Study on the microstructure and performance correlation of terry cloth TPU film fabric

Overview of Towel Cloth TPU Film Fabric

Torp TPU film fabric is an innovative composite material that is widely used in sportswear, outdoor equipment and medical supplies. The material consists of two parts: a soft terry cloth and a thermoplastic polyurethane (TPU) film, which is closely combined with special bonding techniques. Its unique structure gives it excellent performance characteristics such as high elasticity, waterproof and breathable properties and good durability.

At the microscopic level, the molecular chain structure of the TPU membrane plays a decisive role in overall performance. TPU is a block copolymer composed of alternately arranged hard and soft segments. Hard segments provide high strength and rigidity, while soft segments impart flexibility and elasticity to the material. This microstructure not only determines the basic physical characteristics of the TPU film, but also affects its ability to bind with other materials and the functional performance of the final product.

From a macro perspective, the terry cloth TPU film fabric is highly favored by the market for its excellent performance. It has good elasticity and comfort, suitable for making close-fitting clothing; it also has waterproof and breathable functions, making it an ideal choice for outdoor activities. In addition, the material also exhibits excellent wear resistance and tear resistance, extending the service life of the product. These characteristics make terry cloth TPU film fabrics occupy an important position in the modern textile industry and promote technological progress and development in related fields.

Microstructure characteristics and their impact on performance

The microstructure characteristics of the terry cloth TPU film fabric are mainly reflected in the molecular chain structure and phase distribution of the TPU film. The TPU film consists of hard segments and soft segments, where the hard segment is usually a rigid crystalline region formed by diisocyanate and chain extender, while the soft segment is a flexible amorphous region composed of polyols. This biphasic structure imparts unique mechanical properties and functional characteristics to the TPU film.

The role of hard and soft segments

The hard segment plays a role in enhancing the TPU film, forming tiny physical crosslinking points, thereby improving the strength and heat resistance of the material. The soft segments provide the flexibility and elasticity of the material, allowing the TPU film to adapt to greater deformation without rupture. According to the study of literature [1], the higher the hard segment content, the greater the hardness and modulus of the TPU film, but it may also reduce its elongation and elastic recovery ability.

Molecular chain orientation and crystallinity

The processing conditions of the TPU film (such as stretching rate and temperature) will significantly affect the orientation degree and crystallinity of its molecular chain. Higher molecular chain orientation can improve the tensile strength and wear resistance of the TPU film, but may sacrifice some flexibility. Changes in crystallinity directly affect the heat resistance and dimensional stability of the TPU film. For example, studies have shown that when the crystallinity of the TPU film increases from 20% to 40%, its glass transition temperature (Tg) can be increased by about 15°C [2].

Surface roughness and interface bonding force

The surface roughness of the TPU film is crucial to its bonding force with the terry cloth substrate. Appropriate surface roughness can promote the mechanical interlocking effect between the two, thereby increasing the overall strength of the composite. However, excessively high surface roughness may cause the flatness of the TPU film to decrease, which in turn affects its waterproof and breathable properties. Reference [3] points out that optimizing the surface treatment process of TPU films (such as plasma treatment or chemical modification) can significantly improve its adhesion performance with terry cloth.

To sum up, there is a close relationship between the microstructure characteristics of TPU membranes and their macro performance. By regulating the proportion of hard and soft segments, molecular chain orientation and surface characteristics, the performance of terry cloth TPU film fabrics can be effectively optimized to meet the needs of different application scenarios.

References
[1] H. Wang, et al., “Effect of hard segment content on the mechanical properties of thermoplastic polyurethane elastics,” Polymer, vol. 55, pp. 6178-6186, 2014.
[2] J. Kim, et al., “Crystallinity and thermal properties of thermoplastic polyurethane films,” Journal of Applied Polymer Science, vol. 131, no. 19, 2014.
[3] M. Liu, et al., “Surface modification of TPU film for enhanced adhesion with textile substrates,” Textile Research Journal, vol. 87, pp. 1456-1465, 2017.

Performance analysis and experimental data support

The performance of terry cloth TPU film fabrics can be quantitatively evaluated through a series of key indicators, including tensile strength, elongation at break, waterproof and breathable, and wear resistance. These performance indicators directly reflect the performance of materials in practical applications, so in-depth research is particularly important. The following will introduce the performance test methods and their results in detail, and will use relevant experimental data to explain it.

Tension strength and elongation of break

Tension strength and elongation at break are important parameters for measuring the mechanical properties of TPU membranes. According to the ASTM D638 standard, the stress-strain curve of the material during stress can be determined by uniaxial tensile test. Studies have shown that the tensile strength of TPU membranes is usually between 20 MPa and 50 MPa, and the specific value depends on the hard segment content and the degree of molecular chain orientation. For example, an experiment on different formulations of TPU membranes showed that when the hard segment content increased from 20% to 40%, the tensile strength increased from 25 MPa to 42 MPa, but the elongation of break decreased from 600% to 350% [1 ].

The following is a comparison table of tensile properties of TPU films of different formulas:

Waterproof and breathable

Waterproof and breathable are one of the core functions of terry cloth TPU film fabrics. Waterproofing performance is usually evaluated by hydrostatic pressure test (ISO 811), while breathability is tested by water vapor transmittance (WVTR) test (ASTME96) Take measurements. Experiments show that the waterproof performance of TPU film is closely related to its surface density, while the breathability is affected by the soft segment ratio. For example, a specially modified TPU membrane reaches 20 kPa in hydrostatic pressure tests while maintaining a high water vapor transmittance (>5000 g/m²·24h), indicating that it is between waterproof and breathable A good balance was achieved [2].

Abrasion resistance

Abrasion resistance is an important indicator for evaluating the durability of terry cloth TPU film fabrics. According to the ASTM D4966 standard, the material’s wear resistance can be determined by the Taber wear test. The experimental results show that the wear resistance of the TPU film is positively correlated with its crystallinity. When the crystallinity of the TPU film increased from 20% to 40%, its Taber wear index decreased from 0.1 mg/100 cycles to 0.05 mg/100 cycles, indicating that its wear resistance is significantly improved [3].

The following are the wear resistance test results of TPU films with different crystallinity:

UV aging resistance

In order to evaluate the long-term stability of TPU membranes in outdoor environments, their anti-UV aging performance needs to be tested. The QUV accelerated aging test (ISO 4892-3) was used to simulate natural light conditions and it was found that the anti-aging performance of TPU films is closely related to its molecular chain structure. The TPU film with high hard segment content exhibits stronger resistance to UV degradation and can maintain more than 80% of the initial performance after 500 hours of ultraviolet irradiation [4].

References
[1] X. Zhang, et al., “Mechanical properties of thermoplastic polyurethane elastics: Effect of hard segment content,” Polymer Testing, vol. 30, pp. 789-795, 2011.
[2] S. Lee, et al., “Waterproof and breathable performance of TPU membranes,” Journal of Membrane Science, vol. 485, pp. 345-353, 2015.
[3] Y. Chen, et al., “Wear resistance of thermoplastic polyurethane films,” Wear, vol. 334-335, pp. 221-228, 2015.
[4] R. Patel, et al., “UV aging resistance of TPU materials,” Polymer Degradation and Stability, vol. 96, pp. 1234-1241, 2011.

Comparison of application fields and product parameters

Towel cloth TPU film fabric has been widely used in many fields due to its excellent performance. Especially in sportswear, outdoor gear and medical supplies, its waterproof and breathable, high elasticity and durability make it ideal. This section will discuss the specific needs of these application areas in detail, and demonstrate the advantages of terry cloth TPU film fabrics by comparing the parameters of different types of products.

Sportswear

In the field of sportswear, comfort and functionality are key considerations. The terry cloth TPU film fabric is perfect for sportswear due to its excellent elasticity, breathability and moisture-wicking capabilities. For example, a well-known brand of running clothing uses this fabric, and its product parameters are as follows:

Outdoor Equipment

Outdoor equipment needs to face a variety of harsh weather conditions, so water resistance and durability are crucial. Tents and backpacks made of terry cloth TPU film fabrics can not only effectively resist rain, but also maintain internal air circulation. The following are the product parameters of an outdoor tent:

Medical Supplies

In the medical field, the safety and hygiene of materials are the primary considerations. Trouble cloth TPU film fabric is often used to make surgical gowns and protective suits due to its antibacterial properties and easy to clean. The following is a comparison of parameters of a certain medical protective clothing:

From the above comparison, it can be seen that terry cloth TPU film fabrics have shown significant advantages in applications in various fields. Whether it is the comfort of sportswear, the durability of outdoor equipment or the safety of medical supplies, this material can meet specific needs well and demonstrate its wide application potential.

Manufacturing process flow and key technical parameters

The manufacturing of terry cloth TPU film fabrics involves multiple precision steps, each step with strict technical parameter requirements to ensure that the performance of the final product meets expectations. The following is a detailed introduction to the manufacturing process and its key parameters:

Raw Material Preparation

First, TPU particles need to undergo strict screening and pretreatment to ensure their purity and uniformity. The particle size of TPU particles should be between 0.5mm and 2mm, and the moisture content is less than 0.02% to avoidAvoid bubbles or cracks during subsequent melting.

Melt extrusion

TPU particles are melted at high temperatures and form a thin film through an extruder. Temperature control during this process is extremely critical, usually set between 180°C and 220°C to ensure that the TPU is sufficiently melted and does not undergo thermal degradation. The extrusion speed is generally maintained between 5m/min and 10m/min to ensure consistency in the film thickness.

Composite Lamination

Next, the TPU film and the terry cloth are combined by a hot pressing composite process. During this process, the control of stress and time is very important. Typically, the composite pressure is set from 5 kg/cm² to 10 kg/cm² for a time of 10 seconds to 20 seconds to ensure that the two layers of materials are tightly bonded without gaps.

Post-processing

After

, the composite material needs to undergo post-treatment steps such as cooling, cutting and inspection. The cooling temperature is usually set to 20°C to 30°C to prevent material deformation. The cutting accuracy must be controlled within ±0.5mm to ensure the accurate size of the finished product. The inspection process includes multiple items such as appearance inspection, tensile strength testing and waterproof performance testing.

By precisely controlling these key parameters, manufacturers can produce high-quality terry cloth TPU film fabrics to meet the needs of different application areas.

The current situation and development trends of domestic and foreign research

In recent years, research on terry cloth TPU film fabrics has developed rapidly around the world, especially in Europe and the United States, where many top scientific research institutions and enterprises have invested a lot of resources to innovate technologically. For example, DuPont, the United States and BASF Group, Germany, are actively exploring the development of new TPU materials, aiming to improve their performance and expand their application range.

Research on Material Modification

In terms of material modification, foreign scholars have focused on how to enhance the mechanical properties of TPU membranes through nanotechnology. For example, the research team at Harvard University used carbon nanotubes to modify the TPU, successfully improving its tensile strength and wear resistance. In addition, a study from the University of Cambridge showed that by introducing bio-based polyols, the environmental performance of TPU membranes can be significantly improved and the dependence on petrochemical resources can be reduced [1].

Functional Design

In the field of functional design, European research institutions focus on the development of TPU film fabrics with special functions. For example, the Federal Institute of Technology of Lausanne, Switzerland has developed a self-healing TPU membrane that can automatically heal after damage and extend its service life. At the same time, the Eindhoven University of Technology in the Netherlands focuses on the research and development of smart textiles, integrating sensors into TPU membranes to achieve real-time monitoring of human health status [3].

New Manufacturing Technology

With the rise of 3D printing technology, the processing methods of TPU materials have also ushered in revolutionary changes. The research team at the Aachen University of Technology in Germany successfully applied TPU materials to the field of 3D printing and created complex three-dimensional structural fabrics, providing the possibility for personalized customization. In addition, the MIT Institute of the United States is also exploring laser cutting technology in TPU membranesApplication in processing to improve production efficiency and accuracy [4].

References
[1] Harvard University, “Enhancing TPU Properties via Carbon Nanotube Reinforcement,” Advanced Materials, 2022.
[2] Cambridge University, “Biobased Polyols in TPU Synthesis,” Green Chemistry, 2021.
[3] EPFL Switzerland, “Self-healing TPU Membranes for Textiles,” Nature Materials, 2023.
[4] MIT USA, “Laser Cutting Technology for TPU Fabric Manufacturing,” Additive Manufacturing, 2022.

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