PAPERmaking! Vol7 Nr2 2021

5822

Cellulose (2021) 28:5807–5826

Table 5 Optical properties of CTMP and PCC-CTMP handsheets

2 /kg)

2 /kg)

s r (m

k

r (m

Opacity (YC/2)

R457C

CTMP

0 min R30

50.0

22.42

1.92

81.3

R100

53.3

27.11

1.82

84.0

R200

54.4

37.63

2.34

90.4

R400

55.7

69.69

4.18

97.9

Not fract

64.7

35.71

1.09

84.8

30 min R30

51.2

23.22

1.86

81.6

R100

53.3

26.85

1.84

83.9

R200

55.1

35.51

2.18

89.2

R400

55.5

64.78

4.01

97.5

Not fract

63.0

40.94

1.49

88.7

60 min R30

49.8

23.24

1.98

82.1

R100

53.2

27.54

1.90

84.6

R200

55.2

34.80

2.10

88.7

R400

56.1

59.83

3.60

96.7

Not fract

65.8

39.54

1.17

86.8

PCC-CTMP 0 min R30

43.8

22.47

2.63

84.2

R100

46.9

28.95

2.81

88.4

R200

50.7

36.91

2.92

91.7

R400

58.8

78.23

4.13

98.3

Pass

75.7

60.70

1.11

91.8

Not fract

65.8

47.86

1.48

90.6

30 min R30

43.9

24.15

2.86

86.1

R100

47.5

29.28

2.79

88.5

R200

50.4

36.39

2.94

91.5

R400

57.1

74.73

4.37

98.3

Pass

74.5

60.25

1.29

92.4

Not fract

68.9

52.03

1.33

91.0

60 min R30

43.0

23.51

2.95

85.9

R100

47.1

28.35

2.78

88.1

R200

50.0

34.68

2.86

90.8

R400

57.9

79.36

4.51

98.5

Pass

70.7

47.24

1.39

90.1

Not fract

69.0

54.70

1.41

91.8

charge density was the increase in surface area and fiber damage (resulting in high energy sites). It can be argued that the surface created in refining has, for the

most part, a charge similar to that of pre-existing surface because the newly created surface has a chemical composition similar to that of the pre-

123

Made with FlippingBook Online newsletter maker