Cleaning method for polyethylene terephthalate containers

A method for cleaning polythylene terephthalate containers, said method comprising the steps of soaking the container in an alkaline wash solution having a temperature ranging from about 50° C. to 60° C., said alkaline wash solution formulated from a first concentrate, a second concentrate, an alkalinity source, and a balance of water;

• (a) said first concentrate comprising a first nonionic surfactant, a first builder, and acid in an amount effective to provide a phase stable solution having a pH of less than about 2;
• and
• (b) said second concentrate comprising a second noniomic surfactant, and a second builder wherein said first and second concentrate are present in the wash solution in a concentration ranging from about 0.3 wt-% to 2.0 wt-%, said first nonionic surfactant having a cloud point ranging from about 5° C. to 60° C.

A method for cleaning polyethylene terephthalate containers, said method comprising the steps of contacting the container with an alkaline wash solution having a temperature ranging from about 50° C. to 60° C., said alkaline wash solution formulated from a first concentrate, a second concentrate, an alkalinity source, and a balance of water;

• (a) said first concentrate comprising a first nonionic surfactant, a first builder, acid in an amount effective to provide a phase stable solution, and a coupling agent comprising a phosphate ester;
• and
• (b) said second concentrate comprising a second nonionic surfactant, and a second builder wherein said first and second concentrate are present in the wash solution in a concentration ranging from about 0.3 wt-% to 2.0 wt-%, said first nonionic surfactant having a cloud point ranging from about 5° C. to 60° C.