The breaking length and tear index were both improved with
the addition of NCC. Breaking length of the handsheet kept increasing with the increase of the NCC dosage. It was increased
by 14.8% with 2.5% of NCC. The tear index increased significantly at
a relatively small dosage of NCC. It was increased by 12.2% when
0.02% of NCC was added, and changed insignificantly afterwards.
The maximum increase of tear index achieved was 13.6% at addition
of 0.5% NCC.