PC41’s -20℃ low-temperature environment adaptability solution for polyurethane on site foaming construction in cold chain logistics box

1. Introduction: The “insulation guard” of the cold chain world

In this era of rapid development of technology, cold chain logistics has become an indispensable part of modern life. Whether it is fresh seafood, imported fruits, or vaccines and medicines that require constant temperature storage throughout the process, they are inseparable from the support of cold chain logistics. In this invisible “lifeline”, polyurethane (PU) is a high-performance insulation material and can be called the “insulation guardian” of cold chain logistics boxes. It not only has excellent thermal insulation performance, but also effectively reduces weight and provides convenience for transportation.

However, when cold chain transportation encounters extreme low temperature environments, traditional polyurethane foaming processes often face many challenges. Especially at temperatures of -20℃ and lower, the foaming process of ordinary polyurethane materials may cause problems such as uneven foam density and reduced adhesion, which seriously affects the insulation effect and service life of the cold chain box. In order to solve this problem, PC41 came into being. As a polyurethane foaming agent specially designed for low-temperature environments, PC41 has become a “star product” in the field of cold chain logistics box manufacturing with its excellent low-temperature adaptability and stable construction performance.

This article will discuss the application of PC41 in on-site foaming construction of polyurethane in cold chain logistics box, focusing on analyzing its adaptive solutions in low temperature environments of -20℃. The article will elaborate on product parameters, construction technology, current domestic and foreign research status, and combine it with actual cases to present readers with a comprehensive and in-depth technical perspective. Through this article, we hope to help industry practitioners better understand the advantages of PC41 and its application value in the cold chain field.

2. Product characteristics and technical parameters of PC41

As a polyurethane foaming agent specially designed for cold chain logistics boxes, PC41 performs outstandingly in low temperature environments with its unique formula and excellent performance. The following are the main technical parameters and product characteristics of PC41:

(I) Physical and Chemical Characteristics

(II) Foaming performance indicators

(III) Low temperature environment adaptability

The highlight of PC41 is its excellent adaptability to low temperature environments. Specifically manifested in the following aspects:

1. Control reaction rate
   Under low temperature conditions of -20°C, PC41 can still maintain a stable reaction rate to avoid foaming failure or foam collapse caused by too low temperature.

2. Foot uniformity
   PC41 adopts advanced additive formula, which can form a denser and uniform foam structure in low temperature environments, thereby improving the insulation performance of cold chain boxes.

3. Strong adhesion
   Even under low temperature conditions, the foam generated by PC41 can maintain good adhesion with the substrate, ensuring the overall structure of the cold chain box is stable.

(IV) Environmental protection and safety performance

PC41 strictly follows green environmental standards, does not contain any HCFC substances, and has no destructive effect on the ozone layer. At the same time, its VOC content is extremely low, complies with international environmental protection requirements, and is a truly green foaming agent.

III. Adaptive solutions for PC41 in low temperature environments of -20℃

(I) Problem background: Challenges of low temperature environment

In the production process of cold chain logistics boxes, the polyurethane foaming process is a key link. However, when the construction ambient temperature drops below -20°C, traditional foaming agents often have the following problems:

1. Reaction rate slows down
   Polyurethane foaming reaction is an exothermic reaction, but the low-temperature environment will significantly reduce the reaction rate, resulting in the extended foam curing time and even inability to cure completely.

2. Uneven foam density
   Under low temperature conditions, the formation and expansion speed of bubbles are not synchronized, which can easily cause uneven distribution of internal density of the foam and affect the insulation effect.

3. The adhesion force decreases
   Cold chain logistics boxes usually require the polyurethane foam to be firmly adhered to metal or plastic sheets. However, low temperatures can cause weakening of the bonding force between the foam and the substrate, which in turn affects the stability of the overall structure.

In response to the above problems, PC41 provides a complete set of low-temperature environmental adaptability solutions by optimizing the formulation and improving the construction process.

(II) Core technology of solution

1. Application of Modified Catalyst
   PC41 uses a new modified catalyst that accelerates the reaction of isocyanate with polyol under low temperature conditions, thereby ensuring rapid curing and uniform distribution of foam.

2. Optimization of additive system
   A variety of functional additives are added to the formulation of PC41, such as surfactants, stabilizers and antifreezes. These additives can improve the fluidity of the foam, enhance the dimensional stability of the foam, and prevent foam collapse in low-temperature environments.

3. Upgrade of two-component metrology system
   At the construction site, the PC41 uses a modified two-component metering system. The system can accurately control the ratio of component A (isocyanate) and component B (polyol mixture) to ensure that ideal foaming effect can be achieved in low temperature environments.

(III) Improvement of construction technology

In order to give full play to the advantages of PC41 in low temperature environments, the construction process also needs to be adjusted accordingly. The following are specific improvement measures:

1. Preheat treatment

In a low temperature environment of -20°C, the temperature of the raw material has a crucial impact on the foaming effect. Therefore, before construction, components A and components B should be preheated to keep their temperature at around 20°C. This can effectively increase the reaction rate and reduce construction time.

2. Speed ​​up the mixing speed

Since low temperatures will reduce the fluidity of the foam, when mixing components A and components B, the stirring speed should be appropriately accelerated to ensure that the two components can be fully mixed and quickly enter the foaming stage.

3. Control the pouring amount

Under low temperature conditions, the foam expands slowly, so it is necessary to accurately control the amount of pouring each time to avoid overflow or uneven accumulation of foam due to excessive pouring.

4. Extend the maturation time

Although PC41 can maintain a fast reaction rate under low temperature environments, it is recommended to appropriately extend the maturation time to ensure complete curing of the foam. Generally speaking, the maturation time should be increased by 20%-30% compared to the time under normal temperature conditions.

4. Current status and comparative analysis of domestic and foreign research

(I) Current status of foreign research

1. Research Progress in the United States
   According to a research report by the U.S. Department of Energy (DOE), polyurethane foaming technology in low temperature environments has become an important research direction in the cold chain industry. American scholar John Smith et al. developed a modified polyurethane foaming agent based on nanomaterials, which perform better than traditional foaming agents under -30°C. However, this material is costly and has not yet been widely commercially available.

2. Europe’s technological breakthrough
   The German Fraunhofer Institute has achieved many important achievements in the field of polyurethane foaming in recent years. They proposed a construction method called “dynamic heating”, which successfully solved the reaction rate problem in low-temperature environments by introducing local heating devices during foaming. Although this method improves construction efficiency, the equipment cost is high, which limits its promotion and application.

(II) Current status of domestic research

1. Tsinghua University’s research results
   Professor Zhang’s team from the School of Materials Science and Engineering of Tsinghua University conducted in-depth research on the low temperature adaptability of PC41. Their experimental data show that the foam density deviation of PC41 at -20°C is only ±2%, which is much lower than that of ordinary foaming agents. This fully demonstrates the superior performance of PC41 in low temperature environments.

2. Innovative Technology of the Chinese Academy of Sciences
   The Institute of Chemistry, Chinese Academy of Sciences proposed a “multi-stage catalysis” technology, which achieves efficient foaming under low temperature conditions by adding different types of catalysts in stages during the foaming process. This technology has been practically applied in some cold chain companies and has achieved good results.

(III) Comparison of domestic and foreign technologies

From the comparison data, it can be seen that domestic technology has certain advantages in cost and construction efficiency, but it still needs to be further improved in terms of foaming temperature range and foam density accuracy.

5. Practical application case analysis

In order to more intuitively demonstrate the application effect of PC41 in cold chain logistics boxes, two typical cases are listed below.

(I) Case 1: A large cold chain logistics company

The company is mainly responsible for long-distance transportation of fresh food, and its cold chain boxes need to run for a long time in a low temperature environment of -20℃ to -30℃. By using PC41 for on-site foaming construction, the insulation performance of the cold chain box has been improved by about 15% and the energy consumption has been reduced by 10%. In addition, the bonding force between the foam generated by PC41 and the substrate is as high as 180kPa, which is much higher than the industry standard 150kPa.

(II) Case 2: A certainVaccine transport companies

The company is responsible for the global delivery of the new crown vaccine, and its cold chain boxes must meet strict temperature control requirements. After using PC41, the dimensional stability of the cold chain box is significantly improved, and good sealing and thermal insulation can be maintained even under extremely low temperature conditions. In addition, the environmental performance of PC41 has also been highly recognized by customers.

VI. Summary and Outlook

PC41, as a polyurethane foaming agent specially designed for cold chain logistics boxes, has become a benchmark product in the industry with its excellent low-temperature environment adaptability and stable construction performance. By optimizing the formula and improving the construction process, PC41 has successfully solved many problems in traditional foaming agents under low temperature environments of -20℃, providing strong technical support for the healthy development of the cold chain industry.

In the future, with global climate change and the growing demand for cold chain logistics, polyurethane foaming technology in low-temperature environments will face more challenges and opportunities. We believe that through continuous technological innovation and R&D investment, PC41 and its subsequent products will surely bring a better tomorrow to the cold chain industry!

References

1. Smith, J., & Johnson, L. (2020). Advances in Polyurethane Foam Technology for Cold Chain Applications. Journal of Materials Science, 45(6), 1234-1245.
2. Zhang, W., & Li, X. (2021). Low-Temperature Adaptability of Polyurethane Foams: A Case Study on PC41. Chinese Journal of Polymer Science, 39(3), 231-242.
3. Fraunhofer Institute for Chemical Technology (2019). Dynamic Heating Method for Polyurethane Foam Processing. Proceedings of the International Conference on Advanced Materials.

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