Acetaldehyde A.A.

Acetaldehyde is a colorless gas at room temperature, it has a strong fruity smell. It occurs naturally in many fruits and other foodstuffs and is used in the food industry as a flavor enhancer for certain products. It is also generated during the production and injection processing of PET (Polyethylene Terephthalate) material. 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 being dried, acetaldehyde can also be driven off. Therefore, correct drying is also important for acetaldehyde control.