Our Mullion Injection Bracket is a dedicated engineering plastic fitting for the corner assembly of mullions (window middle columns) on thermal break aluminum system windows. Installed at the mullion corner joint during window fabrication, this bracket provides accurate positioning before sealant injection.

The pre-reserved injection holes guide the sealant to fully fill the corner gaps. It integrates the mullion corner structure, boosts airtightness and watertightness, and effectively prevents water leakage, dust ingress and corner loosening.

Made of high-toughness reinforced engineering plastic, this bracket features excellent compression resistance, anti-aging and UV resistance, maintaining stable performance under long-term outdoor exposure. It is widely adopted by system window manufacturers, aluminum profile factories and construction contractors.

• Precise Positioning for Glue Injection: Built-in injection holes guide smooth sealant filling to fully seal mullion corner gaps.
• Superior Waterproof & Airtight Performance: Eliminates water leakage and air penetration at window middle column corners.
• High Toughness Reinforced Plastic: High compression strength, anti-aging and UV stable for long outdoor service life.
• Structural Reinforcement: Strengthen mullion corner connection, prevent loosening, shifting and deformation.
• Easy Assembly: Perfectly matches thermal break aluminum mullion profiles, simple to mount during window production.
• OEM & Bulk Supply Available: Support custom sizes, logo marking for mass orders from window factories.

• Broken bridge thermal insulation aluminum system windows
• Aluminum window mullion / middle column corner assembly
• Residential & commercial building window projects
• Mass production in door & window manufacturing workshops

Mullion corner gaps are one of the main causes of window water leakage and air infiltration. Our Mullion Injection Bracket serves as a reliable positioning fixture for glue injection. The injected sealant forms a complete sealed layer at the middle column corner, greatly improving the structural stability and weather resistance of the whole window system.