Using Cycles and Security Discussion on HDPE Container Load of High Purity Chemical

• Main Authors: Mao-Sen Wen, 温茂森
• Other Authors: Chi-Min Shu
• Format: Others
• Language: zh-TW
• Published: 2016
• Online Access: http://ndltd.ncl.edu.tw/handle/5j9w3e

碩士 === 國立雲林科技大學 === 環境與安全衛生工程系 === 104 === At present, the quality of High Density Polyethylene (HDPE) which used for high purity chemicals storage has not been regulated by related ordinance or authority. From the cost consideration of high purity chemical suppliers, the HDPE containers will be washed and reused after collecting from users. To determine the life time of containers, the appearance of containers and manufacturer’s recommended life time would be generally taken into account. The guideline of determination of HDPE container’s life time has not yet clearly defined. It led frequently leakage of high purity chemicals during transportation. This research summarized related literatures and revealed pro-longed storage of chemicals was possibly the one of the major causes of deterioration of HDPE containers. In order to determine the change in physical properties of HDPE toward pro-longed storage of different high purity chemicals and suggested life time of HDPE, different testing equipment including Universal testing machine, Impact testing machine, Field-Emission Scanning Electron Microscope (FE-SEM), Energy Dispersive Spectrometer (EDS), Differential Scanning Calorimetry (DSC) and Thermogravimetry (TG) were applied in this research. According to above test analysis, with more immersion time of high purity chemicals, more chemical was diffused into HDPE by osmosis. The ductility and tensile strength of HDPE trended to decrease especially nitric acid which cause the 50% decrease in ductility. Regarding to the analysis of different heating rate toward thermal property of HDPE by DSC and TG, the pyrolysis and heating rate were possibly no obvious relationship. However, a high heat release (exothermic) was recorded during each heating rate test of HDPE. It revealed the deterioration of HDPE would be affected by storage conditions. This research revealed the mechanical properties including ductility, malleability and tensile strength of HDPE containers were possibly degraded if prolonged storage of high purity chemicals. The result of this research could be a reference for the safety in storage and transportation. In order to reduce the accidental leakage of chemicals due to the deterioration of HDPE, integrated and approved regulations for loading, transportation and storage of HDPE containers should be established.