Which raw materials are commonly used to produce hot melt TPU film?

Overview of Hot Melt TPU Film Raw Materials

Hot Melt TPU Film is a thermoplastic polyurethane material widely used for bonding, laminating, and coating applications due to its excellent flexibility and adhesion properties. The performance and characteristics of the film largely depend on the raw materials used in its production. Understanding these components can help manufacturers optimize film properties for specific applications.

Primary Components of Hot Melt TPU Film

The production of Hot Melt TPU Film generally involves three main categories of raw materials: polyols, diisocyanates, and chain extenders. Each plays a specific role in determining the physical, chemical, and adhesive properties of the final film.

Polyols

Polyols act as the soft segment in TPU, providing flexibility, elasticity, and thermal stability. Commonly used polyols include:

• Polyether polyols: Offer excellent hydrolysis resistance and flexibility.
• Polyester polyols: Provide superior mechanical strength and abrasion resistance.
• Polycaprolactone polyols: Ensure good elasticity and low-temperature performance.

Diisocyanates

Diisocyanates form the hard segment of TPU and are responsible for high tensile strength and adhesive properties. Common diisocyanates include:

• MDI (Methylene Diphenyl Diisocyanate): Provides excellent mechanical performance and thermal stability.
• TDI (Toluene Diisocyanate): Offers good processing flexibility and adhesion.
• HDI (Hexamethylene Diisocyanate): Used for special applications requiring non-yellowing properties.

Chain Extenders

Chain extenders connect the soft and hard segments in TPU, improving molecular weight and film strength. Common chain extenders include:

• Butanediol (BDO): Provides high tensile strength and abrasion resistance.
• Ethylene Glycol (EG): Enhances flexibility and processing properties.
• Hexanediol (HDO): Improves low-temperature performance and elasticity.

Additives and Functional Materials

To improve the performance of Hot Melt TPU Film, manufacturers often include additional additives. These materials can enhance UV resistance, color, adhesion, and processability.

• Stabilizers: Prevent thermal and UV degradation during processing and use.
• Plasticizers: Improve flexibility and reduce brittleness at low temperatures.
• Colorants: Provide desired transparency or coloration for aesthetic or functional purposes.
• Antioxidants: Protect the film from oxidation and maintain long-term performance.

Comparison of Raw Material Properties

Conclusion

The selection of raw materials for Hot Melt TPU Film directly impacts its physical properties, adhesion, and processing performance. By understanding the roles of polyols, diisocyanates, chain extenders, and additives, manufacturers can tailor the film for specific industrial applications, from footwear laminates to protective coatings and medical devices.