Risk assessment craft in bronze alloy melting process for the production of Balinese gamelan.
2012 Southeast Asian Network of Ergonomics Societies Conference (SEANES)
Risk Assessment Craft in Bronze Alloy Melting
Process for the Production of Balinese Gamelan
IGN. Priambadi1, N. Adiputra2, Ketut Tirtayasa, IGB. Wijaya Kusuma3
1
Faculty of Medicine
Dept. of Ergonomics
3
Dept. of Mechanical Engineering, Faculty of Engineering
University of Udayana, Bali, Indonesia
[email protected], [email protected], [email protected], [email protected]
2
Abstract—Activity especially in Balinesse cultural and religious
activities cannot be separated from the acoustic instrument called
gamelan. It is an existence value of the Balinese Hindu
civilization which has been maintained from generation to
generation. In the development device gamelan instruments has
got functional development rapidly from utilization of the
religious to the cultural activities. The sound harmonization
produced by the gamelan cannot be separated from the
traditionally process starting from the manufacture of bronze
alloy composition, melting, molding, forging through the
establishment of sound as well as the alignment for gamelan
sound in a single device. Bronze alloy composed of two elements
ie metals copper (Cu) and tin (Sn) in which these elements are
fused at a temperature of ± 1083 oC. In the process of alloy
melting bronze, craftsmen use an open stove model so the heat
produced exposure in the workplace. It will give the risk of
craftsmen such as radiation risks, these conditions impact to the
so that they will be quickly fatigue. The of the study research
showed temperatures exposure in the workplace based on the
method of gamelan craftsmen mean radiant temperature (MRT)
was 42.69 ± 0.732 ° C with levels of radiation 563.47 ± 5.175
W/m2, wind speed 0.1 m/s and relative humidity 25%. In the
melting process was carried out craftsmen average pulse rate
were measured before work 81.9 ± 2.47 pulse / min and an
average pulse rate was measured after working before the
breaking was 118.47 ± 4.274 pulse / minute. This condition
describes, the activities who did by craftsmen in the production
process shows a fairly heavy workload.
raw materials to be a set of gamelan use more traditional
methods that have been heritaged from generation to
generation. The process of gamelan starting from the making of
bronze alloy consist of copper (Cu) and tin (Sn) with a
composition of 80% and 20%, the composition has been
commonly used by craftsmen and provide the best quality of
gamelan. The alloy bronze is formed through the working of
process heat that melted reached boiling point in temperature of
± 1083 º C [1], to reach the boiling point need fire smelters to
have higher temperatures, then cast (casting) in the mold after
freezing process followed by forging and the last is a alignment
process (the establishment of the fundamental tone) with a
stingy or grinding.
Keywords-gamelan; smelting furnace;, bronze alloy; the
workload
Gamelan craftsmen working conditions generally work in
hot area, it is caused during the melting process in the furnace
bronze alloy. The amount of radiation energy emitted heat from
the furnace [2].
I.
PRELIMERY
The life existence of Balinesse gamelan cannot be separated
from religion, especially Hinduism, even though its
development the Balinese gamelan has dominance in various
types of performances that are not in a religious context.
Almost every Banjar Pekraman Peoples of Bali has all the
equipment complement of this ceremony. The village of
Tihingan Banjarangkan Klungkung District is located 3 km
towards the west of the town of Klungkung, a small famous
village that know as the centre of gamelan craft and known
well all over the world. Craftsman (pande) in processing the
Copyright of this paper belongs to the author(s).
Daily activities in the process of gamelan is very risky for
the gamelan craftsmen, such as during the melting process in
the furnace (furnace) at high temperatures where the risk of
workers/craftsmen to be quickly fatigue due to workplace
exposured by high temperatures. Based on the Ministry of
Labor SE-01/MEN/1978, decided the value of noise exposure
at work place about 85dBA for 8 hours a day, 40 hours a week,
the requirements for ambient temperatures between 21-30
degrees Celsius, 65-95% humidity levels, and requires
employers to take specific actions to reduce the air temperature
above 30 degrees. DEPNAKERTRANS.
II.
HEAT EXPOSURE
Eb = σ.T4 W/m2 (BTU/h.ft2)
where:
Eb = energy radiated
= 5.669 x 10-8 W/m2.R4
= 0.1714 x 10-8 BTU/h.ft2.K4
(1)
2012 Southeast Asian Network of Ergonomics Societies Conference (SEANES)
T = temperature of exposure (K), is measured from the
method of mean radiant temperature
According to ISO 15265 [3], the radiation exposure that
occurs should be on interventions that work can provide
comfort for crafters. Form of intervention can be based on six
factors in accordance with ASHRAE Standard comfort 55P [4]
above. Mean radiant temperature can be calculated by the
equation below:
MRT
T1 . 1 T2 . 2 T3 . 3 ... Tn . n
(2)
360
V. METHOD
Assessment of the risk of gamelan craftsmen when melting
process is done by performing measurements on the
workplace or the subject as follows:
The design of the study using the same subjects [6],
where the influence of heat in the workplace on the
subject was measured before and after the melting
process is carried out before the lunch break;
Workplace temperature measurement when melting
process occurs every hour before the break, this is
done by the method of MRT (mean radiant
temperature);
Perform measurements with the method of pulse 10
beats before and after work, to see artisans working
load;
Assessing subjective of the crafters fatigue
subjectively before and after working with the filling
of the questionnaires.
where:
T = temperature of the surface of the corresponding point
of measurement (° C)
θ = angle of exposure (o)
III.
EVALUATION OF WORKLOAD BASED ON THE PULSE
A. Workload
The measurement of workload based on the pulse during
working is a method to assess cardiovascular strain using the
method of 10 pulse.
B. Fatique
The fatigue of workers is burden accumulation of an
acceptable body due to work activities for long time to produce
the production. This situation is natural sign to get a break, it is
important to avoid the permanent fatigue that can cause the
body damage, but most of people would accentuate the effect
of fatigue as a factor of decreasing efficiency work.
Determinant the two theories of fatigue, namely: (1) based on
chemical theory, fatigue is due to reduced energy reserves and
increasing metabolic waste that causes loss of muscle
efficiency, and (2) based on the neuro theory of nerves, fatigue
is a chemical change in muscle cells, which lead to stimulate
neuro sensory channeled through to the brain, which is
recognized as muscle fatigue [5]. Fatigue can be using
measured subjectively a questionnaire rating scale of 30 items
issued by the Japan Association of Industrial and Health.
Assessment of the craftsmen risk made before the lunch
break and be repeated three times in the same time but different
days.
VI. RESULT AND DISCUSSION
Assessments of the craftsmen in the process of smelting
bronze alloys are carried out as follows. Due to hot work
environments, where the data are measured according to the
following figure:
IV. PROBLEM
The process of formation of the bronze alloy as a raw
material made by melting the metals copper (Cu) and tin (Sn),
where the fusion occurs at a temperature of ± 1083 º C. In
reaching that temperature of the fire in melting process has
higher temperature than melting temperature. High
temperatures in the workplace would be exposed to radiation
on the body of crafters because it forms an open fireplace, so
that fast craft experience fatigue and decrease the comfort of
the craftsmen working environment itself. Radiation exposure
that occurs in the workplace area should be minimized, so the
craftsman can work comfortably, and environmental conditions
can be maintained.
Figure 1. Exposure to radiation heat
From Fig. 1 shows that the average of radiation exposure
occurs high sufficient amounts to 563.466 ± 5.175 W/m2 with
a temperature of 42.670 ± 0.732 ° C and tended to increase
with time crafters work. At the time of the measurement of
relative humidity in the workplace 25% with wind speed 0.1 m
/ sec. Comfort zone for the country with two seasons tolerate
hot temperatures 35 ÷ 40 oC work environment or the level of
radiation 510.163 ÷ 544.106 W / m2 [7].
2012 Southeast Asian Network of Ergonomics Societies Conference (SEANES)
VII. CONCLUSION AND SUGGESTIONS
A. Conclusion
From the observations that have been done show that the
activity of craftsment in the process of smelting bronze alloys
have a high sufficient risk to the heat radiation emitted by the
smelting furnace. Thermal radiation at the working conditions
of craftsment rapidly create physical fatigue this caused quite a
heavy workload crafters.
B. Suggestion
Reduce the impact of radiation on the body, at least crafters
need to equip themselves with protective clothing, keep the air
circulation in the workplace.
REFERENCES
[1]
Figure 2. The pulse
[2]
Fig. 2 is based on the workload of the crafters of the
melting process measured by increased pulse rate before and
after working an average of 36.5 ± 2.635beats /min it indicates
that the workload is quite heavy crafters. Increased resting
pulse rate to the allowable working pulse 35 beats / min for
males (calculated when sitting) and 30 beats / minute for
women [7].
[3]
[4]
[5]
[6]
[7]
[8]
Figure 3. Fatigue score
Based on at Fig. 3 score of fatigue that occurred in prior
work where the craftsmen average before work 1.130 ± 0.079
and 1.990 ± 0.2 after work flat.
According [8] the above data show that the average crafter
physical exhaustion in performing activities of a bronze alloy
melting process.
S. Tata and C. Kenji, Teknik Pengecoran Logam, 7th ed. Jakarta:
Pradnya Pramita, 1996.
J. P. Holman, Perpindahan Kalor (Heat Transfer), 5th ed. Jakarta:
Penerbit Erlangga, 1984.
ISO 15265: 2004: Ergonomics of the Thermal Environment—Risk
Assessment Strategy for the Prevention of Stress or Discomfort in
Thermal Working Conditions. Geneva: International Organization for
Standardization, 2004b.
ASHRAE Standard 55P. Thermal Environmental Conditons for Human
Occupancy. 2003.
V. DeKeyser, “Analysis Of Activities, Taks And Work Systems” In:
Stellman, J. M., Editor. Encyclopedia Of Occupational Health and
Safety, 4th ed., vol. 1. Geneva: International Labour Offuice (ILO), 1998.
T. D. Cook and D. T. Campbell, Quasi Experimentation. Design &
Analysis Issues for Field Settings. London: Houghton Mifflin Company,
1979.
E. Grandjean and Kroemer, Fitting the Task to The Human. A textbook
of Occupational Ergonomic, 5th ed. Piladelphie: Taylor & Francis, 2000.
N. Adiputra, Metodologi Ergonomi. Program Studi Ergonomi-Fisiologi
Kerja, Program Pascasarjana Universitas Udayana, 1998.
Risk Assessment Craft in Bronze Alloy Melting
Process for the Production of Balinese Gamelan
IGN. Priambadi1, N. Adiputra2, Ketut Tirtayasa, IGB. Wijaya Kusuma3
1
Faculty of Medicine
Dept. of Ergonomics
3
Dept. of Mechanical Engineering, Faculty of Engineering
University of Udayana, Bali, Indonesia
[email protected], [email protected], [email protected], [email protected]
2
Abstract—Activity especially in Balinesse cultural and religious
activities cannot be separated from the acoustic instrument called
gamelan. It is an existence value of the Balinese Hindu
civilization which has been maintained from generation to
generation. In the development device gamelan instruments has
got functional development rapidly from utilization of the
religious to the cultural activities. The sound harmonization
produced by the gamelan cannot be separated from the
traditionally process starting from the manufacture of bronze
alloy composition, melting, molding, forging through the
establishment of sound as well as the alignment for gamelan
sound in a single device. Bronze alloy composed of two elements
ie metals copper (Cu) and tin (Sn) in which these elements are
fused at a temperature of ± 1083 oC. In the process of alloy
melting bronze, craftsmen use an open stove model so the heat
produced exposure in the workplace. It will give the risk of
craftsmen such as radiation risks, these conditions impact to the
so that they will be quickly fatigue. The of the study research
showed temperatures exposure in the workplace based on the
method of gamelan craftsmen mean radiant temperature (MRT)
was 42.69 ± 0.732 ° C with levels of radiation 563.47 ± 5.175
W/m2, wind speed 0.1 m/s and relative humidity 25%. In the
melting process was carried out craftsmen average pulse rate
were measured before work 81.9 ± 2.47 pulse / min and an
average pulse rate was measured after working before the
breaking was 118.47 ± 4.274 pulse / minute. This condition
describes, the activities who did by craftsmen in the production
process shows a fairly heavy workload.
raw materials to be a set of gamelan use more traditional
methods that have been heritaged from generation to
generation. The process of gamelan starting from the making of
bronze alloy consist of copper (Cu) and tin (Sn) with a
composition of 80% and 20%, the composition has been
commonly used by craftsmen and provide the best quality of
gamelan. The alloy bronze is formed through the working of
process heat that melted reached boiling point in temperature of
± 1083 º C [1], to reach the boiling point need fire smelters to
have higher temperatures, then cast (casting) in the mold after
freezing process followed by forging and the last is a alignment
process (the establishment of the fundamental tone) with a
stingy or grinding.
Keywords-gamelan; smelting furnace;, bronze alloy; the
workload
Gamelan craftsmen working conditions generally work in
hot area, it is caused during the melting process in the furnace
bronze alloy. The amount of radiation energy emitted heat from
the furnace [2].
I.
PRELIMERY
The life existence of Balinesse gamelan cannot be separated
from religion, especially Hinduism, even though its
development the Balinese gamelan has dominance in various
types of performances that are not in a religious context.
Almost every Banjar Pekraman Peoples of Bali has all the
equipment complement of this ceremony. The village of
Tihingan Banjarangkan Klungkung District is located 3 km
towards the west of the town of Klungkung, a small famous
village that know as the centre of gamelan craft and known
well all over the world. Craftsman (pande) in processing the
Copyright of this paper belongs to the author(s).
Daily activities in the process of gamelan is very risky for
the gamelan craftsmen, such as during the melting process in
the furnace (furnace) at high temperatures where the risk of
workers/craftsmen to be quickly fatigue due to workplace
exposured by high temperatures. Based on the Ministry of
Labor SE-01/MEN/1978, decided the value of noise exposure
at work place about 85dBA for 8 hours a day, 40 hours a week,
the requirements for ambient temperatures between 21-30
degrees Celsius, 65-95% humidity levels, and requires
employers to take specific actions to reduce the air temperature
above 30 degrees. DEPNAKERTRANS.
II.
HEAT EXPOSURE
Eb = σ.T4 W/m2 (BTU/h.ft2)
where:
Eb = energy radiated
= 5.669 x 10-8 W/m2.R4
= 0.1714 x 10-8 BTU/h.ft2.K4
(1)
2012 Southeast Asian Network of Ergonomics Societies Conference (SEANES)
T = temperature of exposure (K), is measured from the
method of mean radiant temperature
According to ISO 15265 [3], the radiation exposure that
occurs should be on interventions that work can provide
comfort for crafters. Form of intervention can be based on six
factors in accordance with ASHRAE Standard comfort 55P [4]
above. Mean radiant temperature can be calculated by the
equation below:
MRT
T1 . 1 T2 . 2 T3 . 3 ... Tn . n
(2)
360
V. METHOD
Assessment of the risk of gamelan craftsmen when melting
process is done by performing measurements on the
workplace or the subject as follows:
The design of the study using the same subjects [6],
where the influence of heat in the workplace on the
subject was measured before and after the melting
process is carried out before the lunch break;
Workplace temperature measurement when melting
process occurs every hour before the break, this is
done by the method of MRT (mean radiant
temperature);
Perform measurements with the method of pulse 10
beats before and after work, to see artisans working
load;
Assessing subjective of the crafters fatigue
subjectively before and after working with the filling
of the questionnaires.
where:
T = temperature of the surface of the corresponding point
of measurement (° C)
θ = angle of exposure (o)
III.
EVALUATION OF WORKLOAD BASED ON THE PULSE
A. Workload
The measurement of workload based on the pulse during
working is a method to assess cardiovascular strain using the
method of 10 pulse.
B. Fatique
The fatigue of workers is burden accumulation of an
acceptable body due to work activities for long time to produce
the production. This situation is natural sign to get a break, it is
important to avoid the permanent fatigue that can cause the
body damage, but most of people would accentuate the effect
of fatigue as a factor of decreasing efficiency work.
Determinant the two theories of fatigue, namely: (1) based on
chemical theory, fatigue is due to reduced energy reserves and
increasing metabolic waste that causes loss of muscle
efficiency, and (2) based on the neuro theory of nerves, fatigue
is a chemical change in muscle cells, which lead to stimulate
neuro sensory channeled through to the brain, which is
recognized as muscle fatigue [5]. Fatigue can be using
measured subjectively a questionnaire rating scale of 30 items
issued by the Japan Association of Industrial and Health.
Assessment of the craftsmen risk made before the lunch
break and be repeated three times in the same time but different
days.
VI. RESULT AND DISCUSSION
Assessments of the craftsmen in the process of smelting
bronze alloys are carried out as follows. Due to hot work
environments, where the data are measured according to the
following figure:
IV. PROBLEM
The process of formation of the bronze alloy as a raw
material made by melting the metals copper (Cu) and tin (Sn),
where the fusion occurs at a temperature of ± 1083 º C. In
reaching that temperature of the fire in melting process has
higher temperature than melting temperature. High
temperatures in the workplace would be exposed to radiation
on the body of crafters because it forms an open fireplace, so
that fast craft experience fatigue and decrease the comfort of
the craftsmen working environment itself. Radiation exposure
that occurs in the workplace area should be minimized, so the
craftsman can work comfortably, and environmental conditions
can be maintained.
Figure 1. Exposure to radiation heat
From Fig. 1 shows that the average of radiation exposure
occurs high sufficient amounts to 563.466 ± 5.175 W/m2 with
a temperature of 42.670 ± 0.732 ° C and tended to increase
with time crafters work. At the time of the measurement of
relative humidity in the workplace 25% with wind speed 0.1 m
/ sec. Comfort zone for the country with two seasons tolerate
hot temperatures 35 ÷ 40 oC work environment or the level of
radiation 510.163 ÷ 544.106 W / m2 [7].
2012 Southeast Asian Network of Ergonomics Societies Conference (SEANES)
VII. CONCLUSION AND SUGGESTIONS
A. Conclusion
From the observations that have been done show that the
activity of craftsment in the process of smelting bronze alloys
have a high sufficient risk to the heat radiation emitted by the
smelting furnace. Thermal radiation at the working conditions
of craftsment rapidly create physical fatigue this caused quite a
heavy workload crafters.
B. Suggestion
Reduce the impact of radiation on the body, at least crafters
need to equip themselves with protective clothing, keep the air
circulation in the workplace.
REFERENCES
[1]
Figure 2. The pulse
[2]
Fig. 2 is based on the workload of the crafters of the
melting process measured by increased pulse rate before and
after working an average of 36.5 ± 2.635beats /min it indicates
that the workload is quite heavy crafters. Increased resting
pulse rate to the allowable working pulse 35 beats / min for
males (calculated when sitting) and 30 beats / minute for
women [7].
[3]
[4]
[5]
[6]
[7]
[8]
Figure 3. Fatigue score
Based on at Fig. 3 score of fatigue that occurred in prior
work where the craftsmen average before work 1.130 ± 0.079
and 1.990 ± 0.2 after work flat.
According [8] the above data show that the average crafter
physical exhaustion in performing activities of a bronze alloy
melting process.
S. Tata and C. Kenji, Teknik Pengecoran Logam, 7th ed. Jakarta:
Pradnya Pramita, 1996.
J. P. Holman, Perpindahan Kalor (Heat Transfer), 5th ed. Jakarta:
Penerbit Erlangga, 1984.
ISO 15265: 2004: Ergonomics of the Thermal Environment—Risk
Assessment Strategy for the Prevention of Stress or Discomfort in
Thermal Working Conditions. Geneva: International Organization for
Standardization, 2004b.
ASHRAE Standard 55P. Thermal Environmental Conditons for Human
Occupancy. 2003.
V. DeKeyser, “Analysis Of Activities, Taks And Work Systems” In:
Stellman, J. M., Editor. Encyclopedia Of Occupational Health and
Safety, 4th ed., vol. 1. Geneva: International Labour Offuice (ILO), 1998.
T. D. Cook and D. T. Campbell, Quasi Experimentation. Design &
Analysis Issues for Field Settings. London: Houghton Mifflin Company,
1979.
E. Grandjean and Kroemer, Fitting the Task to The Human. A textbook
of Occupational Ergonomic, 5th ed. Piladelphie: Taylor & Francis, 2000.
N. Adiputra, Metodologi Ergonomi. Program Studi Ergonomi-Fisiologi
Kerja, Program Pascasarjana Universitas Udayana, 1998.