ABSTRACT
Plastic film has plays an important role in agricultural production in China. The internal cooling system is one of the key methods used to improve production efficiency and product quality of the film. In foreign countries, the internal cooling technology has been applied to practical film production in the last century. Similar techniques have been successfully developed in 2003 in China, and rapidly popularized. However, in practice we found that the domestic internal cooling systemhas the disadvantages of poor control precision, long adjustment period, lack of stabilization, complicated operation and other shortcomings. For stringent specifications, these disadvantages often make it difficult to meet the requirements, which results in large losses. Therefore, the development of a high control accuracy, long-term, stable internal cooling system is necessary.
