Study On Repair And Protection Of Cellulose Acetate Film

Cellulose acetate film is the most widespread used film and is one of the larger amount collected in museum. However, the mildew, fading of image, acetic acid syndrome and other diseases occured, because of the composition of the film and the collection environments. Among them, the acetic acid syndrome is the most serious problem. The symptoms of acetic acid syndrome is mainly presented as the film emitting acetic acid smell, a large amount of white crystals precipitation on the film surface, and even serious distortions, which can cause the copy, digital conversion and digital restoration of film to be impossible. Finally, the emulsion layer will become liquid, fall off from film and even disappear, if the proper restoration and conservation is not been applied.At present, the studies focused on the prevention, detection, the mechanism of Acetic acid syndrome and the proper collection temperature and humidity in order to delay the occurrence of disease. And the intrinsic viscosity, tensile properties, acidity of the base, wet strength, melting point of the emulsion layer were tested. But the study on other properties of the film such as the surface morphology, hydrophilicity, gloss of the emulsion layer, the alteration of base material, crystal structure, the thermal stability, mechanical strength and pH have been rarely reported. The studies on the above properties of film under different temperature, humidity and acetic acid atmosphere have very important reference significance to the protection of film. The most important thing is there are no reports about the methods which can effectively protect and collect the decomposed film which has been repaired.Based on serious situation of the acetic acid syndrome, the alteration in structure and properties of the film caused by the acetic acid syndrome, the relationship between performance and the actual storage conditions of cellulose acetate film archives have been studied. The protective agent, collection container to restore film and the Protection Restoration Engineering Equipment were designed. The above research results have been applied to the restoration and conservation project of the decomposed film.The paper consists of six chapters:Chapter I:It mainly introduces the construction and composition of the film, imaging principle, the main diseases of the film archives. The research progress in cellulose acetate film, the significance and research ideas and methods of this dissertation was proposed.Chapter II:The causes and influence factors of the acetic acid syndrome are analyzed briefly on the basis of the literature, the changes in structure and performance of the cellulose acetate-based films after the acetic acid syndrome are characterized by Super Depth of Field Microscope, SEM, XRD, IR, TG/DSC, Film Densitometer, Digital Glossness Meter. The main influence factors in the process of cellulose acetate film preservation such as temperature, humidity and acetic acid concentration on the film acidity, size shrinkage, strength, and the base structure, the mutual relationship have been investigated.Chapter III:The decomposed film can be quickly eroded due to its hydrophilic surface, the protective agent of the cellulose acetate film was prepared through the experiments on screening of material. It was composed of acrylic polymer, appropriate amount of nanometer silica and antioxidants. The effects of protective agent to the film-forming, the mechanical strength, durability and other aspects of the film were studied. The results show that the protective agent meets the requirements of protection and can slow down the film deteriorate.Chapter IV:The cellulose acetate film disease collected in tin boxes and paper boxes was studied, the results show that packaging materials with acid absorption ability can delay the degradation of cellulose acetate film. The collection container based on microenvironment controlling and operation at room temperature was put forward, which could delay the acetic acid syndrome disease occur. And the experiment results show that the durable collection container can delay film distortion. It is conducive to the film long-term preservation.Chapter V:The cleaning and repairing engineering equipment were designed. The cleaning processes were optimized according to the cleaning effect, mechanical strength and the acidity. The experiment show that the film was not be destructed by the above cleaning method. The repairing equipment has the advantages of highwork efficiency, capability of being operated by one person, etc.Chapter VI:The cleaning and repairing engineering equipment, collection container were applied to the restoration and conservation project of decomposed film, and have good results.