investigating the suitability of the two materials – dri...

LUX STARS, UNITY PRIMARY SCHOOL

Investigating the Suitability of the two materials – Dri‐FIT and Cotton – in Singapore’s Weather Conditions National Weather Study Project 2009

Ang Yu Jia, Low Jing Wen, Low Wei‐Ning Raelynn, Tammy Wong Ying Qi and Tan Bao Xuan

Abstract: In this project, four experiments were carried out to find out if the Dri‐FIT shirt or the cotton shirt is a better fabric in terms of its absorbency and removal of perspiration and its ability to keep the wearer cool in Singapore’s weather conditions. We found out that the cotton shirt can absorb water faster, but the wet Dri‐FIT shirt dries faster than the wet cotton shirt. Also, the Dri‐FIT shirt can keep the wearer cooler in gaining heat and losing heat conditions.

Investigating the Suitability of the two materials – Dri‐FIT and Cotton – in Singapore’s Weather Conditions

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Content

OUR INITIAL PROJECT IDEAS ......................................................................................................................... 2

CREATING A WEATHER WEBSITE ................................................................................................................................ 2

BUILDING AN ENERGY‐ & WATER‐SAVING MACHINE ..................................................................................................... 2

OUR FINAL DECISION – INVESTIGATING THE TWO MATERIALS .......................................................................................... 4

INTRODUCTION............................................................................................................................................ 5

LITERATURE REVIEW ................................................................................................................................................ 5

OUR EXPERIMENT FOCUS ......................................................................................................................................... 5

METHODS AND MATERIALS .......................................................................................................................... 6

QUESTIONS ............................................................................................................................................................ 6

HYPOTHESES .......................................................................................................................................................... 6

EXPERIMENTS ......................................................................................................................................................... 6

Thermal Property Part 1 ................................................................................................................................. 6

Thermal Property Part 2 ................................................................................................................................. 7

Absorbency of Perspiration ............................................................................................................................ 7

Removal of Perspiration via Evaporation ....................................................................................................... 7

RESULTS ....................................................................................................................................................... 8

THERMAL PROPERTY PART 1 – HOW FAST THE FABRICS GAIN HEAT? ................................................................................. 8

THERMAL PROPERTY PART 2 – HOW FAST THE FABRICS LOSE HEAT? .................................................................................. 9

ABSORBENCY OF PERSPIRATION ............................................................................................................................... 10

REMOVAL OF PERSPIRATION VIA EVAPORATION ........................................................................................................... 10

DISCUSSION ............................................................................................................................................... 11

CONCLUSION ............................................................................................................................................. 12

POST‐PRESENTATION DISCUSSION (WITH JUDGES’ COMMENTS) ................................................................ 12

ACKNOWLEDGEMENTS .............................................................................................................................. 14

LITERATURE CITED ..................................................................................................................................... 15

APPENDIX I – DETAILED DATA FROM EXPERIMENTS ................................................................................... 16

APPENDIX II – PHOTOGRAPHS TAKEN DURING EXPERIMENTS ..................................................................... 19

THERMAL PROPERTY PART 1 ................................................................................................................................... 21

THERMAL PROPERTY PART 2 ................................................................................................................................... 23

ABSORBENCY OF PERSPIRATION ............................................................................................................................... 25

REMOVAL OF PERSPIRATION VIA EVAPORATION ........................................................................................................... 29


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Our Initial Project Ideas

Creating a Weather Website Initially, we used the ‘Suggested Weather Project Topics’ and thought of using the suggestion of building a website. We chose that as we are all very interested in learning more about how to use ICT (Information and Communication Technologies) in our work. Also, some of our group members have just completed a project on setting up of a blog in Young Marine Biologist 2008. We thought these skills might be relevant.

Figure 1: A Print screen of the PowerPoint Slides, ‘Suggested Weather Project Topics’

Building an Energy- & Water-Saving Machine Mr Ng, another teacher who had helped us in some ways, gave us the suggestion of building a machine. We loved the idea of building. Last year, we were the same team which took part in Singapore Amazing Machine Competition. The thought of building a machine from scratch sounds really challenging, and yet exciting. Therefore, we brainstormed and came up with a design (please see design on the following page). There were two main objectives for the machines. Firstly, there will be a rain water collection point at the bottom of the machine. Secondly, when running rainwater hit a turbine, it will allow the generator to generate electricity. We wanted this electricity to light up a bulb to indicate the possibility of a lightning on a rainy day. However, after thorough thinking and discussion with our teacher mentor, we decided that the machine may not be feasible for two main reasons. Firstly, our school already has an effective lightning-warning system. Moreover, our idea that a lightning will only occur when it rains is not true. We have observed cases of the lightning-warning system sounded first before the rain pours. Secondly, during the months of our project, it happens to be the North-East Monsoon Season (Climatology of Singapore, 2002). We are expecting a drier period


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from February to early March. Therefore, have to change our project topic to something else again.

Figure 2: Design of Our Energy‐ and Water‐Saving Machine


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Our Final Decision – Investigating the Two Materials Eventually, we took up the idea suggested by our teacher. It was initially a lesson plan that she found from the Internet (Zarske, Forbes, Sirakavit, & Yowell, 2007). The lesson requires students to investigate materials engineering as it applies to weather and clothing. The students will design and analyse different combinations of materials for effectiveness in specific weather conditions. We took up the idea and applied it locally. We realised that nowadays, for some sport jerseys and some other school P.E. attires, the choice is Dri-Fit T-shirt while our school is still using the usual cotton T-shirt. We want to find out if the T-shirt is really better. Our teacher introduced to us the journal-style scientific writing. It was difficult to understand as the articles found online on Google Scholar were usually very detailed and contained a lot of information that we do not understand. We needed our teacher’s asistance to explain what the articles were writing about. We made an attempt to write our report in a scientific journal way by using resources online (Anderson, 2004). Although we need our teacher’s help in the formatting of the layout of the report, we have learned the scientific process in this project via four main experiments.

Ask a question

Make a hypothesis

Carry out the experiment

Check with the hypothesis

Make a conclusion


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Introduction

Literature Review A research (Sazama, 2001) was done to test whether the attires of workers in a paper mill factory will affect their comfort level. In his research, Dri-Fit shirt is referred to vapour-permeable shirt. The results show that the Dri-FIT shirt reduced body core temperatures by about 0.3 to 0.5ºC compared to the cotton shirt. In addition, the Dri-FIT shirt was rated to be more comfortable and to have a faster drying time than the cotton shirt. The data suggests that Dri-FIT shirts allow more skin cooling to take place, thereby reducing the body core temperature. From the earlier research, ‘heat stress’ was mentioned in the journal. What we understood is that hot condition puts the body under a lot of stress. In Kentucky, heat stroke and heat-related injuries are quite common among the footballers and high school players (Warren, 2009). In the worst cases, the injuries led to death of the players. Although we seldom hear of heat-related injuries among students in Singapore, we should not ignore the fact that there are people who suffered from heat-related injuries during exercise. The ‘Overview And Recommendations For Sport Safety In Singapore’ (2007) indicated that there were a total of 822 heat-related injury cases in Singapore Armed Forces from 1995 to 2005. Also, based on our personal experience, we feel that it is quite difficult to concentrate during the period after P.E. lesson. The increase in body temperature makes us uncomfortable and restless sometimes. Another research (Kar, Fan, Yu, & Wan, 2007) tested on several properties of fabric on different stages of exercise. It was found that the fabric material with a poorer thermal insulation will make wearer feel warmer at all stages of exercises. In the middle of the exercise when body starts to sweat, clothes with better water vapour transmission property can result in cooler sensation. Lastly, fabric’s water absorption and air permeability are important factors after exercise as these properties determine how quickly the skin can be dried after sweating.

Our Experiment Focus Our aim is to investigate and find out what is a suitable material for school P.E. T-shirt based on the absorbency and removal of perspiration, and keeping the wearer comfortable in Singapore’s weather condition. Therefore, we made use of past research and came up with four different questions, hypotheses and experiments to make one conclusion.


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Methods and Materials In all our experiments, we compared our school P.E. T-shirt that is made of mostly cotton (according to the uniform vendor, there is a small percentage of polyester in the fabric) and the prefect’s white T-shirt that is made of Dri-FIT material. ‘Dri-FIT’ is actually a high-tech fabric developed by Nike. Quoted from Nike website, “Dri-FIT is a high-tech proprietary fabric developed by Nike which quickly moves sweat to the outer layer of the fabric, away from your skin, where it can quickly evaporate. The result is that you have a dry, cool fabric against your skin even when heat and humidity levels are high.” We can confirm that the prefect’s white T-shirt is not made from Nike’s Dri-FIT, but we do not have the exact content of the fabric.

Questions Thermal Property Part 1 – How fast the fabrics gain heat? Thermal Property Part 2 –How fast the fabrics lose heat? Absorbency of Perspiration – How fast the fabrics absorb sweat? Removal of Perspiration via Evaporation – How fast the wet fabrics become dry?

Hypotheses Based on the past researches, we are told that Dri-FIT material is of a superior quality than normal cotton shirt as it can keep the wearer cooler and it will dry off the sweat faster (Sazama, 2001). Therefore, here are our hypotheses. Dri-FIT shirt gains heat slower than the cotton shirt. Dri-FIT shirt loses heat faster than the cotton shirt. Dri-FIT shirt absorb sweat faster than the cotton shirt. Wet Dri-FIT shirt dries up faster than the wet cotton shirt.

Experiments Thermal Property Part 1 Steps:

1. Place three mannequins at the same spot under the sun. 2. Tie the Dri-FIT shirt and the cotton shirts onto the heads of two separate mannequins

with the same head-size. 3. Use the third mannequin as a ‘control’ (no shirt should be covering this mannequin). 4. Set up the data logger. 5. Insert the temperature sensor of the data logger into the covered heads of the

mannequin. 6. Set the status of the data logger, e.g. Time to record the data. 7. Press "start" and start recording the temperature change of each set-up. 8. After 30 minutes, save the data in the data logger. 9. The mannequin which has the lower temperature after 30 minutes is covered by the

cloth which gains heat slower.


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Thermal Property Part 2 The steps for this experiment are mostly the same, except for steps 1 and 9.

1. Place three mannequins on the tables in an air-conditioned room. 9. The mannequin which has the lower temperature after 30 minutes is covered by the

cloth which loses heat faster. Absorbency of Perspiration Steps:

1. Cut strips of the same sizes from the two materials (Dri-FIT and Cotton shirt). 2. Prepare two Petri dishes filled with equal amount of water and dye. 3. Put the two cloths close to the Petri dishes, each on one dish. 4. Lay them into the dyed water at the same timing. 5. After two minutes, remove both cloths from the Petri dish. Observe how much water

each cloth has absorbed. Measure the length of the water absorbed using a ruler. Compare the amount of water.

6. To ensure accuracy of results, repeat the same experiment for a few times. 7. If the cloth absorbs more water compared to the other, it is more absorbent than the

other cloth, and vice versa. Removal of Perspiration via Evaporation Steps:

1. Weigh the two pieces of cloth (1 P.E. T-shirt and 1 Dri-FIT T-shirt) 2. Fill the beaker with 200ml of water 3. Put the pieces of cloth into each beaker each. 4. Wait till all the water is absorb. 5. Weigh the two pieces of cloth. 6. Hang the cloths side by side over the railing for 30 minutes. 7. After 30 minutes, weigh the two pieces of cloth again and find out the difference from

the first weight and second weight. 8. Repeat the step 6 and 7 a few more times to get more data.

Please look at Appendix II for our pictures taken during experiments.


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Results

Thermal Property Part 1 – How fast the fabrics gain heat?

From the graph, it can be seen that in the first 2 minutes (120s), as the slopes of the graphs look similar in steepness, the temperature of the air inside the Dri-FIT shirt is increasing as fast as the temperature of the air inside the cotton shirt. However, after 25 minutes (1500s), the temperature of the air inside the Dri-FIT shirt is lower than the temperature of the air inside the cotton shirt. Look at Table 2 in Appendix I for detailed data.


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Thermal Property Part 2 – How fast the fabrics lose heat?

From the graph, it can be seen that in the first 5 minutes (300s), as the slopes of the cotton graph is steeper than the slope of the Dri-FIT graph, the temperature of the air inside the cotton shirt is decreasing faster the temperature of the air inside the Dri-FIT shirt. However, after 25 minutes (1500s), the temperature of the air inside the Dri-FIT shirt is lower than the temperature of the air inside the cotton shirt. Look at Table 3 in Appendix I for detailed data.


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Absorbency of Perspiration

Table 1: The absorbency rate of the two shirts in 2 min

Trials Length of strips that is wet (cm)

Cotton Dri-FIT 1 18 16 2 14.5 13 3 19 18

As the table shown, in all three experiments, the cotton shirt could absorb water faster than the Dri-FIT shirt.

Removal of Perspiration via Evaporation

The graph shows that the Dri-FIT shirt is drying up faster than the cotton shirt as the slope of the Dri-FIT shirt graph is getting steeper than the cotton shirt graph. Look at Table 4 and 5 Appendix I for detailed data.


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Discussion Let us recall the objective of our project. Our aim is to investigate and find out what is a suitable material for school P.E. T-shirt based on the absorbency and removal of perspiration, and keeping the wearer comfortable in Singapore’s weather condition. To find out how to make the wearer comfortable, we were trying to look for a material that is gaining heat slowly and losing heat quickly, thus making the wearer cooler. Our data showed that Dri-FIT gained heat slower and lost heat faster than the cotton shirt. At first, we did not understand how these two properties could exist at the same time. In our science lesson, we learn that a material is a good conductor of heat if it gains heat and loses heat quickly, and that a material is a poor conductor of heat if it gains heat and loses heat slowly. How can a material gain heat slowly and yet lose heat quickly? Our teacher pointed out to us that water on the Dri-FIT shirt evaporates very quickly. Since evaporation causes cooling, it quickens the rate which Dri-FIT shirt loses heat. There are three ways which heat is being transferred. They are show in the table below. We have not learnt them in Primary Science, but they could be factors which affect the rate at which Dri-FIT gain and lose heat.

Conduction The transfers of heat in particles of matters with direct contact, e.g. we can feel the heat after some time when we hold a metal rod and heat the other end.

Convection The transfer of heat in fluid’s motion, e.g. in when a pot of liquid boils even with any stirring.

Radiation The transfer of heat in vacuum, e.g. heat from the Sun travels through vacuum in space and reach us on Earth.

There were many other considerations when we conducted the thermal property experiments. They are as follow:-

Since we are only using the head of the mannequins, the body size does not matter The mannequins should not be touching one another The shirts should not be touching the ground The data loggers should only be touching the head of the mannequins During the experiment, do not move the mannequins

When we were writing this report, we thought of ways of improving the experiment. We could actually put the mannequins in the Sun for 30 min to simulate 30 min of P.E. lesson and then leave the mannequins indoors to simulate the period after P.E. lesson. However, due to lack of time, we could not carry out the experiments again. We can also get real people to participate by wearing the shirt during PE lesson while we take their temperatures. However, we are not sure if it is possible as it would not be convenient to carry the data sensor while exercising.


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Conclusion If we look at the four factors again, absorbency test is the only one that shows that cotton is a better material than Dri-FIT since the cotton strip absorbed water faster than the Dri-FIT strip. However, there are other factors which make Dri-FIT shirt a better choice of P.E. shirt. Dri-FIT shirt gains heat slower and lose heat faster than the cotton shirt and the Dri-FIT shirt also dries faster than the cotton shirt. Therefore, the findings in this project can be used to suggest to our principal that there are good reasons to use Dri-FIT material for our P.E. shirts. ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Post-Presentation Discussion (With Judges’ Comments) After presentation to the judges, we felt that there are a few more things that could be done. We would like to note them down so as to serve as a reference for future teams who would like to explore more on fabric and its application. Firstly, there are other physical properties that can be tested to check for the suitability of shirt materials. Our project only focuses on the following four physical properties:

Thermal Property Part 1 – How fast the fabrics gain heat Thermal Property Part 2 –How fast the fabrics lose heat Absorbency of Perspiration – How fast the fabrics absorb sweat Removal of Perspiration via Evaporation – How fast the wet fabrics become dry

One of the judge suggested that we can also check the “durability” of the fabric. According to the judge, as a mother, she noted that most white cotton shirt will look old and yellow after several wash. However, Dri-FIT shirt usually continues to look new even after several wash. In school, we are always reminded to put on clean uniforms and shirts, so switching to the use of Dri-FIT may be good choice for school. Another factor that we did not consider is how comfortable the material feels when the wearer puts on the shirt for exercise. A simple survey could be conducted to find out pupils’ preference. For instance, just in our group, four of us prefer Dri-FIT while one prefers the cotton shirt. Those who prefer Dri-FIT claimed that it feels cooler when they put on Dri-FIT shirt. The pupil who prefers cotton claimed that the cotton shirt could absorb her sweat better and it is unlike Dri-FIT shirt which clings onto her skin when she sweats. We know that this is more of a personal choice. However, a survey would allow us to know what the preference of my schoolmates is in general. Therefore, after our presentation to the judges, we went back to survey our classmates and some prefects. In total, 50 pupils helped us in our survey. All pupils had a chance to look at and feel the material before doing the survey. Here are the two questions and the results.

Questions Response YES NO

Do you prefer Dri-FIT material as our school P.E. shirt instead of cotton?

25 25

Do you think it is affordable if our school changes the P.E. shirt to Dri-FIT material?

13 37


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Here are some responses from our friends when they were asked for the reasons. “I think Dri-FIT is warmer than cotton,” said Shawn. “I respect our (current) school P.E. shirt as our Principal had made the decision for it,” said Sarah. “Cos’ cotton is softer,” said Zhen Ming. “It (Dri-FIT) looks more formal!” said May. “It (Dri-FIT) is cooler!” said May Thu. Last but not least, it is the cost factor. Our principal, Mr Teoh Tiong San, has seen our presentation once. It was during that time that we brought up the suggestion of changing our cotton shirt to Dri-FIT shirt. He told us that he agreed that Dri-FIT shirt is better but he is concerned about the addition cost. Our school is a neighbouring school with about 7.9% of the pupils who are in Financial Assistance Scheme. Increasing the price of our shirts may bring problems to some families who have difficulties buying the shirts. Since cost is a factor, we also went to find out about the additional cost for switching from cotton to Dri-FIT. The shirt vendor told us that each Dri-FIT shirt will cost $2 to $3 more. Since the price of our cotton P.E. shirt is only about $6, $2 to $3 increase is about 33% to 50% increase in price. This is quite a lot for low-income families. As Singaporeans, we all believe that products must be “value for money”. However, we also realised that so-called Dri-FIT by some vendors is not close to the real Nike’s Dri-FIT at all. Some of them are just polyester mixed with cotton, with high percentage in polyester. If that is the case, our increase in spending may not be worthwhile. In conclusion, we learned that there are three other factors that we can look at, beside the four properties which we have tested for. If we want to find out whether a new material is better than the current one, we can also to look at durability, comfort level and cost factor. After considering the additional three factors, we decided that at this moment, we shall stick to the cotton shirt that our school is using. This is because most of our peers come from average-income families. We should choose a material that is more affordable to most families. Also, we personally like the comfort that cotton shirts bring us as it can absorb our sweat. However, the advantages of Dri-FIT are very luring. We have showed that Dri-FIT is better than cotton as it gains heat slower and lose heat faster than the cotton shirt. Wet Dri-FIT shirt also dries faster than the cotton shirt. The only weakness is that Dri-FIT has is that it could not absorb sweat very well. So, considering all advantages of Dri-FIT shirts have over cotton shirts, we should go for it. If in future, our peers’ parents can spend a few more dollars, we shall then suggest to our Principal to use the Dri-FIT shirts. (But by then, we would not be in school. Our juniors will have to do it for us.)


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Acknowledgements We would like to thank the following people for their help given in this project. Ms Yap ST, our teacher mentor. Mr Kelvin Ng, for his advice during the study. Mr Lee, the school OM, for his help in looking for the mannequins. Ms Fatimah, for her donation of the mannequins. Mdm Ros and Ms Ain, for their donation of prefects’ Dri-FIT shirts. Our school office staffs, for their donation of school’s P.E. shirts. School Uniform Vendor, for telling us the content of our school P.E. shirt Our school, for giving us the space and equipment (like Data logger) for our experiments. The Senoko Company for organising this project for us to learn more about climate changes.


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Literature Cited Anderson, G. (2004). How to Write A Paper in Scientific Journal Style and Format. Retrieved from

Bates College: http://abacus.bates.edu/~ganderso/biology/resources/writing/HTWtoc.html

Climatology of Singapore. (2002). Retrieved from National Environment Agency:

http://app.nea.gov.sg/cms/htdocs/article.asp?pid=1088

Google Scholar. (2009). Retrieved from Google: http://scholar.google.com.sg/

Kar, F., Fan, J., Yu, W., & Wan, X. (2007). Effects of thermal and moisture transport properties of T‐

shirts on wearer’s comfort sensations. Fibers and Polymers , 8 (5), 537‐542. Retrieved from:

http://www.springerlink.com/content/5q518x8152u17l88/fulltext.pdf

(2007). Overview And Recommendations For Sport Safety In Singapore. Singapore: Sports Safety

Committee. Retrieved from:

http://sportssafety.ssc.gov.sg/publish/etc/medialib/my_media_lib/sports_safety_images.Par.0006.F

ile.tmp/Sports_Safety_Committee_26SEPO7.pdf

Sazama, M. G. (2001). The effect of vapor permeable versus non‐vapor permeable shirts on heat

stress. Thesis‐‐PlanB (M.S.)‐‐University of Wisconsin‐‐Stout . Retrieved from:

http://www.uwstout.edu/lib/thesis/2001/2001sazamam.pdf

Warren, J. (10 March, 2009). Player safety bill might be put off until fall. Retrieved from

Kentucky.com: http://www.kentucky.com/news/state/story/720185.html

Zarske, M. S., Forbes, M., Sirakavit, G., & Yowell, J. (2007). TeachEngineering Free Curriculum for K‐

12. Retrieved from Integrated Teaching and Learning Program, College of Engineering, University of

Colorado:

http://teachengineering.org/view_activity.php?url=http://www.teachengineering.org/collection/cu

b_/activities/cub_weather/cub_weather_lesson01_activity1.xml


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Appendix I – Detailed data from experiments

Table 2: How fast the fabric gain heat?

Time (s)

Temperature (°C)

Cotton Shirt Control Dri‐FIT Shirt

0 36.2045209 40.03283547 37.45810876

30 37.84471822 42.63088637 38.85587979

60 39.29925379 44.70333912 40.11167291

90 40.5329049 46.28215373 41.11416649

120 41.51182347 46.91264167 41.88393264

150 41.53837206 46.52855835 41.75093074

180 41.45874053 45.89962848 41.45874053

210 41.61804619 45.6814575 41.51182347

240 41.59148342 45.21882977 41.45874053

270 41.2465992 43.81188241 41.03476468

300 40.95540644 42.81818673 40.61202804

330 40.61202804 42.09697836 40.21686041

360 40.29580396 41.72434442 39.84905987

390 39.95404383 41.22010305 39.45610603

420 39.63933904 40.69119563 39.11650055

450 39.29925379 40.32212853 38.77779903

480 39.06433335 40.1379622 38.51788535

510 38.88191757 39.77037582 38.31035222

540 38.69976733 39.71794558 38.12905433

570 38.54385197 39.09041427 37.94803336

600 38.3622021 38.82984743 37.79309506

630 38.31035222 38.85587979 37.71570352

660 38.3622021 39.0382578 37.74149493

690 38.46596873 39.42995083 37.84471822

720 38.67376771 39.8228267 38.02557969

750 38.75178301 40.11167291 38.10317717

780 38.75178301 40.19055596 38.10317717

810 38.64777356 39.40380088 37.97387644

840 38.5698241 39.32538264 37.89636434

870 38.5698241 39.48226649 37.89636434

900 38.82984743 40.26948441 38.10317717

930 39.42995083 41.67118589 38.67376771

960 39.48226649 41.99041828 38.77779903

990 39.50843219 42.23028275 38.77779903

1020 39.74415812 42.81818673 38.96006341

1050 40.00656649 43.2739839 39.19479143

1080 40.00656649 42.92531549 39.16868913

1110 39.84905987 42.09697836 38.98612282

1140 39.63933904 41.35263169 38.75178301

1170 39.40380088 40.9289634 38.46596873

1200 39.11650055 40.5329049 38.20671968

1230 38.80382051 39.8228267 37.89636434

1260 38.41407429 38.90796078 37.535326

1290 37.99972522 37.99972522 37.14976968

1320 37.61259578 37.30383281 36.79112649

1350 37.22677454 36.68887466 36.43367351

1380 36.89347548 36.30630431 36.10283754

1410 36.5867205 35.89977292 35.84907006

1440 36.35723338 35.64651357 35.59593848

1470 36.10283754 35.39389603 35.36866986

1500 35.87441831 35.14192752 35.14192752


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Table 3: How fast the fabric lose heat?

Time (s)

Temperature (°C)

Cotton Shirt Control Dri‐FIT Shirt

0 25.70049376 24.0754696 24.65120093

30 25.56588175 23.74468153 24.5180599

60 25.40908668 23.59063042 24.45155383

90 25.29725377 23.5466513 24.42939456

120 25.09629097 23.43677071 24.29653655

150 25.02939783 23.45873923 24.29653655

180 24.91801232 23.45873923 24.25228727

210 24.8512421 23.45873923 24.25228727

240 24.80675378 23.50268763 24.25228727

270 24.74005868 23.56863892 24.25228727

300 24.60680132 23.48071153 24.14174293

330 24.65120093 23.52466755 24.25228727

360 24.60680132 23.50268763 24.23016943

390 24.60680132 23.61262583 24.29653655

420 24.5180599 23.61262583 24.25228727

450 24.49588648 23.61262583 24.23016943

480 24.40723997 23.56863892 24.20805609

510 24.42939456 23.63462517 24.23016943

540 24.40723997 23.63462517 24.23016943

570 24.40723997 23.65662846 24.23016943

600 24.31866803 23.56863892 24.18594724

630 24.36294475 23.63462517 24.20805609

660 24.29653655 23.52466755 24.16384286

690 24.31866803 23.63462517 24.18594724

720 24.31866803 23.65662846 24.20805609

750 24.36294475 23.65662846 24.23016943

780 24.29653655 23.59063042 24.18594724

810 24.18594724 23.52466755 24.05338726

840 24.25228727 23.59063042 24.14174293

870 24.34080409 23.65662846 24.18594724

900 24.34080409 23.72266223 24.20805609

930 24.25228727 23.65662846 24.11964742

960 24.34080409 23.74468153 24.20805609

990 24.34080409 23.76670489 24.20805609

1020 24.27440964 23.70064697 24.11964742

1050 24.18594724 23.65662846 24.05338726

1080 24.34080409 23.76670489 24.18594724

1110 24.31866803 23.76670489 24.18594724

1140 24.23016943 23.65662846 24.11964742

1170 24.16384286 23.50268763 24.0754696

1200 24.03130926 23.30503757 23.98716622

1230 23.94304033 23.19535964 23.96510114

1260 23.87688327 23.08576926 23.87688327

1290 23.87688327 23.06386144 23.83279951

1320 23.85483931 23.08576926 23.81076386

1350 23.89893141 23.19535964 23.83279951

1380 23.98716622 23.32698392 23.89893141

1410 23.87688327 23.23922014 23.76670489

1440 23.96510114 23.39284489 23.85483931

1470 24.00923559 23.41480594 23.89893141

1500 24.00923559 23.43677071 23.87688327


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Table 4: Mass of the shirts before they were wet

Mass (g) Cotton shirt Dri-FIT shirt

161 203

Table 5: Mass of the wet shirts over two hours

Time (min) Mass (g)

Cotton shirt Dri-FIT shirt 30 352 396 60 321 354 90 295 312

120 271 274


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Appendix II – Photographs taken during experiments

Figure 3: The two shirts in our investigation

Figure 4: Initially, we used recycled bottles, instead of the mannequins, to hold the cloth,.


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Figure 5: Hardworking girls trying to understand the article

Figure 6: This is what we read!


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Thermal Property Part 1

Figure 7: Putting on the shirt on the mannequin's head for the experiment

Figure 8: Getting the data logger ready


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Figure 9: Inserting the sensor inside the 'clothing'.

Figure 10: Gaining heat...


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Thermal Property Part 2

Figure 11: The mannequins and us in the NE room

Figure 12: The data logger


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Figure 13: Putting on the cloths for the mannequins

Figure 14: The 3 musketeers! Oops? It’s mannequins!


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Absorbency of Perspiration

Figure 15: We are making sure that the correct amount of water is being poured into the cylinder; 'eye level'

Figure 16: Before and after some dye was being dripped into each Petri dish filled with water.


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Figure 17: Cutting the shirt into strips

Figure 18: Making sure that the both cloth are starting at the same point


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Figure 19: Dyed water being poured into the Petri dishes

Figure 20: The two cloths absorbing the dyed water


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Figure 21: Time to measure the length of water absorbed!

Figure 22: Pupils washing the apparatus after the experiment


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Removal of Perspiration via Evaporation

Figure 23: Apparatus needed for evaporation experiment

Figure 24: Weighing the shirt several times and then take the average mass


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Figure 25: Let's wet the shirt!

Figure 26: Do our best to make the shirt absorb every drop of water


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Figure 27: Hanging our shirts to dry

Figure 28: Our warning sign for others to keep out


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Figure 29: Take average mass of the wetted shirts

Figure 30: Take the mass of the shirts every 30 min

investigating the suitability of the two materials – dri...

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