Dilek YAYLALI, Canan URAZ, Esat GÜMÜŞKAYA
colour, the colour of the resultant handsheet lightened as the hemp bast fibre percentage increased (from 0% to 100%).
Fig. 6. The physical appearance of the hand sheets Physical strength tests
In this study, physical strength tests were performed on the handsheets produced from wastepaper pulp and hemp bast fibre pulp (20°SR). The effect of the hemp ratio of the blend on the CMT, CCT, RCT, SCT and stiffness values of the papers were investigated, and the graphical results are included in the thesis of Yaylali [2020]. As shown in Fig. 7, the CMT, CCT, RCT SCT and stiffness indexes increase as the hemp bast fibre pulp ratio in the paper increases. The subsequent positive increase in the resultant compressive and bending strengths of the paper was due to the high stiffness of hemp bast fibres and the drawbacks of wastepaper. Hemp bast fibres are similar to pine in length and have thick cell walls. These properties increase the stiffness of hemp bast fibres. Recycling wastepaper results in flexibility decline, hornification, decreased fibre length and increased fines content [Kumar et al. 2020].
0,7 0,8 0,9 1 1,1
R² = 0,8326
0,99028
1,03355
0,8755
0,80887
0,799
0,8076
0 0,2 0,4 0,6 0,8 1 Hemp ratio
Fig. 7. The effect of hemp ratio of blend on the CMT value of paper
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