International Journal of Scientific & Engineering Research, Volume 5, Issue 7, July-2014 401
ISSN 2229-5518
Afaf Ghais Ahmed, May Mutwly Mohammed
Abstractــــ Continued improvement of paper of paper qualities is essential to meet development needs. Therefore, one way in dealing with the problem is to recycle or just decrease the use of paper made entirely from primary components, mainly wood fibers. Analysis of mechanical properties of waste samples with and without deinking agent was carried out to explore the prospect of paper recycling. Experiments were performed on four samples, two A4, two booklets with and without deinking agent. Results, obtained from measurements, confirm that the A4 and booklets strength are improved when deinking agent was added. Shrinkage rate of less than 20 was obtained.
Index Termsــــــ Deinking, Mechanical properties, Recycled Paper
—————————— ——————————
Recycling faces many challenges, one of which is the
deinking. The deinking process increase the degree of
whiteness and cleanliness. The chemical materials used are
HE success of waste paper recycling is highly dependent on securing a satisfactory level of public participation. Wenger and Nakamura stated that
countries measure effectiveness of their waste reduction programs mainly upon two general approaches. First, on the basis of recycling rates and second, on the disposal reduction rates [1],[2].
Sustainable consumption and production is in the most challenging aspect of the waste paper and it requires changes to the way products and services are designed, produced, used and in the end, disposed [3]. The investigation possibilities to replace conventional AR4 Roffice paper and used booklets with recycled ones can assist the sustainable production of paper.
For sustainable paper recycling, specifications shall satisfy the end use characteristics such as paper grammage , thickness, strength ..ect. Paper strength is mainly influenced by the type of fiber and the alignment of the fibres in the microstructure of the paper. An important paper strength characteristic is the burst strength which is used extensively in pulp and packaging papers evaluation, [4].
————————————————
• Afaf Ghais Assistant Professor, University of Khartoum, Khartoum 321, Sudan
• May Mutwly Chemical Engineer, University of Khartoum, Khartoum
321, Sudan
hydrogen peroxide , special types of soap or detergents
. Alank ,[5] , found that d inking chemicals could have a
beneficial effect on fibers inter- bonding which removed
oleophilic materials from fiber surfaces. Another challenge
is paper shrinkage .Weise and Paulaouro observed that at
relatively drying stage of up to70%, solids caused uneven
fibers shrinkage and became visibly wrinkled,[6].
The present study used waste AR4R office papers and booklets from University of Khartoum ,Sudan, to establish the effect of recycling on paper properties in order to examine the technical possibility of utilizing waste paper .The effect of deinking on the waste papers properties were conducted. Also the shrinkage extent was determined so as to verify
the expected product loss.
Two types of waste paper , AR4R high quality office paper
(sample A) ,low quality booklets ( sample B), were collected
from University of Khartoum to be recycled and reused. A
detergent was used as a deinking material.
Samples A and B were shredded and 500 gm of each was
prepared. Three percent NaOH was added to each sample
for 1 hour. For the pulping step, samples A and B were put
in a Turbo pulper for 6 min to turn it into pulp. Each
sample was divided into two parts ( AR1R,AR2R ) and (BR1R,BR2R) of
250g each. Five percent of the detergent was added to AR1R,BR1R
for 1 hour, while AR2R,BR2R where processed without detergent .
The 4 samples (AR1R,AR2R,BR1R,BR2R) were put in a strainer to ensure
separation of fiber .The samples were placed in cloth bags
for drying , then the average moisture content (MC), and
the average moisture content factor (MCF) were calculated
IJSER © 2014
http://www.ijser.org
International Journal of Scientific & Engineering Research, Volume 5, Issue 7, July-2014 402
ISSN 2229-5518
for each sample so as to determine the equivalent paper dry
weight.
2.3 Pulp to Paper Manufacture
For each sample the wet pulp equivalent of15.6 g dry
weight was prepared and placed in desintegrator for 5
minutes to ensure fiber distribution. After distribution the
pulp was placed in a measuring cylinder and filled to 5200
m l of water. For one paper manufacture, 400 ml was taken
to the hand sheet forming machine, then the yield and the
shrinkage percentage for each paper sample was calculated.
0.6
0.5
0.4
0.3
0.2
0.1
0
A1 A2 B1 B2
The properties of the four recovered papers ( A1 ,B1 ,A2 .B 2 ) were tested according to the Technical Association of the Pulp and Paper Industry (TAPPI) standards, Table 1
.Grammage , density, tensile strength , burst strength and paper shrinkage as shown in Fig 1 to 5 .
Table 1: Technical Association of the Pulp and Paper
Industry,[6]
Fig 2:Density
3
2.5
2
1.5
1
0.5
0
Specimen
A1 A2 B1 B2
Specimen
Fig 3:Tensile Strength
67
66
65
64
63
62
61
60
59
58
A1 A2 B1 B2
Specimen
120
100
80
60
40
Fig. 1 :Grammage 20
0
A1 A2 B1 B2
Specimen
Fig 4:Burst Strength
IJSER © 2014
http://www.ijser.org
International Journal of Scientific & Engineering Research, Volume 5, Issue 7, July-2014 403
ISSN 2229-5518
25
20
15
10
5
0
A1 A2 B1 B2
[1] B .Norman. and D .Wahren., “Mass Distribution of Sheet Properties of Paper”, Trans. BPBIF Symp. Fund. Props Paper Related to Uses, Cambridge; pp7-70, 1976 .
[2] S. Nakamura,’’An inter industry approach to analyzing economic and environmental effects of the recycling of waste’’, Ecological Economics. 28(1-2), pp.133-145,1999.
[3] H. Packard Inc. ,’’Office paper recycling study’’, Bristol, UK.,2005.
[4] H.A. NasH, ’’The European commission’s sustainable consumption and production and sustainable industrial policy action plan’’. Journal of Cleaner Production. 17(4), pp.496-498, 2009.
[5] www.testingmachines.com/pdf/guidstrn.pd, Paper
Fig 5: Shrinkage
Specimen
strength testing application information,25 June 2014. [6] K. Alanko, H., Paulapuro, and P.,Stenius
,’’Recyclability of thermo mechanical pulp fibers’’,
The basis weight or grammage is the most fundamental
property of paper and paperboard. The Basis weight of
paper is the weight per unit area. For new paper the
standards grammage for office paper is (60-90) g/m2 .The
samples ( A1 ,B1 ,A2 .B 2 ) grammage range from 60 to
65which is within the range of office paper grammage . The
deinked samples A1 ,B 1 have lower grammage than A2 ,B2 .
Fig.1.
Bulk or density is another very important parameter of paper, particularly for printers. Bulk is a term used to indicate volume or thickness in relation to weight. It is the reciprocal of density . Decrease in bulk or in other words increase in density makes the sheet smoother, glossier, less opaque, darker, lower in strength etc. Samples A1 ,B 1 with detergents ,Fig. 2 have lower densities than A2 ,B2 with mean higher strengths . This means that the deinking process lowers the density while improving the strength and quality of paper, Fig 3.
Bursting strength tells how much pressure paper can tolerate before rupture. Bursting strength is measured as the maximum hydrostatic pressure required rupturing the sample by constantly increasing the pressure. A1 ,B1
specimens showed high burst strength ,Fig 4. The shrinkage is high in samples A1 ,B1 ,the deinking increases the loss of fibers .Fig 5
The results showed that A4 office paper and booklets kept most of their original properties, even after reuse. Recycled paper produced from secondary cellulose fibers, meets the required standards and expectations. In spite the shrinkage of fibers the presented work showed positive results of recycling A4 and booklet papers .
The authors present their great thanks for the National Research Centre Laboratories staff ,Sudan ,deep appreciation for Dr.Mohammed Yousif for his great help.
paperi Puu 77(5),315-317,319-321.323-325,327-328, 1995.
[7] Anon.”TAPPI test methods, Tappi, Atlanta,1988.
IJSER © 2014
http://www.ijser.org