- Home
- Companies
- IDM Instruments Pty Ltd.
- Products
- IDM - Model IDM-G0002-M1 - Gelbo Flex ...
IDM - Model IDM-G0002-M1 -Gelbo Flex Tester
Gelbo Flex Tester determines whether a certain plastic laminate material can withstand repetitive strain. It involves attaching sample pieces of plastic to the two circular clamping disks. This is via hose clamps. And then the machine twists and turns the specimen in specific movements. This process will show a visual result of pin holding. Thus, testing if the plastic can sustain the strain. If not, check plastic quality. this is usually useful within the plastic industry. The Gelbo Flex Tester has been designed to determine the resistance of flexible barrier materials to pin holing as stated in the ASTM F 392.
Flex Failure is determined by measuring the pinholes formed in a barrier structure after being subjected to the Gelbo Flex test. Pinholes are determined by use of coloured turpentine and allowing it to stain through the pinholes onto a white background. Depending on the test specimen, conditions, severity and number of test strokes can vary. The flexing is done at a rate of 45 cpm with a twisting motion repeatedly twisting and crushing the film.
While being an efficient way of determining the resistance of barrier materials to pin holing, this test method does not measure any abrasion component relating to the flex failure. Physical holes completely through the test sample are the only failures measured by the colour turpentine procedure. Gas permeation or moisture vapour transmission can be used in conjunction with the flex test to measure the loss of ply integrity.
The IDM Gelbo Flex Tester consists essentially of a 90 mm (3.5in.) diameter stationary mandrel and a 90 mm diameter moveable mandrel spaced at a distance of 180 mm (7in.) apart from face to face at the starting position (that is a maximum distance) of the full stroke.
The mandrels contain vents to prevent pressurisation of the sample. The motion of the moveable mandrel is controlled by a grooved shaft, to which it is attached. The groove is designed to give a twisting motion of 440° in the first 90 mm of the stroke of the moveable mandrel, followed by a straight horizontal motion of 65 mm (2.5in.), so that at the closed position the mandrels are 25mm (1 in.) apart. The motion of the Gelbo Flex Tester is reciprocal with a full cycle consisting of the forward and return strokes.
For the partial flex test cycle, the moveable mandrel is set up to travel only 80 mm (3.25in.) of the 180 mm (7in.) spacing. Therefore, only 90% of the twisting stroke is utilised giving a twisting motion of only 400°, and none of the horizontal stoke is utilised. A stainless steel template 200 mm x 280 mm (8 x 11in.) is used for ease of preparing test samples size. Clamps are supplied to hold the sample on to the mandrels, which will need to be supplied by the user along with a paint brush, absorbent tissue paper, white paper and coloured, water free turpentine.