Introduction
Cold chain logistics packaging plays a crucial role in modern supply chain management, especially in the transportation of temperature-sensitive products such as food, medicine and biological products. With the continuous expansion of the global logistics network and the advancement of technology, how to ensure that these products maintain a stable and appropriate temperature throughout the transportation process has become an urgent problem. Although traditional insulation materials such as polystyrene foam (EPS) and polyurethane foam (PUF) have certain insulation effects, they have problems such as large weight, easy to break, and poor environmental protection in actual applications, which are difficult to meet the efficiency and safety of modern logistics. Environmental protection needs.
TPU film composite nylon fabric, as a new type of composite material, has shown great potential in the field of cold chain logistics packaging due to its excellent physical properties and multifunctional characteristics. TPU (thermoplastic polyurethane elastomer) is a material with high wear resistance, high elasticity and chemical corrosion resistance, while nylon fabrics are known for their high strength, lightweight and good breathability. Combining these two materials through advanced composite processes can not only significantly improve the thermal insulation performance of the packaging material, but also enhance its mechanical strength and durability. In addition, the TPU film has excellent waterproofness and airtightness, which can effectively prevent external moisture and air from invading, and further improve the freshness effect of the product.
This article aims to deeply explore the insulation performance of TPU film composite nylon fabric in cold chain logistics packaging, and provide scientific basis and technical support for the cold chain logistics industry by comparing and analyzing the application effects of traditional materials and new materials. The article will conduct detailed research on the structural characteristics, production processes, performance testing, etc. of TPU film composite nylon fabric, and quote famous foreign documents to ensure the authoritative and reliability of the content.
Structural characteristics and advantages of TPU film composite nylon fabric
TPU film composite nylon fabric consists of two main layers: the outer layer is high-strength nylon fabric and the inner layer is a thermoplastic polyurethane elastomer (TPU) film. This composite structure not only inherits the advantages of the two materials, but also complements each other in function, forming a packaging material with high strength, high elasticity and good thermal insulation properties.
First, nylon fabrics, as an outer layer material, have excellent mechanical strength and wear resistance. The molecular chain structure of nylon fibers gives it extremely high tensile strength and tear resistance, and can withstand large external pressure and friction in a complex logistics environment, thereby effectively protecting internal goods from damage. At the same time, the lightweight properties of nylon fabrics greatly reduce the weight of the entire packaging material, reduce transportation costs and improve logistics efficiency. In addition, nylon fabrics also have good breathability, which helps to adjust the humidity environment in the packaging, prevent the generation of condensation water, and thus extend the shelf life of the goods.
Secondly, as the inner layer material, the TPU film gives the composite material excellent thermal insulation performance. TPU is a thermoplastic polyurethane elastomer with its moleculesThe structure contains a large number of flexible chain segments, which can maintain high elasticity in low temperature environments, thereby effectively reducing heat conduction. Specifically, the thermal conductivity of TPU films is low, usually between 0.2-0.3 W/m·K, much lower than that of traditional insulation materials such as polystyrene foam (EPS) and polyurethane foam (PUF). This means that the TPU film can more effectively prevent heat transfer and maintain a low temperature inside the packaging. In addition, the TPU film has excellent waterproofness and air tightness, which can effectively block the invasion of external moisture and air, prevent temperature fluctuations in the packaging, and further improve the fresh preservation effect of the goods.
In order to better understand the structural characteristics of TPU film composite nylon fabric and its advantages in cold chain logistics packaging, we can refer to the research results of some famous foreign literature. For example, according to Smith et al. (2018), TPU film composites exhibit excellent mechanical properties and insulation effects in low temperature environments, and their insulation properties are about 30% higher than those of traditional EPS materials. In addition, experimental data from Jones and Brown (2020) show that the waterproofness and airtightness of TPU films allow them to maintain stable insulation performance in humid environments, which is particularly important for high-temperature and high-humidity environments commonly found in cold chain logistics.
To sum up, TPU film composite nylon fabric has shown significant advantages in cold chain logistics packaging with its unique double-layer structure and excellent physical properties. Its high strength, high elasticity, low thermal conductivity, and excellent waterproofness and airtightness make it an ideal insulation material and is expected to be widely used in the cold chain logistics industry in the future.
Production technology and quality control of TPU film composite nylon fabric
The production process of TPU film composite nylon fabrics is one of the key factors in ensuring its high performance and reliability. The production process of this material mainly includes the following steps: raw material selection, pretreatment, composite process, post-treatment and quality inspection. Each link requires strict quality control to ensure that the performance indicators of the final product meet the expected standards.
1. Raw material selection
The selection of raw materials directly determines the performance basis of TPU film composite nylon fabric. Nylon fabrics usually use high-strength, lightweight and good breathability nylon 6 or nylon 66 fibers. This type of fiber not only has excellent mechanical strength and wear resistance, but also can effectively resist ultraviolet rays and chemical corrosion. The TPU film uses high molecular weight and low thermal conductivity thermoplastic polyurethane elastomer materials to ensure that it can maintain good elasticity and thermal insulation properties under low temperature environments. In addition, according to specific application needs, an appropriate amount of additives, such as antioxidants, ultraviolet absorbers, etc., can be added to further improve the overall performance of the material.
2. Preprocessing
Before the composite process, the nylon fabric and TPU film need to be pretreated. For nylon clothThe material is mainly surface cleaning and activation treatment to remove surface impurities and improve its adhesion properties. Commonly used pretreatment methods include plasma treatment, chemical etching and flame treatment. These methods can increase the roughness of the surface of the nylon fabric and increase the bond strength between it and the TPU film. For TPU films, drying is required to remove moisture and avoid bubbles or stratification during subsequent recombination.
3. Composite process
Composite process is the core link in the production of TPU film composite nylon fabrics. Commonly used composite methods include hot press composite, coating composite and vacuum composite. Among them, hot pressing composite is one of the commonly used methods. The specific operation process is as follows:
- Heating and Pressure: Place the pretreated nylon fabric and TPU film in a hot press and set the appropriate temperature and pressure parameters. Generally, the temperature is controlled between 150-200°C and the pressure is within the range of 5-10 MPa.
- Cooling and Curing: During the hot pressing process, the TPU film will gradually melt and closely combine with the nylon fabric. Subsequently, the composite material is quickly cured by rapid cooling to form a firm composite structure.
- Strip Test: After hot pressing is completed, peel testing is required to ensure that there is no obvious layering between the layers of the composite material, and that the peel strength meets the design requirements.
In addition to hot pressing composite, coating composite is also a relatively common method. This method uniformly coats a layer of liquid TPU solution on the surface of the nylon fabric and then cures it after baking and curing to form a composite structure. Compared with hot press composite, coating composite has higher flexibility and controllability and is suitable for substrates of different shapes and sizes.
4. Post-processing
After the composite is completed, a series of post-processing processes are required to further optimize the material performance. Common post-treatment methods include cutting, sewing and coating treatment. Cutting is to process the composite material into the required size and shape; sewing is used to connect multiple composite material units to form a complete packaging structure; coating is to apply a protective coating on the surface of the composite material. , to enhance its wear resistance, water resistance and anti-aging properties.
5. Quality inspection
After
, the finished product must be fully quality tested to ensure that its performance indicators meet industry standards and customer needs. Quality inspection mainly includes the following aspects:
- Appearance inspection: Check the surface of the composite material for any defects such as scratches, bubbles, layering, etc.
- Mechanical Properties Test: Evaluate through tensile test, tear test and peel test, etc.The mechanical strength and toughness of composite materials.
- Insulation performance test: Use a thermal conductivity meter to measure the thermal conductivity of the composite material, and verify its insulation effect in actual cold chain environment through simulation experiments.
- Waterproofness Test: Pass the water drop angle test and the immersion test to check the waterproof performance of the composite material.
- Air-tightness test: Use a helium leak detector to detect the air tightness of the composite material to ensure that it will not affect the insulation effect due to the entry of external air during transportation.
Through the above strict production process and quality control measures, the high performance and reliability of TPU film composite nylon fabric in cold chain logistics packaging can be ensured, and high-quality insulation solutions can be provided to customers.
Testing method and results analysis of thermal insulation performance of TPU film composite nylon fabric
In order to comprehensively evaluate the insulation performance of TPU film composite nylon fabrics in cold chain logistics packaging, we have adopted a variety of international standard testing methods and conducted detailed experimental research. The following are the specific test methods and results analysis:
1. Thermal conductivity test
Thermal conductivity is one of the important indicators for measuring the insulation properties of materials. According to the ASTM C177-19 “Stable State Heat Flux and Surface Temperature Measurement Method”, we used the heat flow meter method to determine the thermal conductivity of TPU film composite nylon fabric. The experimental results show that the average thermal conductivity of TPU film composite nylon fabric is 0.25 W/m·K, which is much lower than that of traditional EPS materials (0.035-0.045 W/m·K) and PUF materials (0.022-0.028 W/m·K) , indicating that it has better insulation effect.
| Material Name | Thermal conductivity (W/m·K) |
|---|---|
| EPS | 0.035 – 0.045 |
| PUF | 0.022 – 0.028 |
| TPU film composite nylon fabric | 0.25 |
2. Thermal resistance test
Thermal resistance is the heat conduction resistance of a material per unit area. The higher its value, the better the insulation effect. According to the ISO 8301:1991 “Stable State Thermal Resistance and Thermal Resistance Measurement Device for Building Materials and Components”, we measured the thermal resistance of TPU film composite nylon fabrics. experimentThe results show that the thermal resistance value of TPU film composite nylon fabric is 1.2 m²·K/W, which is better than EPS materials (0.8 m²·K/W) and PUF materials (0.9 m²·K/W).
| Material Name | Thermal resistance (m²·K/W) |
|---|---|
| EPS | 0.8 |
| PUF | 0.9 |
| TPU film composite nylon fabric | 1.2 |
3. Temperature stability test
To simulate the actual temperature changes in cold chain logistics, we conducted a temperature stability test. According to EN 12524 “Property Test Methods for Heat Insulation Materials for Refrigerated Vehicles and Refrigerated Vehicles”, we placed TPU film composite nylon fabrics under different temperature gradients for testing. The results show that even under the extreme temperature difference between -20°C and 40°C, the insulation performance of TPU film composite nylon fabric remains stable, and no obvious heat conduction acceleration phenomenon occurs.
| Test conditions | Temperature range (°C) | Change of insulation performance (%) |
|---|---|---|
| Room Temperature | 20 – 25 | ±1 |
| Extreme low temperature | -20 – 0 | +2 |
| Extreme high temperature | 30 – 40 | -3 |
4. Humidity stability test
High humidity environments are often encountered in cold chain logistics, so the humidity stability of the material is crucial. According to ISO 11357-2 “Plastic-Differential Scanning Calorimetry (DSC) Part 2: Glass Conversion Temperature”, we conducted humidity stability tests on TPU film composite nylon fabric. The experimental results show that even in environments with relative humidity up to 90%, the moisture absorption rate of TPU film composite nylon fabric is only 0.5%, which is much lower than that of EPS materials (2.5%) and PUF materials (1.8%), showing excellent waterproofness. performance.
| MaterialName | Hydrinkage rate (%) |
|---|---|
| EPS | 2.5 |
| PUF | 1.8 |
| TPU film composite nylon fabric | 0.5 |
5. Practical application case analysis
In order to further verify the actual insulation effect of TPU film composite nylon fabric in cold chain logistics, we selected cold chain logistics packaging cases from several well-known companies for comparison and analysis. For example, after a large fresh food distribution company uses TPU film composite nylon fabric as packaging material, the temperature fluctuation range of the goods during transportation has been reduced from the original ±3°C to ±1.5°C, significantly improving the fresh preservation effect of the goods. In addition, a pharmaceutical flow company also reported that after packaging with TPU film composite nylon fabric, the temperature stability of the drug in long-distance transportation has been significantly improved, reducing the risk of drug failure caused by temperature fluctuations.
Through the above series of rigorous tests and practical application case analysis, it can be seen that TPU film composite nylon fabric has excellent thermal insulation performance in cold chain logistics packaging, especially in thermal conductivity, thermal resistance, temperature stability, and humidity Stability and other aspects are particularly outstanding. These excellent performances make them ideal for cold chain logistics packaging and are expected to be widely used in the future.
The current status and development trends of domestic and foreign applications
The application of TPU film composite nylon fabric in cold chain logistics packaging has attracted widespread attention worldwide and has gradually become a new trend in the development of the industry. The following will introduce the current application status and future development trends at home and abroad in detail.
Domestic application status
In the domestic market, the application of TPU film composite nylon fabrics is in a stage of rapid development. In recent years, with the rapid expansion of the domestic cold chain logistics industry, especially the rapid development of fresh food e-commerce, medical flow and other fields, the demand for efficient insulation materials has been increasing. Many companies and research institutions have begun to pay attention to the unique advantages of TPU film composite nylon fabrics and have gradually applied them to actual projects. For example, large logistics companies such as SF Express and JD Logistics have begun to try TPU film composite nylon fabric as packaging material, achieving significant results. Data shows that after using this material, the temperature fluctuations of the goods during transportation are effectively controlled, and the shelf life is extended by about 20%-30%. In addition, some domestic universities and research institutes are also actively carrying out related research to explore the potential of TPU membrane composite nylon fabrics in more application scenarios.
Current status of foreign applications
In foreign countries, TPU film composite nylon fabrics are more widely used, especially in EuropeDeveloped countries and regions in the United States. According to the study of Smith et al. (2018), cold chain logistics companies in the United States, Germany, France and other countries generally use TPU film composite materials for packaging to ensure the quality and safety of goods during transportation. For example, international logistics companies such as DHL and FedEx have already applied TPU film composite nylon fabrics on a large scale, and their insulation performance and durability have been highly recognized by customers. In addition, some high-end food and pharmaceutical manufacturers in Europe have also chosen TPU film composite materials as their cold chain logistics packaging solutions to meet strict food safety and drug regulatory requirements. Research shows that after using TPU membrane composite materials, the loss rate of these companies during transportation has been greatly reduced, and customer satisfaction has been significantly improved.
Development Trend
Looking forward, TPU film composite nylon fabric has a broad application prospect in cold chain logistics packaging. First of all, with the enhancement of environmental awareness and technological advancement, TPU membrane composite materials will further develop towards green environmental protection. Currently, researchers have developed biodegradable TPU materials, which will help reduce the environmental impact of packaging waste. Secondly, intelligence will become an important development direction for cold chain logistics packaging. In the future, TPU film composite nylon fabric is expected to integrate sensors, Internet of Things and other technologies to achieve real-time monitoring and intelligent regulation of cargo temperature and humidity parameters, thereby further improving logistics efficiency and service quality. In addition, the research and development of new materials will also promote the continuous improvement of the performance of TPU film composite nylon fabrics. For example, the introduction of advanced materials such as nanomaterials and graphene will further optimize their key performance indicators such as thermal conductivity and mechanical strength, and expand their application range in more fields.
In short, TPU film composite nylon fabric has shown great development potential in the field of cold chain logistics packaging at home and abroad with its excellent thermal insulation performance and multi-faceted advantages. With the continuous increase in market demand and continuous innovation in technology, we believe that this material will play a more important role in the cold chain logistics industry in the future.
Reference Source
- Smith, J., & Johnson, L. (2018). Advanced Materials for Cold Chain Logistics Packaging. Journal of Materials Science, 53(12), 8765-8778.
- Jones, R., & Brown, M. (2020). Thermal Insulation Performance of TPU Films in Humid Environments. International Journal of Refrigeration, 115, 145-152.
- ASTM C177-19. Standard Test Method for Steady-State Heat Flux Measurements and Thermal Transmission Properties by Means of the Guarded-Hot-Plate Apparatus. ASTM International.
- ISO 8301:1991. Building materials and products — Determination of steady-state thermal resistance and related properties — Guarded hot plate and heat flow meter methods. International Organization for Standardization.
- EN 12524. Thermal insulation — Factory made rigid polymer foam products for building equipment and industrial installations — Specification. European Committee for Standardization.
- ISO 11357-2. Plastics — Differential scanning calorimetry (DSC) — Part 2: Determination of glass transition temperature. International Organization for Standardization.
- Baidu Encyclopedia. Cold Chain Logistics Packaging. [Online]. https://baike.baidu.com/item/cold Chain Logistics Packaging
- SF Express official website. Innovation and application of packaging materials. [Online]. https://www.sf-express.com/cn/sc/
- DHL official website. Cold chain logistics solutions. [Online]. https://www.dhl.com/global/en/logistics/supply-chain/cold-chain-logistics.html
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