PN-IBT paper and Cardboard internal bonding strength Tester is a testing instrument for the internal bonding of paper and Cardboard designed and developed according to the national standard GB/T26203. It is mainly suitable for single-layer and multi-layer paper and Cardboard, including Spreader paper and paper and Cardboard covered with synthetic polymer. It is not suitable for low-weight, multi-empty, soft or low-density paper and Cardboard.