• Journal of the Korean Society of Safety
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• v.34 no.4
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• pp.32-40
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• 2019

During the manufacturing process of a printed circuit board(PCB), fumes and mists are generated as the ink dries on the PCB surface. The generated fumes and mists are deposited in the dryer wall and the exhaust duct. Deposited fumes and mists may present a fire hazard if the dryer temperature control system fails. In this study, the thermal stability of the fumes and mists deposited in the dryer and ducts has been analyzed by experimental methods such as thermo gravimetric analysis (TGA), differential scanning calorimetry (DSC), auto ignition temperature (AIT), and multiple mode calorimetry(MMC). According to the experimental analyses, experimental samples are likely to generate gas at the temperature ($180{\sim}240^{\circ}C$) that deviates from the normal operating temperature ($150{\sim}156^{\circ}C$). It has been shown that the thermal stability is degraded when the temperature is deviated from the normal operating temperature. In the end, engineering and management safety measures of accidental prevention have been suggested.

• Food Science and Biotechnology
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• v.15 no.5
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• pp.651-663
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• 2006

Hazard Analysis and Critical Control Point (HACCP), a systematic process that identifies, assesses, and controls hazards, has been developed as an effective alternative to conventional end-point analysis for food safety control. The importance of HACCP has been emphasized recently due to the development of new food processing technologies and the increase in international trade demanding worldwide of food product safety. This paper provides a review of HACCP and a generic HACCP template for its implementation for aseptic processing of a juice drink.

• Journal of environmental and Sanitary engineering
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• v.14 no.4
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• pp.93-98
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• 1999

We had investigated combustion properties of rice bran dusts. Decomposition of rice bran dusts with temperature were investigated using DSC and the weight loss according to temperature using TGA in order to find the thermal hazard of rice bran dusts, and the properties of dust explosion in variation of their dust with the same particle size. Using Hartman's dust explosion apparatus which estimate dust explosion by electric ignition after making dust disperse by compressed air, dust explosion experiments have been conducted by varying concentration and size of rice bran dust.According to the results for thermodynamic stability of rice bran dust, there are little change of initiation temperature of heat generation and heating value for used particle size. But initiation temperature of heat generation decreased with high heating rate whereas decomposition heat increased with particle size. Average maximum explosion pressure was $10kgf/cm^2$ for 60/70 mesh and $1.5mg/cm^2$ dust concentration.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.17 no.4
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• pp.322-334
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• 2007

This study covers the investigation of the actual condition in the workplace to produce plastics products using synthetic resins and the investigation on the trends amount of the domestic production of thermoplastic resins. To analyze the monomers included in thermoplastic resins frequently used in the workplace, we analyzed thermal characteristics for test compounds using thermogravimetric analysis and did the qualitative analysis using Pyrolyzer GC-MSD & TDS GC-MSD. And then we classified the health hazard of monomers based on GHS classification criteria using information toxicity & carcinogenicity. The number of the workplace to produce plastics products among all domestic manufacturers of 73,884 was 4,391 (5.94%). The number of workers to produce plastics products among all workers of 2,522,750 in all domestic manufacturers was 104,971 (4.16%). The amount of production per year for thermoplastic resins is in the order of PP, HDPE, LDPE, PVC, ABS, PS and such compounds was producing over 1 Million ton per year each. The classification result based on GHS classification criteria for 22 main compounds included thermoplastic resins says 2 compounds of acrylonitrile, naphthalene are in Acute oral category 3 and benzene is in Acute dermal category 1. The classification results of health hazard of carcinogenicity based on IARC & ACGIH carcinogen classification says 2 compounds of benzene, vinyl chloride are in category 1A (known to be human carcinogens).

• Journal of the Korea Academia-Industrial cooperation Society
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• v.14 no.6
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• pp.2559-2565
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• 2013

Material of boat hull has been used mainly with FRP composite materials until now. FRP boat hull manufacturing began to be restricted after the 2000's under international regulation on ocean environment safety. Shipyard on a small scale has manufactured polyethylene canoe and kayak hulls. Polyethylene has the melting point lower than the existing hull materials. Thermal stress occurs on outer hull surface when the polyethylene boat hull is exposed to sunlight. If it happens everyday, boat hull undergoes fatigue damage due to thermal fatigue. Therefore, this study presents the statistical fatigue life estimation on the HDPE boat hull subject to repeated thermal stress under three point bending condition.

• 한국가스학회:학술대회논문집
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• no.5
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• pp.143-148
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• 2002

• Journal of the Korean Institute of Gas
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• v.15 no.2
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• pp.82-87
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• 2011

Heat transfer oils are used in applications such as heating systems of chemical plant, refinery heat exchange systems, gas plant process, injection molding systems, and pulp and paper processing. These oils are extremely stable and resistance to thermal and oxidative degradation. In the event of a spill or accidental release of heat transfer oils, it can be ignite easily when there is an ignition source. This paper discusses the flammability and thermal stabilities of new and used oils. The flammability of the oils are assessed by measuring changes in flash point and auto ignition temperature. The thermal stability of oils are evaluated by the thermal screening unit ($TS^u$) and the differential scanning calorimeter (DSC). From the experimental results, it is suggested to give fire hazard characteristics to safe precautions for the proper use and treatment of heat transfer oils.

• 한국방재학회:학술대회논문집
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• 2008.02a
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• pp.815-818
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• 2008

Titanium was oxidized with oxygen plasma and calcinated with rapid thermal annealing for degradation of humic acid dissolved in water. Titania photocatalytic plate was produced by titanium surface oxidized with oxygen plasma by Plasma Enhanced Chemical Vapor Deposition(PECVD). RF-power and deposition condition is controlled under 100 W, 150 W, 300 W and 500 W. Treatment time was controlled by 5 min and 10 min. The film properties were evaluated by the X-ray Photoelectron Spectroscopy (XPS) and X-Ray Diffraction (XRD). From the experimental results, we found the optimal condition of titania film which exhibited good performance. Moreover photocatalytic capacity was about twice better than thermal spray titania film, and also as good as titania powder.

• Journal of the Korean Society of Safety
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• v.11 no.4
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• pp.97-106
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• 1996

Some of accidents are based on unstable chemical substances. These chemicals are easily decomposed or Ignited by heats or mechanical shocks like sodium azide. Sodium azide is commonly used as propellant for inflating automotive safety bags and the other chemical manufacturing purposes. The investigation of thermal hazard potential of sodium azide is very important because unexpected traffic accident can be occureed. The experiments were carried out by DSC, TG an ARC in air, oxygen, argon and nitrogen atmosphere. The decomposition temperatures were about $410^{\circ}C$~$420^{\circ}C$ by DSC and $330^{\circ}C$~$370^{\circ}C$ by ARC, this is very significant result for treatment of chemical. The heats of decomposition were about 81 kcal/mol in ai. and 10 kcal/mol in other atmosphere.

• Journal of the Korean Society of Safety
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• v.26 no.5
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• pp.46-53
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• 2011

The risk assessment of thermal behavior and runaway reaction cased by an exothermic batch process in manufacture of the vinyl acetate resin are described in the present paper. The aim of the study was to evaluate the risk of runaway reaction with operating parameters such as a reaction inhibitor, reaction temperature and a mount of methanol charged in the vinyl acetate polymerization process. The experiments were performed by a sort of calorimetry with the Multimax reactor system as a screening tool to investigate runaway reaction. From the experimental results, it was found that we could occur the auto acceleration for reaction of raw materials with operating parameters over $65^{\circ}C$ of reaction temperature in the vinyl acetate polymerization process.