Biaxial stretching of polymers using a novel and versatile stretching system

A novel versatile biaxial stretching module that can be adapted to any uniaxial traction testing machine was developed to generate consecutive or simultaneous two‐directional biaxial stretching at various stretching ratios and draw rates. The module allows direct conversion of the uniaxial machine displacement to transverse displacement with a precise adjustment of the stretch ratio between the transverse of the longitudinal strains. Additionally, the developed device allows simultaneous measurements of films mechanical properties in the two directions. The efficiency and the accuracy of the module were verified without and with standard polymer films such as polypropylene and high density polyethylene. POLYM. ENG. SCI., 2011. © 2011 Society of Plastics Engineers