Non-carbonated drinks such as juices and other products such as sports drinks or highly acidic drinks need to be hot-filled into PET bottles. In these cases, the package must be heat-set in order to improve the temperature resistance of the container. Thus PET resins with a faster rate of crystallization are the preferred packaging material.
Generally lower levels of copolymers are preferred and IV (intrinsic viscosity) levels of about .80 are acceptable. As non-carbonated drinks are sensitive to microbiological spillage they need to be pasteurized before entering the filler unit in the beverage processing area. To avoid re-contamination during the filling and capping process there are four available solutions: addition of shelf life enhancers (preservatives) which chemically exclude bacteria growth; hot-filling; pasteurization tunnel; cold aseptic filling. Based on their pH levels, these drinks are categorized as low acid (pH > 4.5) and high acid (pH < 4.5). The vulnerability of these drinks is directly related to their pH value. The lower the pH value, the smaller the environment for bacterial growth. All products with a pH value between pH 0 and pH 4.3 can easily be "decontaminated" by heat treatment. Products with pH values over 4.3 must be bottled in safer, aseptic conditions.
The main requirements of a container for juices and isotonic (non-pressurized) drinks:
- Oxygen barrier
- UV and visible light barrier (for some products)
- Ultra Clean or Aseptic bottles
- Heat resistant bottles (Hot-Fill bottles)