Philippine Journal of Science 141 (2): 179-185, December 2012 ISSN 0031 - 7683 Date Received: 20 Sept 2011

Parchment-Like Using Water Hyacinth

Erlinda L. Mari

Forest Products Research and Development Institute Department of Science and Technology College, Laguna

Water hyacinth pulps, obtained by open-vessel cooking of fresh, air-dried, and ground water hyacinth stems, were mixed with abaca and wastepaper pulps to form handsheets. The handsheets had natural glaze and those from pure hyacinth pulps were fairly translucent, with Cobb values of 38-40 g/m2 that compare well with commercial parchment paper. Compared with either pure abaca or pure wastepaper pulp, replacement with water hyacinth pulp by 25 to 75% significantly improved burst index and tensile index, suggesting better formation and bonding of fibers. Inversely, however, any amount of the soft and short-fibered hyacinth pulp with either pulp reduced tear index, understandably because this property is dependent more on fiber length. With wastepaper pulp, water hyacinth pulp improves the tensile property to a level comparable with that of paper from abaca pulp as well as parchment paper.

Key Words: Cobb values, fiber formation, tensile index

INTRODUCTION Interestingly, water hyacinth is already widely used in handmade (HMP) in Kenya (http:// Local studies on the pulp and papermaking potential of www.unep.org/roa 2008) and Bangladesh (http:// water hyacinth conducted in the late seventies (Zerrudo www. Bangladesh.com/ 2008) and is also becoming an et al. 1978, 1979) followed the conventional method alternative fiber material for HMP in some regions of the of pulping at high temperature and pressure using Philippines where it is abundant. steam-heated closed digesters. Results of these studies concluded that depithed water hyacinth stalks may be HMP makes use of different non-wood fibers, such as pulped satisfactorily by any conventional process but abaca, cogon, banana fiber, which are pulped by cooking the low pulp yields and low initial freeness of the pulp in open vessels under open-fire, unlike the steam-heated negate its use for ordinary paper. However, the high water closed digester method of cooking. Considering that resistance, non-porous, and oil-proof properties of the water hyacinth is similar to these non-wood fibers, its paper produced suggest that water hyacinth pulps may be abundance and the reported water resistance of its pulp used for specialty such as the parchment type of is an encouragement for its use particularly for special papers. Much earlier references cited by the authors also or high end HMP, such as for parchment, lamp shades, mention similar results. or special packaging. This should compensate for the very low dry solid content (about 5 %, green basis) that The cooking method used, however, is capital intensive discourages serious consideration. and energy consuming for a material with very low dry solid content of only about 5 %. The use of water hyacinth Problems arising in the use of water hyacinth need to be for pulp and papermaking, thus, did not prosper this way. addressed, however. When used as fresh, the material is very bulky that a 200-L drum usually used for cooking can accommodate only a fraction of the usual load of dry fibers. *Corresponding author: [email protected]

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Thus, air-drying prior to cooking would be advantageous; but Preparation of handsheets this would require large space and additional time for drying. Moisture contents of the pulps were determined to Moreover, water hyacinth material, even when dried, cannot calculate the respective oven-dry mass. The three pulp be stored for a long time because it is easily attacked by fungi. materials were then mixed at the following proportions on oven-dry basis: Incidentally, in a previous study aimed at taking advantage of the mucilaginous property of water hyacinth (Mari et al. Pulp Proportions 2010), water content of the plant’s stems was mechanically Abaca (A) Wastepaper (W) Water Hyacinth (F, D, G) extracted and successfully used as formation aid in 100 0 0 making handsheets from equal proportions of abaca and 75 0 25 wastepaper pulp. The extract significantly increased the 50 0 50 tensile strength of the resulting handsheets while residual 25 0 75 mass after extraction can be used for other purposes. 0 100 0 0 75 25 Considering the above information, this study evaluated 0 50 50 0 25 75 the suitability of water hyacinth pulp for specialty 0 0 100 handmade paper using this residual mass and compared the results with those from the fresh and air-dried stalks. The evaluation focused specifically on the strength Testing and evaluation of properties of handsheets properties and water resistance of standard laboratory Hand sheets were tested for Cobb, burst, tensile, and handsheets from pure water hyacinth pulp and in mixture tear strength properties in accordance with the standard with either abaca or wastepaper pulp. Proportional cost of procedures, ISO 535, ISO 2758, ISO 1924-2, and ISO water hyacinth as raw material in comparison with abaca 1974, respectively (ISO 2003). For burst test, 10 sample was also estimated based on pulp yield and purchase cost data were obtainable; the rest, only 5 sample data per of raw material. Results from this study will significantly treatment. add to the considerations (advantages and disadvantages) in using water hyacinth as a raw material for paper. Analysis of variance (ANOVA) in completely randomized design (CRD) and Duncan Multiple Range Test (DMRT) were conducted to evaluate the effect of the different proportions of pulps on the handsheets. MATERIALS AND METHODS Estimation of costs Materials Estimation of cost was limited to the cost of abaca and The fiber materials were commercial semi-bleached water hyacinth materials based only on their respective abaca pulp, trimmings, and water hyacinth pulp yield and purchase cost. stems from three preparations prior to pulping, namely, fresh (F), air dried (D), and the residual mass (G) after the extraction of the stems’ juice. RESULTS AND DISCUSSION Preparation of pulps The commercial semi-bleached abaca pulp lap and bond Pulp Freeness paper trimmings were simply disintegrated into pulp. The freeness of pulp is a measure of the rate at which a dilute suspension of pulp may be drained (ISO 5267- The water hyacinth materials were separately cooked with 2:2001 (ISO 2003). It is a measure used in controlling the NaOH at 15% chemical charge (based on oven-dry mass) beating operation as it relates to the speed at which paper in an 80-L vessel for two hours. The cooked fibers were could be made as well as the corresponding changes in squeezed off residual cooking chemical, washed with strength of paper from the beaten pulps. water, and then disintegrated in the valley beater. The pulp was bleached with 5% calcium hypochlorite for 30 Figure 1 shows the freeness values in Canadian Standard minutes and washed thoroughly. Freeness (CSF) mL of pulp stocks from different proportions of water hyacinth (F only), abaca, and wastepaper pulps. Pulp Freeness The freeness of water hyacinth, abaca, and wastepaper pulps, In this study, the freeness of the water hyacinth pulps after singly or in combination with each other, was measured disintegration was measured first. Pulp G’s freeness could following the standard ISO 5267-2:2001 (ISO 2003). not be determined as water could hardly drain. Pulps F and

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show the difference when water hyacinth pulp is partly substituted to these materials. This is limited to this study only and does not necessarily suggest elimination of beating for other purposes. As Figure 1 shows, 100% abaca pulp had the highest freeness value of 674 CSF mL, followed by wastepaper pulp wit 473 CSF mL. Partial substitution with water hyacinth pulp caused proportional decrease in the values. Tables 1 and 2 show the results of ANOVA on the properties of handsheets from different proportions of hyacinth pulp (F, D, and G) with abaca and wastepaper pulps, respectively. Incidentally, no hand sheet was successfully formed with 100% pulp from ground (G) Figure 1. Freeness values of different pulp stocks. hyacinth stems, as the pulp slurry could not drain. Thus, Note: A – abaca; W – wastepaper; FH – fresh water hyacinth instead of factorial in CRD with type of hyacinth pulp and pulp ratio as variables, ANOVA in simple CRD was D (no longer shown) had very low freeness, which indicate conducted for each pulp combination with only pulp ratio the pulps’ very fine nature and the probable cohesion or as the variable. Data indicate highly significant effect of pulling together of the hemicelluloses and other softened the treatments on all properties. substances in the pulp as the water is drained. In view of Figures 2 and 3 illustrate the property mean values. In this, it was decided that the other materials (abaca and both figures, the left set of data is with abaca and water wastepaper) would also no longer be beaten to clearly

Table 1. ANOVA on the properties of handsheets from different proportions of water hyacinth and abaca pulps.

F:A pulp mixtures Source of Variation Mean Square DF Burst Index DF Tear Index Tensile Index Cobb Treatment 4 5.554** 4 1241.650** 292.525** 4254.421** Error 45 0.584 20 31.478 64.425 54.422 Total 49 24 R-square, % 45.8 88.8 47.6 94.0 Coefficient of variation 19.158 22.758 16.301 8.227 D:A pulp mixtures Source of Variation Mean Square DF Burst Index DF Tear Index Tensile Index Cobb Treatment 4 6.267** 4 1035.651** 321.869* 4603.824** Error 45 0.380 20 23.144 92.616 62.214 Total 49 24 R-square, % 59.4 89.9 41.0 93.7 Coefficient of variation 13.819 24.778 19.381 9.506 G:A pulp mixtures Source of Variation Mean Square DF Burst Index DF Tear Index Tensile Index Cobb Treatment 3 3.786** 3 920.751** 532.801* 806.006** Error 36 0.244 16 31.104 101.353 114.113 Total 39 19 R-square, % 56.3 84.7 49.6 57.0 Coefficient of variation 10.984 22.769 19.063 11.116 ** - Statistically significant at 1 % probability level F, D, G - pulps from fresh, air-dried and ground hyacinth stalks, respectively. * - Statistically significant at 5 % probability level A and W - pulps from abaca and wastepaper, respectively. ns – not significant

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Table 2. ANOVA on the properties of handsheets from different proportions of water hyacinth and wastepaper pulps.

F:W pulp mixtures Source of Variation Mean Square DF Burst Index DF Tear Index Tensile Index Cobb Treatment 4 3.900** 4 48.855** 439.024** 2847.453** Error 45 0.114 20 0.887 27.994 15.578 Total 49 24 R-square, % 75.2 91.7 75.8 97.3 Coefficient of variation 17.394 13.065 16.482 4.925 D:W pulp mixtures Source of Variation Mean Square DF Burst Index DF Tear Index Tensile Index Cobb Treatment 4 9.465** 4 52.643** 685.823** 2601.355** Error 45 0.242 20 0.848 13.635 12.166 Total 49 24 R-square, % 77.7 92.5 90.9 97.7 Coefficient of variation 17.640 13.263 9.337 4.826 G:W pulp mixtures Source of Variation Mean Square DF Burst Index DF Tear Index Tensile Index Cobb Treatment 3 5.815** 3 47.123** 572.204** 1966.796** Error 36 0.077 16 0.725 35.091 104.878 Total 39 19 R-square, % 86.3 92.4 75.4 77.9 Coefficient of variation 12.774 11.048 17.109 11.161 ** - Statistically significant at 1 % probability level F, D, G - pulps from fresh, air-dried and ground hyacinth stalks, respectively. * - Statistically significant at 5 % probability level A and W - pulps from abaca and wastepaper, respectively. ns – not significant hyacinth combinations; the right set, for wastepaper and substitution with hyacinth pulp improved burst and tensile water hyacinth combinations. Values for parchment paper properties comparable with those of abaca and hyacinth cross as a horizontal line for comparison purposes. pulp in the same proportion. Figure 2 shows the burst index (upper graph) and tensile Figure 3 (upper graph) on the other hand, shows that any index (lower graph) of the different pulp combinations. amount of hyacinth pulp reduced tear index, whether with Compared with hand sheet from pure abaca pulp, abaca or wastepaper combinations. This is understandable combining with hyacinth pulp from 25 to 75% resulted in because this property is dependent more on fiber length. an improvement in both burst and tensile indices with the Handsheets from abaca registered the highest tear index. best results around 50 A: 50H. Burst index significantly This is not unexpected as abaca fiber (about 6 mm in length) improved by 7 to 39% and tensile index by 52 to 58%, has been recorded with outstanding tear strength (Atchison suggesting better formation and bonding of fibers that 1993). In this study fiber dimensions were not measured. may be attributed to the hyacinth pulp acting as dry However, the tear index data decreasing with addition of strengthening agent. The tendency to decrease from a hyacinth pulp suggests that the fibers of water hyacinth peak with more hyacinth pulp indicates a limitation. (about 1.53 mm in length according to Zerrudo et al. 1978), Nonetheless, even a 75% substitution with hyacinth pulp may be much shorter than the already degraded wastepaper. is comparable with parchment paper. Regarding water resistance, Figure 3 (lower graph) shows With wastepaper, burst and tensile indices almost the parchment paper with a Cobb value of 40 g/m2. Values continuously increased by 20 to 183% and 65 to 141 for the handsheets from pure water hyacinth pulp come %, respectively, with an increase in the proportion of in very close at 38-40 g/m2. These are almost the same hyacinth pulp. Wastepaper is secondary fiber that could values by which the diploma and waterleaf papers (Cobb have undergone several recycling. With each recycling, values 35.1 and 40.1 g/m2, respectively) from pure water fiber properties suffer degradation (Kleinau 1993; Mari et hyacinth pulp (prepared by closed vessel alkaline sulfite al. 2011). Despite the degraded wastepaper fibers, 75 % pulping) are considered water resistant (Zerrudo et al.

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Figure 2. Burst and Tensile properties of handsheets from different Figure 3. Tear and Cobb properties of handsheets from different proportions of water hyacinth (H) pulp with abaca (A) or proportions of water hyacinth (H) pulp with abaca (A) or wastepaper (W) pulps compared with parchment paper. wastepaper (W) pulps compared with parchment paper. Note: MD and CD – machine and cross directions, respectively

1979). This implies that with the closeness in Cobb The introduction of other fibers into the system may have values, the pulping process has no remarkable effect on broken this reorientation of molecules on the boundary the self- ability of the generated water hyacinth pulp surface thereby opening hydrophilic surfaces on the sheet to impart water resistance on the formed paper. resulting in poor water resistance. This self-sizing effect is also manifested in the translucent appearance and natural Self-sizing occurs when “ and extractives with low glaze of the handsheets from pure water hyacinth pulp softening point are redistributed on the fiber material by similar to parchment paper. Figure 4 shows the SEM surface diffusion or by gas-phase diffusion and condensation” micrographs of handsheets from pure hyacinth pulp and (Eklund and Lindstrom 1991). In this case, self-sizing may 50A:50H pulp combination. The former shows a smooth have been due to redistribution of the hemicelluloses and surface of partly dissolved fibers while the latter has the dissolved substances in water hyacinth fibers. more visible but well-laid abaca fibers (A) partly overlaid Interestingly, however, this ability is adversely affected by the partly dissolved, translucent hyacinth (H) fibers. by the introduction of any amount of other pulps to the Incidentally, although no handsheet was formed with the material. Thus, the Cobb values significantly increased for pulp (G) from ground stems, the preceding data indicate a the handsheets from water hyacinth pulp combined with trend where there seems to be not much difference among even the least amount of either abaca or wastepaper pulp. the pulps from the three methods of preparation for water The result indicates that the abaca or wastepaper pulp hyacinth stems. Pulp yield was also around 30% for all served to break the relatively hydrophobic bonds probably three. It may be inferred that it is indeed possible to extract formed by self-sizing in water hyacinth pulp sheet.

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HV mag  WD 400 μm HV mag  WD 400 μm 10.00 kV 500 x 10.0 mm Dry Water hyacinth - Abaca 10.00 kV 500 x 10.0 mm Dry Water hyacinth - Abaca Figure 4. SEM micrographs of handsheets. Note: Abaca (A) and water hyacinth (H) fibers as indicated by arrows

Table 3. Cost estimates for abaca and water hyacinth raw materials (based on pulp yield) at different pulp proportions.

Fiber Raw Pulp (Abaca:Hyacinth),kg / FRM Cost Estimated Pulp FRMCost/kg, Material 75: 0: Yield, % PhP 100:0 PhP PhP 50:50 PhP PhP (FRM) 25 100 Abaca 60 30 367 11000 275 8250 184 5500 0 0 Water 30 10 0 0 330 3300 660 6600 1330 13300 Hyacinth Total Cost 11000 11550 12100 13300 Difference from 100% Abaca +5% +10% +21% first the juice from water hyacinth for use as formation with other compost materials or as animal feeds in aid (Mari et al. 2010), and then pulp the residual mass for neighboring areas. Furthermore, production shall not be mixing with other pulps. This will lessen the difficulty in limited to the processing and use of pure water hyacinth pulping large volumes of fresh water hyacinth stems and pulp. The use of ground stems after extraction of juice is do away with pre-drying. worthy of consideration to simplify pulping. Although not estimated in this study, it is believed that the cost of energy due to grinding and extraction may be possibly Estimation of costs recovered from the use of the juice as formation aid for Despite the seemingly huge volume of water hyacinth other pulp materials. The water hyacinth pulp shall also obtainable from bodies of water, production of paper from be in combination with wastepaper or other fibers. pure water hyacinth pulp, though technically feasible, has not progressed to commercial production of paper. This Table 3 shows cost estimates for the raw materials for a study also confirmed the technical feasibility of producing production capacity of 200 sheets per day at 25 days per parchment-like paper from pure water hyacinth pulp. It month. For a 44-gram 24” x 36” sheet, the total pulp further showed the technical feasibility of mixing water requirement per month would be 220 kg of dry pulp. hyacinth pulp with either wastepaper or abaca pulp to Based on a PhP10/kg cost of fresh water hyacinth (which produce handsheets with strength properties better than is actually for labor cost for collection), increasing the either the pure abaca or wastepaper. proportion of water hyacinth pulp results in a more costly material due to its low recovery. Thus, handmade paper The use of water hyacinth pulp appears to be more feasible from water hyacinth may be recommended for special for handmade papermaking as the fiber requirement end-use due to its natural glaze, greater tensile strength is smaller. The non-fibrous portion may be disposed

184 Philippine Journal of Science Mari EL: Parchment Paper from Water Hyacinth Vol. 141 No. 2, December 2012 and water resisting property (from 50 % proportion and Rio, for the assistance during the experiments; Ms. Adela up) but probably at higher price to compensate for the S. Torres and Mildred M. Fidel, for some suggestions; and additional cost due to lower recovery. Ms. Socorro Dizon, for the statistical analyses of data. It is a sad reality that although water hyacinth is considered a “pest,” there is definite cost for its collection and use as raw material. REFERENCES ATCHISON JE. 1993. Data on non-wood plant fibers. In: Pulp and Paper Manufacture. Vol. 3. Secondary CONCLUSIONS AND RECOMMENDATIONS Fibers and non-wood pulping. Hamilton F, Leopold B. Technical Eds., Kocurek MJ, Series Ed. Joint Textbook The residual mass after extraction of juice from water Committee of the Paper Industry. Canada: TAPPI USA hyacinth stalks can be pulped but the low freeness or poor and CPPA Canada. p. 4-16. drainage of the resulting pulp prevents it from forming into paper. Low freeness is an indication of short fibers. EKLUND D, LINDSTROM T. 1991. Chapter VIII. Water However, the pulp, similar to those from the fresh and penetration and internal sizing. In: paper Chemistry. An st air-dried stalks, can be used in mixture with abaca or Introduction. 1 English Edition. Finland: DT Paper wastepaper pulps for sufficient freeness to produce paper. Science Publications. p. 203-215. Compared with either pure abaca or wastepaper pulp, KLEINAU JH. 1993. Secondary fibers and recycling. replacement with water hyacinth pulp by 25 to 75% In: Pulp and Paper Manufacture. Vol. 3. Secondary significantly improves burst index and tensile index, Fibers and Non-Wood Pulping. Hamilton F, Leopold B, indicating better formation and bonding of fibers due to eds. Joint Textbook Committee of the Paper Industry, the water hyacinth pulps’ self-sizing ability. TAPPI USA and CPPA & Canada.p.127-131. Inversely, any amount of the soft and short-fibered MARI EL, TORRES AS, AUSTRIA CO, HABON ABP. hyacinth pulp combined with either abaca or wastepaper 2011. Recycling mimeograph-printed paper. pulp reduces tear index, understandably because this ASEAN J Sc Technol Dev 28(2):156-167. property is dependent more on fiber length. MARI EL, AUSTRIA CO, LAPUZ ARP. 2010. Effect of water hyacinth extract on paper. Philipp. Forest Water hyacinth pulp’s self-sizing ability is manifested more Products J. Vol. 1 (In press.). by the natural glaze, translucent appearance and Cobb values of 38-40 g/m2 of handsheets from the pure pulp [ISO] International Standards Organization. 2003. that are comparable with commercial parchment paper. Standards Handbook. Paper, board and pulps. Vol. 1. The water resistance imparted by this self-sizing ability is, Third Ed. Switzerland. 834p. however, adversely affected by the presence of any amount ZERRUDO JV, TADENA OB, EXCONDE AM. 1978. of other fiber material combined with water hyacinth pulp. Utilization of water hyacinth for pulp and paper The use of water hyacinth pulp for handmade paper manufacture. I. Depithing, morphological, and chemical requires careful consideration on processing, end use, and properties of fibers. NSDB Technol J 3 (4): 51-57. price to compensate for the additional cost due to low pulp ZERRUDO JV, TADENA OB, EXCONDE AM. 1979. yield of water hyacinth stems. Extraction of juice (before Utilization of water hyacinth for pulp and paper pulping) for use as formation aid for other pulps may manufacture. II. Pulping and papermaking of depithed recover some of the additional cost when hyacinth pulp fiber. NSDB Technol J 4 (3): 33-42. from the residual mass itself is combined with other pulps. http://www.unep.org/roa/Nairobi_River_Basin/ The results of the study can help in the pro-active control Downloads/Phaseii_publications/reports/KICK- of the damage brought by of uncontrolled growth of water FinalReport.pdf. Retrieved 1/3/2008. hyacinth through proper utilization. http://www. Bangladesh.com/producer_work/mcc_ enterprises. Html) Retrieved 1/3/2008.

ACKNOWLEDGEMENT The author is grateful to FPRDI staff, namely, Messrs. Cesar Austria, Anniver Ryan P. Lapuz, Mario Ramos, Raul A. Felismino, Justino C. Buendia and Ms. Jasmin B. del

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