The Impact of Fabric Layering and Pressure Distribution by MelissaKuwana

THE IMPACT OF FABRIC LAYERING AND PRESSURE DISTRIBUTION

THE IMPACT OF FABRIC LAYERING AND PRESSURE DISTRIBUTION INTRODUCTION

PHASE ONE - Research

3-12

PHASE TWO - Development

13-28

PHASE THREE - Results

29-34

H00103899 MELISSA KUWANA

INTRODUCTION. A technical project will be carried out with the aim of investigating ways that layers can be used in order to increase pressure. This will be a journey that will gain insight on the use of pressure garments,the science behind compression and the best test methods to use in order to measure pressure. The ‘journey’ will be divided into three sections:

/Phase 1: RESEARCH /Phase 2: DEVELOPMENT /Phase 3: RESULTS/FUTURE RECOMMENDATIONS

/PHASE 1 - Research 09/14 - 11/14

The first three months were spent developing

knowledge in the field of pressure garments and necessary test methods. This included familiarising myself with pressure garments, methods of monitoring pressure and figuring out what researchers have recommended. I also analysed the fabric types and needed to truly understanding on the methods that are used in order to test pressure exerted by pressure garments. This is the â&#x20AC;&#x2DC;researchâ&#x20AC;&#x2122; phase. There will be various questions asked and I am sure that I will encounter some issues, but will find ways of solving them accordingly.

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/Understanding Pressure Garments and Their Use

I began to explore the types of

pressure garments that are used in the sportswear, medical and foundation-wear industry. I started the research development phase of the project by understanding the types of garments used, and how they are constructed. This was achieved through literature exploration and a series of fabric/ stitch studies.

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Medical Pressure Garment Research

Research on medical pressure garments was very vast. I began by investigating the common garment types, fabric types, and garment styles that may be available. I was also trying to investigate the use of layers in pressure garments. I researched the main characteristics as well as the complexities of pressure garments. The main issue found was that there was no clarity in the appropriate level of pressure for effective treatment.

/pressure exerting

/reduces scar size

/elasticated

/neutral colours

Sportswear Pressure Garment Research

I realised that pressure garments are also extremely popular in the sportswear industry.It appeared that researchers are trying to establish ways of improving the performance of individuals through compression. There are different ways that pressure can be increased through the designs of the garments. This was to be further investigated. I found out that sportswear pressure garments may be in the form of leggings, bras, sleeves or even cuffs. My main issue was to find areas in these garments that use layers in order to exert high levels of pressure.

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/Fabric Types

I needed to the fabrics this was an the fabrics

understand the fibre composition of that I was going to be testing as important aspect in finding out how may perform

Polyester Cotton Elastane

/Commonly used fabric types contain high levels of elastane in order to apply pressure to the desired body part. /Powernet is known to exert high levels of pressure as it contains high inherent tensions. /Majority of pressure fabrics contain Polyester, and Nylon with blends of elastane.

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/Stitch Types

/Zigzag Stitch /Flatlock Stitch

/I found that the stitch types that can be used to prepare sleeves are zigzag and flatlock stitches. /The issue encountered was that I needed to know the appropriate stitch type to use for my own sleeves. /I did not know what the effect of stitch choice would be on my future samples, therefore I needed to choose the appropriate seam type that would withstand high stretch.

/I found that there are several machines that may be used, however my issue was to find out the most relevant tool that I needed. My requirements were for a small-scale laboratory test. /I did not need to use the machine on human subjects and results needed to be relatively accurate, although the main concern was to monitor if pressure significantly increased due to layers. /I decided to use the PicoPress sensor as it is quick to use and could be easily checked if pressures exerted were consistent by placing a small weight on the sensor in between

/The PicoPress sensor : monitors interfacial pressure: the amount of pressure that a pressure garment exerts onto the surface is mesaured in mmHg. The sensor is placed between the sleeve and test object/patient.

/I-Scan pressure mapping: A sensor which allows the researcher to scan the amount of pressure being exerted onto the individual.

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/I spent some time researching the methods of measuring pressure that is exerted by pressure garments.

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Understanding Pressure Measuring Tools

Understanding the Law of Laplace Now that I had established ways that I am able to measure pressure, I needed to understand the measurement units I would need to use and the pressure measuring concepts. I learnt that I needed to the Law of Laplace equation in order to predict the level of pressure that a specific garment would exert onto the test object. At first, the equation seemed very complicated, however I learnt the simplified version, which is P=T/R, which means, Pressure=Tension/ Radius. This meant that I could predict pressure by simply knowing the tension of the fabric and the radius. This made a lot of sense when understanding how tension may relate with the test object. Even more so, an even better equation was found, which was proposed by Macintyre (2007) which can require only the circumference of the shape. This is as following: Pressure=4.713*N/m/ circumference of cylinder.

T/R “The Laplace Law initially explained the surface tension phenomenon in liquids and their ability to form droplets or soap bubbles”

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ISSUES WITH MEASURING PRESSURE ENCOUNTERED FROM PREVIOUS STUDIES

Although I started to understand greatly, the ways that pressure may be measured and the necessary tools that are needed, I wanted to research methods that have been previously established by scientists. I did some extensive research and found out that a lot of researchers found problems with measuring pressure on the human body. One of the key problems were body curvature.

BODY CURVATURE: /Author Perrey (2008) reported that body curvature makes pressure measuring difficult as previous is not distributed evenly to curved areas.

/Ito (1995) and Yamada (1997) tested the pressure of hosiery and report that the change of body curvature with pressure makes calculations complicated.

/Fan and Hunter (2009) found that the curvature of the body affects fabric tension, which suggests that a more uniform surface may be easier to measure pressure on.

Encountered Problems

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24/10/14

/When observing literature, I realised that there were limited topics on the role of layers in pressure garments. /Based on the main findings on issues related with testing on human volunteers, I decided to use methods that have dealt with sleeves and test objects when testing pressure.

/PHASE 2 - Development

10/10/14-12/01/15

During this period, I needed to begin developing my test objects that I was going to conduct the experiments on in the laboratory. I needed to fully analyse the appropriate materials, cylinder size and any issues with the test object could not be detrimental to the application of the sleeves. I wanted to reduce any chances of variability in my tests.

The most crucial part of the project is to follow as it is the development process. This was the time that I spent perfecting the correct way of testing my sleeves with the reduced chances of variability. I had several meetings with my supervisor in order to ensure that I was taking the correct steps in choosing the best test methods. I encountered a lot of stumbling blocks during this period of time, as each test object and sleeve needed to be so mathematically correct, that results were unvaried.

Investigations into garment construction techniques and areas that double layers may be found in sportswear garments. I took some close-up images of design features that would benefit my project. I needed to really understand how garments are constructed, so I de cided to conduct a study in areas where double layers are used in sportswear garments and the best construction methods. I realised that the most common stitch types were flatlock, zigzag and over-locking. I could also see that there were a lot of panels that were used in various garments, which had different materials used in panels so that pressure would be increased in these areas. This was interesting for me to find as I realised that the best way to make my sleeves would be through a fabric with a blend of either polyester or nylon and elastane. In order to choose the appropriate seam, I sought some advice from a sewing technician at my university, who recommended a flatlock seam.

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03/10/14

Observations of garment labels showed that the idea of clever marketing is very prevalent. There were labels that stated that garments were tightfitting (especially in the panelled areas) in order to boost performance. I also observed any marketing efforts that may have attempted to link pressure with layers, however the only garment label that did so was the sports bra and some running leggings that supported the chest/ waist. These reasons were not for pressure. Although I did not find exactly what I wanted to from the study, I felt more familiar with the construction of sleeves.

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I had read in my literature review that various sportswear companies market their clothingâ&#x20AC;&#x2122;s ability to compress certain areas of the body, and in turn boost performance. I felt like this clever marketing has helped aid the growth in sportswear pressure garments.

/Development of Test Objects

I started developing the test objects that I needed to apply the sleeves on and had to experiment with various materials in order to find the most appropriate method.

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I spent a significant amount of time developing the test objects. Test Object 1 was a play-dough clay model, which proved to be too hard to compress. Test Object 2 was a PVC pipe wrapped in upholstery foam and this test object seemed very suitable for testing. This is because it could be compressed and go back to its original shape. Test Object 3 was a prepared dough mixture wrapped around the PVC pipe. Issues were very salient; the dough mixture shifted to the bottom of the wipe, which may have been a problem in the future.

/Further Development

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/Test Object 4 was a lentil filled cylinder which was ideal for being compressed. /Test Object 5 was a PVC pipe that was covered in alginate.

/Chosen fabric for testing /Fabric A

/Fabric B

/Fabric C

/Fibre Composition I had previously learnt about how the fibre content in a particular garment affects various properties such as drape, tightness and comfort.. The three chosen fabrics were sourced from Liebaert, Belgium and the fabric composition was derived from each fabricâ&#x20AC;&#x2122;s bale.

/Fabric A

/Fabric B

/Fabric C Elastane 10%

Elastane 23%

Elastane 13%

Polyester 25% Nylon 77%

Powernet fabric

I researched the characteristics of powernet fabric and found that this fabric would be likely to exert the highest pressures.

Nylon 65%

Sleeknit fabric

It was worth observing that this fabric has a blend of both nylon and polyester. The finish was very sleek; I felt that this fabric would be most easy to apply onto the test object.

Elastane 29%

Nylon 58%

Two-way stretch fabric

Fabric C was a two-way stretch. The fabric was very stretchy due to the high elastane content of 29% in one way and 13% in the other.

/Sleeve Selection SLEEVE TYPE 1 This layer top there

SLEEVE TYPE 1

was an individual to be applied on of another until were three layers.

SLEEVE TYPE 2

This was a sleeve with two layers on one side and one layer on the other side.

SLEEVE TYPE 2

SLEEVE TYPE 3 SLEEVE TYPE 3

This was a sleeve with two layers on one side and one layer on the other side. The researcher expected the three-layered side to exert more pressure on the three-layered side, however both sides were sharing the load.

12/01/15

Encountered Problems

/I quickly realised that I was not going to have enough time in order to sew samples for every test carried out. This was mainly due to the time it took in order to develop the test objects (buying alginate, mixing, finding PVC pipes and ensuring that test objects were of equal size). /In order to resolve this issue, I suggested to my supervisor that Iâ&#x20AC;&#x2122;d record the tension lost before and after each test in order to show that the samples were not losing too much tension. This may have affected how much pressure distributed to each test object.

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SLEEVE FABRIC CUTTING

/From fabric to sleeve

Each time I cut the samples, I had to ensure that I was as accurate as possible. This meant that I needed to know exactly where I cut each sleeve component from. This would mean that if I had encountered any problems with the sample, I could further investigate into where the sample was cut from, and if any other samples would test the same.

Laboratory Testing

Now that I had prepared my sleeves ready to be tested, I was well-equipped with the knowledge that I needed in order in to test my sleeves. I had a lab book that I used for my calculations and pressure measurements. The test method was as following: /Record the tension in the fabric before testing /Rest the sample for 10 minutes. /Place the sleeve on the test object and record how much pressure is exerted by the layers with the PicoPress sensor. /Rest sample for 10 minutes.

The Instron machine used to measure tension loss from testing.

FABRIC TESTING

Samples resting before/after test at the standard period of 10 minutes.

2 27

3 28

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The PicoPress was used in order to measure pressure in(mmHg)

/Fabric testing on the instron machine: I spent a good four weeks solidly testing fabric samples by stretching them on the Instron machine in order to record the load loss in fabric. When I conducted my tests, I realised that even if the samples had been stretched, the amount of layers in the sleeves still exerted the same pattern of pressure.

/Phase 3

R e s u l t s

I needed to record the results on Microsoft Excel. I had to paste the RawData from the tests into the software and then calculate the loss in tension. I was also able to predict how much pressure each sleeve would exert using the Law of Laplace.

In my dissertation, I needed to be able to analyse greatly what the chart means: the extension % means how long the fabric was stretched in millimetres. The Load (N) means how much load (tension) was in the fabric. My main issue was to be able to pinpoint exactly what each percentage of extension was likely to perform.

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I used the Raw Data from the cyclic tests that were conducted on the Instron machine.

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DETERMINATION OF EACH FABRIC’S TENSION BASED ON RAW DATA

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One layered-sleeve over the other: Pressure (mmHg) was almost doubling in each time a layer was added.

The results that I gathered showed that the first sleeve type (sleeve type 1, was exerting double the amount of pressure on each test object each time a layer was increased. The powernet fabric delivered the highest amount of pressure.

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One layer against two layers: The one layered side and two layered side were exerting the same amount of pressure to the test objects regardless of the fabric type. I documented that this may have been because both sides were sharing the load equally between them.

One layered side against a three-layered side. Based on the results documented below, I realised that adding another layer adjacent to the one-layered side did not make a difference in pressure. The three layered side was also exerting the same level of pressure as the one-layered side. Although this was slightly disappointing as I expected something significant to happen, I learnt that these findings could be further developed.

Overall, I have benefited greatly from understanding how to research the properties of fabric and how it can exert pressure. I have learnt to be very analytical and critical of any findings that I document and not to be afraid to analyse numbers. The results have shown that layers can be used in order to increase pressure, but only to an extent. If an individual sleeve is placed on top of another, the pressure exerted to the test object usually doubles. In contrast, a sleeve that has one layer vs. various layers on the other side exerts an even and equal amount of pressure on each side. There is definitely room for further research into the project. I suggested in my dissertation that the psychology behind layers and pressure should be further investigated. Other techniques of using layers to exert more pressure may also be explored.

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/Further Recommendations

/References

/Fan, J and Hunter, L (2009), Engineering Apparel Fabrics and Garments. Garments. Journal of the Textile Institute; Jul2013, Vol. 104 Issue 7, p668-674, Elsevier /Laing, R.M and Webster, J (1998) Stitches and Seams. Manchester /Macintyre, L (2007), ‘Designing pressure garments capable of exerting specific pressures on limbs’ Burns, vol 33, no. 5, pp. 579-586., 10.1016/j.Burns.2006.10.004 /Maklewska,E Nawrocki,A,Kowalski,K, Andrzejewska,E Kuzański,W (2007) “New measuring device for estimating the pressure under compression garments”, International Journal of Clothing Science and Technology, Vol. 19 Iss: 3/4, pp.215 - 221 /www.made-by-rae.com /www.backjoy.eu/en/accessories-gear/posturewear-elite-sportsbra.htm /The Textile Institute p17 /www.makemeheal.com/mmh/product.do?id=33329 /www.norikoambe.com /www.anneliegross.com/#!defects-2013/c15hk /cdn.shopify.com