This standard primarily specifies the technical requirements and testing methods for unoriented PET sheets produced from virgin PET resin or recycled materials. It applies to sheets with a thickness of less than 2.0 mm but excludes foamed sheets and shrink films. The core content of the standard includes product classification and detailed physical and chemical performance indicators. For instance, it requires a tensile yield stress of at least 45 MPa and specifies testing methods for optical properties such as light transmittance and haze, as well as barrier properties like water vapor transmission rate. To ensure the accuracy and uniformity of quality evaluation, the standard recommends the use of equipment such as intelligent electric tensile testing machines for mechanical performance testing.