically 300 to 350 mg/m²—is recommended. TEK-A75 washes off easily with water around 40°C and should be stored in stable, low-humidity conditions for optimal performance.
TEK-A55
Best for: Float and tempered glass
Recommended for float and tempered glass, TEK-A55 is a blend of 55% adipic acid and 45% acrylic (PMMA) beads. The slightly larger bead size (mean: 134 ± 28 microns) helps create a greater gap between glass sheets, improving the effectiveness of robotic destacking systems. This powder is also water-soluble and easy to wash off after use, typically at temperatures around 40°C.
TEK-A50
Best for: Float and tempered glass
TEK-A50 is a balanced 50/50 blend of adipic acid and acrylic (PMMA) beads designed for float and tempered glass stored for weeks to a few months. The PMMA beads ensure physical separation while adipic acid helps resist surface corrosion. With a mean particle size of 156 microns (range: 127–169 microns), TEK-A50 applies well at 200–250 mg/m² and washes off easily with water around 40°C, offering consistent and dependable performance.
Final Thoughts
Interleaving powder may seem like a small detail in the grand scale of glass manufacturing, but its impact is significant. By minimizing surface damage, enhancing automation compatibility, and ensuring the long-term integrity of glass products, interleaving powders help glass manufacturers meet high standards of quality and reliability. To see more information on the powders we offer such as Technical Data Sheets,
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If your business requires glass packaging solutions, PTI’s expertise can provide the answers that you are looking for! 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.
