Study On Several Key Technologies Of Edible Film Casting Machine

Edible film is a new kind of healthy and environmental packaging material, which can beused as food ingredient, replacing the plastic bags increasingly. Nowadays the film is producedby casting machine that has been used to make a variety of plastic films. However, theproduction efficiency has been low. There is instability and uneven temperature in the dryingtunnel of the machine that easily lead to some change in physical properties of edible film,including permeability, soluble and barrier property, one of which is decisive factor for filmperformance. The steel strip is easily caused the slide as well as breakage that bearing film in thetunnel is affected by the changed temperature. All those lead to the decrease of stability andefficiency of the machine. Therefore, study on the key technology of the machine has a greatsignificance.In this paper the design was based on the improvement of stability and productionefficiency of the casting machine, combining with existing characteristics of protein edible filmcasting machine in The Engineering Research Center for Intensive Processing of AquaticProducts based at Jimei University in Fujian province, in which several key technologies werestudied. First of all, the stress variation of the steel belt affected by changed temperature in thetunnel was studied and checked by analyzing the faults of steel strip of the machine. Secondly,the fluid finite element simulation for the drying tunnel of the machine was put forward for theshortcomings of drying efficiency as well as the increase of energy consumption. The simplifiedmodel of the tunnel was established by PRO/E software. The fluid in the tunnel was numericallysimulated, which was based on the advantages of simulation analysis on ANSYS CFX. Thestructure defects of drying tunnel and the distribution of flow and temperature field in a varietyof different technology parameters was analyzed. The simulated results were checked by test.Third, in view of the tunnel structure defects, the tuyere as well as the relevant parts wasimproved. The advantage of the improved structure was studied by the simulation analysis.Finally, a kind of temperature control system based on fuzzy control for electric control valvewas designed because of the insufficient control to drying temperature on the drying tunnel ofthe casting machine. The temperature deviations and the change rate were fuzzed as inputlanguage variable of the control system. The PWM duty cycle was selected as output of languagevariable. The fuzzy control rules were established. The valve switch was controlled by the pulse width modulation technology of MCU. Therefore the fuzzy control of drying temperature on themachine was achieved.The several key technologies can greatly improve the structure of the casting machine in thepaper. The drying efficiency, stability and reliability were enhanced as well. Moreover, the studymethod can be used on some variety of devices with drying tunnel, which is of more wideadaptability.