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76:11 (2015) 37–41 | www.jurnalteknologi.utm.my | eISSN 2180–3722 |
Jurnal
Teknologi
Full Paper
ERGONOMIC IMPROVEMENTS IN THE HANDLING OF
FIBRE INSULATOR SHEETS CUTTING
Loo Huck-Soo, Nor HayatiSaad*, Amirul Abdul Rashid,
NoriahYusoff, Mohd. Ridhwan Mohammed Redza
FKM,UniversitiTeknologi MARA (UiTM), 40450 Shah Alam, Malaysia
Article history
Received
15February 2015
Received in revised form
30April 2015
Accepted
31May 2015
*Corresponding author
drloohs@gmail.com
Graphical abstract
Abstract
This paper gives emphasis to an ergonomics study conducted in a fibre insulation bay of a
medium-sized air handler manufacturing plant. Work-related musculoskeletal disorders and
other health problems in the fibre insulator sheets cutting operations were closely looked
into. Unstructured interviews were initially conducted to uncover the und erlying problems,
while Direct Observation (DO) and Participative Assessment (PA) methods were utilized to
identify ergonomics risk factors. Ergonomics interventions by means of real life experiments
were implemented. These included 1) providing semi leather gloves to r eplace cotton hand
gloves, 2) providing plastic chairs with back rest for occasional sitting, and 3) installing a
fiberglass rolling mechanism for fiberglass cutting on table top. Post survey incorporating
both DO and PA methods was subsequently condu cted to gauge its effectiveness in
minimizing work-related musculoskeletal disorders and other health problems. This action-
oriented study finally produced fruitful results which includedinsignificant low back pain and
legs ache, minimized hand irritation sensations, relieved tiredness of operators, reduced
nose irritation, eye itchiness, sore throat and dizziness.
Keywords: Ergonomics intervention, direct observation, participative assessment, work-
related musculoskeletal disorder (WMSD)
© 2015Penerbit UTM Press. All rights reserved
1.0INTRODUCTION
Ergonomics is the science of fitting tasks to working
personnel. In the manufacturing environments,
various ergonomics studies have been conducted to
bring improvements in human-machine interactions.
These include (1) Steel Manufacturing Sector [1], (2)
Automotive Sector [2-6], (3) Electronics Field [7-9], (4)
Air Conditioning Field [10-18]. In this research, the
authors extended their effort of finding ergonomic
improvements in a medium-sized air handler
manufacturing plant in terms of reducing work-
related musculoskeletal disorders (WMSDs) and other
occupational health and safety (OHS) problems.
Before ergonomics interventions, the operators
suffered from WMSDs and poor OHS in the handling
of cutting glass fibre material causing their poor
productivity. The operators’ limitations and
capabilities in handling the cutting process were
investigated. Ergonomics concepts and methods
were utilized to improve the operations via the
introduction of new facilities to ease their cutting
tasks with the main objective of improving work
comfort leading to job satisfaction [19-21].
2.0 METHOD
2.1 Survey Techniques
A factory surveybegan with the sub-assembly
workstation. A general idea of the workplace
activities and ergonomics problems in handling
fibreglass cutting were obtained via an unstructured
interview [22] in the presence of employees of
different seniority (manager, engineer and
supervisor). Participative Assessments (PAs) [23] on
major work-related problems were carried out by
38 Loo Huck-Soo et al. / JurnalTeknologi (Sciences & Engineering) 76:11 (2015) 37–41
conducting structured questionnaire interviews with
six male operators involvedin fibreglass cutting
activities. The questionnaire was designed, tested on
two operators and revised before finalising it for all
the six operators using Sinclair’s PA [23] method. The
complaints about WMSDs such as low back pain, legs
ache and other OHS problems such as dizziness, nose
irritation etc. were gathered during the interviews.
Direct Observations (DOs) [24] were made using
video recordings to confirm the findings of the PAs
and to further investigate the work problems. One
hour recording was made on each team of two
operators in their glass fibre cutting activities. This
sums up to a total of 3 hours of video recording
covering six operators. The recordings were analysed
by playing them in slow motion to investigate each
operator’s problems in detail (e.g. bending of back
to reach the fibreglass material on floor, etc). The
recordings were also played in fast motion to search
for occurrence of a particular problem (e.g.
squatting posture to place a measurement panel on
top of glass fibre sheet before cutting).
Figure 1 Fibre insulator dispenser (FID) – final structure for real life operations at Fibre Insulation Bay
2.2 Ergonomics Interventions Study
After obtaining a clear picture of the major problems,
a meeting was held to report the findings to the
management. Three ergonomics interventions were
proposed to include 1) providing locally made semi
leather hand gloves to all the 6 operators in the
workstation to replace existing cotton gloves (i.e.
Intervention I), 2) providing two locally obtained
simple plastic chairs with back rest for occasional
sitting (i.e. Intervention II), and 3) installing a new
fibreglass dispensing apparatus, named Fibre
Insulator Dispenser (FID) (Figure 1) (i.e. Intervention III)
to match with a work table to prepare for fibreglass
cutting task on table top (Figure 2). After obtaining
the management’s approval to go ahead with the
proposals, ergonomics interventions was
implemented to solve the problems one at a time.
This was to ensure a clear relationship between the
cause and effect, i.e. between each intervention
and its effects on the problems. Non-parametric test
was used to determine the effectiveness of the
interventions.
Two months after each ergonomic intervention, PAs
and DOs were conducted again on the six operators
to determine its effectiveness in reducing WMSDs and
other OHS problems.
39 Loo Huck-Soo et al. / JurnalTeknologi (Sciences & Engineering) 76:11 (2015) 37–41
Figure 2 Fibre insulator dispenser (FID) – pulling the leading
edge of glass fibre sheet to unroll the fiberglass roll
3.0 RESULTS AND DISCUSSION
3.1 WMSDs and OHS Problems
From the survey and analysis, it was found that there
were eight problems reported namely low back pain,
legs ache, tiredness, hands irritation, sore throat, nose
irritation, eyes itchiness and dizziness. They are listed in
Table 1 below. The table also summarises the
observations of the reported problems and the
methods used to investigate those problems involving
six operators in the workstation.
Table 2 below presents the paired samples t-test on
the Likert Scale Ratings (LSR) of WMSD and other OHS
problems before and after ergonomics interventions.
3.2 Ergonomics Interventions Results
In Table 2, the Improvements in Interventions I and III
are encouraging. The adoption of semi leather hand
gloves (Intervention I) in place of the cotton knitted
structuresgave a significant impact (see Table 2).
More benefits were reaped via the introduction of
theFID(Intervention III) resulting in major reduction in
WRMDs and other OHS problemssince most of the
ergonomic risk factors were removed. All the six
operators involved in the study experienced stress
relief.
Table 1 Ergonomics methods used to investiga te reported problems of six operators in the workstation.
No.
Problems (WMSD & OHS)
Methods
Observations
1
Low back pain
PA of operators on lower back
problems
High operators’ rating on lower back pain (LSR 4.2 +
0.8)
DO of operators’ postures whi le
performing fibreglass cutting
All operators bent their back 4.08 + 0.59 hours/day* to
cut glass fibre sheet due to material placed on floor.
2
Legs ache
PA of operators on leg problems
High operators’ rating on leg ache (LSR 3.8 + 0.8)
DO of operators on their
squatting postures
All operators squatted on floor 2.53 + 0.35 hours/day*
to place metal plates (with handlers) on glass fibre
sheet to take measurements for cutting.
3
Tiredness
PA of operators on their degree
of fatigue
Slightly higher than neutral operators’ rating on
fatiguing (LSR 3.3 + 0.5)
DO of operators on their general
FIB activities
All operators showed sign of slowness in their glass fibre
cutting operations after 45 minutes to 1 hour of
continuous squatting and bending of back in the
cutting task. They took rest by sitting on floor
occasionally with their back leaning against a pillar, or
sit on carton boxes as makeshift chairs.
4
Hands irritation
PA of operators on irritation
problems
High operators’ rating on hand irritation (LSR 4.8 + 0.4)
DO of operators on their hand
wear
All operators were using cotton gloves, similar to the
type widely used by all maintenance technicians in the
plant for machine service and repair. They did not use
them during meal hour and tea breaks. They removed
them while not handling glass fibre for a short rest.
5
Sore throat
PA of operators on throat
condition
Higher than neutral opera tors’ rating on sore throat
(LSR 3.5 + 0.5)
DO of operators’ mouth
protection
Operators used face masks. They did not use them
during meal time and tea breaks. They removed them
while not handling glass fibre for a short rest due to
discomfort.
PA of operators on their nose
Higher than neutral opera tors’ rating on nose irritation
40 Loo Huck-Soo et al. / JurnalTeknologi (Sciences & Engineering) 76:11 (2015) 37–41
6
Nose irritation
sensation
(LSR 3.7 + 0.5)
DO of operators’ nose protection
Operators used face masks. They did not use them
during meal hour and tea breaks. They removed them
while not handling glass fibre for a short rest due to
discomfort.
7
Eyes itchiness
PA of operators on their eye
problems
High operators’ rating on eye itchiness (LSR 4.5 + 0.5)
DO of operators on the use of
eye goggles
The operators used eye goggles only when they
performed glass fibre cutting task. Eye goggles were
removed during meal hour and tea breaks.
8
Dizziness
PA of operators if they
experienced dizziness
Higher than neutral opera tors’ rating on dizziness (LSR
3.5 + 0.84)
DO of operators’ postures whi le
taking measurements and
cutting glass fibre on floor
All operators bent their back 4.08 + 0.59 hours/day*
and squatted on floor 2.53 + 0.35 hours/day* to take
measurements and cut glass fibre on floor.
FIB ≡ Fibre Insulation Bay; PA ≡ Parti cipative Assessment; DO ≡ Direct Observ ation
x + y ≡ mean + standard deviation; LSR ≡ Likert Scale Rating
* The figure was extrapolated from the one-hour DO (of the 6 operators) to an 8-hour work shift (excluding meal time and tea breaks)
Table 2Paired samples t-test on Likert Scale Rating (LSR) of work -related problems before and after ergonomics interventions.
No
Problem
LSR Before
Intervention
(Mean + SD)
Intervention
LSR After
Intervention
(Mean + SD)
t-value
p-value
Result
1
Lower back pain
4.2 + 0.8
III
1.3 + 0.5
7.059
< 0.05
significant difference
2
Legs ache
3.8 + 0.8
III
2.2 + 0.8
5.000
< 0.05
significant difference
3
Tiredness
3.3 + 0.5
II
3.2 + 0.4
1.000
> 0.05
insignificant
III
2.2 + 0.4
7.000
< 0.05
significant difference
4
Hands irritation
4.8 + 0.4
I
2.5 + 0.5
7.000
< 0.05
significant difference
5
Sore throat
3.5 + 0.5
III
1.3 + 0.5
5.398
< 0.05
significant difference
6
Nose irritation
3.7 + 0.5
III
1.3 + 0.5
7.000
< 0.05
significant difference
7
Eyes itchiness
4.5 + 0.5
III
1.5 + 0.5
8.216
< 0.05
significant difference
8
Dizziness
3.5 + 0.8
III
2.3 + 0.8
3.796
< 0.05
significant difference
LSR = Likert scale Rating; SD = Standard devi ation
4.0 CONCLUSIONS
Ergonomics interventions in the fibre insulator sheets
cutting process helped in significant reduction in
WMSDs and other OHS problemswhich included the
resulting insignificant low back pain and legs ache,
minimised hand irritation sensations, relieved tiredness
of operators, reduced nose irritation, eye itchiness,
sore throat and dizziness. Such improvement studies
are the solution to the problems of poor working
conditions which have deprived the workers of a
conducive working environment.
Acknowledgement
The support of Research Excellence Fund via
ResearchManagement Institute (RMI) of
UniversitiTeknologi MARA (UiTM) forfunding this
research is acknowledged with gratitude.
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