Even strength within specifications and across the reel width

L&W ZD Tensile Tester measures internal bond strength – or Z-direction (ZD)

tensile forces – of paper and multi-layered paper products, such as linerboard

and box board. The tester uses an automated method and you obtain fast

and reliable measurement values, which make it possible to achieve uniform

strength across the reel width. All in compliance with customer specifications,

as well as in accordance with applicable standards (ISO, TAPPI, SCAN).

Full control of the internal bond strength, is particularly important in the

production of multi-layered paper products. Low or unevenly distributed

internal bond strength can cause material splitting in an offset press with

sticky printing ink. In the creasing or scoring operation of boxboard the

material should delaminate “just enough”. Otherwise after folding there

will be poor folding lines or cracks in the outer layer. Internal bond strength

tests can predict this.

Enough internal bond strength is also needed in heat-set web offset printing

of highly coated paper. Otherwise blistering will occur when moisture will try

to escape during the heating process. Too high internal bond strength impedes

the creasing of the boxboard and high values also mean a waste of raw material

and energy. In other words, the aim is to achieve an even strength within

specifications and across the reel width. L&W ZD Tensile Tester can achieve this.