TPU
The best adhesive for TPU is typically High-Strength Epoxy, with excellent bond strength. As a plastic material, TPU has unique bonding characteristics that require specific adhesive selection. Common applications include phone-cases,footwear,tubing.
Bonding TPU requires understanding its unique surface properties and chemical characteristics. As a plastic material, TPU presents specific challenges that can be overcome with the right adhesive selection and proper surface preparation techniques. This comprehensive guide provides expert recommendations, bond strength data, and step-by-step instructions to achieve strong, durable bonds with TPU.
Material Properties & Characteristics
TPU exhibits medium surface energy, which allows for good adhesion when proper surface preparation is performed. The low nature of TPU presents bonding considerations that depend on surface preparation and adhesive selection. As a flexible material, TPU requires adhesives that can accommodate movement and stress without cracking or delamination. Flexible polyurethanes and silicones are typically preferred over rigid epoxies. The high chemical resistance of TPU makes it resistant to degradation from solvents and chemicals, but also makes it challenging to bond because it resists interaction with adhesive chemicals. Specialized primers and surface treatments are often necessary. Understanding these fundamental properties is essential for selecting the appropriate adhesive and surface preparation method.
Surface Preparation Best Practices
Achieving strong, durable bonds with TPU depends heavily on proper surface preparation. Begin by cleaning all bonding surfaces with appropriate cleaners to remove dirt, oils, and surface contaminants. Ensure surfaces are at room temperature (15-25°C or 60-80°F) for optimal bonding conditions. Temperature extremes can affect adhesive flow, wetting, and cure times. Apply adhesive within minutes of surface preparation to prevent recontamination from dust, moisture, or oils. Proper surface preparation significantly improves bond strength, durability, and long-term performance.
Why TPU Requires Special Attention to Bond
Flexible Material
Flexible materials require elastic adhesives that can withstand movement and stress without cracking or delaminating. Avoid rigid epoxies in favor of flexible polyurethanes or silicones.
Chemical Resistance
Materials with high chemical resistance are difficult to bond because they resist interaction with adhesive chemicals. Mechanical abrasion and specialized primers help improve adhesion.
Surface Preparation Guide
Proper surface preparation is critical for achieving strong, durable bonds with TPU. Follow these steps:
- Clean with soap and water or degreaser to remove dirt and oils
- Dry thoroughly before applying adhesive
- Ensure surfaces are at room temperature (60-80°F) for optimal bonding
- Apply adhesive within minutes of surface preparation for best results
Basic Information
Category
plastic
Surface Energy
medium
Surface Type
non-porous
Flexibility
flexible
Porosity
low
Chemical Resistance
high
Chemical Information
CAS Number
9009-54-5
Aliases
thermoplastic polyurethane
Chemical Composition
- thermoplastic polyurethane (100%)
Common Uses
phone-cases,footwear,tubing