目的 改善外卖箱的保温性能，解决低温条件下热餐食物在配送过程中热量大幅度流失的问题。方法 应用发热性能良好且环保的碳系水性电热油墨，结合丝网印刷技术制备发热器件并装配在发泡聚丙烯(EPP)外卖箱中，从而维持箱内恒温。结果 所制备的发热器件在18 V电压条件下饱和温度可达到76.7 ℃，温度和功率密度呈线性关系，斜率高达782.6 ℃.cm²/W。在使用了发热器件之后，恒温箱内温度可长时间保持在60 ℃以上。在从环境温度开始加热的恒温箱中经过1 h的配送过程模拟实验，初始温度约为60 ℃热餐食物温度下降仅有5 ℃。在对比测试中，初始温度为60 ℃的热水分别放置在恒温箱和普通EPP外卖箱内，20 min后恒温箱保温效率比普通外卖箱的高27.3%。结论 碳系水性电热油墨制成的发热器件具有低功耗和高加热性能的特点，应用于外卖恒温箱中提高了保温效果，有效减少外卖食物温度流失。

The work aims to improve the heat preservation performance of takeaway boxes to solve the problem of large heat loss in distribution of hot meals at low temperature. Carbon water-based electric heating ink with good heating performance and environmental protection was used in combination with screen printing technology to prepare a heating device and assemble it in a foamed polypropylene (EPP) takeaway box, so as to maintain constant temperature in the box. The saturation temperature of the heating device could reach 76.7 ℃ at 18 V. The temperature and power density were linear, and the slope was as high as 782.6 ℃.cm2/W. After the heating device was installed, the temperature in the thermostat could be maintained above 60 ℃ for a long time. After 1 hour of simulated distribution in the constant temperature takeaway box heated from the ambient temperature, the temperature of the hot food with an initial temperature of about 60 ℃ dropped by only 5 ℃. In the comparison test, hot water with an initial temperature of 60 ℃ was placed in the constant temperature takeaway box and the ordinary EPP takeaway box respectively. After 20 minutes, the heat preservation efficiency of the constant temperature takeaway box was 27.3% higher than that of the ordinary takeaway box. The heating device made of carbon water-based electric heating ink has low power consumption and high heating performance. Its application in constant temperature takeaway boxes improves the heat preservation effect and effectively reduces the temperature loss of takeaway.