The Zwick Roell burst tester is an accessory of the testing machine for performance of the burst test. The testing machine takes over the functions of the hydraulic pump, the data acquisition and evaluation. This makes the burst test a program controlled test which assures correct test results with a minimum of manual operation.
When clamping a corrugated board specimen, it is important for the reproducibility of test results, to apply and maintain an accurate clamping force. For easy use, Zwick offers a pressure preselector, which allows for the application of 5 different clamping pressures by simply turning the selector knob.
Special attention must be paid to the dynamics of the testing instrument when determining the burst strength. Since a burst test is performed within a few seconds, the maximum pressure should applied precisely, the data acquisition rate of the testing instrument must be correspondingly high. If comparing results between different laboratories, the data acquisition rate of the instruments must be identical. Zwick Roell instruments can control the data acquisition rates so that systematic deviations between different laboratories can be prevented.
Similar conditions are true for the stability of the volume flow during the test. Zwick Roell testing machines work with a digital control to insure a constant volume flow, independent of the loading.
Further, the easy serviceability and the simple membrane monitoring must be pointed out. If a constant volume is pumped into the test chamber without a specimen, the maximum pressure indicates if the membrane is still in good condition or if it has become weak. The time dependant membrane behavior is automatically displayed and stored with the connected PC.
For burst testing of paper materials, there are two standards: ISO 2758 describes tests on paper, ISO 2759 describes the requirements for carton, corrugated board and corrugated base paper. Zwick offers a test instrument for each of these standards and thereby covers the range from paper to heavy corrugated board.
The advantages:
- The operator does not need to worry about the details and is free to concentrate directly on the test at hand.
- The tests are performed under constant conditions even when there is a change in operators.
- The bursting of the specimen is recognized by the machine and the test is ended. This way, the membrane is stressed less and has a longer lifetime.
- A variable data acquisition rate guarantees comparable results between producer and processor.
- The flow is controlled in a very narrow tolerance range and remains constant even at high loading.
- With the real-time graphics, the operator immediately sees if the test has been performed correctly.
- Service interfaces and maintenance friendly construction reduce idle times and consequential costs.
