Preface

In building waterproofing engineering, the structural design of flexible flashing tape directly determines its performance ceiling. In addition to the basic butyl rubber sealing layer, aluminum mesh interlayer is widely used as a reinforcing structure in high-performance products. Through the composite advantages of "rubber elasticity + metal strength", it meets the sealing and deformation resistance requirements in complex scenarios. Combining manufacturing processes, this article focuses on analyzing the material composition and key production links of flexible flashing tape with aluminum mesh interlayer.

Material Composition of Flexible Flashing Tape: From "Single Sealing" to "Composite Reinforcement"

1. Core Sealing Layer: Basic Properties of Butyl Rubber

As the main material, butyl rubber provides the core sealing function: the high elasticity of its molecular chain ensures adaptability to substrate deformation, and its excellent air tightness and chemical resistance can block the penetration of water vapor and oxygen, providing a stable "sealing matrix" for the aluminum mesh interlayer.

2. Functional Additives: Optimizing Interface and Weather Resistance

• Tackifier: Enhances the adhesion between butyl rubber and aluminum mesh/building substrate to avoid interlayer peeling.
• Antioxidant/Ultraviolet Absorber: Delays rubber aging and protects the aluminum mesh from corrosion.
• Softener: Adjusts the compound hardness to ensure fluidity and wrapping property when compounding with aluminum mesh.

3. Aluminum Mesh Interlayer: "Rigid Skeleton" for Structural Reinforcement

Material Characteristics: Uses thin aluminum-magnesium alloy mesh (thickness 0.1-0.3mm), featuring lightweight, high strength, and corrosion resistance. The mesh density is usually 10-20 mesh (pore size 1-2mm), balancing breathability and support.

Core Functions:

• Tear Resistance Enhancement: Increases product tensile strength (30%-50% higher than pure butyl rubber products), preventing cracks during construction or structural deformation.
• Dimensional Stability: Restrains excessive shrinkage or expansion of the rubber layer, ensuring uniform thickness and non-warping edges during long-term use.
• Puncture Resistance Protection: Resists damage from sharp objects or substrate burrs, extending service life.

Manufacturing Process of Flexible Flashing Tape

1. Raw Material Preparation: Pretreatment of Aluminum Mesh and Rubber Compound

Aluminum Mesh Pretreatment:

• Cleaning: Remove surface oil and oxide layer through alkaline cleaning to improve adhesion with rubber.
• Cutting: Slit according to product width (e.g., 50mm, 100mm) to ensure flat edges without burrs.
• Annealing (Optional): Perform low-temperature annealing on hard-state aluminum mesh to reduce brittleness and improve flexibility.

Butyl Rubber Compound Preparation: Knead butyl rubber, tackifier, filler, etc., according to the formula, and control the kneading temperature (80-100°C) to ensure uniform and fine compound.

2. Composite Molding: "Interface Fusion" of Aluminum Mesh and Rubber Compound

Lamination Compounding Process:

• Feed the pretreated aluminum mesh into the calender via guide rollers, and apply molten butyl rubber compound (temperature 120-140°C) to the upper and lower layers simultaneously.
• Through three-roll calendering (pressure 5-8 MPa), the rubber compound fully wraps the aluminum mesh, forming a "rubber layer-aluminum mesh-rubber layer" sandwich structure.
• Cooling and Shaping: Control temperature via water-cooled rollers to avoid thermal deformation of the aluminum mesh, ensuring the thickness tolerance after compounding is ≤±0.1mm.

3. Vulcanization and Slitting: Enhancing Structural Stability

Vulcanization Treatment: The composite sheet enters the vulcanizing tank and is vulcanized at 150-160°C and 0.5 MPa for 20-30 minutes to promote rubber molecular cross-linking and enhance the interface bonding force between the rubber compound and aluminum mesh.

Slitting and Trimming: Cut according to specifications to ensure no exposed aluminum mesh edges, avoiding scratches on the substrate or operators during construction.

4. Special Inspection: Quality Control of Aluminum Mesh Interlayer

• Adhesion Strength Test: Ensure the peel strength between aluminum mesh and rubber layer is ≥3N/cm through peel test (90° peel angle).
• Weather Resistance Verification: After simulated ultraviolet aging (1000h), check for no corrosion on the aluminum mesh and no cracking on the rubber layer.
• Structural Integrity Inspection: Use X-ray or ultrasonic scanning to detect defects such as poor aluminum mesh lap joints and rubber layer bubbles.

Conclusion

Through the synergistic design of "flexible sealing + rigid support", flexible flashing tape breaks through the performance bottleneck of traditional pure rubber products: in dynamically deformed parts such as roofs and curtain walls, the aluminum mesh can limit excessive stretching of the rubber layer (elongation rate controlled at 20%-30%), avoiding leakage risks caused by fatigue cracking. Meanwhile, the metal barrier property of the aluminum mesh further improves the waterproof grade, making it suitable for harsh environments such as heavy rain and strong ultraviolet radiation.

For construction enterprises, when selecting flexible flashing tape with aluminum mesh interlayer, attention should be paid to the standardization of aluminum mesh pretreatment, the stability of the compounding process, and the interface adhesion quality of the finished product—these details directly determine the long-term reliability of the product in engineering.

Kejian focuses on the R&D and production of high-performance flexible flashing tape, committed to providing customers with high-quality sealing solutions. If you have any questions about the production process, selection, or customization needs of flexible flashing tape, please feel free to contact us for professional advice and high-quality products!