Overview of the principles of waterproof and breathable technology of towel cloth TPU film fabric
Tornament TPU film fabric is an innovative composite material that combines textile technology and polymer material science, and is widely used in outdoor equipment, sports clothing and medical protection fields. This fabric achieves excellent waterproofing and good breathability by combining TPU (thermoplastic polyurethane) film with a terry cloth substrate. Its core principle lies in the microporous structure design of the TPU film, which allows water vapor molecules to pass through and prevent liquid water from penetration, thus providing reliable protection while maintaining comfort.
TPU film, as a functional film material, has excellent elasticity, wear resistance and chemical corrosion resistance. It is evenly attached to the surface of the terry cloth through a special process, forming a protective layer that is both thin and strong. This composite process not only enhances the overall physical properties of the fabric, but also gives it unique functional characteristics. Specifically, the microscopic pore diameter of the TPU membrane is much smaller than the size of the liquid water droplets, but is enough to allow smaller water vapor molecules to pass smoothly, which is the so-called “selective transmission” mechanism. This feature allows the terry cloth TPU film fabric to maintain a dry and comfortable state in harsh environments.
In addition, the development of this fabric involves cross-disciplinary technical support, including knowledge in the fields of materials science, fluid mechanics, and textile engineering. For example, in actual production, it is necessary to accurately control the thickness, porosity and composite process parameters of the TPU film to ensure that the performance of the final product meets the expected goals. These technical details not only determine the functional performance of the fabric, but also directly affect its market competitiveness and application scope.
The following content will discuss in detail the waterproof and breathable technology principle of terry cloth TPU film fabric, analyze its key parameters, and quote relevant literature to support the discussion, aiming to provide readers with a comprehensive and in-depth understanding.
The microstructure of TPU membrane and its influence on waterproof and breathable performance
The core function of the TPU membrane is derived from its unique microstructure, which directly determines its waterproof and breathable performance. According to the study, TPU membranes are usually composed of a continuous network of polymers and micropores dispersed therein, and the size and distribution of these micropores play a crucial role in gas permeability and liquid barrier properties. According to a study by the Massachusetts Institute of Technology (Smith et al., 2019), the micropore diameter of TPU membranes is generally between 0.1 and 10 microns, a range that just satisfies water vapor molecules (about 0.0004 nanometers) Free pass requirements while effectively blocking the penetration of liquid water droplets (usually greater than 20 microns).
Analysis of Characteristics of Microstructure
| parameter name | Description | Typical value range |
|---|---|---|
| Porosity | Indicates the proportion of micropores occupying the total volume of the material | 30%-60% |
| Pore size | Key factors that determine gas permeability and liquid barrier properties | 0.1-10μm |
| Continuity | Whether the micropores are connected to each other, affecting the overall breathability efficiency | High Connectivity |
As can be seen from the table, the higher the porosity of the TPU film, the better its breathability; however, excessive porosity may reduce the mechanical strength of the material, so optimized balance is required at design time. In addition, the continuity of micropores is also one of the important factors that determine the breathable effect. If an effective communication channel cannot be formed between the micropores, ideal gas exchange efficiency cannot be achieved even if the pore size is appropriate.
Physical barrier mechanism
The waterproof performance of TPU membranes depends mainly on the size limitations of their micropores. According to a study by Delft University of Technology in the Netherlands (Van der Meer, 2020), when liquid water contacts the surface of the TPU membrane, due to the effect of surface tension, water droplets will be limited to a larger scale range and cannot enter the micropores due to the effect of surface tension and will not enter the micropores. internal. In contrast, the body of water vapor molecules is actively small and can easily pass through these micropores, thus achieving the effect of “only breathable and not water permeable”. This phenomenon can be explained by classic capillary management theory: Only when the external pressure exceeds a certain critical value can the liquid overcome the surface tension and enter the micropores, and under normal conditions, the TPU membrane can effectively prevent moisture penetration.
In addition, the hydrophobic modification treatment of the TPU membrane further enhances its waterproofing ability. By introducing fluorinated or siloxane-like substances on the surface of the film, the water contact angle can be significantly reduced, making the water droplets more likely to slide off without residue. This modification technology has been widely used in the manufacturing of high-performance waterproof and breathable fabrics.
To sum up, the microstructure design of the TPU membrane is the basis of its waterproof and breathable performance. By accurately controlling the pore size, porosity and surface characteristics, selective permeability of gases and liquids can be achieved, providing solid technical support for subsequent application development.
Influence of composite process on the performance of terry cloth TPU film fabric
In the production process of terry cloth TPU film fabrics, the composite process plays a crucial role. This link not only determines the bonding strength between the TPU film and the terry cloth substrate, but also directly affects the waterproof and breathable performance and other physical characteristics of the final product. At present, mainstream composite processes include hot press composite, coating composite and vacuum bonding, and each method has its own unique advantages and limitations.
Hot press compositeCrafts
Hot pressing composite is a process in which the TPU film is tightly bonded to the towel cloth after heating to a softened state. The advantage of this method is that it is simple to operate and low cost, and is suitable for large-scale industrial production. However, the control of temperature and pressure during hot pressing is crucial, and excessively high or too low parameter settings can lead to adverse consequences. For example, if the temperature is too high, it may cause partial melting of the TPU film and clogging of the micropores, thereby weakening the breathable performance; while insufficient pressure will make the bond between the film and the substrate not firm enough, affecting the service life.
| parameter name | Best range | Impact |
|---|---|---|
| Temperature | 180°C – 220°C | Control the degree of softening of TPU membrane |
| Suppressure | 20 – 40 bar | Ensure full bonding |
| Time | 5 – 15 seconds | Balanced efficiency and quality |
Study shows that terry cloth TPU film fabrics produced by hot press composite process have excellent performance in tensile strength (Johnson & Lee, 2018). This is because under high temperature and high pressure conditions, the TPU film can better penetrate into the fiber gap of the terry cloth, forming a mechanical interlocking structure, thereby enhancing overall stability.
Coating composite process
The coating composite is to form a film by applying a liquid TPU solution evenly on the surface of the terry cloth, and then undergoing drying and curing steps. The advantage of this method is that it can flexibly adjust the thickness and uniformity of the TPU film, and is especially suitable for application scenarios with high requirements for breathability. However, it is difficult to control the solvent volatility rate and coating thickness during the coating process, and a slight inattention may lead to surface defects or performance degradation.
| parameter name | Best range | Impact |
|---|---|---|
| Solution concentration | 10% – 20% | Determine the film thickness |
| Drying temperature | 120°C – 160°C | Prevent solvent residue |
| CureTime | 10 – 20 minutes | Ensure complete chemical crosslinking |
An experiment at the Fraunhof Institute in Germany showed that the terry cloth TPU film fabric prepared using a coating composite process performed well in breathability tests, with a water vapor transmittance of up to 20,000 g/m²/ More than 24 hours (Klein et al., 2021). This is due to the precise control of the coating thickness, allowing the micropore structure to be completely retained.
Vacuum bonding process
Vacuum bonding is a relatively advanced composite technology that uses the negative pressure in a vacuum environment to closely adhere the TPU film to the surface of the terry cloth. This method can effectively avoid possible heat damage problems during traditional hot pressing, while ensuring higher bonding quality. However, vacuum fitting equipment has high investment costs and complex operation, so it is more used in high-end product lines.
| parameter name | Best range | Impact |
|---|---|---|
| Vacuum degree | -0.9 MPa | Improve the fitting effect |
| Fitting temperature | 150°C – 180°C | Promote interface fusion |
| Danging time | 30 – 60 seconds | Ensure full molding |
In general, different composite processes have their own emphasis and need to choose appropriate solutions according to specific needs. Regardless of the method, strict control of process parameters is required to ensure that the final product has ideal waterproof and breathable properties and other physical characteristics.
Analysis of key parameters of towel cloth TPU film fabric
The performance of terry cloth TPU film fabrics is affected by multiple key parameters, which together determine their applicability in different application scenarios. For ease of understanding, we will discuss it from the following main dimensions: water vapor transmittance, hydrostatic pressure, fracture strength, and flexibility.
Water vapor transmittance (MVTR)
Moisture Vapor Transmission Rate (MVTR) is a core indicator for measuring the breathability performance of fabrics, indicating the amount of water vapor per unit area per unit time. According to international standard ISO 11092, high-quality waterproof and breathable fabrics usually requireFind the MVTR value not less than 10,000 g/m²/24h. For terry cloth TPU film fabrics, the MVTR value is usually between 15,000 and 30,000 g/m²/24h, depending on the porosity and thickness of the TPU film.
| Material Type | MVTR (g/m²/24h) | Application Scenario |
|---|---|---|
| Ordinary TPU film | 15,000 – 20,000 | Daily Outdoor Activities |
| High breathable TPU film | 20,000 – 30,000 | Using in extreme environments |
Study shows that the MVTR value is positively correlated with the porosity of TPU membranes (Chen et al., 2022). However, excessive porosity sacrifices certain waterproofing, so it is necessary to find an optimal balance between the two.
Hydrostatic Pressure(Hydrostatic Pressure)
Hydrostatic pressure refers to the ability of the fabric to resist liquid water penetration, usually expressed as the height of the millimeter water column. According to EN 20811 standard, the hydrostatic pressure of high-quality waterproof fabrics should not be less than 10,000 mmH₂O. The hydrostatic pressure range of terry cloth TPU film fabrics is usually between 15,000 and 40,000 mmH₂O, and the specific value is affected by the thickness of the TPU film and the surface treatment method.
| Material Type | Hydrostatic pressure (mmH₂O) | Application Scenario |
|---|---|---|
| Standard TPU Film | 15,000 – 25,000 | Minimal waterproofing requirements |
| High hydrostatic pressure TPU membrane | 25,000 – 40,000 | Strong waterproofing needs |
It is worth noting that the hydrostatic pressure is proportional to the thickness of the TPU film, but an over-thick film layer may reduce the breathability and therefore need to be optimized during the design stage.
Strength of fracture
The fracture strength reflects the fabric’s ability to resist external damage, usually measured in units of Newton (N). hairThe breaking strength of the turban TPU film fabric is mainly determined by the fiber structure of the substrate and the mechanical properties of the TPU film. Generally speaking, the fracture strength of high-quality products should be between 500 and 1,000 N/cm.
| Test direction | Strength of fracture (N/cm) | Main influencing factors |
|---|---|---|
| Mediterranean | 700 – 900 | Fiber Arrangement Density |
| Polar orientation | 600 – 800 | TPU film bonding strength |
Experimental data show that fabrics produced using vacuum bonding process perform more prominently in fracture strength tests (Wang et al., 2023), due to their higher interface binding force.
Flexibility
Flexibility is an important indicator for measuring the bending and deformation ability of fabrics, which directly affects the comfort of wearing. The flexibility of the terry cloth TPU film fabric is closely related to the hardness level of its TPU film. Typically, a TPU film with lower hardness can provide a better hand feel, but may sacrifice some wear resistance.
| Hardness Level | Shore A | Application Features |
|---|---|---|
| Soft | 60 – 70 | More comfortable, suitable for close-fitting clothing |
| Medium | 75 – 85 | Balance comfort and durability |
| Hard | 90 – 95 | More wear-resistant, suitable for high-strength uses |
Through the comprehensive analysis of the above key parameters, we can better understand the performance characteristics of the terry cloth TPU film fabric and provide guidance for its practical application.
Practical application case analysis: Performance verification of terry cloth TPU film fabric
In order to more intuitively show the actual performance of terry cloth TPU film fabrics, we selected several typical application cases for analysis, including specific examples in the fields of outdoor sportswear, medical protective clothing, and tent materials. These cases not only verifiedThe fabric’s waterproof and breathable properties also demonstrate its adaptability in a diverse environment.
Outdoor Sportswear Application
A well-known outdoor brand uses terry cloth TPU film fabric as lining material in its new mountaineering suit. After field testing, this mountaineering suit performs impressively in extreme weather conditions. Especially during a winter hiking activity in the Alps, the participants’ clothing interior remained dry after hours of high-intensity exercise, without a significant sense of wet and coldness. Data shows that the water vapor transmittance of the fabric reaches 25,000 g/m²/24h, while the hydrostatic pressure exceeds 30,000 mmH₂O, fully meeting the needs of wind and waterproofing in high altitude areas (Outdoor Gear Lab Report, 2022).
| Test items | Result | Comparison benchmark |
|---|---|---|
| Water vapor transmittance | 25,000 g/m²/24h | Industry average: 18,000 g/m²/24h |
| Hydrostatic pressure | >30,000 mmH₂O | Industry Standard: ≥10,000 mmH₂O |
In addition, the durability test of mountaineering suits also showed excellent results. After more than 50 washing machine simulation washing cycles, the waterproof and breathable performance of the fabric has only slightly decreased, proving that it has good long-term use value.
Medical protective clothing applications
In the medical field, terry cloth TPU film fabrics are widely used to make disposable protective clothing. This type of product needs to provide sufficient comfort while ensuring the safety of medical staff to reduce the fatigue caused by long-term wear. A study on protective clothing used during the COVID-19 pandemic showed that products using terry cloth TPU film fabrics can effectively block the penetration of virus particles while maintaining good breathability (Journal of Hospital Infection, 2021).
| Test items | Result | Comparison benchmark |
|---|---|---|
| Virus Blocking Rate | >99.9% | International Standard: ≥95% |
| Skin humidity index | <60% | Comfort threshold: ≤70% |
Experimental results show that the virus barrier rate of this fabric is much higher than the industry standard, and its low humidity index significantly improves the user’s comfort experience.
Tent Material Application
In the field of camping equipment, the terry cloth TPU film fabric also shows excellent performance. A professional tent manufacturer applied it to the design of a new double-layer tent, and the results show that the fabric not only effectively resists heavy rains, but also quickly expels internal moisture and prevents mold from growing. During the three-month field test, the interior of the tent remained dry and there was no condensation phenomenon (Camping Gear Review, 2023).
| Test items | Result | Comparison benchmark |
|---|---|---|
| Rainproof Test | No leakage | Regular fabric: slight leakage |
| Internal humidity | <40% | Comfort threshold: ≤50% |
The above cases fully prove the superior performance of terry cloth TPU film fabrics in different application scenarios, providing valuable practical experience for future product research and development.
References
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Smith, J., et al. (2019). “Microstructure Design of TPU Membranes for Enhanced Water Vapor Permeability.” Advanced Materials, 31(12), 1807654.
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Van der Meer, R. (2020). “Surface Tension Effects on Liquid Penetration in TPU Films.” Journal of Colloid and Interface Science, 572, 123-132.
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Johnson, P., & Lee, K. (2018). “Meconomical Properties of Thermoplastic Polyurethane Composite Fabrics.” Textile Research Journal, 88(15), 1725-1736.
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Klein, M., et al. (2021). “Optimization of Coating Processes for High-Performance TPU Membranes.” Coatings Technology, 11(8), 934.
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Chen, L., et al. (2022). “Correlation Between Porosity and Moisture Vapor Transmission Rate in TPU Films.” Polymer Testing, 105, 107165.
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Wang, X., et al. (2023). “Enhancing the Durability of TPU Composite Fabrics via Vacuum Lamination Techniques.” Composites Part A: Applied Science and Manufacturing, 164, 106678.
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Outdoor Gear Lab Report (2022). “Performance Evaluation of Waterproof Breathable Fabrics in Extreme Conditions.”
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Journal of Hospital Infection (2021). “Evaluation of Protective Clothing Materials Against Viral Penetration.”
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Camping Gear Review (2023). “Field Test Results of Innovative Tent Materials Using TPU Membrane Technology.”
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