OAKLAND
INSTRUMENT CORPORATION
Offering a complete line of material flexibility testing instruments including the
model GFT-
Model GFT-392 Gelbo Flex Durability Tester
TM
Applications: Flexible plastic films
Coextruded structures
Coated films and paper
Designed to determine the flex resistance of flexible barrier materials by applying repetitive strain. Pinholes formations are the criteria for measuring failure and are determined by use of colored liquid and allowing it to stain through the pinholes onto a white backing. The flexing action consists of a twisting motion combined with a horizontal motion, thus, repeatedly twisting and crushing the film. The frequency is at a rate of 45 cycles per minute. There are 5 test conditions to choose from; one may choose a test cycle that simulates real conditions from partial flex for 20 cycles to full flex for 2700 cycles.
This test is used to determine flex resistance. Favorable flex resistance may reduce the risk of the material developing pinholes during transportation. A predetermined number of cycles are completed during the test and then the material is removed from the tester and tested for pinholes using a blue dye.