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Created page with "{{TurningpageNWFP |title=Coppen, ''Gums, resins and latexes of plant origin'', 1995 |titlepreviouspage=Sorva (FAO, NWFP 6) |previousshortname=Sorva |titlefollowingpage=Balat..."
{{TurningpageNWFP
|title=Coppen, ''Gums, resins and latexes of plant origin'', 1995
|titlepreviouspage=Sorva (FAO, NWFP 6)
|previousshortname=Sorva
|titlefollowingpage=Balata (FAO, NWFP 6)
|followingshortname=Balata
}}
*Extract from : NWFP 6. Coppen J.J.W., 1995. ''Gums, resins and latexes of plant origin''. FAO, Rome. 142 p. (''Non-Wood Forest Products'', '''6'''). [http://www.fao.org/3/a-v9236e.pdf on line]
[127]
<center>'''6 — LATEXES'''</center>
<center>'''COPAL'''</center>
GUTTA PERCHA
DESCRIPTION AND USES
Gutta percha is the coagulum produced from the latex of certain trees of the Sapotaceae
family indigenous to Southeast Asia, particularly those found in the Malay and Indonesian
archipelagos.
In contrast to rubber, which is an elastic material, gutta percha is non-elastic; it becomes
plastic when heated but retains its shape when cooled. The differences between the two
materials arise from their different chemical compositions: rubber and gutta percha both
contain a large proportion of the polymeric hydrocarbon polyisoprene, but in the former it
is the cis isomer while in the latter it is the trans isomer. The presence of trans polyisoprene
in balata-like materials originating from tropical America is referred to elsewhere (BALATA
and MAÇARANDUBA), and confers on them their non-elastic properties.
Towards the middle of the last century it was discovered that gutta percha had excellent
insulating properties which were retained under water, and its most important use was in
providing the insulating material for submarine and underground cables. It was also used (as
was balata) for the manufacture of golf ball covers and other moulded products. However,
the advent of synthetic resins and other, petroleum-based polymeric materials led to the rapid
decline in use of the natural material.
WORLD SUPPLY AND DEMAND TRENDS
Markets
Average annual world consumption of gutta percha in the early part of the century (40 years
up to 1936) has been stated to be approximately 850 tonnes, of which about 450 tormes were
used for submarine cables, 300-400 tonnes for the manufacture of golf balls, and the
remainder for miscellaneous industries such as machine belting (READER, 1953).
LOCKHART-SMITH (1972), on the other hand, states that exports of gutta percha and
inferior guttas from Singapore averaged nearly 14 000 tornes annually between 1900 and
1920. By the 1960s/1970s, golf ball manufacture was the only significant end use for gutta
percha (and balata).
In the 1960s, the United States was by far the largest importer of gutta percha; average
annual imports from Indonesia over the 10 years 1963-72 were 1 140 tonnes (LOCKHARTSMITH,
1972). Recent US data are not available.
It is not easy to draw conclusions about present day consumption of gutta percha on the basis
of trade statistics alone. Gutta percha is not always disaggregated from other non-elastic
gums, and although an attempt has been made to do this in the case of recent imports into
Japan of "chicle, balata, gutta percha and guayule" (Table 32), the average annual figure of
about 970 tonnes for assumed gutta percha imported from Indonesia is much greater than total
recorded exports of gutta percha out of Indonesia for the same period (Table 35, annual
average 190 tonnes). Furthermore, of these total exports, only 6 tonnes (in 1993) went
directly to Japan.
[128]
Supply sources
In past years, Indonesia and Malaysia have been the dominant producers of gutta percha, with
minor quantities coming from Thailand and a few other countries in the region. Singapore
is often the first destination for exports, which are then re-exported to end-user countries.
Indonesia is believed to be the largest producer and exporter of gutta percha today, although
it is not clear whether the quantities given in Table 35 are a true reflection of the size of this
trade.
Quality and prices
The quality of gutta percha, both in its crude and processed form, depends largely on its
hydocarbon (gutta) content, since it is this that confers on gutta percha its thermo-plastic
properties. Most of the remaining material is "resin". Gutta percha which has been extracted
from leaves by non-solvent methods (see VALUE-ADDED PROCESSING below) contains
around 70-75% hydrocarbon and 6-10% resin; the balance is moisture and a few per cent
of solid impurities. Fully refined, solvent-extracted gutta percha ("white gutta") contains less
than 1% resin.
FOB export values for gutta percha of Indonesian origin have been quite steady for the last
three years of data (1991-93): approximately US$ 1 200/tonne. In 1990 it was about
US$ 1 900/tonne.
PLANT SOURCES
Botanical names
Family Sapotaceae:
Palaquium gutta (Hk. f.) Baillon
Other Palaquium spp., including P. obovatum (Griffith) Engler, P. oblongifolium,
P. oxleyanum Pierre and P. treubii.
Payena leerii (Teys. et Binn.) Kurz
Description and distribution
Palaquium species are medium to very tall trees. P. gutta is a medium tree, up to 25 m in
height and 1.5 m in girth, with small buttresses. Payena leerii grows up to 40 m high.
The main gutta percha-yielding trees are found in Indonesia and Malaysia, particularly the
islands of Sumatra and Borneo and smaller surrounding ones. However, they occur as far
north as the Philippines and mainland Southeast Asia, and as far east as Papua New Guinea.
Pala quium species are amenable to cultivation and plantations were established in Java for
gutta percha production as early as the 1890s. Commercial plantations were also being
worked in Malaysia in the 1950s, but the last of these ceased operation in 1967.
LOCKHART-SMITH (1972) reported that the plantation at Cipetir, West Java, was the only
active one in the early 1970s; its status today is not known. Although P. gutta produces the
highest quality gutta percha, P. oblongifolium is the species most suited to planting.
[129]
COLLECTION/PRIMARY PROCESSING
In the early 1900s, when demand for gutta percha was at its greatest, collection of the latex
from wild trees was entirely by destructive means, so as to obtain as much as possible: the
tree was felled, the branches lopped off, and a number of wide cuts made through the bark
at intervals along the trunk. When it became clear that this was leading to significant losses
of forest, such methods were banned and techniques for tapping the living tree were
developed.
Usually these methods entailed making a series of V-shaped cuts in the bark of the tree about
20-30 cm apart, with a central, vertical channel. Most of the latex coagulated in the cuts and
was collected by rolling it into small balls along the cuts; the remainder flowed into small
cups fixed to the tree. A rest period of at least two years was said to be necessary between
successive tappings to keep the tree economically productive. Unlike rubber trees, which
contain laticiferous tubes in the bark, Pala quium spp contain irregular cavities which are not
connected, and tapping cannot be done in a manner similar to that for rubber.
In plantations, extraction of gutta percha from the leaves of the trees is more productive than
collection of latex by tapping. Harvesting is done partly by plucking (about four times a
year) and partly by collecting prunings (which comprise leaves, twigs and small branches).
Primary processing of the latex entails pressing the partially formed coagulum into blocks
after first softening it in hot water and removing larger pieces of foreign matter. The blocks
are then transported to the factory for further processing; if they need to be stored for any
length of time before transportation they are best kept under water to avoid spoilage by aerial
oxidation.
Extraction of the gutta percha from leaves is briefly described under VALUE-ADDED
PROCESSING, since some aspects of it are similar to methods used for further processing
of the crude gutta percha blocks.
Yields
Tapping yields of latex depend on both genetic and environmental factors, as well as the part
of the tree which is tapped. In P. oblingifolium, for example, the latex hardens after a few
minutes of exposure to the air, and the yield is considerably lower than that from P.
obovatum. Cloudy, moist conditions allow the latex to flow more easily than during hot,
sunny periods, when there is some loss of water by evaporation. Higher yields are also
obtained from the upper portion of the trunk and branches than from the lower part. Yields
of gutta percha per tree are also very variable, but about 1.5 kg has been stated to be a good
average.
The gutta percha content of leaves increases with the age of the leaf: results reported in the
older literature state about 3% (dry basis) in young leaves, 8% in medium-aged leaves and
10% in old leaves.
VALUE-ADDED PROCESSING
Preparation of purified gutta percha involves chopping the blocks of crude material into small
pieces, removing the resinous ("non-gutta") fraction by dissolution in cold petroleum spirit,
and then dissolving the remaining, separated gutta fraction in hot petroleum spirit. This hot
[130]
extract is drained from any insoluble foreign matter and then allowed to cool, whereupon the
purified gutta percha separates out. After separation and distillation of residual solvent the
hot, plasticized gutta is rolled into sheets and stored, either in the dark in well sealed tins,
or in water.
Solvent extraction of gutta from harvested leaves follows the same principles as above, but
involves pulverized leaf material instead of chopped crude gutta percha. Bleaching earth is
added to the hot mixture to remove unwanted leaf pigments.
An alternative method of processing the leaves involves digesting the leaf pulp in hot water,
and collecting and pressing the coagulated latex which separates out into blocks.
PRODUCTS OTHER THAN LATEX
No other products of economic value are believed to come from the gutta-yielding species.
DEVELOPMENTAL POTENTIAL
Although recent Indonesian export data show a modest upward trend, there is insufficient
infolmation, here, to be able to make an informed judgement as to the developmental
potential of Pala quium and gutta percha production. In particular, it is not known whether
the gutta percha produced in Indonesia (or elsewhere) comes from plantation or wild sources.
SELECTED BIBLIOGRAPHY
LOCKHART-SMITH, C.J. (1972) Market prospects for gutta-percha. Report of the Tropical Products
Institute, London [now Natural Resources Institute, Chatham].
READER, D.E. (1953) Gutta-percha. Colonial Plant and Animal Products, 3(1), 33-45.
SERIER, J.B. (1986) [Tree secretions] [includes balata and gutta percha] (in French). Bois et Forets
des Tropiques, (213), 33-39.
STERN, H.J. (1939) Gutta percha and balata: purification in the factory. The Rubber Age, (Oct.),
245-249 and 258.
TONGACAN, A.L. (1971) Gutta Percha. FPRI Technical Note No. 106. 2pp. Laguna, the
Philippines: Forest Products Research and Industries Development Commission.
WILLIAMS, L. (1962) Laticiferous plants of economic importance. II. Mexican chilte (Cnidoscolus):
a source of gutta-like material. Economic Botany, 16, 53-70.
[131]
Table 35. Gutta percha: exports from Indonesia, and destinations, 1988-93
(tonnes)
1988 1989 1990 1991 1992 1993
Total 3 75 156 316 366 241
Of which to:
Singapore 72 119 316 363 234
USA 2 3 36 3
Belgium/Luxembourg I 1
Japan - - - 6
Source: National statistics
[[Category:FAO, NWFT 6]]
|title=Coppen, ''Gums, resins and latexes of plant origin'', 1995
|titlepreviouspage=Sorva (FAO, NWFP 6)
|previousshortname=Sorva
|titlefollowingpage=Balata (FAO, NWFP 6)
|followingshortname=Balata
}}
*Extract from : NWFP 6. Coppen J.J.W., 1995. ''Gums, resins and latexes of plant origin''. FAO, Rome. 142 p. (''Non-Wood Forest Products'', '''6'''). [http://www.fao.org/3/a-v9236e.pdf on line]
[127]
<center>'''6 — LATEXES'''</center>
<center>'''COPAL'''</center>
GUTTA PERCHA
DESCRIPTION AND USES
Gutta percha is the coagulum produced from the latex of certain trees of the Sapotaceae
family indigenous to Southeast Asia, particularly those found in the Malay and Indonesian
archipelagos.
In contrast to rubber, which is an elastic material, gutta percha is non-elastic; it becomes
plastic when heated but retains its shape when cooled. The differences between the two
materials arise from their different chemical compositions: rubber and gutta percha both
contain a large proportion of the polymeric hydrocarbon polyisoprene, but in the former it
is the cis isomer while in the latter it is the trans isomer. The presence of trans polyisoprene
in balata-like materials originating from tropical America is referred to elsewhere (BALATA
and MAÇARANDUBA), and confers on them their non-elastic properties.
Towards the middle of the last century it was discovered that gutta percha had excellent
insulating properties which were retained under water, and its most important use was in
providing the insulating material for submarine and underground cables. It was also used (as
was balata) for the manufacture of golf ball covers and other moulded products. However,
the advent of synthetic resins and other, petroleum-based polymeric materials led to the rapid
decline in use of the natural material.
WORLD SUPPLY AND DEMAND TRENDS
Markets
Average annual world consumption of gutta percha in the early part of the century (40 years
up to 1936) has been stated to be approximately 850 tonnes, of which about 450 tormes were
used for submarine cables, 300-400 tonnes for the manufacture of golf balls, and the
remainder for miscellaneous industries such as machine belting (READER, 1953).
LOCKHART-SMITH (1972), on the other hand, states that exports of gutta percha and
inferior guttas from Singapore averaged nearly 14 000 tornes annually between 1900 and
1920. By the 1960s/1970s, golf ball manufacture was the only significant end use for gutta
percha (and balata).
In the 1960s, the United States was by far the largest importer of gutta percha; average
annual imports from Indonesia over the 10 years 1963-72 were 1 140 tonnes (LOCKHARTSMITH,
1972). Recent US data are not available.
It is not easy to draw conclusions about present day consumption of gutta percha on the basis
of trade statistics alone. Gutta percha is not always disaggregated from other non-elastic
gums, and although an attempt has been made to do this in the case of recent imports into
Japan of "chicle, balata, gutta percha and guayule" (Table 32), the average annual figure of
about 970 tonnes for assumed gutta percha imported from Indonesia is much greater than total
recorded exports of gutta percha out of Indonesia for the same period (Table 35, annual
average 190 tonnes). Furthermore, of these total exports, only 6 tonnes (in 1993) went
directly to Japan.
[128]
Supply sources
In past years, Indonesia and Malaysia have been the dominant producers of gutta percha, with
minor quantities coming from Thailand and a few other countries in the region. Singapore
is often the first destination for exports, which are then re-exported to end-user countries.
Indonesia is believed to be the largest producer and exporter of gutta percha today, although
it is not clear whether the quantities given in Table 35 are a true reflection of the size of this
trade.
Quality and prices
The quality of gutta percha, both in its crude and processed form, depends largely on its
hydocarbon (gutta) content, since it is this that confers on gutta percha its thermo-plastic
properties. Most of the remaining material is "resin". Gutta percha which has been extracted
from leaves by non-solvent methods (see VALUE-ADDED PROCESSING below) contains
around 70-75% hydrocarbon and 6-10% resin; the balance is moisture and a few per cent
of solid impurities. Fully refined, solvent-extracted gutta percha ("white gutta") contains less
than 1% resin.
FOB export values for gutta percha of Indonesian origin have been quite steady for the last
three years of data (1991-93): approximately US$ 1 200/tonne. In 1990 it was about
US$ 1 900/tonne.
PLANT SOURCES
Botanical names
Family Sapotaceae:
Palaquium gutta (Hk. f.) Baillon
Other Palaquium spp., including P. obovatum (Griffith) Engler, P. oblongifolium,
P. oxleyanum Pierre and P. treubii.
Payena leerii (Teys. et Binn.) Kurz
Description and distribution
Palaquium species are medium to very tall trees. P. gutta is a medium tree, up to 25 m in
height and 1.5 m in girth, with small buttresses. Payena leerii grows up to 40 m high.
The main gutta percha-yielding trees are found in Indonesia and Malaysia, particularly the
islands of Sumatra and Borneo and smaller surrounding ones. However, they occur as far
north as the Philippines and mainland Southeast Asia, and as far east as Papua New Guinea.
Pala quium species are amenable to cultivation and plantations were established in Java for
gutta percha production as early as the 1890s. Commercial plantations were also being
worked in Malaysia in the 1950s, but the last of these ceased operation in 1967.
LOCKHART-SMITH (1972) reported that the plantation at Cipetir, West Java, was the only
active one in the early 1970s; its status today is not known. Although P. gutta produces the
highest quality gutta percha, P. oblongifolium is the species most suited to planting.
[129]
COLLECTION/PRIMARY PROCESSING
In the early 1900s, when demand for gutta percha was at its greatest, collection of the latex
from wild trees was entirely by destructive means, so as to obtain as much as possible: the
tree was felled, the branches lopped off, and a number of wide cuts made through the bark
at intervals along the trunk. When it became clear that this was leading to significant losses
of forest, such methods were banned and techniques for tapping the living tree were
developed.
Usually these methods entailed making a series of V-shaped cuts in the bark of the tree about
20-30 cm apart, with a central, vertical channel. Most of the latex coagulated in the cuts and
was collected by rolling it into small balls along the cuts; the remainder flowed into small
cups fixed to the tree. A rest period of at least two years was said to be necessary between
successive tappings to keep the tree economically productive. Unlike rubber trees, which
contain laticiferous tubes in the bark, Pala quium spp contain irregular cavities which are not
connected, and tapping cannot be done in a manner similar to that for rubber.
In plantations, extraction of gutta percha from the leaves of the trees is more productive than
collection of latex by tapping. Harvesting is done partly by plucking (about four times a
year) and partly by collecting prunings (which comprise leaves, twigs and small branches).
Primary processing of the latex entails pressing the partially formed coagulum into blocks
after first softening it in hot water and removing larger pieces of foreign matter. The blocks
are then transported to the factory for further processing; if they need to be stored for any
length of time before transportation they are best kept under water to avoid spoilage by aerial
oxidation.
Extraction of the gutta percha from leaves is briefly described under VALUE-ADDED
PROCESSING, since some aspects of it are similar to methods used for further processing
of the crude gutta percha blocks.
Yields
Tapping yields of latex depend on both genetic and environmental factors, as well as the part
of the tree which is tapped. In P. oblingifolium, for example, the latex hardens after a few
minutes of exposure to the air, and the yield is considerably lower than that from P.
obovatum. Cloudy, moist conditions allow the latex to flow more easily than during hot,
sunny periods, when there is some loss of water by evaporation. Higher yields are also
obtained from the upper portion of the trunk and branches than from the lower part. Yields
of gutta percha per tree are also very variable, but about 1.5 kg has been stated to be a good
average.
The gutta percha content of leaves increases with the age of the leaf: results reported in the
older literature state about 3% (dry basis) in young leaves, 8% in medium-aged leaves and
10% in old leaves.
VALUE-ADDED PROCESSING
Preparation of purified gutta percha involves chopping the blocks of crude material into small
pieces, removing the resinous ("non-gutta") fraction by dissolution in cold petroleum spirit,
and then dissolving the remaining, separated gutta fraction in hot petroleum spirit. This hot
[130]
extract is drained from any insoluble foreign matter and then allowed to cool, whereupon the
purified gutta percha separates out. After separation and distillation of residual solvent the
hot, plasticized gutta is rolled into sheets and stored, either in the dark in well sealed tins,
or in water.
Solvent extraction of gutta from harvested leaves follows the same principles as above, but
involves pulverized leaf material instead of chopped crude gutta percha. Bleaching earth is
added to the hot mixture to remove unwanted leaf pigments.
An alternative method of processing the leaves involves digesting the leaf pulp in hot water,
and collecting and pressing the coagulated latex which separates out into blocks.
PRODUCTS OTHER THAN LATEX
No other products of economic value are believed to come from the gutta-yielding species.
DEVELOPMENTAL POTENTIAL
Although recent Indonesian export data show a modest upward trend, there is insufficient
infolmation, here, to be able to make an informed judgement as to the developmental
potential of Pala quium and gutta percha production. In particular, it is not known whether
the gutta percha produced in Indonesia (or elsewhere) comes from plantation or wild sources.
SELECTED BIBLIOGRAPHY
LOCKHART-SMITH, C.J. (1972) Market prospects for gutta-percha. Report of the Tropical Products
Institute, London [now Natural Resources Institute, Chatham].
READER, D.E. (1953) Gutta-percha. Colonial Plant and Animal Products, 3(1), 33-45.
SERIER, J.B. (1986) [Tree secretions] [includes balata and gutta percha] (in French). Bois et Forets
des Tropiques, (213), 33-39.
STERN, H.J. (1939) Gutta percha and balata: purification in the factory. The Rubber Age, (Oct.),
245-249 and 258.
TONGACAN, A.L. (1971) Gutta Percha. FPRI Technical Note No. 106. 2pp. Laguna, the
Philippines: Forest Products Research and Industries Development Commission.
WILLIAMS, L. (1962) Laticiferous plants of economic importance. II. Mexican chilte (Cnidoscolus):
a source of gutta-like material. Economic Botany, 16, 53-70.
[131]
Table 35. Gutta percha: exports from Indonesia, and destinations, 1988-93
(tonnes)
1988 1989 1990 1991 1992 1993
Total 3 75 156 316 366 241
Of which to:
Singapore 72 119 316 363 234
USA 2 3 36 3
Belgium/Luxembourg I 1
Japan - - - 6
Source: National statistics
[[Category:FAO, NWFT 6]]
