The 2-point bending test rigs determine the bending stiffness according to ISO 2493 and ISO 5628.
Bending stiffness is very important in the processing of paper and carton. So that processing operations in packaging and filling machines run dependably and without problems, the paper or carton must be flexible within certain limits. During the changing of paper charges, a uniform stiffness characteristic is also required for constant working conditions of a packing machine.
The 2-point bending test unit from Zwick Roell covers two applications: calculation of bending stiffness and the determination of the folding behavior at an angle of 90°. Zwick´s high resolution and exact measurement technology allows for one load cell to cover a wide range of applications.
When testing fine paper at 15 mm bending length, the forces may be below the lower measuring limit. In such cases, bending lengths from 1 mm should be applicable. Zwick offers a unit which covers bending lengths of 1, 2 and 5 mm in fixed precision steps. Its jaws are spring operated, so that specimens are always clamped under constant conditions without pre-damaging the sample. In a limited range, this bending rig allows crease tests according to DIN 55437.
Advantages:
- Bending forces from 50 mN to 10 N are measured with one load cell
- The force measurement error is 1% of the measured force
- The load cell is placed separately from moving machine parts so that the data at the lower forces are reproducible.
- Bending angles larger than 90° are precisely measured without changing the load cell or tools
- An extremely high angle resolution of 0.001° guarantees highest dependability of measured values
- Specimen can be gripped with widths up to 38 mm
- The bending lengths can be easily adjusted to 1, 2 and 5 mm in precise steps
- The test program simultaneously determines the bending resistance, modulus, and bending stiffness
- Graphik display always shows the force-deformation behavior
