White biaxially oriented polyester film comprises a base layer sandwiched between a heat-sealable layer and another layer

摘要

White biaxially oriented polyester film comprises a base layer B sandwiched between a heat-sealable layer A and another layer C. White biaxially oriented polyester film comprises a base layer B sandwiched between a heat-sealable layer A and another layer C, where layer A has a minimum weld temperature of 110[deg] C or less and a weld strength of at least 1.3 N/15 mm. An independent claim is also included for a process for producing the film, comprising: compressing and melting the polymer mixtures for each layer in an extruder; extruding the melts through a fishtail die; withdrawing the film over one or more rollers; biaxially stretching and thermofixing the film; and optionally surface-treating the film by corona discharge or flame treatment.