造纸机的传统寿命周期受国际竞争性和市场情况的影响，总的来说它遵照人们最初认识的特性曲线，即随着纸机限定能力的递增而下降。在寿命的中期进行改造，以维持纸机的竞争能力和产品质量。本文将就这方面的经济性进行探讨。 The traditional life cycle of a paper machine is affected by international competitiveness and market conditions. In general, it follows the characteristics curve that people initially recognized, that is, the decline in the capacity of paper machines. In the middle of the lifespan, it will be transformed to maintain the competitiveness and product quality of the paper machine. This article will discuss the economy in this area.