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Showing posts from April, 2009

Safety precautions for extrusion blow molding

Safety is everyone's responsibility in the workplace. Safety is most often related to good maintenance practice and good housekeeping. Safety needs to be an attitude that is always present in your daily activities. Employees should not be hesitant to voice safety concerns in the workplace. Management is just as committed to safety as the operators on the floor; the primary difference is that the operators are usually the closest to unsafe conditions; keep management advised of unsafe conditions. The following list includes items which should be maintained to assure a safe working environment: 1. Floor and machine should be kept free of oil. 2. Floor and machine should be kept free of pellets. 3. Never reach over or under machine guards. 4. Never climb between the tie bars when hydraulic pumps are running. 5. Never disconnect or by-pass safety switches on guards. 6. In order to prevent mechanical hazards such as limbs being drawn into or trapped in the machinery, operators shoul

Acetaldehyde A.A. in poly(ethylene terephthalate) processing

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Acetaldehyde A.A. is an organic chemical compound with the formula CH 3 CHO . Is a colorless gas at room temperature and has a strong fruity smell. It occurs naturally in many fruits and other foodstuffs is used as a flavor enhancer for certain products and is produced by plants as part of their normal metabolism. Acetaldehyde is also generated during the production and injection processing of poly(ethylene terephthalate), PET material. It can cause an off-taste in bottled water. Generally, most acetaldehyde problems originate in the barrel during the injection process. All PET resins have some residual acetaldehyde after being manufactured, the quantity will vary according to the grade. Acetaldehyde is only generated while the PET resin is in its melt condition, therefore it can only be controlled by adjustments in the barrel (90%) and hot runner (10%) of the machine. The generation of acetaldehyde is not linked to moisture content of the material, although in the process of be