Dart Impact Tester Used in Plastic Testing Industry

FARIDABAD, India - Sept. 7, 2013 - PRLog -- Presto Dart Impact Tester (http://www.prestoquality.com/instruments-for-pipes/dart-impact-tester-1) is traditionally used for evaluating the impact strength or toughness of a packaging material, by determining the mechanical properties of the plastic film/laminates/paper used for packaging. This test procedure involves a single dart configuration dropped from varying heights, while the weight of the dart is constant. The hemispherical dart is held by strong electromagnetic force of its holder and is released at the press of a button. The impact of this fall causes the plastic sample under test to fail/tear. Test results thus, obtained can be used either as a quality control evaluation or for end use comparisons.

The Presto Dart Impact Tester (http://www.prestoquality.com/instruments-for-pipes/dart-impact-tester-1) comprises a sturdy horizontal base-plate on which a vertical column of steel has been erected. A release mechanism, in which the falling dart can be inserted, is fitted on the top of the column. The dart has a diameter of 38.1 mm (1.5 in.) and is partly made of aluminum. It has a polished surface and consists of a vertical shaft in the center of the flat top surface in order to accommodate additional weights, if required. A circular clamping device has been incorporated on the base-plate in the vertical center line of the inserted dart. This special clamping device consists of a firm and a movable cylinder, which is operated by means of a handle. The test sample can be easily clamped between both cylinders and the impact of the falling dart on the centre of the sample film is measured accurately.

Generally, the "Bruceton Staircase" method is used for analysis. In this method, a series of 20 to 25 impacts are conducted. If the sample under test passes i.e. does not tear by the impact, the drop weight is increased by one unit. On the contrary, in case a test specimen fails or tears by the impact of the weight, the drop weight is decreased by one unit. The results from these impacts are then complied to calculate the Impact Failure Weight. This Impact Failure Weight is defined as the point at which 50% of the test specimens will fail under the impact.

The equipment is built on a rigid metallic base plate and finished in Autumn Gray & Blue combination painting and bright chrome / zinc plating is provided in order to give it a corrosion resistant finish. The Instrument comes complete with Instruction Manual, Electrical Wiring Diagram & Calibration Certificate traceable to NABL approved Labs.