ITTO-PROJECT PD 74/90 (F, I)

BETTER UTILIZATION OF TROPICAL TIMBER RESOURCE IN ORDER TO IMPROVE SUSTAINABILlTY

AND REDUCE NEGATIVE ECOLOGICAL IMPACTS

, Volume 1, Part 1 :

Summary of the Project Coordinator's Final Report

by

Professor Dr. D. Noack

Hamburg, 1995

Collaborating Institutions: Federal Research Centre for Forestry and Forest Products (BFH), Hamburg, Germany University of Hamburg, Germany Forestry Research Institute of GHANA (FORIG), Kumasi, GHANA Office National de Developpement des Forets (ONADEF), Yaounde, CAMEROON Mulawarman University (UNMUL), Samarinda, EAST KALlMANTAN, INDONESIA Forest Department Headquarters, Kuching, SARAWAK, MALAYSIA

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l I

PREFACE

It w()uld be almost trivial to declare that the utilization of tropical forests is one of the most

disputed issues worldwide, due to its wide-ranging social, economic and ecological implications.

Approaches are therefore required which allow the use of forest resources that take into account

all the values of the forest. One such approach is ecosystem management. The key target here

is tile delivery of a continuous flow of desired forest products and services as spelt out in the

ITTO's definition of sustain ability.

Several ingredients are required to achieve sustainability, one of which is the efficient and

environm entally friendly utilization of timber resources at all levels of timber harvesting and

pr()cessing.

In ()rder to promote best practices in timber harvesting and wood processing, project

PO 74/90 (F,I) "Better Utilization of Topical Timber Resources in Order to Improve Sustainability

antd Reduce Negative Ecological Impact" was approved and financed by ITTO with the generous

finoancial support of the Government of the Federal Republic of Germany, and implemented by

the Federal Research Center for Forestry and Forest Products in Hamburg, Germany, with the

cOt:>peration of national institutions in Cameroon, Ghana, Indonesia and Malaysia.

Apart from a literature review, the project was composed of two main activities. Firstly, an

inV'estigation was carried out in 12 forest stands to determine the level of forest residues arising

fro m logging and harvesting operations and to assess the related ecological impact. Secondly,

26 wood processing mills were studied in order to determine the rates of recovery for different

op tions of wood processing. Factors affecting the importance of forest residues, the ecological

im pact on the forest stand during logging and harvesting operations and rates of recovery for

wood pr()cessing were analyzed in order to derive recommendations for best practices to ensure

better timber utilization and reduce negative ecological impact.

For timber harvesting, recommendations emerged form the study on the necessity to

ensure careful planning before and after logging (pre-Iogging inventory, road density planning,

post-logging storage planning), the appropriate training of loggers and the promotion of the

economic use of residues. For wood processing, proper sorting of raw material, mill integration,

quality control, training and the use of appropriate technology for wood processing and energy

production were the key elements.

Although further investigation is needed to document completely factors related to the

improvement of yield in timber harvesting and wood processing and to the possibility of reducing

negative ecological impact during such operations, the study provides a good base for reflection

and action that could contribute to sustainability in the utilization of forest resources. I have

th erefore no hesitation in recommending this report to those who are interested ,in sustainable

tropical forest management.

B.C.Y. Freezailah

Executive Director of ITTO

ITTO-PROJECT PD 74/90 (F, I)

BETTER UTILIZATION OF TROPICAL TIMBER RESOURCE IN ORDER TO IMPROVE SUSTAINABILlTY

AND REDUCE NEGATIVE ECOLOGICAL IMPACTS

Part 1: Summary of the Final Report on Forest Field Studies and Mill Studies

carried out in GHANA, CAMEROON, EAST KALlMANTAN (INDONESIA),

and SARAWAK (MALAYSIA)

T Glble of Contents: PAGE:

1 INTRODUCTION 1

2 BACKGROUND OF THE PROJECT 1 3 OBJECTIVES OF THE PROJECT 2

4 EVALUATION OF FOREST FIELD AND MILL STUDIES 2 5 FOREST FIELD STUDIES 3

5.1 Selection of the Concessions 3 5.2 Methodology 8 5.3 Summary of the Main Results 10 5.4 Recommendations 19

6 MILL STUDIES 20 6.1 Background and Objectives 20 6.2 Selection of Mills 20 6.3 Methodology 21 6.4 Summary of the Main Results 22 6.5 Recommendations 36

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1. INTRODUCTION

The ITTO-PROJECT PD 74/90 with the aim of making better use of tropical timber resources was implemented at the end of 1990 on the basis of the relevant Project Document (see Appendix 1) accepted by the INTERNATIONAL TROPICAL TIMBER COUNCIL at its VII. Session.

One essential factor influencing the sustainability of tropical forests as well as the yield in forest industries of tropical countries is the level of waste that occurs both in the forests and in wood-processing mills. A reduction of such wastage, therefore, could substantially improve the present situation of the whole wood chain of utilization of tropical forests.

2. BACKGROUND OF THE PROJECT

The present situation of the utilization of tropical forests can still be characterized by the following facts: - Large areas in the order of 6 million km2 of the original tropical rain forests have been

devastated as a result of shifting cultivation, establishment of new farming communities, firewood production, large-srale agricultural and industrial (e.g. mining, water reservoir installations, road constructions) projects as well as of tropical timber exploitation.

- The quantity of wood harvested in tropical rain forests is estimated to be about 1 billion m3 per year; 86 % of this quantity is used as firewood and only about 14 % as utility timber.

- Tropical deforestation as well as degradation of tropical forests have not only detrimental consequences to soil, water and climate, but lead also to the weakening of a commercial raw material base and to the loss of the potential for sustained tropical timber production.

The removal of wood from tropical rain forests is largely dependent upon the forest management practices employed. In the present study only those forest areas are taken into consideration which have to be preserved as forests in the future with the aim that these forests will not only serve continuously as a source of timber but that they also remain in a healthy and ecological stable condition. To maintain stability and sustainability of tropical rain forests the timber utilization has to be carried out carefully by selective cutting of desired individual trees.

As a result of a study of the existing literature, it can be stated that, up to now, only vague estimations exist about the intensity of the selective harvesting of tropical forests and of the utilization of the harvested wood.

A m ore complete utilization of tree stems removed from the forests, as well as of those stems which are accidentally destroyed or damaged through poor and inadequate harvesting and transport methods will result in a decrease of the total amount of wood to be cut and, consequently, minor areas of tropical rain forests have to be harvested in order to supply the needs.

Simi larly under-utilized are the wood residues which accumulate during the processing of roundwood to products of various kinds (e.g. sawn timber, lumber, furniture parts, construction elements). Thus, a large proportion of the roundwood extracted from the forests becomes. residues which are only occasionally used for energy production. A better utilization of the logs in the wood-processing mills will also decrease the total amount of wood to be cut in the forests.

1

• Concession 2 of GHANA which belongs to EHWIA WOOD PRODUCTS LTD. (EPL), was located in the moist semi-deciduous forest of ASUKESE, where the annual rainfall of 1250 to 1700 mm was a little less than in concession 1, and also the number of tree species determined in 25 m x 25 m plots amounted only to about 100. Notable tree species of this forest are Entandrophragma cylindricum, E. utile, E. angolense, Khaya ivorensis, K. anthotheca, and Tieghemella heckelii.

• Concession 3, belonging to EHWIA WOOD PRODUCTS LTD. was located in the dry semi-deciduous forest type of AFRAM with 40 to 100 tree species in 25 m x 25 m plots and the most predominant economic timber trees Milicia exce/sa, Triplochiton scleroxylon, and the savanna species Afzelia africana and Diospyros mespiliformis.

Therefore, these concessions represent typical forest sites which according to the long-term land-use planning of GHANA are classified as permanent tropical forests.

5.1.2. CAMEROON

In CAMEROON (Figure 1-2), the study areas were selected in three different ecological zones of the COASTAL REGION (concession 1), th~ CENTER REGION (concession 2), and EAST PROVINCE (concession 3):

4

• The forests of the COASTAL REGION are moist evergreen forests with the characteristic tree species Lophira alata and Saccoglotis gabonensis. These forests have been exploited since 1930. Therefore, they are poor of highly valuable wood species.

• The forests in the CENTER REGION belong to the moist semi-deciduous tropical rain forest type. Also these forests have been exploited since 1950 .

• In the EAST PROVINCE, where the semi-deciduous forests have not been exploited before, concession 3 was situated near the transition zone to the Savanna.

Forsl dense humide == Sem;.d6ddue ~ Se",,*,,~en ..

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r.;-;-;-l Secteur pr.rarestter ~

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5.1.3. EAST KALlMANTAN, INDONESIA

In EAST KALlMANTAN (INDONESIA) (Figure 1-3), the three concessions are located in both typical forest types, the lowland Dipterocarp forests, and the mountain Dipterocarp forests, located close to the equatorial line. The major tree species in all three study areas are Keruing (Dipterocarpus spp.), Red, White, and Yellow Meranti (Shorea spp.), Bangkirai (Shorea laevis), Majau (Shorea johorensis), Kapur (Dryobalanops spp.), Tengkawang (Shorea spp.), and non-Dipterocarp species such as Anggi (Sindora spp.), Kayu Bawang (Scorodocarpus borneensis), and Ulin (Eusideroxylon zwagen).

Dipterocarps dominate in all forest sites, but with regard to the species composition there is so'me difference between the three study areas:

• In the forests of concession 1, belonging to the private enterprise INTERNATIONAL TIMBER CORPORATION INDONESIA - ITCI, for example, 46 genera are growing with a tree density of about 80 trees/ha and a standing stock of about 265 m3 . The Dipterocarps, for which the ratio between the volume of the extracted log and the volume of the whole stem - ranging between 60 and 66 % - is considerably greater than for non-Dipterocarps, dominate with 74 % of the tree species.

• Concession 2 belongs to the private company MARINUM TIMBER INDUSTRY - MIT. The forest of concession 2 consists of 33 genera with a tree density of about 88 trees/ha and a standing stock with 85 % Dipterocarps of about 314 m3.

• The third concession 3 is owned by the State enterprise INDUSTRI HUTAN INDONESIA -IHTN. The number of genera in the forests of this concession is as low as 12 with 95 % Dipterocarps. Tree density was about 74 trees/ha with a standing stock of 378 m3.

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5.1.4. SARAWAK, MALAYSIA

IN SARAWAK (MALAYSIA) (Figure 1-4) two rather different types of tropical forests are the typic::al major forest types, one are the hill mixed Dipterocarp forests, from which two concessions have been chosen (concession 1 - DAPOI HILL and concession 2 - MUKAH HILL), and the other are the peat swamp forests, where the third concession - RASAU SWAMP was located. But eve n between the two study areas in the hill mixed Dipterocarp forests show remarkable differences with regard to the number of trees, the basal area, and the net industrial stemwood volume by diameter classes (bdh-classes) per hectare basis.

• Concession 1, located in the mixed Dipterocarp hill forests of the DAPOI HILL area, is a heavy density forest type with about 211 trees per hectare, but the number of bigger tress with a dbh >- 45 cm is about 51 per hectare.

• Concession 2 was located in the mixed Dipterocarp hill forests of the MUKAH HILL. This forest 13elongs to the medium density forest type with about 212 trees per hectare from which about 58 trees are bigger trees with a dbh > 45 cm.

• Quite another type of forests are the peat swamp forest from which concession 3 was chosen in the RASAU SWAMP area. In the mixed swamp forest, the tree species are classified into commercially valuable timber and those of less important timber. The valuable commercial species make up only 26 % (about 50 trees per hectare) of the trees with a bhd > 20 cm. The most important timber with about 12 trees per hectare is Ramin (Gonystylus bancanus) , whereas the commercially less important tree species with about 147 trees per hectare include among others, Regas Hutan (Bachanania spp.), Nyatoh (ling. Sapotaceae) , and Jelutong (Oyera spp.), as the main commercial species.

It may be mentioned that also the logging techniques in the peat swamp forests (railway s'ystem) are different from that in the mixed Dipterocarp forest because of th~ swampy ground which consequently results in a more intensive cutting of commercial trees.

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7

5.2. Methodology of Forest Field Studies

The methodology of the field studies in the forests, naturally, was based on the specific situation in each country. Differences in the methodology have their reasons in different topography, vegetation type, tree density, volume of standing stock, felling intensity (number and volume of logs extracted), logging machinery (width of skidding roads), etc. Before starting the field studies, it was therefore necessary to develop a common methodology which shall be used independently from local circumstances in all countries and ecological zones concerned. This methodology should be as uniform as possible in order to allow far-reaching comparison of the results.

For the development of an uniform methodology, a PILOT STUDY has been carried out at the beginning of the PROJECT in the NKRABIA FOREST RESERVE concession in GHANA. The detailed results of this pilot study are reported in Appendix 2 and have been discussed and agreed upon in all four countries prior to applying a common methodology

- of forest inventory before and after logging, - of measuring thefellihg gaps and the area of skidding trails, - of measuring the volume of different parts of the felled trees (stump, buttress, stem

offcuts, branches with a diameter> 20 cm, and extracted log), - of measuring the extent of felling and skidding damages to the residual stand of trees

with a dbh > 20 cm, as well as of working out recommendations related to the reduction of felling and skidding damages and to a better utilization of the felled tree.

to all field studies in the different forest sites.

This common methodology can, in general, be characterized by the following agreements:

• In all concessions under investigation, a compartment of 100 to 200 hectares, in which felling and logging operations of selected trees were about to take place, has to be chosen for the field studies (see Figure 1-5). The existing National forest inventories will be taken into consideration.

• Within each compartment one or two "large" sample plots with an area of about 20 hectares -or a greater number of "smaller" sample plots of 6 hectares - were selected. The selected plots shall have a "normal" composition of tree species with a representative density of commercial and non-commercial wood species of the relevant forest type, representing a normal intensity of selective tree cutting in accordance with the National Forest Management Legislation in order to ensure sustainability.

• In these sample plots, pre-Iogging inventories were carried out to enumerate and record by species, diameter and location all trees with a diameter at breast height dbh > 30 cm.

Trees with a diameter dbh < 30 cm, normally, were not taken into consideration because this seemed not to be justified due to high costs of a complete inventory and to the fact that the natural mortality of these smaller trees is considered to be rather high.

• All trees with dbh > 30 cm are plotted in the map of the entire sample plot (see Figure 1-6).

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Legend

." ,".,par' .. on' bDundary L:.J and numb.r C e. W. 11

f.,t.1 studiod co.,par'men' rood

rivlr

NKRABIA FOREST RESERVE PROGRESS MAP

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1 (HAIN = 20METERS

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Part of Tree

Crown

Stump

Buttress

Stem Offcuts

Total Forest Residues

Extracted Log

Extracted Log Related to Bole & Crown

Extracted Log Related to Bole only

GHANA

29,9%

3,2%

6,3 %

12,5 %

51,9 %

48,9%

49,6 %

71,8 %

Forest residues in GHANA

For the GHANAIAN study a total of 38 timber trees were felled and investigated in the three study sites ASUKESE (14 trees), AFRAM (15 trees), and NKRABIA (9 trees). Among the species Triplochiton scleroxylon was dominating with 12 trees followed by Milicia exce/sa with 8 and Guibortia ehie with 4 trees. The volume and the proportion of different residue types are illustrated in Table 1-2.

Study site Trees Whole Extracted Stump Stem Crown studied tree log residue

Asukese - total 14 343,28 179,88 11,47 33,82 83,54 - per tree 24,52 12,82 0,82 2,49 5,97

Afram - total 15 735,30 367,65 19,26 62,70 246,45 - per tree 49,02 24,51 1,71 4,18 16,43

Nkrabia - total 9 244,95 11,00 11,79 68,60 66,06 - per tree 27,22 1,31 1,31 7,62 7,34

Forest residues in CAMEROON

In CAMEROON, the study on forest residues was not related to the forest area but to the tree species. Altogether, 12 commercially important trees were felled and studied with respect to the volume of the extracted log and the amount of residues left over in the forest. As given in Table 1-3 and Figure 1-8, the results obtained show that the crown comprises a considerable part of the total tree volume. Its proportion varies from 25 % for Tali to 58 % for Iroko. In case of Sapeli and Iroko the volume of branches are even more than that of stem.

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Timber Number Log Residues Total species of trees Extracted stump buttress crown Tree

felled [m3] i [%] [m3] i [m3] i [m3] i [m3] i [%] [%] [%] [%]

, , Ayous 3 51,0 54,7 3,17 : 3,3 7,6 8,2 31,5 33,8 93,2 : 100 , , Sapeli 2 17,0 39,2 2,3 i 5,3 1,7 3,9 22,3 51,6 43,2 i 100 Iroko 2 22,5 i 27,9 3,0 l 3,7 8,2 i 10,1 47,1 i 58,3 80,8 i 100 Sipco 2 40,6 i 52,8 3,8 i 4,9 7,7 i 10,0 24,8 i 32,3 76,9 i 100

, , , : 324

, Movingui 2 11,4 : 50,2 2,9 : 13,0 1,0 : 4,5 7,3 22,6 : 100 , ,

, , , , , Tali 1 12,4 i 65,3. 1,5 : 7,75 0,4 : 1,9 4,7 : 25,0 190 : 100 , , , ,

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Yield 17,:1 Yield 1%1

100 100

90 90

80 80

70 70

60 60

50 50

40 40

30 30

20 20

10 10

0 3 trees 2 Irees 2 Irees 2 trees 2 Irees 1 tree

0

Ayous SapeU Iroka Movingui TaU Sipa

11 Stem 888 Stump D Buttress II!!II Crown 888 resIdue. resldues II1II resldues Forest residues in EAST KALlMANTAN (INDONESIA)

Factors affecting the volume of forest residues are tree species, size of tree, terrain, market demand, and logging operation system. To carry out the study on wood residues, samples were taken from 36 to 42 trees in the three study areas. As the results indicate, poles and branches show by far the highest proportion of the total residues. Details of the proportion of various residues such as stump, buttress, etc. are given in Table 1-4 and in Figure 1-9.

Study site Tree Log Stump Buttress Log Poles & Total number volume defects branches

MTI 40 390,8 32,8 13,8 12,9 150,6 599,6

volume/tree 9,8 0,8 0,3 0,3 3,8 15,0

ITCI 36 628,0 48,7 53,2 76,6 165,8 972,2

volume/tree 17,4 1,4 1,5 2,1 4,6 27,0

IHTN 42 282,9 25,5 10,4 25,0 122,6 466,4

volume/tree 6,7 0,6 0,3 0,6 2,9 11,1

Total 1301,7 106,2 77,4 114,5 438,6 2038,2

sample mean 433,2 35,4 25,8 38,2 147,5 679,4

mean volume/tree 11,0 ,0,9 0,7 1,0 3,7 17,3

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Yield 1%1 1 ____ r100

90

80

70

60

50

40

30

20

10

36 logs 42 logs 118 logs o

972 m3 466 m 3 2038 m 3

ITCI IHTN Total

11 Commercial ~ Stum - l3ullress D Log woed 00 p. defects f%§tl Foie &< ~bronch Forest residues in SARAWAK (MALAYSIA)

For the determination of wood residues in the forests of SARAWAKlMALAYSIA in each of three study sites 10 trees were felled and measured. The results summarized in Table 1-5 and Figure 1-10, and indicate the volume of extracted logs and that of residues. The stem residues are among others the sections between stump and log and between log and crown which are also defined as lower and upper stem offcuts, respectively. Very impressive are the considerable differences between the mixed Dipterocarp hill forests and the Peat Swamp forest, where especially the proportion of branches of Ramin can be neglected.

Study site Extracted Logs Stump Stem Branches Total residues [m3]

, [%] [m3] i [%] [m3] [%] [m3] i [%] [m3] [%] , , ,

Dapoi Hill 11,8 : 61,7 2,5 13,1 2,2 11,6 2,60 : 13,6 7,3 38,3 , ,

Mukah Hill 5,7 : 51,8 0,7 6,5 2,5 22,5 2,10 : 19,2 5,3 48,2

Rasau Swamp , , , , ,

_ Rama 1) 2,4 87,1 0,03 1,1 0,3 11,8 --- --- 0,35 12,9 _ Alan 2) 9,9 51,3 0,5 2,7 1,4 7,1 7,51 38,9 9,4 48,7 _ Rehu & Nyto 3) 4,0 59,0 0,5 7,9 1,6 24,1 0,61 1 9,0 2,8 : 41,0 1) Ramin telur (Gonysty/us bancanus)

2) Alan (Shorea a/bida) 3) Rengas Hutan (Buchanania spp.) and Nyatoh (Fam. Sapotaceae: Pa/aquium spp.)

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Yield 1%1 Yield 1%1 100

90 1~.:::-:::::--::::.-.=11=.=-==.=1I1 80

70

60

50

40

30

20

10

Alan Rehu&Nyla 0

Dopai Mukah Rama

Hill Hill Rasau Swamp Forest

E~tracted888 Stump log ggg Stem Branches

If we consider the general picture of forest residues, given in Figure 1-7 and Table 1-1 (page 12), it may be allowed to generalize, that that the total forest residues, left in the forest, amount to about 46 %, whereas only 54 % of the wood volume of a tree is extracted in form of a log. The forest residues can be classified in crown wood (branches with a diameter > 20 cm) which amount to about 26 % of the total wood volume of the tree, the stump and buttress with 5 % each, and the offcuts of the stem which amounts to about 10 % of the total wood volume of the tree.

It is quite obvious that it will not be possible to utilize the whole forest residues of about 46 % of the tree totally, because the stump cannot be used to an amount worth mentioning, and also the utilization of branches will be limited. But even if we relate the volume of the extracted log to the volume of the stem, including parts of the thicker branches, which should be usable in wood processing and for energy production, at present more than 25 % of a tree are still forest residues. An utilization of these forest residues, therefore, should be taken into closer consideration.

5.3.3. Forest Disturbance

The disturbance of the forest caused by felling and logging operations is characterized by a direct opening of the stand on the one hand and by a damage of other remaining trees on the other hand.

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Felling gaps and skidding trails

Felling gaps and skidding trails are negative, but unavoidable effects which, therefore, should be minimized as much as possible.

Both ch aracteristics vary in rather broad limits between the different forest areas studied in this PROJECT. This is demonstrated by the fact that the area of felling gaps .and skidding trails varied between 3 and 15 % of the total logging area, depending first of all of the logging intensity. Therefore, the openings of the stand in the peat swamp forests of SARAWAK, MALAYSIA, even amounted to more than 20 % of the forest cover.

A comparison of the average size of the gap area per felled tree is given in Table 1-6. The investigations show that there is obviously a relationship between the diameter of the felled tree and the gap size. Especially in EAST KALlMANTAN, it was found that the largest gap area per tree in two forest sites was measured for the diameter class above 100 cm, and in the third forest site for the diameter class 90 to 99 cm.

:::I~pl~1.t~!:::: :::Ay~t?g§~~P:~f.#§P€[!t~~£~q§gg::;t?.Y:tq!llq~:9pgtit(gn~··:::::::::::::::p:::::::r::dL:::::::::::::··:·:::::::;:::::i::::::·:::·:

Country Study Site and Gap size per tree (m2)

INDONESIA MTI: 254 ITCI: 296 IHTN: 286

MALAYSIA Dapoi Hill: 406 Mukah Hill: 402 Rasau Swamp: 317

GHANA Asukese: 345 Afram: 602 Nkrabia: 606

CAMEROON Centre: 138 East: 236 Coastal area: 178

The mean size of felling gaps in the four countries concerned ranges from about 140 m2 per tree in CAMEROON (Center Region) up to more than 600 m2 per tree in GHANA, NKRABIA forest.

The area of the skidding trails depends first of all of the length of the skidding track because the width of the skidding tracks was rather similar in all concessions varying between 4 to 6 m on account of using similar heavy logging machinery. However, the length of skidding trails was considerably different in the different concessions. The longest skidding track of about 3000 m was measured in the Concession of MTI/SARAWAK, but those long skidding tracks should be avoided in order to reduce the damage of remaining trees.

Logging Damage

Also the number of severe damaged trees growing at the border of felling gaps and skidding trails varied over a wide range from about 1 to 9 trees per extracted tree from which the number of dam aged trees related to felling gaps was in the range of 1 to about 5. A more detailed evaluation of the local situation, therefore, is necessary.

In GHANA the felling damage was more frequent and severe in the crowns than on stems. Furthermore, trees with a diameter dbh < 50 cm were the most affected ones. Among the destroyed trees over 80 % had a dbh < 30 cm. Furthermore, the results obtained indicate that for every 100 m skidding trail up to 4 trees of 10 to 50 cm dbh were completely destroyed at ASUKESE and AFRAM forest sites. A summary of felling damage in the three study sites of GHANA is given in Table 1-7.

17

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Study site Total felling Section of Damage category I Number of trees Gap [ha] tree slightly severely uprooted

damaged no

damage damaged damaged

Nkrabia 0,546 whole tree 52 16 5

Asukese 1,175 stem 67 85 23 64

crown 28 53 94

Afram 1,084 stem 125 89 14 45

crown 93 95 40

The damages caused by felling operations in CAMEROON are summarized in Table 1-8.

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Study site Number of trees damaged

slightly damaged heavily damaged dead trees

total [%] No.lfelled total [%] No.lfelled total [%] No.lfelled No tree tree tree

Centre 41 20,0 i 1,5 82 l 40,0 j 3,0 82 40,0 i 3,0 East 68 201 : , , 1,3 62 : 265: , , , 1,2 104 44,4 i 2,0

, , , , , Coastal area 112 33,4 :' 2,4 145 : 43,3 : 3,2 78 : 23,3 : 1,7 , , , , ,

In the study areas of EAST KALlMANTAN, INDONESIA damages to the residual stand regarding trees with a diameter dbh > 20 cm, determined on the basis of about 400 trees felled, were associated with felling and skidding activities and also related to the volume of the extracted log with the result, that the number of damaged trees per felled tree ranged between 1, 1 and 2,3 and the number of damaged trees per m3_log extracted was in the order of 0,2 trees/m3• The percentage of the heavy damaged trees were in the order of 40 %, the other damaged trees fell ~nder the category of light and medium damage.

The felling and skidding disturbance in SARAWAKlMALAYSIA, determined with 35 trees, were somewhat higher than in EAST KALlMANTAN and amounted to about 4 damaged trees per extracted log, from which most of them belonged to the diameter range between dbh of 20 to 45 cm. This relatively high proportion of the category of severe damage is an important problem with respect to the sustainable management of tropical forests. It, therefore, should be reduced in favour of the damage category light and medium.

In the RANSAl:J peat swamp forest site of SARAWAK, MALAYSIA, it was not possible to satisfactorily determine the number and volume of trees damaged by felling and logging because of the completely different extraction method which is based on a rail line system. In this case, pole-sized trees in the vicinity of the extraction routes are cut for the rail line stringers and sleepers.

18

5.4. Recommendations Derived from the Forest Field Studies

The forest field studies highlight an enormous potential for efficiency gains in the harvesting of tropical forests. Based on this study, a number of general conclusions and recommendations can be made. The realization of those recommendations in the different tropical countries has to happen in the frame of National forest policy individually under consideration of the specific local conditions.

• A thorough pre-Iogging inventory is an important step in efficient logging, enabling decisions to be made on logging intensity and aiding the development of harvest plans ensuring sustainable forest management.

National forest inventories indicate that lesser used species occur in commercially valuable quantities - up to 40 per cent of forest stocking in GHANA and 25 per cent of the Dipterocarp forests of SARAWAK, MALAYSIA - and an increased use of these lesser-used tree species is possible, having the effect of broadening the raw material base of the forest products industry. Today, only small quantities are converted to lumber for the local market and for core veneers of plywood, but the present utilization is by far not in a reasonable relation to the potential of the lesser-used species as raw material resource.

• Logging techniques need to be improved in order to reduce logging damage. An improvement in this field requires both regulation and stimulating measures for the concessionaires, training of logging personnel and research into most appropriate machinery as far as research on helicopter logging avoiding any skidding damage in the forests. To aid better logging and to maintain a minimum road intensity for site protection, proper road planning is recommended.

Government policy should aim to encourage the use of forest residues without compromising the sustainability of forest management. A balance should be sought between the use of forest residues by local people for the development of cottage industries (and subsistence use as fuel and shelter) on the one hand and by the timber industry on the other. Social political solutions must be found in this respect, which avoid a negative influence on the principle of sustainability in forest management.

Concessionaires should be encouraged to make better use of large-dimensioned forest residues without increasing damage to the residual stand. In this connection, also the feasibility of stationary or mobile equipment for processing of small diameter logs and branches should be considered.

• The economics of local production of charcoal and firewood should also be taken into consideration.

• Studies on the losses created by post-logging storage in the forest and in the log yard are needed to develop measures which reduce these losses.

19

6. MILL STUDIES

6.1. Background and Objectives

In most of the papers evaluated, it is emphasized that there is a growing interest for the potential utilization of residues generated in the forest or in wood processing mills, either because of an apparent shortage of other raw materials or because of escalating prices for the traditional raw materials. Another important motivation for the enhanced utilization of wood residues is the wish to encourage employment in and increase revenues from the forest products sector in the tropical countries without depleting the natural forest resource base. This goal can be reached through the extension of downstream wood processing retaining higher added value in the producer countries and through the establishment of production facilities for new products, e.g. wood-based panels, pulp and paper, furniture, and flooring materials, for the domestic but also for the international market. Both alternatives imply a growing need for industrial wood material which should not be fulfilled by harvesting more trees in the natural forests but by commercializing wood residues and using non-established wood species to diversify the resource base.

The objectives of this study were • to describe the state of the art in wood processing in typical mills in the four countries

concerned to find out which kinds and quantities of wood residues are generated, • to find out whether and how the quantity of residues generated in wood processing can be

reduced and • to study how the remaining residues can be used to enhance the employment, revenue, and

technology situation in the four countries concerned.

Regarding the recommendations for the utilization of wood residues in downstream processing and for the production of new products

• the infrastructure, • the technical situation, • the employment potential as well as • the demands on the domestic and the international markets of the four countries were

considered.

6.2. Selection of Mills

The basis of the investigation are case studies in wood processing companies which were selected according to the following criteria:

• The willingness and ability of the mill management and personnel to cooperate with the researchers according to the PROJECT objectives and methods was of essential importance for the success and the quality of the research. The mill staff had to accept the review of production figures and the collection of data at the production lines.

• The mills must be typical of different sources and kinds of raw material, i.e. logs or other timber materials of different wood species from different origins/forest types.

• The mills must be typical of different processing technologies and different types of products manufactured, i.e. mills typical of the primary, secondary, and tertiary wood processing sectors in the countries.

20

• Different mill sizes (number of employees) and capacities (quantity of product output) within the different types of processing mills should be selected.

• The mills must be typical of different market outlets, Le. domestic or international market.

The following mills/products were selected for the studies:

SAWMILLS

• 3 in GHANA, • 2 in CAMEROON, • 2 in EAST KALlMANTAN; both mills belong to one major wood processing industries group,

• 2 in SARAWAK

MOLDING MILLS • 1 in GHANA; profile boards and parquet flooring, • 2 in EAST KALlMANTAN; different profiled strips, • 1 in SARAWAK; dowels of different diameters

FURNITURE MILLS AND JOINERIES • 4 in GHANA; two types of chairs, toilet seat covers blanks, round culverts, U-drains, school

chairs and tables, door and window frames • 1 in CAMEROON; arm chairs and chairs • 2 in EAST KALlMANTAN; table and chair components

VENEER SLICING MILLS

• 2 in GHANA, • 1 in CAMEROON

VEN EER PEELING AND PLYWOOD MILLS

• 1in GHANA, • 1 in CAMEROON, • 2 in EAST KALlMANTAN, • 2 in.SARAWAK

In integrated wood processing factories (e.g. two of the GHANAIAN mills and one group in EAST KALlMANTAN), in all four countries, high quality logs are usually sliced or peeled, while smaller logs and 'logs with defects are normally sent to the sawmill for sawn timber production.

6.3. . Methodology

The methodology for the case studies should be similar or at least comparable for all mills studied in the four countries. The common methodology was developed during a PILOT STUDY in GHANA performed by GERMAN and GHANAIAN researchers and later Slightly modified for application in CAMEROON, INDONESIA (EAST KALlMANTAN), and MALAYSIA (SARAWAK). Following the common methodology, the entire process of wood conversion from logs or billets to semi-finished or finished products should be studied in each mill to record types and volu metric quantities of wood residues and products at different processing stages.

21

As the responsibility for the comparability of the study methods applied in wood processing

mills in the four countries was with the PROJECT coordinator at the FEDERAL RESEARCH

CENTER FOR FORESTRY AND FOREST PRODUCTS, HAMBURG, GERMANY, the preparatory

work for the mill studies was always conducted by a working group of GERMAN coordinators and

researchers from the partner institute in each of the four countries concerned. During group

meetings held in each of the four countries in the beginning of each series of mill studies, the

objectives of the PROJECT, the selection of mills to be studied, and the research methodology

were discussed in detail. In some cases these group meetings were attended by representatives

from wood processing companies who were interested in contributing to the research.

6.4. Summary of the Main Results

6.4.1. Log yards - bucking practice

In the log yards of five CAMEROONIAN companies, two plywood mills in EAST KALlMANTAN, and two plywood mills in SARAWAK the bucking practice was studied. 49 sample stems (280 m3 ) of major wood species were investigated in CAMEROON, in EAST KALlMANTAN 20 logs with a total volume of about 90 m3 , and for the two mills studied in SARAWAK the number of logs was not specified.

Overall, the losses due to normal bucking practices in the CAMEROONIAN mills studied amounted to about 0,25 % sawdust and about 3 % solid residues, i.e. log offcuts of the stems arriving in the log yard. At SMP in EAST KALlMANTAN, the yield after cross-cutting constituted 90 to 98 % billets, 1,3 to 9,2 % log end offcuts and about 0,5 % sawdust. At SLJ in EAST KALlMANTAN, the yield of billets was in most cases close to 99 %. Similar to the study performed at SMP, about 0,5 % dust from the chain saws was generated in the log yard. The relatively high yield of billets at SLJ is mainly due to the flexibility of the lathes in this mill which can be fed with logs of 1,2 to 3 m length. At SARAWAK Co., the yield after cross-cutting constituted 95,3 % billets, 3,9 % short logs and 0,8 % sawdust. At Rimbunan Hijau Sdn. Bhd., the yield was 98,4 % billets, 0,8 % short logs and 0,8 % sawdust.

Corresponding with the bucking results obtained in CAMEROON, the data from SARAWAK show . that between 2 and 5 % of the incoming stems are converted into particulate and solid residues in

the log yard. In the mills studied in EAST KALlMANTAN, the variation between the stems was much wider but a mean yield of about 95 % billets, 0,5 % sawdust and varying quantities of solid residues is also realistic.

The yield of billets and the quantity of residues after cross-cutting in the log yard are clearly influenced by the coordination of the bucking practice in the forest and the dimensional requirements of the mills processing the logs. Higher product yields could be achieved through an improved planning of bucking, transportation, and processing of logs in the forest and the mills.

6.4.2. Sawmills

The results obtained in GHANAIAN sawmills are summarized in Figure 1-11. The sampled wood volume is given below the columns.

22

~I i

The case studies in GHANA showed that the yield of main export products from most of the species varies between 40 and 45 % of the log input, 5 to 10 % of the logs were converted into by products for the domestic market, about 45 to 50 % are converted into solid residues and 10 % of the logs become sawdust. About half of the solid residues consist of sapwood which has to be flitched e::lff according to customers requirements. The variation of product yield figures between the three sawmills was rather small. Exceptionally low yield values had to be attributed to log defects.

GAP sawmill. Ghana Yield 1%1 Yield 111

MTC sawmill. Ghana Yie Id 10:; I Yield 1%1

100 11 ~,- -,,------, I " If 100 100 1, , ,-----------, , , , If 1 CO

90 90 90 90

&0 80 80 BO

70 70 70 '70

6·0 60 60 60

1»;;:;~·~;;;;,.:1 5·0 jW-:':~':?>l ,v .... W.'N.~

\v",-'Yh"'x 50 50 50

4.0 40 40 40

~o 30 30 3D

2:0 20 20 20

10 10 10 10

o 6 logs of 6 logs of 6 logs of 6 logs of 6 logs of o o 6 logs of 6 logs of 6 logs of 6 logs of o

Wawa Mahogany Koto Odun, Utile Wawa Mahogany Sop .. l.. Edinam

27m3 16m3 17m3 15m3 43m 3 39 m 3 34 m 3 28 m 3 39 m 3

All sawmill, Ghana Yield le!1 Yield 1%1 100 1, , ,--------, I , , I I I I I I If 100

90 90

80 1\0

70 70

60 60

50 50

40 40

30 30

20 20

10 10

o 6 logs of 6 logs of 6 logs of 6 logs of 6 logs of 1 log of 1 log of o Wawa Mahogany Guorea Hyedua Cellis Oohoma Of,am

30 m 3 40 m 3 11 m 3 13 m 3 14 m 3 4 m 3 8 m 3

Main ~BY-produc.ls ~ products

Sclid D residues Sawdust

As storage decay may reduce the yield of main and by-products considerably, the timing of log harvesting, transport and processing must be optimized, particularly in mills which purchase logs

23

from the market. Sprinkling the logs with water in the log yards is an additional means to avoid fungal decay and insect attack.

The sawn timber yield could be increased if the mills would use log rotation devices on the carriages at the head rig which would enable the sawyer to cut each log in the optimal plane with respect to cracks, shakes, etc .. Cutting inaccuracies at the head rig leading to thickness variations of up to 10 mm within single boards or flitches reduce the recovery rate.

Semi-finished products should be processed in the mills without delay because longer storage of boards cause considerable discoloration. Proper stacking, handling and storage of products under shed minimizes biodeterioration, discoloration, checking and board deformation.

Solid residues are used loca"y for furniture manufacture and joinery, as firewood, and for charcoal production. Sawdust has no commercial utilization in GHANA yet.

The results obtained in CAMEROONIAN sawmills are summarized in Figure 1-12.

SEse sawmIll, CClmeroon Paiot sawmill, Comeroon Propa'm-Bo's sawmlll, CClmeroon YIeld 17.1 Yield 17.1 Yield I'ZI Yield I~I Yield 1%1 YIeld 1%1

100 11':':;':

The yield of sawn timber obtained in the sawmills studied in EAST KALlMANTAN is higher as compared to wood recovery data obtained in GHANA and CAMEROON. Most likely, the heterogeneity in dimension, properties, and quality of the wood species processed in Africa contriblltes essentially to the lower recovery of products. The sawing and timber grading proced lIres can be optimized to a higher level in Indonesia where primarily wood species of the relatively homogeneous Dipterocarpaceae-family are sawn.

The bu Ik of the wood residues in the sawmills studied in EAST KALlMANTAN is generated in the form of solid residues at the resaw/edger (20 to 30 %) and at the trimmers (6 to 12 %). About 14 % of the log input is converted into sawdust, most of it being generated at the resaw/edger. The proportion of sawdust is related to the size of the final products as. smaller dimensions of sawn timber require more sawcuts, while the amount of solid residues is related to the quality of logs and products as well as to the technological status of the process.

PT. Kalimanis Plywood Industries sawmill East Kalimontan

Yield 1%1 Yield 1%1 1 DD 11 It 100

90 90

BO

I 80

70 70

60 60

SO 50

40 40

30 3D

20 20

10 10

0 0 23 logs of

Red Merenli

67.5m3

PT. Kioni Sakti sawmill Ecst Kalimanton Yield 1%1

';;-'" I~ 1 DO

gO

80

70

60

50

40

30

20

10

o 16 logs of 3 logs of 2 logs of Rec! tolerant! Bangklral Kapur

68.4 mJ 3.6 m3 10.9 m3

90

BO

70

60

50

40

30

20

10

o

Edgings and other smaller wood pieces are to a large extent used to produce small raw pieces for mold ing. At KPI, solid residues were used as boiler fuel, at KS solid wood residues were used as raw material in an integrated particle board and blockboard plant. At KS even parts of the sawdust can be sold to the chemical industry.

It is strongly recommended t9 use as much small solid wood pieces to produce smaller items such as moldings or reconstituted wood products such as wood-based panels in mills integrated with the sawmills in EAST KALlMANTAN to minimize transport costs.

The results gathered in sawmills in SARAWAK are summarized in Figure 1-14.

25

Huo Seng sowmill

Yield 1%1 Sorowok Yield 1%1 100 100

90 90

80 80

70 70

60 60

50 50

40 40

30 30

20 20

10 10

o 8 logs of 2 logs of 1 log of 1 log of o Alan Nyotoh Sikat Kowi

15.8m3 1:2m3 0.6m3 12.5m3

Samling 'Hood Industries sawmill Yield 1%1 Sarawalc Yield 1%1 100 L ~

III 90 90

80 80

70 70

60 60

50 50

40 40

30 .30

20 20

10 10

o . 0 1 6 logs of 2 logs of 2 logs of

Selangcn Bctu Red Merantl White Mercntl

12.5m3 5.4m3 3.1 m3

ff(gqm~1~!;:·§Ymm~P49r!~Ylf~.9~t~lq~~fq!~YKmm~!~·§~Bdve~B;·· .... At Samling about 36 % solid residues and 6 % sawdust were produced from Dipterocarp-species. In comparison with the sawmill studies on Dipterocarp-Iogs conducted in EAST KALlMANTAN the yield of sawn timber in Samling was only slightly higher (5 to 7 %). Samling Wood Industries exclusively processed high-quality logs while the mills in EAST KALlMANT AN also processed second and third quality grade'. Most likely, the dimensions of the sawn timber produced in the mills in EAST KALlMANTAN were smaller than those of the timber sawn in SARAWAK, which resulted in a markedly higher portion of sawdust (about 14 %) in both mills in EAST KALlMANTAN as compared to that recorded in the mill in SARAWAK (about 6 %).

The processing efficiency of Hua Seng sawmill cannot be compared with data obtained in other mills, as no other company sawing logs from swamp-species has been studied. At Hua Seng sawmill about 26 to 45 % (net volume) of the Swamp-logs were converted into solid wood residues and other 6,5 to 9 % into sawdust.

In conclusion, for the sawmilling sector in SARAWAK it would be beneficial to increase the quality of logs available for local processing instead of encouraging the export of prime grade logs at relatively high prices but with a very low value added in SARAWAK.

Pertaining to all sawmills studied, the following recommendations are made:

• It is strongly recommended t~ improve the qualification (theoretical and practical training) and the payment of personnel in the sawmills. Qualified personnel staying permanently on the job may significantly contribute to a better utilization of the machinery, a better product quality and an increase of product yield .

• Technical improvements of the sawmill equipment, especially the edgers and trimmers, should be encouraged in connection with the enhancement of the skill of workers. Enhanced edging and trimming technology would reduce the volume of solid residues, improved saws may reduce the proportion of sawdust through the minimization of sawkerf width.

26

• Serious efforts have to be made to tailor the product mix of the sawmills in quantity, dimensions, and quality to the raw material base under consideration of market requirements instead of C?onsidering exclusively the market demand.

6.4.3. Molding mills

Due to substantial differences in the raw materials and production processes.as well as the shape and the quality and finishing grade of products studied in the molding and furniture mills, it is hardly possible to compare figures on product/components yield and residues obtained from different production processes. Hence, it was the main objective of this part of the study to demon strate which raw materials are used to manufacture various value-added wood products in privately-owned, small-scale enterprises as well as industrialized factories in the four countries. In view of the main objectives of this PROJECT, it is important to stress that a substantial portion of the val ue-added products studied in this chapter is made by many qualified craftsmen from relative Iy cheap recycled solid wood residues.

At MTC in GHANA the production of Koto profile boards for export and Bombax and Odum moldings for the local market gave relatively uniform product yields of about 50 % plus about 43 % shavings, 5 % trimming residues and 1 % overmeasure (Figure 1-15). Although the quality deman€:ls of GHANAIAN customers are by far lower than those of .overseas customers, the mean yield of profile boards of 'mixed red woods' (MRW) for the local market was approximately 20 % lower because of excessive trimming. The relatively low yield of MRW-profile boards must be attributed to the poor quality of the input lumber. The raw material for MRW-moldings is one of the by-products of the sawmill.

MTC moulding mill, Ghana Yield 1%1

~~iiiiii~~iiiiii~(;~~iiill'f 100

90 151 ••• [ 90 "', "?7,:)o' . 80 ::%~, L. " 80 70 70

60 60

50 50

40 40

30 30

20 20

10 10

0 285 boards 375 bo~rds 96 boards 29 boords

0

Kolo Mixed red wood Sombax Odum

5.7 rn3 1.7.,,3 1.3.,,3 0.5.,,3

11 P'cHl, •

In the production of parquet flooring strips, about 44 % of the residues occurred in the form of shavings, 8 % sawdust was produced at the resaws and trimsaw when cutting the slats into raw blocks. The trimming also implies a pre-grading of the raw blocks causing about 10 to 15 % solid rejects. The volume of molded rejects varied between 6 and 24 %, depending on the quality of the raw material and the quality requirements of the overseas customers. Most of the rejects were recycled into the production of shorter strips. A greater tolerance of the overseas importers of parquet flooring towards such natural and manufacturing defects which disappear when the parquet flooring is finally sanded could increase the total product yield by at least 5 %. Inappropriate dimensions of the raw blocks also contribute to the wastage of wood. The production of parquet flooring strips from raw blocks of appropriate dimensions and graded according to present quality standards should yield about 50 % of the input wood volume in the finished product. Assuming a slightly lower quality standard, the production of parquet flooring could yield 55 to 60 % finished product.

It was hardly possible to compare the efficiencies of the three molding mills studied in GHANA, EAST KALlMANTAN (Figure 1-16), and SARAWAK (Figure 1-17) because all mills produced different profiles from raw materials of different wood species and dimensions as well as varying qualities. In all cases the molding process itself caused the greatest portion of the wood residues generated in the entire production line. The molding losses predominantly depend on the shape of the profile but they are also influenced by the molding allowance made for the raw material. Trimming residues are mainly influenced by the actual product quality in relation to the customers quality demands. In SARAWAK the trimming residues for most of the dowels were extremely high which shows that many defective parts of the finished products had to be cut off due to quality requirements. The significant discrepancy between the actual product quality and the requirements of the customers may to a great extent be explained with the extremely light calor of Ramin which makes the wood extremely susceptible for fungal attack.

SKP moulding mill. East Kalimantan KPI moulding mill. East Kalimonton

Yield 1%1 Yield 1%1 YIeld 17.1 Yield 1%1 lOO 100

90 90

Ba Ba

70 70

100 11'"" 90 90 Ba Ba 70 70

60 60 60 60

50 50 50 50

40 40 40 40

30 30 30 30

20 20 20 20

10 10 10 10

o 0 o . 0 30 boards 30 boards 30 boards

1.3m3 0.2 m3 0.1 m 3

Mouldings Shovings ~ Tri'!"dming D Oversize ~resl ues

28

In GHA NA and EAST KALlMANTAN, the selection and preparation of the raw material for the moldrng plants should be improved which means that the molding allowance could be reduced by about 5 to 10 %.

If the product quality standards set by the customers, mainly overseas importers, could be lowered to a level that matches the normal wood quality in the three countries concerned more perfectl y, the trimming losses could be reduced and the processing efficiency of molding mills could be increased significantly.

In most cases, particulate wood residues (all machining residues and sawdust) are used as boiler fuel wOfJd, are burnt or dumped. Such materials could serve as raw material for the production of wood based panels. Both molding mills studied in EAST KALlMANTAN will start using solid wood pieces of more then 10 cm length to produce laminated raw material for their molding mills.

C. T. C. moulding mill, Sarawak Yield 1%1

100 jr_--_--_--_--_--_--_--_--_--_--_--_--_--_--_--_--_--_--_--iiiiIiiiiI--o 100 90 90

80 80

70 70

50 60

50 50

40 \~!

The yield of finished products in furniture manufacture is primarily influenced by the quality and the dimensions of the input material in relation to the quality, the dimensions, and the shape of the furniture components. In the case of the CAMEROONIAN mill, the quality of the input boards seemed to be appropriate for the products because only relatively small amounts of residues occurred in the cross cutting and rip sawing section where wood defects were cut off and only a minor amount of machined components was rejected before assembling the products. In GHANA, unedged boles served as raw material for the chair manufacture. Hence, the amount of pre-cutting residues was distinctly higher than that in CAMEROON although observations at the pre-cutting station showed that quality and dimensions of the raw material were appropriate.

From the yield figures obtained from the machining section of the factory in CAMEROON it can be concluded that the dimensions of the input material may be significantly reduced to improve the material balance. Most of the residues were generated at the surface planers where the raw components were dimensioned before shaping, jointing and sanding. As the shape of the chair and arm chair components was relatively straight and rectangular, it is estimated that the planing losses could be reduced by at least 50 % if the width and the thickness of the input material were optimal. In GHANA, most of the rejected chair components were rejected because of natural wood defects which are not accepted by the buyers of the products in Europe.

SML furniture factory. Ghana

Yield 1'0:;1 Yield 1;

In comparis

MTC veneer slicing mill. Ghana Yield I~I Yield I~I

100 100

90 90

80 80

70 70

60 60

50 50

40 40

30 30

20 20

10 10

0 0 Makore Asanfena Mahogany Sapele

Ecam - Placage venee'- slicing mill

Yield 1%1 Carneroon Yield 1%1 1 00 fi= -----, ,------.- ---, I I t- 1 00

90 90

80 ilY~

GAP plywood mill. Ghana Yield 1'7c1 Yield 1701 SFlO plywood mill. Cameroon

Yield 1"1 Yield IXI 10011 11 11 11 1t-100 100 ~I .. hili iIliiiil~1 00

90

80

70

60

50

40

30

20

10

o 8 billets of 6 billets of 3 billets of 6 billets of

Mahogany Edinam Candollei Ceiba

11.9m 3 6.3m 3 6.0m3 11.4m3

Plywood I' . , Peeler core

90

80

70

60

50

40

30

20

10

o

110 110

BO BO

70 70

EO EO

SD SO

4CI 4()

;10 ;10

20 20

10 10

010 blDllt. af 10 bOle" tit 0

Ayau. Sap.1II 12..2 m 3 1 D.l m l

Finishing m Wet veneer residues ~ residues

• Dry veneerD Sh . k • Shrinkage and residues nn age dry veneer residues

Due to a smaller peeler core diameter, the study in CAMEROON rendered higher yield of Ayous veneer .as compared to most of the species studied in GHANA although the Ayous logs were smaller than the logs studied in GHANA (Figure 1-20). Lower yield was found for CAMER()ONIAN Sapelli veneer as compared to Mahogany, Edinam, and Candollei studied in

. GHANA. The relatively low yield of Sapelli veneer in CAMEROON has to be attributed to the fact that exclusively high-quality Sapelli veneer was produced for the international market. More than 20 % of the Sapelli veneer was rejected after drying. Furthermore, the Sapelli logs were about 15 cm smaller in diameter than the logs studied in GHANA. Rounding-off and wet clipping resit:lues were higher in GHANA as compared to CAMEROON. Plywood trimming residues are simi lar in the GHANAIAN and the CAMEROONIAN mill studied. In CAMEROON the mean plywood yield was calculated at 57,8 % of the input logs for Ayous and at 44,2 % for Sapelli.

The yield of veneer and plywood in the GHANAIAN mill could be increased through improvements at the lathes in order to minimize rounding-off residues, reduce the peeler core volume, and minimize the thickness variation of the peeled veneer.

In CAMEROON and GHANA, the yield of plywood per unit volume of logs could also be increased if the clrpping of the veneer sheets could be performed more precisely either by an automated device or by a skilled machine operator. It is estimated that plywood trimming residues could be reduced to about 3 to 5 % if the over-measure of the wet veneer sheets would be limited to 25 to 50 mm in width and length.

33

SLJ plywood mill. East Kalimantan Yield 1%1 Yield 1%1

100 jl 11 11 11 11 1 1TTlTTTTTTTTT1 1 ,\ [_It 100 90

80

70

60

50

40

30

20

10

o I log of 2 logs of 1 log of 1 log of 1 log of

White - Red Meran!i Kapur Eulung 8. Keruing

6.5 m 3 10.8 m 3 5.4 m 3 5.3 m 3 5.0 m 3

1 log of

Aga!his

3.2 m 3

SMP plywood mill. East Kalimantan

1 log of 2 logs of

Nyatoh 8enuang

6.6 m 3 7.5 m 3

Yield 1%1 Yield I~I tOOil " " II Irl00

90j~~.~l 80

70

60

50

40

30

20

10

o 2 logs of 1 log of 2 logs of 5 logs of Y"lIow - White - Red Meranti Kapur

6.6m3 4.0m3 10.lm3 17.3m3

90

80

70

60

50

40

30

20

to

o

Plywood

'xx .~'$%?>;i Peeler ::::«:~:~ cor e :::-~.?w ~

Finishing ~ Wet ve~eer residues ~ residues

• Dry veneerD Sh . k • Shrinkage and residues nn age dry veneer residues

90

80

70

60

50

40

30

20

10

o

The yield of veneer and plywood is considerably higher in the mills studied in EAST KALlMANTAN as compared to most of the results obtained in African mills (Figure 1-21). The mean plywood yields were 60 and 64 %, respectively, in the two mills in EAST KALlMANTAN. Most likely, this is due to the homogeneity of the wood of 'dipterocarp-Iogs' on the one hand and to the greater diameters of the logs processed in Indonesia as compared to those studied in Africa on the other hand. The variation of yield figures for logs of different Indonesian tree species is fairly small as compared to those studied in African mills which may be due to the greater homogeneity of dipterocarp-Iog quality and shape. Due to the greater diameters of logs

34

and the smaller diameters of the peeler cores in Indonesia, the peeler core percentages are significantly lower than in the African mills.

In the mills in EAST KALlMANTAN, the peeler cores were either used to generate energy for the veneer dryers and hot presses, sold as raw material for particle board manufacture, or converted into sawn timber and block board strips. All particulate residues are used as boiler fuel.

Sarawak Ca. plywood mill. Sarawal<

Yield 1,,1 Yield 1%1 100 100

90 90

80 80

70 70

60 60

:: •• 50 40 30 ~:l •• f~: o 1210gs of

R .• d and Yellow ~.tero.ntj

B.7 rn 3

9 logs 01 0 Ped. Yellow and White Mercntl 4.7 m 3

Veneer .::.; Peeler ;'1""'0:' s"eets ~.~ core

DShrinkoge

Rimbunon Hijou plywood mill

Yield 1"'"1 Sarawak Yield I~I 100

90

80

70

60

50

40

30

20

10

o 5 logs 01 Red and Yellow Meronti

5.1 rn3

100

5 logs 01

MengklJlong

1.02 m3

90

80

70

60

50

40

30

20

10

o

m. ~. Wet veneerlJ] Dry veneer ~ residues residues

In comparison with the recovery factors for dry veneer sheets determined in GHANA (50 to 73 %), CAMEROON (49 to 64 %), and EAST KALlMANTAN (60 to 76 %), the recovery factors for veneer obtained in SARAWAK (48 to 60 %, Figure 1-22) are relatively low. The mills in EAST KALlMANTANattain about 10 to 20 % higher veneer recovery from 'dipferocarp-Iogs' although the peeler cores were smaller in mills in SARAWAK. This marked difference must be attributed to a significant difference between the sizes of logs processed in EAST KALlMANTAN and SARAWAK. Due to the significantly smaller size of billets processed in SARAWAK, the relative amount of rounding off residues and peeler cores was higher than in the mills in EAST KALlMANTAN.

In SARAWAK the plywood manufacturing process had to be studied separately from the veneer peeling study. Therefore, in Figure 1-22 only yield figures for graded, jointed veneer sheets are· given. Under consideration of the results of the plywood manufacturing study, the yield of finished plywood relative to volume of the input billets was calculated at about 44 % plus trimming and sanding residues. Hence, the yield of plywood in relation to the laid-up packages of veneer sheets is also relatively low in the mills studied in SARAWAK (about 3 % less plywood recovery relative to the input billets) in comparison with the mills studied in CAMEROON and EAST KALlMANTAN. The relatively high proportion of trimming and sanding residues in the mills studied in SARAWAK must be due to technical reasons. Either the veneer sheets are relatively large in

35

relation to the desired plywood size which leads to high trimming residues and/or the thickness variation of the plywood is high before sanding which leads to high amounts of sander dust.

6.5. Recommendations

In conclusion, the following strategic recommendations pertaining to the wood processing industries studied in the four PROJECT partner countries could be derived:

+ To minimize wastage of materials in wood processing, different processing lines should be integrated to the largest extent possible and the manufacture of value-added products should be encouraged. Timber sorting for dimension and quality in centralized log yards according to the requirements of different wood processing mills, such as sawmills, veneer and plywood manufacturing, as well as mills for moldings and other value-added products, may increase the efficiency in wood utilization considerably. Logging, bucking and processing of logs should be coordinated as closely as possible.

+ Processes using small-dimensioned wood particles and solid residues should also be integrated with primary processing facilities. The development of merchantable products made from wood residues, such as blockboard, particleboard, fiberboard and finger-jointed boards, should be supported.

+ There is an urgent need to raise the level of technology in certain sectors of the wood processing industry in the four countries. In sawmilling, for instance, higher accuracy of sawing and reduced saw kert thickness are recommended, log rotating devices for the adjustment of the saw kert in the log may reduce wood residues considerably and may simultaneously increase product quality. Furthermore, edging and trimming should be optimized. Therefore, modern equipment and machinery adapted to the special local conditions is needed, especially for critical parts of the process.

+ Related to the modernization of machinery is the need to raise the skill of workers, mainly machine operators at headrig, edgers and trimmers, by practical training and education. Without such training, efforts to raise the yield in the wood processing industry will be futile.

+ Another instrument for increaSing yield and revenue in the wood proceSSing industry is the establishment of quality control systems in the mills. This important element of efficient wood utilization and processing is either missing or underdeveloped in most of the mills studied.

+ Downstream wood processing, such as furniture manufacturing, parquet flooring and profile board production, should be encouraged. This will help creating jobs and. raise the level of manufacturing technology in the four countries. Serious efforts have to be made to help the tropical countries to market value-added products at acceptable prices on remote markets.

+ Serious efforts have to be made to tailor the product mix of the wood processing mills in quantity, dimensions, and quality to the raw material base under consideration of market requirements instead of considering exclusively the market demand.

+ Finally, the conversion of wood into energy, especially to provide heat and power for the wood processing industry itself, should be developed, because wood residues and bark possess a considerable potential as an environmentally friendly fuel.

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Published by

INTERNATIONAL TROPICAL TIMBER ORGANIZATION (ITTO)

INTERNATIONAL ORGANIZATIONS CENTER, 5TH FLOOR

PACIFlCO-YOKOHAMA, 1-1-1, MINATO-MIRAI, NISHI-KU, YOKOHAMA, 220-0012 JAPAN

TEL: (81-45) 223-1110, FAX: (81-45) 223-1111, E-mail :itto@mail. itto-unet.ocn.ne.jp http://www.itto.or.jp/

International Tropical Timber Organization (ITIO)

~-----------------------------------

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J

INTERNATIONAL TROPICAL TIMBER ORGANIZATION

International Organizations Center - 5th Floor, Pacifico-Yokohama, 1-1 -1, Minato-mirai, Nishi-ku, Yokohama 220-0012, Japan

Telephone 81-45-223-1110 Facsimile 81-45-223-1111 E-mail : itto@mail.itto-unet.ocn.ne.jp http ://www.itto.or.jp/

-@ Recycled paper

©IITO 1999 Printed by HAKUSHUDOH PRINTING INC., Japan I Designed by C.S.!. INC., Japan

,

, to.

INTERNATIONAL TROPICAL TIMBER ORGANIZATION

International Organizations Center - 5th Floor, Pacifico-Yokohama, 1-1-1, Minato-mirai, Nishi-ku, Yokohama 220-0012, Japan

Telephone 81-45-223-1110 Facsimile 81-45-223-1111 E-mail : itto@mail.itto-unet.ocn.ne.jp http ://www.itto.or.jp/

~ Recycled paper

©ITTO 1999 Printed by HAKUSHUDOH PRINTING INC .• Japan I Designed by C.S.1. INC., Japan