REVIEW OF LITERATURE -...
Transcript of REVIEW OF LITERATURE -...
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Chapter - 2
REVIEW OF LITERATURE
The essential aspect of an investigation is the review of literature which
is a general retrospective survey of previous writings pertaining to one‟s
problem. Review of literature gives an insight about the problem. It is regarded
as the backbone of any research work and is a crucial aspect in planning of
study. In fact the researcher who undertakes the research project systematically
reviewing other studies related to the problems completes the research
successfully. Identification of the problem, development of research design and
determination of the size and scope of a problem, all depend to a great extent
on the care and intensity with which a researcher has examined the literature
related to the intended research.
Mira (2000) has rightly observed “the key to the vast store house of
published literature opens doors to the sources of significant problem and
provides helpful orientation for definition of problem, background for selection of
procedures and comparative data for interpreting results‟‟.
Before undertaking the study a survey of related literature based on
books and investigations, in order to become familiar with research work, which
has already been done by other investigator in this field was carried. An attempt
has been made to present the available literature relevant to the field under the
following headings and subheadings.
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2.1 STEPS OF MANUFACTURING GARMENTS FROM DELICATE FABRICS 2.1.1 PRE-SEWING OPERATION 2.1.1.1 Pattern preparation 2.1.1.2 Selection of incoming material 2.1.1.3 Fabric preparation: 2.1.1.4 Spreading 2.1.1.5 Marking 2.1.1.6 Cutting 2.1.1.7 Preparation for sewing 2.1.2 SEWING OPERATIONS 2.1.2.1 Stitching 2.1.2.2 Hem / edge finishing 2.1.3 POST SEWING OPERATION 2.1.3.1 Pressing and finishing 2.1.3.2 Wash and care 2.1.3.3 Storing and packaging
2.2 PROBLEMS FACED WHILE MANUFACTURING GARMENTS FROM DELICATE FABRICS 2.2.1 CONSTRUCTION RELATED PROBLEMS 2.2.1.1 SEAM PUCKERING 2.2.1.1.1 Studies done on seam pucker 2.2.1.1.2 Factors affecting seam puckering 2.2.1.1.3 Assessment of seam pucker 2.2.1.2 SEAM SLIPPAGE 2.2.1.2.1 Factors affecting seam slippage 2.2.2 HEALTH RELATED PROBLEMS 2.2.2.1 EFFECTS OF WORK ENVIRONMENT AND CONDITIONS 2.2.2.2 HEALTH RELATED ISSUES 2.2.2.2 1 Accidents and injuries 2.2.2.2.2 Illness and diseases 2.2.2.2.3 Musculoskeletal disorder 2.2.2.3 SIGNIFICANCE OF BREAKS 2.2.2.4 TASK VARIATION 2.2.2.5 IMPACT OF POSTURES 2.2.2.6 EFFECTS OF EXERCISE 2.2.2.7 ROLE OF ERGONOMICS
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2.1 STEPS OF MANUFACTURING GARMENTS FROM
DELICATE FABRICS
Bheda (2003) stated that the clothing industry manufactures a vast
variety of garments from sheer fabrics. They range from work cloths to ball
gowns. Garment manufacturing needs highly technical information especially in
case of delicate fabrics. This profession cannot be started successfully without
the formal training or practical experience. Success in this field is largely a
question of understanding properly the characteristics of delicate fabrics,
managing them properly, selecting and handling the equipments correctly and
controlling the related problems.
The garment construction process from sheer fabrics is classified in
three main levels namely: Pre-sewing, sewing and post-sewing.
2.1.1 PRE-SEWING OPERATION
2.1.1.1 PATTERN PREPARATION
While manufacturing garments, first step is the designing of sketch for
the dresses that have to be prepared from sheer fabrics. Lewis (1984)
suggested that patterns with minimum seams should be selected in case of
sheer fabrics. Soft sheers need designs that have loose fitting and over sized
silhouette. Details such as gathers, ruffles, shirring or draping are suitable for
soft sheers. Crisp sheers can be sewn from patterns with tailor-made details
(www.cauky.edu/fcs/FACTSHB/CTMMB.179pdf).
Beazley and Bond (2004) mentioned that the patterns can be prepared
by two means that is manual method or CAD/CAM method.
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2.1.1.2 SELECTION OF INCOMING MATERIALS
It is well acknowledged that the overall quality of garment is determined
by the characteristics of each of its components. The components include
selection of fabric and accessories.
2.1.1.2.1 Fabric
Mehta and Bhardwaj (2000) explained various fabric inspection systems
like 4 Point system, 10 Point system, Graniteville “78” system, Textile
distributors institute system, Dallas system and 4 Point system (revised) for
fabric inspection.
It is reported by Kawabata and Niwa (1991) that in the garment export
industry most of the manufacturers follow 4-Point system in case of delicate
fabrics. The 4–point system has received widest acceptance in the textile trade
because it is simple and easy to understand.
2.1.1.2.2 Accessories
Sproles (2004) stated that accessories play a vital role in appearance of
garment. They are a major source of value-addition in garments and contribute
to a great extent in quality of garments. Accessories can be grouped in two
categories that is those made of fibrous material and the non-fibrous
accessories. If the accessories are composed of fibrous material (like laces,
braids, zippers and thread) then in order to assess their quality they should be
checked for shrinkage, colorfastness, strength, crease recovery, abrasion
resistance, pilling and color matching. In non – fibrous accessories (like snaps,
fasteners, hooks and decorative details) the main requirements to be ensured
are strength and rust free surface which withstand normal day -to -day cleaning
process.
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Sewing thread - Prakash and Gaur (2000) stated that the thread used on a
garment goes a long way in determining the appearance of garment. The
suggested properties to be considered while selecting sewing thread for
delicate fabrics are color, count, strength, compatibility of thread with fabric and
with sewing machine.
Color of the thread should match the color of the fabric. Transparent
thread, which is often used to avoid mismatching of color but is of lower quality
and has a tendency to ravel, should not be used. Delicate fabrics must be sewn
with finest possible threads. The strength of sewing thread should be
proportionate to the strength of fabric. When selecting thread for sewing
delicate fabrics it is important to check its compatibility with the sewing machine
otherwise it will create problem while stitching. Threads of same fiber content as
of fabric to be sewn are most suitable because they have more or less same
properties.
Needle - Rao (2006) defines that the function of needle is to carry the thread
through the stitch making process. The size of needle ranges from fine to
coarse and are chosen with regard to interaction of yarns of the fabric and the
type and size of thread. Rao (2006) recommended fine set point needles to
stitch delicate woven fabrics.
Lining - Sheer fabrics being transparent need lining in order to give a proper
cover to the body of wearer. In order to ensure quality of garments made from
sheer fabrics, following points are suggested for selecting linings by Cooklin
(1999), Berk and Gioello (1986) -
The fabric used for the lining should be dense, opaque and should have
compatible care requirements similar to the fabric used for the actual
garment.
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Lining should conceal inner construction of garment without adding
excess bulk.
Color and care of lining fabric should be compatible with the delicate
fabric.
The lining should fit smoothly inside garment with seams aligned.
If the lining is upto hem level then in such cases it should have small
pleats for ease and if it is free hanging then it should be attached at
seams with French tack.
Interfacing - According to Baker and Young (1992) interfacings must be
equally sheer or they spoil the appearance of the garment by showing outside.
Interfacing should only add body and support without adding stiffness.
Interfacing should blend with the color and texture of the fabric.
Fasteners and closures - Turvey (2001) stated that fasteners have to be
chosen with great care otherwise they may distort the sheer fabrics. While
selecting fasteners following points are suggested by Turvey (2001) and
Cooklin (1999) –
For garments without lining press studs or hooks and eyes need to be
used.
Zip can be use with underlined garments.
Button holes if needed can be made using net or interfacing.
Horizontal buttonholes should be kept on sheer fabrics.
All fasteners should be properly placed and well aligned. They should
also be securely attached to the delicate fabrics.
In case of delicate fabrics, bulky fasteners should be avoided.
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In garments of delicate fabrics, fasteners should be placed at point of
strain or pressure.
The fasteners should be reinforced with interfacing.
The placket at which fastener is to be attached should be of appropriate
length and width.
The fiber content or material of fastener, lace and braids should be
compatible with the fabric of garment, otherwise it will create problem
during washing and ironing.
Labels - In most of the cases, garments made of delicate fabrics are high-
fashion garments. So it is advisable to use the labels which are woven and are
of narrow width with the necessary information woven into them as a jacquard
design. These labels normally contain the company„s name, size and other
important details of the garment. They should be sewn flat on facing or can be
inserted under the stitching of a superimposed seam (Cooklin, 1999).
Other decorative details - A few suggestions of Decosse (1988) related to
decorative details on delicate fabrics are given below-
All decorative details, including appliques and trims, should not be too
heavy in weight and should be securely attached. There should be no
sign of unraveling of threads. Sequins and beads should be firm to the
fabric and should not show any signs of pull. The thread holding beads
and sequins should be virtually invisible.
The decorative details of a garment should enhance the overall aesthetic
appeal of the garment. Improperly handled finishes adversely affect the
visual appeal of a garment.
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2.1.1.3 FABRIC PREPARATION
Preshrink – It is advisable to preshrink the washable fabrics, then drying
should be done. To prevent excessive fraying, stitching along cut edges of the
fabric is done before washing. According to manufacturers of delicate fabrics
the fabrics should be immersed in warm water until thoroughly wet. Then the
fabric should be wrapped in towel (do not wring) and placed on flat surface to
dry. Hanging the fabric on the cloth line should be avoided since it will pull fabric
out of shape.
Also preshrink for other fabrics, such as interfacings and linings are
suggested. As stated by Decosse (1998) even a tiny amount of shrinkage on
these inner fabrics will show up as puckers or bubbles on the thin lightweight
outer fabric.
Dyeing and printing- Parmar (2001) mentioned that for dyeing delicate fabrics,
deep – draught winch machine is most suitable. It is a kind of batch dyeing
machine.
Dewatering – The common technique of reducing the amount of water in textile
material are mangling, squeezing, vacuum extraction and centrifugation. Since,
vacuum slots cause less damage they are often used with delicate fabrics.
Pressing- The best approach to press sheer fabric is to work with fabric scraps
first. The optimum temperature setting on iron should begin with low setting.
Use of press cloth or soleplate cover to protect fragile fabric has been advised.
2.1.1.4 SPREADING
This is a preparatory operation for cutting and consists of lying plies of
cloth one on top of the other in a predetermined direction. Cooklin (1999) stated
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that spreading itself can be a completely manual operation or can be performed
by powered machines of various levels of technology. To prevent the delicate
fabric from shifting or slipping, one can use pins, weights, clamps, cork pieces,
cardboard cutting mat and flannel side of a vinyl table cloth or by creating
vacuum (www.kwiksew.com/techinfo/tips/sheer.htm).
2.1.1.5 MARKING
As mentioned by Beverly and Gioells (1986), marking are the
construction symbols transferred from the pattern to the garment section.
Marking may be made on the face, inside or through garment sections.
Markings or tracing indicate the position of points of construction, design detail,
grain lines and centerlines. The various methods of tracing and transfer
markings used for sheer fabrics are chalked marking, chalked thread (Sewing
thread impregnated in with powdered chalk), Color coding (using different
colors threads), pins marking (lines of pins), tailors tack (temporary small
stitches of double through with loose ends), thread tracing (tacking with thread),
notches, perforated markers, spray marking and carbon markers. The method
adopted depend upon one of the factor like the type and weight of fabric, color
of fabric, placement of marking, method of construction, method of fitting and
method of production.
2.1.1.6 CUTTING
The main purpose of cutting is to separate fabric parts of a garment as
replicas of the pattern pieces in the marker plan. Selection of equipment
depends on cutting capacity needed, height of lay, type of fabric, density of
fabric, operation intended and production method employed.
Types of cutting tools as mentioned by Berk and Gioells (1986) are band
knife, die cutting press, rotary cutter, straight knife cutter, drill or thread marker,
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scissors, shears (ball point shears, bent handle, dress markers, pinking),
computerized cutting machine water jet cutting, laser cutting, ultrasonic cutting,
plasma cutting and notchers.
Mehta (2000) listed various defects found in delicate fabrics that may
arise due to cutting. They are frayed edges, single edge fusion, pattern
precision, too deep or shallow notches, fuzz or serrated edges, ply to ply fusion,
too large or small drilling holes. The fastest way to cut out fine fabrics is with a
rotary cutter but most popular one is dress marker shear.
2.1.1.7 PREPARATION FOR SEWING
According to Cooklin (1999), Bake & Young (1992) this group of
operations are concerned with preparing the cut components for sewing and
include the following -
Position marker- Drill marker used for marking pocket positions, dart
lengths, button holes.
Shade marker- This operation ensures that components cut from
different shades of the same color do not mixed up during the
assemble process. Every component of one garment is marked with a
unique number, usually printed on a small ticket which is stuck on the
component.
Bundle preparation and ticketing- Bundles of cut work are prepared
according to size, color and quantities.
Besides preparing the cut components for sewing, adjustment of sewing
machine like upper and lower threading, upper, lower tension adjustments,
selection of thread, pressure adjustments and needle is also important. A
perfect stitch can be obtained only when the machine adjustments are done
according to the properties of fabrics.
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2.1.2 SEWING OPERATIONS
2.1.2.1 STITCHING
Laing & Webster (1998) defined a seam as the application of a series of
stitches to one or several thickness of material. Carr and Latham (2004)
describes that correct selection of various factors of stitch, seams, feed system,
needle and thread together determine seam appearance and performance.
Lewis (1984) & Decosse (1988) gave certain suggestions while joining pieces of
sheer fabrics -
Stay stitch especially on curved areas could prevent stretching.
Since stitches in the inside of a sheer garments show from outside, whether
revealed clearly or as mere shadow details, they must be neat and narrow to
appear as well made. Thus french seam, mock french seam, self bound
seam and double stitched seam with short stitch length (8 -12 Stitches/inch)
would bring desired results.
Puckering could be avoided by loosen the needle tension slightly.
It is advisable to hold the fabric tight in front and behind the pressure foot.
It is advised by Lewis (1984) to place a piece of masking paper while
stitching delicate fabrics otherwise they easily get pushed in the needle hole
of throat plate causing drawing of the fabric.
As stated by Decosse (1998) while filling bobbin, winding should be slowly
done to prevent the thread from stretching which result in puckering.
Jamming of thread could be prevented by avoiding back stitch on sheers.
2.1.2.2 HEM / EDGE FINISHING
The garment should be hanged for at least 24 hours before marking the
hem. Sheer fabrics can have either very deep or very narrow hems. According
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to Turvey (2001) narrow rolled hems are suitable for circular edge whereas
deep or double hems on straight edges help garment to hang better.
Hem of garment made of sheer fabrics can be finished in many ways
which include hand rolled hem, machine rolled hem, narrow machine stitched
hem, double hem, horsehair braid hem, serged hem and serged rolled hem.
2.1.3 POST SEWING OPERATIONS
2.1.3.1 PRESSING AND FINISHING
The basic objective of finishing must be the enhancement of quality and
appearance. This usually refers to pressing, final inspection and packaging.
According to Rao (2006) and Mehta (2000), defects must be within AQL
(accepted quality levels) level and care should be taken of critical points.
Ironing makes a large contribution to the finished appearance of
garments. Ironing includes the application of heat, moisture and pressure singly
or in combination. Chuter (2004) explained that different companies adhere
rigidly to different type of equipments. Many companies use several type of
pressing equipment to achieve satisfactory and economical ironing of garments.
Some of the irons used in industry are electric iron, steam iron, steam air
finisher and stream tunnels. Right cladding of table protects the surface,
distributing steam and pressure evenly and allows vacuum to operate
effectively.
2.1.3.2 WASH AND CARE Clothing made of sheer fabrics are expensive, therefore special care
should be taken so that they can be enjoyed for long. Wash and care would
depends upon many factors like fiber content, dye stuff, type of finish given and
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type of garment stitched. Also laundry of garment could be done in the form of
dry cleaning, hand wash or machine wash.
If sheer garment is hand washed, soapless detergent should be used.
The garment should not be squeezed or wringed. For drying, garment should
be put flat on a spread towel and rolled.
If machine washed, mesh bags (care bags) can be use which would
prevent items from being wrapped around the agitator or having the hooks snag
other items.
Chemicals, bleaches and spot removers should be avoided for sheer
garments. According to Laundry Care Guide (2011) if needed, only chlorine
bleach can be safely applied on sheers.
2.1.3.3 PACKAGING AND STORING GARMENTS
Appropriate method of storing should be based on the style and weight
of garment. For garments made of delicate fabrics, padded and shaped
hangers are most preferred. Use of garment support straps or loops reduces
the stress because these help to distribute the garment weight and minimize the
distortion of garment shape. Enough space should be provided between
hanging garments.
While folding or storage it is advisable to use white tissue paper between
garments to prevent creases. Roll method which minimize storage space is also
another method of storing garments of delicate fabrics.
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2.2 PROBLEMS FACED WHILE MANUFACTURING GARMENTS
FROM DELICATE FABRICS
2.2.1 CONSTRUCTION RELATED PROBLEMS
2.2.2 HEALTH RELATED PROBLEMS
2.2.1 CONSTRUCTION RELATED PROBLEMS
Sheer fabrics require some special techniques at each and every step of
handling and finishing. According to wwwpatternreview.com a great deal of
working successfully with sheers comes down to one word that is “control”.
For the apparel industry product quality is calculated in terms of quality,
standard of fibers, yarns, fabric construction, colour fastness, designs and the
final finished garments. Certain quality related problems often seen in garment
manufacturing are like sewing, color, sizing or garment defects.
Some of the common sewing problems according to Chuter (2004),
Laing (1998) and Mehta (2000) at various stages during garment manufacturing
are –
Breaking needles
Looping of stitches
Skipping stitches
Variation in stitch length
Seams puckering
Upper thread breaking
Lower thread breaking
Machine not feeding properly
Machine working heavily
Layers feed unevenly
Fabric not fed in straight line
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Seam slippage
Feed marks on the under side
Damaged fabric or holes around the stitches
Chuter (2004), Laing (1998) and Mehta (2000) reported that seam
puckering and seam slippage is most common problems faced by
manufacturers during garment construction.
2.2.1.1 SEAM PUCKERING
A seam is the joining of two or more layers of a material by making a
series of stitches with one or more number of threads (Carr & Latham, 2004).
Glock & Kunz (2005) explained that “with the change in the apparel
production method from manual system to line production system, the
interrelationship between fabric properties and various processes in tailoring of
garments have become important. Selection of manufacturing process will
require selection of machine and variables based on the specific properties of
the fabric”.
Puckering is the disruption in the original surface area of a sewn fabric
giving swollen and wrinkled effect along the line of the seam in an otherwise
smooth fabric. Gaur et al (2006) mentioned that “gathering of seam occur either
just after sewing or after laundering causing an unacceptable seam
appearance”.
Consequently seam pucker described by Dorkin & Chamberlain (1960) is
a ridge, wrinkle or corrugation of the material or a number of small wrinkles
running across and into one another, which appear in sewing together two
pieces of cloth. Several factors which contribute to seam pucker are sewing
thread, fabric structure, seam construction, needle size and feeding problems
as well as incorrect thread tensions and unsuitable thread.
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McGinnis (1984) and Aggarwal (2007) explains that there are several
factors which contribute to seam puckering. These factors include fabric
structure, seam construction, needle size, fabric feeding speed, incorrect thread
tensions and unsuitable thread. Pucker may appear when the garment is first
sewn or may not appear until later when the garment is pressed, wetted and
washed. In many cases, seam pucker can occur from more than one cause at
a time, which can make elimination extremely difficult.
2.2.1.1.1 STUDIES DONE ON SEAM PUCKER
The most recurring and troublesome problem facing the apparel industry
over the years has been the problem of seam pucker. Many researchers have
tried to understand seam puckering phenomenon by adopting different
approaches. An attempt has been made to present available literature on the
issues related to seam pucker. However the studies on the problems related to
puckering can be dated before 1960. Among these investigations the most
comprehensive are given below.
A study undertaken by Dorkin and Chamberlain (1960) identified five
basic causes of seam pucker which covered at least 90 percent of pucker. The
five basic causes suggested were extension in sewing thread, differential fabric
stretch, differential fabric dimensional instability, shrinkage in the sewing thread
and structural jamming.
Clarke and Taylor (1967) studied a wide range of threads and fabrics.
They divided the results into two areas, modification of sewing thread and study
of the basic physics relating to seam pucker. The results indicated that
treatments given to fabrics did not show any decrease in tendency of pucker
though resin treatment of threads appeared to be more effective. Pucker due to
dimensionally unstable sewing thread does not occur until the garment is
washed, wetted or given any other after treatment, such as permanent pressing
or hot box laundering. The study suggested that it is important to match
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performance rather than fibre content while selecting sewing thread for the
fabric.
Zorowski and Patel (1970) in their work defined “seam puckering as a
mechanical instability phenomenon”. In their theoretical analysis, it was
recommended that decrease of stitch length and use of fabric with greater
bending stiffness and increased extensibility, make seams free of pucker.
Nisihikawa (1979) suggested that ”when two plies of material are not fed
uniformly, the variations caused feed pucker. When the foot pressure on the
machine was too high, excessive friction would stretch the top ply and if the foot
pressure was too low, the foot would bounce, momentarily losing control of both
plies or when the operator stretched one ply more than the other while feeding
into the machine”.
Nisihikawa (1979) found difficult to insert threads in a fabric with very
little space between the yarns either warp or weft ways which results in the
extension of the fabric along the line of a seam. The term structural jamming of
the fabric or displacement pucker is given to this type of pucker because it
results directly from the act of jamming threads into a structure which is already
too closely set to accommodate them.
McGinnis (1984) explained that puckering was caused by feeding
mechanism when two plies of fabric, to be joined, were not fed uniformly
through the sewing machine or one ply was greater in length than the other.
Seam pucker occurred as both plies were obliged to conform to the fixed length
of the seam. Preventive methods suggested by study include setting of
pressure of the presser foot and selection of finer needle to avoid distortion of
the fabric during sewing.
A study carried by Naskano & Shimazaki (1984) aimed to analyze the
correlation of seam pucker with sewing machine settings. The profiles of
pucker near the seam line were photographed. The photographs showed that
the seam pucker consisted of two kinds of waves which were random and
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periodic waves. The increase in stitch density and thread tension lowered the
frequency of the wave of pucker.
Another work on seam pucker by Schwartz (1984) reported geometrical
relationship between fabric and lockstitch seams in plain woven fabrics in
relation to structural jamming within the fabric. According to his research “the
effect of thread size, fabric structure, stitch count and yarn compression was
discussed”. He conformed the result of Taylor and Clark (1967) which indicated
that “if the thread size was fixed, the tendency to jam structurally increased
with increasing stitch count”.
Stylios and Lloyd (1990) These were correlated with the extent of pucker
which was categorized into severe, critical and acceptable seam pucker. The
thinner the fabric the more severe was the tendency to pucker. If the sewing
thread bending properties are higher than fabric bending stiffness, severe
pucker is expected to appear.
Investigation of Shishoo (1990) suggested a correlation between pucker
and properties of fabrics. He studied three seam types and 14 woven cotton or
cotton/polyester blend fabrics. Good correlation was found between seam
puckering and the logarithm of the product of bending stiffness, surface
roughness of the fabrics and tensile elongation which indicates the formability of
the fabrics.
According to Amirbayat & Miller (1991), seam pucker can occur either
during machining or during the use of the garment. A number of experiments
have been conducted to find out the reasons behind the occurrence of seam
pucker and their corresponding remedies. Incompatibility of the fabric
components in plies affects the balance, appearance and stability of the seam.
Incompatibility includes the use of two different types of fabrics as well as the
same fabric stitched at different bias angle of ply. As reported by Amirbayat
(1991) the incompatibility has a positive effect on extensibility and jammability
which in turn affects the seam appearance.
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Kawabata, Niwa and Nitta (1991) in their study “identified three reasons
which included inappropriate mechanical property of fabric, the relaxation
shrinkage of fabric and poor tuning of the sewing thread on account of which
seam puckering occurs. The experiments revealed that there is a clear
correlation between seam puckering and the mechanical property of the fabric
and the results of the experiment indicate that the puckering occurs easily in the
fabrics which are inextensible, highly elastic, stiff, inelastic in bending and
lightweight”.
Seam puckering due to post garment manufacturing processes were
studied by Riodel (1993). It was observed that when two fabric pieces having
different moisture content are sewn together and steam pressed, fabric surface
looses its flatness and elegance due to puckering.
Cheng et al (1996) reported overfeed in seams as one of the cause of
seam pucker. Blended fabrics were more vulnerable to puckering than 100%
cotton fabrics.
Research work carried out by Chopra (1998) on twenty different types of
fabrics and two types of sewing threads brought out the following major
findings:
- Fabrics made from man made filament fibers exhibited higher seam
pucker compared to fabrics made from spun yarns.
- Thick fabrics having medium to high cover and high tensile extensibility
have low seam puckering.
- Cotton fabrics irrespective of thickness gave low to medium pucker. The
man made filament fabrics gave higher level of pucker.
- The tension of the sewing thread during sewing is mainly released by the
lateral compression of thick fabrics and longitudinal compression (in-
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plane) of thin fabrics. The former helped in reducing and latter in
enhancing the seam pucker.
According to Carr (2004), “the essential feature causing differential
pucker was the relative change in dimensions of upper and lower fabrics while
the seam was being made. Such changes occur if one of the fabrics was
dimensionally unstable while the other was not. In such cases, the seam was
perfectly flat and un-puckered as it leaves the machine but on subsequent
washing one of the fabrics may shrink more than the other. Carr (2004)
suggested that in order to reduce differential seam pucker, before choosing the
fabric for garment production, fabric should be tested for dimensional stability
and be subjected to washing process.
The study by Carr (2004) suggested that in a lockstitch sewing machine
two sewing threads which are used for making a seam have to operate under a
certain amount of tension in order to form a good stitch. The needle thread
operates at a much higher tension than the bobbin thread, since the upper
thread has to snatch lower thread up to form a loop between the back of the
seam, it requires considerable force. Thus the sewing thread enters the seam
in an extended state. When removed from the machine it tends to contract or
relax and recover to its original length, gathering up the seam, thus resulting in
a puckered seam. Carr (2004) & McGinnis (1984) suggested that to prevent
puckering tensions as light as possible should be set in order to maintain
consistently balanced stitch formation. The sewing machine should be in good
working order. Operator should be skillful in handling the sewing machine and
should not push or pull the fabric while sewing.
Aggarwal (2007) tried to find a means of predicting seam pucker in four
different types of fabrics ( Polyester, cotton and polyester cotton blended in
different percentage fabrics) by investigating the effect of fabric type, needle
size, stitch per inch and needle bobbin thread tension for single and double
needle lockstitches. From the study it was found that -
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- For polyester filament yarn fabric with both single and double needle
lockstitch, the extent of seam pucker is less when finer needle size is
used in combination with low stitch per inch with low to medium thread
tension.
- For polyester cotton blended fabric, in case of single needle lockstitch, it
was observed that the extent of seam pucker is less at low stitch per inch
and low thread tension. Needle size has no effect on seam pucker. In
case of double needle lockstitch, all the three variables did not show any
effect on seam pucker.
- For 100% cotton fabric, the effect of all the three variables was quite
negligible in case of single needle lockstitch whereas for double needle
lockstitch, the needle size, stitch per inch and thread tension did not
have any effect on seam pucker.
2.2.1.1.2 FACTORS INFLUENICING DIFFERENT TYPES OF SEAM PUCKER
According to Gaur et al (2006) there are a lot of factors which effect
different types of seam pucker.
Fabric type
Fabric type is responsible for 10% to 20% of all cases of seam pucker.
Following fabric properties are possible sources of pucker.
i. Fabric thickness - More thick fabric means more consumption of thread
which ultimately means better elastic characteristic to the seam, which
results in reducing the relaxation pucker.
ii. Fabric extensibility - Seams running parallel to the warp direction of fabrics
tend to cause relaxation pucker because fabric yarns are in more stretched
position in warp than weft.
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iii. Differential fabric shrinkage - Different fibers react differently due to change
in atmospheric conditions which results in relaxation pucker.
iv. Fabric surface characteristics - Fabric surface characteristics influence the
feeding mechanism during stitching and results in transportation pucker.
Sewing machine settings
Sewing machine setting is responsible for 20% to 30% of all cases of
seam pucker. Following machine settings are possible sources of pucker.
i. Bobbin and needle thread tension
ii. Lower thread winding
iii. Stitch length
iv. Presser foot pressure (adjustment and type)
v. Feed dog setting (height and number of teeth in feed dog)
vi. Throat plate (size and setting )
vii. Fabric feed mechanism
Sewing thread
Sewing thread is responsible for 10% to 15% of all cases of seam
pucker. Following characteristics of sewing threads are possible sources of
pucker
i. Elongation
ii. Friction
iii. Thread size
iv. Shrinkage
Sewing needle
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Sewing needle is responsible for approximately 10% of all cases of seam
pucker. The size and point of sewing needle are possible sources of pucker.
Other factors
Other factors such as seam type, pattern shape, interlining and operators
feeding skill may contribute to about 10% of all cases of seam pucker.
2.2.1.1.3 ASSESSMENT OF SEAM PUCKER
American Association of Textile Chemists and Colourists (AATCC Test
Method-88B-2003). They consisted of photos of sewn materials with varying
seam pucker from 1 to 5 grades. The first strip being the worst and fifth being
the best. In using the photographic standards, three test seams were
compared with the standards by three observers under standardized conditions
which helped to level differences of opinion.
Chopra (1998) suggested to measure seam pucker objectively by
measuring the thickness of the seam. Thickness strain is the index of the extent
of pucker, high pucker will give high value of the thickness strain. Amirbayat et
al (1991) found that the correlation coefficient between the objective (thickness
strain) method and the subjective rating method for pucker was 0.749 which is
significant.
2.2.1.2 SEAM SLIPPAGE
According to Prakash (2006), in sewn fabrics the displacement of the
fabric yarns parallel and adjacent to the stitch line is known as seam slippage.
In ASTM Standard (1998), seam slippage is defined as partial or complete loss
of seam integrity manifested by yarn slippage parallel to or adjacent to the stitch
line.
Shivendra (2008) defined slippage of yarn as the sliding or shifting of
one set of thread (warp or weft) over the other, resulting in some sort of opening
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in the fabrics, under the influence of a load or tension lower than that which is
normally required to rupture the fabric itself. Webster & Laing (1998) reported
that seam slippage changes from a visual failure to a functional failure, when
the slippage continues the width of the seam allowance reduces and results in
seam tearing.
2.2.1.2.1 FACTORS AFFECTING SEAM SLIPPAGE
Seam slippage may occur in a garment because of various factors described
below –
2.2.1.2.1.1 FABRIC PROPERTIES - According to Mahanta (2006), Solinger
(1989), Gupta (1992) and Krasteva (2008), various fabric properties effect seam
slippage.
Fabric thickness - The actual compression that a fabric is capable of is
directly related to its resistance to seam slippage. The seam slippage
decreases with the increase of fabric thickness.
Type of fiber/yarn - A smooth yarn moves readily over other yarns. Continuous
filament yarns in particular are very slippery and can produce fabrics which are
highly susceptible to seam slippage.
Weave - Different methods of interlacement of yarns influence the fabric
structure. Loosely woven fabrics allow yarns to move freely and are most
susceptible to seam slippage.
Crimp ratio - If warp and weft threads are crimp free or have very less crimp,
then seam sewn at right angles to this direction may be susceptible to seam
slippage.
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Finish Applied - A lubricant or softener applied to the fabric may allow yarns
within the fabric to move more freely and result in seam slippage.
Diameter of Yarn- Diameter of yarn affects seam slippage.
2.2.1.2.1.2 THREAD - The properties of thread which affect seam slippage are
fiber content, count of yarn, tensile strength, elongation, smoothness, thickness,
twist and thread finish. Thread with low surface friction will not resist seam
slippage as compare to thread having higher surface friction.
2.2.1.2.1.3 NEEDLE - The quality of a seam is also governed by the
appropriate selection of the sewing needle which in turn has to be compatible
with the sewing thread and fabric. Correct size of needle and point of needle is
essential for good sewing performance and to avoid seam slippage (Rao,
2006).
2.2.1.2.1.4 MACHINE SETTING - To ensure the production of high quality
garments it is essential that correct machine setting to be use while sewing. It is
important to adjust the following machine settings upper and lower thread
tension, stitch density, presser foot presser, feed dog setting, throat plate and
type of seam.
2.2.1.2.1.5 SEAM ALLOWANCES - Seam allowances refers to the area
between the stitching row and cut edge of the fabric. Increasing the width of the
seam allowance was found to decrease slippage (Chuter, 2004).
2.2.2 HEALTH RELATED PROBLEMS
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Health and Safety of the employees are important aspects of an
organization‟s smooth and effective functioning. Garment workers contribute a
major share of the total labor force in the country, which bring most of the
country‟s foreign currency.
According to Armstrong (1982) occupational health hazards are related
to work environment. The first and the most common cause is the harmful
character of materials that they handle while the second cause may be related
to certain motions and postures of the body, due to which the structure of the
machine is so impaired that diseases gradually occur. According to Nag (1996)
“mismatch between man and machine is one of the major factor contributing to
musculoskeletal problems. This may be mainly due to the attempts made by the
workers to „fit the man to the job‟ rather than to „fit the job to the man”.
The reasons for establishing good occupational health and safety
standards identified by Gupta (2008) are moral, economic and legal.
2.2.2.1 EFFECT OF WORK ENVIRONMENT & CONDITIONS ON
WORK PERFORMANCE OF WORKERS
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Since every manufacturer wants to increase the productivity of his unit
with the limited resources, it is essential to consider the working environment as
an important factor in productivity.
2.2.2.1.1 Temperature and Humidity
As reported by Bheda (2004) discomfort produced by exposure to
conditions outside the thermal comfort zone can deteriorate the performance
sharply. Fanger (1979) indicated that the temperatures between 19° C to 26° C
are generally considered comfortable, provided that the humidity is not high.
According to Rodgers (1980) the comfort zone for relative humidity lies between
35 to 65 percent.
Set of guidelines from the American Conference of Governmental
Industrial Hygienists (ACGIH, 1992) give examples of the moderate balance
between rest periods and work at various temperatures for light, moderate and
heavy work in Table 2.1.
Table 2.1 Recommended temperatures at various work rest period and percentage in relation to type of work
Work/rest periods Light work Moderate work Heavy work
Continuous work 30 26.70 25.01
25% rest 75% work: 30.62 28.00 25.90
50% rest 50% work: 31.41 29.44 27.89
75% rest 25% work: 32.21 31.12 30.03
Rodgers (1980) depicted that there are six main factors which influence
intensity of feeling hot or cold. These include temperature, moisture, heat, air
speed, physical activity, clothing and other factors.
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According to set of guidelines from (ACGIH, 1992), “for workers in the
industry, too much heat can result in the following health and safety problems” (
Table 2.2) (www.ccohs.ca).
Table 2.2 Health and safety problems due to excessive heat
Safety
Health
Fatigue and dizziness Heat stress/strain (distress)
Sweating palms (become slippery) Heat cramps
Fogging of safety glasses Heat exhaustion/heat stroke
Possible burns Heat exhaustion/heat stroke
Lower performance/alertness Heat rash (prickly heat)
Increased irritability
Fainting (syncope)
It is not only essential to provide a comfortable temperature inside the
factory, but it is essential to ensure an adequate supply of fresh air; removal of
stale air and prevention of any build up of contaminants (dust, spot cleaning
chemicals etc).
2.2.2.1.2 Noise
The relationship between environmental and individual factors with job
satisfaction and psychological strain symptoms were studied by Jana (2008).
Results among a group of workers in an office revealed that disturbance in work
performance due to noise were greater especially when the estimated noise
level was higher. Symptoms of subjective strain were associated with poor
ergonomics of the worksite and sudden loud noises in the work environment.
Anantharaman & Subha (1980) observed during study that more energy
was used by the subjects during work, which was indicated by measures of
oxygen consumption and muscle action potential. It was also observed that
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some people complained of annoyance at high level of noise. It was
emphasized that different people are affected differently by the same noise.
Dugdill (2000) reported that people in noisy environment suffer from lack of
sleep, irritability, severe tension, mental illness, annoyance, anxiety, tension
and sudden unexpected shocks. Grandjean (1988) remarked that most harmful
effects of noise are hearing impairment, irritability, disturbed sleep and
psychological stress interference, verbal communication and conversation.
Mehta (1977) noted that an individual spends more energy to perform a
particular job in presence of extreme noise level than in normal conditions.
Contrary to this, pleasant voice like music aided the subjects by decreasing
tension, frustration and conflicts of the tasks. The subject‟s anxiety level
decreased during task performance when the musical performance was played.
According to Suter (2011) a safe level of noise basically depends on two
things volume of the noise and the duration of exposure. The Table 2.3 gives
recommended limits of noise exposure for the number of hours exposed.
Table 2.3 Recommended limits of noise exposure along with exposed sound levels
No. of hours exposed Sound level dB
8 90
6 92
4 95
3 97
2 100
1.5 102
1 105
0.5 110
0.25 or less 115
2.2.2.1.3 Lighting
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Lighting is a common source of complaint in modern garment
construction units where it can lead to the adoption of constrained postures
causing discomfort and visual fatigue. The term visible performance especially
in case of high skilled detailed work is used to indicate workers performance in
terms of speed, accuracy and probability of detection in their visual field (ISO
8995, 1989).
According to Light at Work (2002), in a garment factory the
recommended light intensity according to type of work for general tasks is 500
lux, for more detailed work 750 lux and for very fine work 1000 lux.
2.2.2.2 HEALTH RELATED ISSUES
2.2.2.2.1 Accidents and injuries
A study by Pandita (2004) found that accidents, both minor and major,
are common in the garment industry. The common accidents which took place
while operating the cutting machines were cutting of hand. Use of electrical
equipments such as band knife and straight knife cutting machines also lead to
number of accidents in the apparel industry. Injury at both index finger and
middle fingers was due to continuous use of cutting machine.
Mehta (2012) explained that in the sewing section, piercing of finger was
the most common type of injury at the time of stitching. The workers injured
their eyes while stitching since the broken needle flew into the eyes of the
worker. Accidents commonly occur in laundry section due to inadequate safety
system especially while washing and spin drying the garments. In ironing
section, numbers of cases were reported for burning of fingers and arms.
2.2.2.2.2 Illness and diseases
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The apparel industry is generally an industry which yields relatively little
environmental contamination via discharges into air, soil or water. However,
various illnesses and diseases were widespread among the garment workers.
According to Parimalam (2006), in cutting section the maximum number of
workers suffered from vibration induced syndrome and respiratory problems.
Besides this headache, skin problem, hearing and visual discomfort were also
reported. Breathing difficulty due to dust and loose fibers in the cutting section
caused allergies. Cornification of skin at fingers because of excessive use of
shears, leads to swelling of fingers.
Mehta (2012) mentioned that in stitching section majority of workers
complained about neural problem such as headache, respiratory, skin problem,
numbness of hands and fingers, hearing and visual discomfort. It was also
observed that the machines were not properly maintained resulting in arm
vibrations. This led to fatigue, pain, numbness, headache and tingling of fingers
and arms. In this study high levels of noise had been observed in most of the
units engaged in the garment construction specially sewing department.
The study by Mehta (2012) indicated that in case of finishing section,
most of the workers suffered from skin problems, visual discomfort, neural
discomforts, respiratory discomfort and hearing problem. In the finishing
section, the workers had to work really fast. In the washing section, the workers
were exposed to chemicals, particularly bleaches and detergents and were not
aware of their health hazards leading to skin allergies. In the quality section,
there was a lot of stress on the eyes leading to headache and visual discomfort.
Working in humid conditions because of steam ironing, the workers had
respiratory problems such as asthma and breathing difficulty. Also due to
excessive noise the workers had a common problem of hearing.
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Mehta (2012) indicated that the crowded conditions in the textile and
apparel industry created favourable conditions for transmission of
communicable diseases. In particular, TB tuberculosis had been a recurrent
public health issue among workers in the apparel industry.
2.2.2.2.3 Musculoskeletal disorder
Apparel manufacturing is a labor-intensive assembly line process,
requiring significant amounts of repetitive, skilled manipulation. According to
Grandjean (1988), “work-related musculoskeletal disorders (MSDs) are
impairments of body structure. Most work related MSDs are cumulative
disorders, resulting from repeated exposures to high or low intensity loads over
a long period of time”.
According to Kilbom et al, (1988) “work-related musculoskeletal
disorders mentions a wide range of inflammatory and degenerative diseases
and disorders that result in pain and functional impairment”. According to
Occupational Health and Safety Regulations (2012), musculoskeletal injuries
may be caused or aggravated by repetitive motions, vibration, forceful work,
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compression, sustained or awkward postures or action or any other ergonomic
stressors. Work-related MSI tend to happen when the physical action, job,
movement or job exceeds the body‟s tissue tolerance. To reduce the risk of a
work-related MSI or minimize the discomfort of an existing MSI, employers
should make modifications or changes in the workers workstations, equipment,
tools, work practices, work rate, body movements and provide worker training.
A study conducted by Mehta (2012) analyzed “the types and extent of
occupational health hazards of the garment workers of Jaipur”. Results of study
showed that respondents were suffering from a lot of problems like headache,
musculoskeletal disorders and eye strain. The workers in cutting room had
discomfort at neck, shoulder and back as they had to lean forward on cutting
table. In stitching section majorities of workers had back problem followed by
stiffness at neck and shoulder. In the finishing section, the workers complained
for the leg pain, followed by shoulder and back pain. The main stress factors
were identified as repetitive movements and noisy environment.
Grandjean (1985) concluded through survey that 70% of sewing
machine operators using foot controls reported back pain, 35% reported
persistent lower back pain, 81% reported pain at wrist, 14% reported disorder at
elbow, 5% at shoulder and 49% of workers experienced neck pains. It was
found that absenteeism increased as working conditions worsened. Due to
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injuries workers were lost. In an industry turnover was related with working
conditions.
Wang (2007) started “research with an aim to assess the contribution of
work-organizational and personal factors to the prevalence of work related
musculoskeletal disorders (MSDs) among garment workers in Los Angeles”. He
concluded that “the prevalence of moderate or severe musculoskeletal pain in
the neck or shoulder region was in 24% sewing machine operators. Prevalence
of upper body pain was associated with age, gender, being single and having a
diagnosis of systemic illness. Other factors responsible for pain were found as
working for more than 10 years as a sewing machine operator, using a single
sewing machine, higher work–rest ratios, high physical exertion, high physical
isometric loads, high job demand and low job satisfaction”.
The study of 216 workers conducted by Parimalam (et al) (2006) in 18
garment manufacturing units located in Madurai city revealed that there had
been several gaps in work environment, tools and equipment that affect the
health and safety of workers at the work site. Result showed that due to
excessive bending, a majority of workers complained of pain in the lower back,
mid back, shoulders and neck.
Characteristic of working population revealed that there was a general
increase in the rate of back pain as tenure at work increased (Blader, 1991).
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According to Kumar and Narayan (1998) prolonged sitting led to swelling of the
lower extremities and caused musculoskeletal problems in the long term.
Signs and Symptoms of MSD
Signs and symptoms of an injury developing appear suddenly or
gradually over a longer period.
A sign can be observed, such as: A symptom can be felt, but cannot be
observed, such as:
- swelling
- redness
- difficulty moving a body part
- numbness
- tingling
- pain
(www.PreventionPractices.com/msd.html)
These injuries are easier to treat if they are discovered early.
2.2.2.3 Significance of Breaks
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According to (HSE book, 2002) “Workers who perform static or repetitive
work should take frequent breaks to ensure that muscular fatigue does not
reduce performance or adversely influence health”.
Rohmert (1973) found “ the benefits from short rest breaks. He found
that short rest breaks did not compromise a workers adaptation to work”.
2.2.2.3 Task variation
According to Kumar and Narayan (1998) “task variation covered factors
as postural change during work, changes in task characteristics as well as
breaks and breaks that included an exercise regime or a variation in posture
from that when working”.
Galinsky et al. (2007) concluded that “introducing exercise breaks (or
conventional breaks) is an additional way of increasing „variation‟ in the job,
which does not require work tasks to be reallocated among workers”.
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2.2.2.4 Impact of Postures
According to Lock and Colford (2005) posture is defined as the relative state of
orientation of different parts in the space. A person while doing work acquires
many kinds of postures but they broadly classified as seating, standing and
lying down.
Grandjean (1988) indicated that “incorrect standing and sitting posture
were sometimes accompanied by pains in muscles and connective tissues of
tendons, joint muscles and ligaments. The vast majority of injuries could be
attributed to specific faulty movements and awkward postures which caused
fatigue, inflammation of muscles or tendons, compression or entrapment of
nerves as well as pain or weakness in the upper limbs and neck”.
Grandjean (1988) described that “it seemed likely that there was a direct
relationship between the increase in the problems of backaches and long hours
of sitting. Sitting posture caused the abdominal muscle to shrinking and curved
the spine in addition to impairing the function of internal organs, particularly
those of digestion and respiration”.
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Dababneh et al. (2001) described that “bad seating posture or seating
with a hunched back resulted in the intervertebral tissue being compressed.
Excessive musculoskeletal stress at work, especially with static load is believed
to play a major role in low back pain, neck and shoulder. The forward bending
of head with no support on the lower part of spine with the arms in lifted position
was a common posture that led to several injuries. All this leads to a significant
drop in performance and in the long run it may result in serious health
problems”.
According to the literature given in CCOHS
(http://www.ccohs.ca/oshanswers/ergonomics),. To maintain neutral body
posture while working at the workstation it was suggested to align ears,
shoulders and hips straight. Beside this, it was also suggested to keep the soles
of feet flat on the floor or a footrest while sitting.
2.2.2.5 Effects of exercise
Lock and Colford (2005) “investigated the benefits of exercise at work
and referred to different types of exercises. They categorized exercises into four
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main types as limbering up exercises, exercises for general health and fitness,
exercises for rehabilitation and exercising to reduce fatigue”.
Omer et al, (2003/2004) also carried out a study “on the effectiveness of
training and exercise programs in the management of MSDs. In the study they
trained the participants in mobilization, stretching, strengthening and relaxation
exercises. Study revealed these exercises reduced experiences of MSD, pain
and depression levels within participants”.
2.2.2.6 Role of Ergonomics
Das & Sengupta (1996) defined ergonomics as the study of the
relationship between a person and his work environment. In other words
ergonomics is called as science of designing the job, equipment, and workplace
to fit the worker. The objective is to adapt the workplace for the worker in order
to decrease the risk of injury and improve the link between the workers and
their environment. Ergonomics can help manufacturers and industrial engineers
to get maximum work output without causing physical harm to workers.
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According to Galinsky et al. (2007) ergonomics had emerged as a
current issue because it showed the link between certain types of injuries and
the way people performed their jobs. The study suggested that by improving
ergonomic conditions productivity and safety also improved.
The results of the study conducted by Parimalam (2006) revealed that
there had been several gaps in work environment, tools and equipment that
affect the health and safety of workers at the work site. Due to improper
selection of lighting fixtures and their placements, the efforts made to improve
the levels of illumination had failed to give the desired results at the point of
operation.
According to Das & Sengupta (1996), a little understanding of the
principles of ergonomics, can save a lot of discomfort and maximize both
productivity and enjoyment. The study suggested ergonomic principles that
should be followed at workplace. The first principle is to use proper machines or
equipments. Other principles are to minimize repetitive motions, avoid awkward
postures, use safe lifting procedures and to get proper rest.
The review of literature concluded that garment industry is a profitable
industry. In Indian context the manufacturers are facing a lot of challenges
during construction of garments and also health related issues. Reviewing of
existing literature revealed that the studies on garment construction especially
58
of delicate fabrics were mainly in the developed country and only few studies
were carried in India. Therefore, the present study is an attempt to fulfill this gap
by making an extensive investigation in this area in Indian context.